1942: Civil Engineering

Domination of War-generated Construction.

War-generated construction, which had begun to rise to unprecedented heights in 1941, completely eclipsed all other types of civil engineering work in 1942 and carried the total construction volume to nearly $13,000,000,000 or about $1,500,000 above the previous all-time high of nearly $11,500,000 in 1941. The above estimate compiled by the War Production Board, presumably does not include the very considerable amount of construction being done outside the continental United States by the armed forces, but may include contract work for the army and navy on bases in the West Indies and the Pacific Islands.

Total contract awards for engineering construction for the year 1942 as compiled by Engineering News-Record rose to the unprecedented volume of $9,306,000,000 for 1942 as compared to $5,870,000,000 for the year 1941. Of this $8,241,000,000 was Federal works. State and municipal work declined sharply to $509,000,000. Private construction amounted to only $556,000,000 as compared to $1,178,000,000 in 1941.

The figures compiled by Engineering News-Record do not include small house construction nor any waterworks, drainage, irrigation or other contracts under $15,000, public works contracts under $25,000, industrial building work below $40,000 and other building work below $150,000.

Contract totals for the various classifications are as follows: waterworks, $151,000,000; sewerage, $118,000,000; bridges, $50,000,000; earth work and drainage $251,000,000; streets and roads, $531,000,000; public buildings, $5,678,000,000; industrial buildings, $200,000,000; commercial buildings, $292,000,000; unclassified, $2,034,000,000.

Geographically, the construction total was above last year in all areas except the Middle Atlantic States, where it was one per cent below last year. New England showed an increase of 47 per cent; the South, 52 per cent; the Middle West, 72 per cent; west of Mississippi, 80 per cent; Far West, 89 per cent.

It should be noted that these figures, which are the normal breakdowns that have been reported heretofore in these pages, do not fully reflect the way in which war-generated construction dominated the construction field in 1942. For example, most of the work here shown as industrial building was expansion of privately owned plants having war contracts as distinguished from war plants wholly financed by the Federal Government which fall into the classification of 'public buildings.' This class includes all the camp and hospital construction for the Army and Navy. Further, practically all the work classified as waterworks and sewerage was construction of water supply and sanitary facilities for new housing developments, for camps or for expansion of existing facilities in cities having to enlarge their sanitary services to accommodate houses built for war workers.

Curtailment of Construction.

Curtailment of construction not connected with the war effort was begun in 1941 under a system of priorities set up to give war work preference in the purchase of materials and equipment; further curtailment came in April 1942, when the WPB issued an order stopping the inauguration of any new non-residential construction in excess of $5,000; farm construction in excess of $1,000 and residential construction in excess of $500 without specific authority from the board. During the latter part of the year further orders shutting down specific jobs were issued. These applied chiefly to flood control projects and to some projects of the U.S. Bureau of Reclamation, but also included stoppage or curtailment of work on a few large public power projects, including some of those of the Tennessee Valley Authority.

Under the WPB order of April 1942, practically all private construction not already under way was postponed indefinitely, and with a few exceptions, public works not directly connected with the war effort soon were shut down due to inability to get essential materials. An outstanding example is the South District's water purification plant at Chicago, which is badly needed because of increased pollution in Lake Michigan caused by expanding war industries along streams discharging into the lake.

At the end of the year the WPB estimated that it had issued stop orders affecting $1,200,000,000 of construction work, largely non-war buildings. It then expected to issue orders stopping $2,000,000,000 of the $6,000,000,000 of still uncompleted industrial expansion that had been authorized as part of the war effort. The WPB estimates that the construction total for 1943 will be $8,200,000,000 which while over $4,000,000,000 less than 1942 still will be in excess of the total for 1939, which was little affected by war developments.

Dams.

Dam building in 1942 continued the decline begun in 1941. Only a few new structures were started during the year and work on nearly all of them was stopped before the year was out as part of the WPB's program to conserve critical materials and manpower.

Grand Coulee Dam on the Columbia River in Washington, the world's greatest structure, 550 ft. high, 4,350 ft. long and containing 10,500,000 cu. yd. of concrete, was completed late in 1942 except for the power plants and minor details. On June 1, the 151-mile long reservoir had filled and water began to flow over the dam's spillway, which is 300 ft. high and 1,650 ft. long. Work on three additional 108,000 kw. units of the power plant, units L-7, L-8 and L-9, was stopped in November but work on three other units that will go into service in 1943 was continued.

Increasing the height of Ross Dam from 305 ft. to 487 ft. was proposed early in 1941 by the city of Seattle, Wash., to increase the firm output of the Skagit River power system by 79,000 kw. without adding new generators, but inability to get satisfactory bids from contractors delayed start of the work indefinitely. The dam is a variable-radius arch that was designed to permit progressive raising of the crest. The most recent increase in height was completed in 1940.

Friant Dam of the Central Valley power and irrigation project in California was completed in 1942. Work on Shasta Dam, a structure 602 ft. high and to contain 6,000,000 cu. yd. of concrete, was more than two-thirds complete at the end of 1942. Work on Keswick Dam, 9 miles below Shasta, a much smaller structure designed chiefly for power, was stopped in October when the structure was about half completed.

Santa Fe Dam, last of the large flood-control dams for the Los Angeles area to be put under contract was nearing completion at the end of 1942. It is an earth and gravel fill 92 ft. high and 23,800 ft. long.

Contracts for construction of Davis Dam in Bullshead Canyon on the Colorado River 67 miles below Boulder Dam, a rock-fill 140-ft. high for power development, were let in July, but that work also was stopped in October. At Parker Dam, farther downstream, the first power units went into service.

Work on Green Mountain and Grandby dams of the Colorado-Big Thompson irrigation and power project also was stopped late in the year as was work on the Continental Divide tunnel of that project which will divert water from the headwaters of the Colorado to the east slope of the Rocky Mountains.

In Idaho, work was begun on the great Anderson Ranch Dam, an earth-fill structure 330 ft. high to store water for irrigation, but it was stopped before the end of the year.

Dams of flood-control projects in the Southwest that were near completion, generally, were permitted to go ahead but no new work was authorized except at Houston, Texas, where construction of a 10-mi. long earth dike of the Harris County Flood Control & Improvement District was put under contract. Work on Markham Ferry Dam and Fort Gibson of the Arkansas River flood control work was stopped but work on Norfolk Dam and Arkabutla Dam was permitted to go ahead.

In the Southeastern states, work on Allatonna Dam on the Coosa River in Georgia, a flood-control and power project was stopped, as was work on Wolf Creek and Center Hill dams of the Cumberland River flood control work, which was started in 1941. Two dams of the TVA that were started recently, Watauga and South Holston, were ordered stopped. The same is true of High Point Dam on the Yadkin River in North Carolina, a power project. Work on other TVA dams went ahead, including the great Kentucky Dam near the mouth of the Tennessee River.

Up in the Ohio Valley, a contract for Bluestone Dam at the headwaters of the New River was let in January 1941, but that work was stopped in late November. Berlin Dam on the Mahoning River, a unit of the long projected Beaver-Mahoning Canal system to connect the Ohio with the Great Lakes, was put under contract in January to augment the industrial water supply of the Youngstown area. It is an earth-fill structure with concrete outlet works and spillway.

Above Pittsburgh, work continued on Youghiogheny Dam on the river of that name, the third of three dams to be built to reduce floods at Pittsburgh. The completed dams were of material help in reducing the crest of the flood of early January, 1943.

The last two dams of the current flood-control program in Susquehanna River basin were completed in 1942, as were the remaining two in New England. No new dams were started in the North Atlantic region.

Work on Merriman Dam, a major element of the new Delaware water supply system for New York, was largely discontinued during the year. It is an earth fill 200 ft. high and 2,500 ft. long with a concrete cutoff wall sunk to rock. The wall was completed early in 1942.

Bridges.

Bridge construction, especially the construction of large bridges requiring much steel, was drastically curtailed in 1942 because of the need for steel for war work. Contracts declined from $111,600,000 in 1941 to $50,200,000 in 1942, and these were chiefly small bridges of reinforced concrete or timber. Use of timber for bridge construction increased considerably during the year, the most outstanding instance being the 1,670-mile Alaska Highway where all the bridges were built of timber. As some of the streams crossed on that work have permanently frozen bottoms, the bridges are carried on timber cribs sunk to the frozen bottom and filled with rock.

The principal bridges under construction during the year were the new highway bridge over the Connecticut River at Hartford, which was completed following the collapse of one of the main spans during erection on Dec. 4, 1941; the new high-level highway bridge over the Thames River at New London, Conn.; and a long highway bridge over the Mississippi River at Dubuque, Iowa. This latter bridge is notable in that the foundation of one of its main river piers was sand filled to save weight, a saving of 1,120 tons over the weight of a solid concrete pier being attained. This materially reduced the amount of piling required to support the pier in the unfavorable material of the river bottom.

Restrictions on travel across the Canadian border and curtailment of automobile traffic due to the rubber and gasoline shortage made it necessary for two international bridges to default on their bonds, the Thousand Islands Bridge over the St. Lawrence River and the new Rainbow Arch Bridge at Niagara Falls. The Golden Gate Bridge at San Francisco also is in financial difficulties and its operation may be taken over by the state.

Scrapping of the Tacoma Narrows Bridge that collapsed in November 1940, was undertaken during the year, the unspinning of the cables being in progress as the year closed. Design studies for a new bridge are being continued.

Buildings.

Building construction during 1942 was dominated by the needs of war industries and such new developments as occurred were chiefly in industrial types. Many of these were the outgrowth of the shortage of steel for structural purposes. Efforts to find satisfactory ways to substitute reinforced concrete and timber resulted in some novel designs.

Especially notable were building frames in which columns are made of reinforced concrete and in which beams, purlins and rafters are of laminated glued timber. Spans of 61½ ft. were provided in this way in a Wisconsin plant for the Defense Plant Corp.

In a hangar built for Navy blimps, the roof is framed of timber arches of 246-ft. span supported on reinforced concrete A-frames 24 ft. high to give a clear height above floor of 171 ft. Split-ring connectors were used in fabricating these timber arches. The largest span timber arches built heretofore were those of 200-ft. span that were built for one of the exposition buildings at the San Francisco Fair in 1939.

During the year experiments were made in designs for plate girders fabricated out of plywood using ring connectors. One such design was used in a new building at Camden, N.J., for the Radio Corporation of America.

The year saw wide use of substitutes for other scarce building materials. Thus, sheets and ducts of asbestos-cement were widely used in place of copper, galvanized iron and aluminum for roof, siding, gutters and downspouts on buildings.

The most notable building of the year was the Pentagon Building erected in Arlington, Va. to house the War Department. It is the world's largest building, having a frontage of 921 ft. on each of its five facades and a total floor area of 4,000,000 sq. ft. Generally five stories high, the building has a frame and floors of reinforced concrete and walls of brick faced with limestone. All details were simplified to reduce the cost and speed of the construction, which took a little over a year.

The pentagon shape around a 4-acre central court was chosen to minimize travel between sections of the building. Movements between floors is chiefly by large ramps and by stairs. Driveways through the lower floors permit direct bus delivery and collection of the employees.

Provisions for blackouts are made in the design of most of the new buildings, and in some instances, the designers have had to make elaborate provision for the support of camouflage nets above and around buildings for key war industries in exposed locations.

As a means for saving structural steel, the WPB ordered that in all war buildings the allowable stress in structural steel be increased from 20,000 to 24,000 lb. per sq. in. and required designers to certify that they had used designs that were most economical of steel. It also had prepared designs for seven types of mill buildings to demonstrate how steel could be saved, these designs being used as a check against the amount of steel required per unit of space in designs prepared by outside engineers and architects.

Similarly, the WPB ordered the allowable stress in structural-grade reinforcing bars raised from 18,000 to 20,000 lb. per sq. in., and for hard bars, from 20,000 to 24,000 lb. Allowable tension in concrete in reinforced structures was increased from three to four percent depending on the class of work. Wider use of reinforced concrete beyond limits now set by building codes also was authorized.

Highways.

Highway operations in 1942 were characterized by a continuation of the sharp decline in construction that began in 1941. A limited amount of new work on the strategic highway network that had been put under way in 1941 was continued, but all idea of actively pressing work on that network as a war measure was abandoned early in the year. Offsetting in part this curtailment of work on the strategic network was the construction of a large mileage of access roads to military establishments and war industries. Chief among the latter undertaking was the Detroit Industrial Expressway, a superhighway built to give better connections between Detroit and the war industries of the cities to the west. The expressway extends for a distance of 16 mi. westerly from the city limits. Ultimately, it will form part of a superhighway to Chicago. Near Ypsilanti it connects with a large system of access roads serving the Ford Willow Run bomber plant.

Outstanding among highway construction projects of 1941 was the 1,670-mile Alcan highway, built as a war measure. It extends from the end of rail at Dawson Creek in British Columbia north through Yukon Territory to a connection with the Alaska highway system at Big Delta, south of Fairbanks. Begun in March when Army engineer troops were moved in over the frozen rivers and lakes before the spring break-up, the road was opened for its entire length to traffic on Nov. 20, thus establishing a world record for highway building, largely through a rugged wilderness. The road has a gravel surface throughout with a minimum width of 18 ft., and a width of 20 to 24 ft. for much of its length. Some of it is built over permanently frozen ground, and other parts are on locations that may be flooded by high water in the spring. Bridges at present are all of timber, largely cut in clearing the right-of-way. Many are of a temporary nature that will be destroyed in the spring freshets and will have to be replaced. Steel structures on concrete piers are being built for some of the major river crossings.

Construction of the road was carried forward by Army engineer units and a large force of civilian road contractors from this country and Canada.

Another military road-building operation put under way during 1942 was completion of the missing links in the Inter-American Highway from southern Mexico to Panama. About 1,000 miles of the proposed road from the southern border of Mexico to Panama have been completed and there remains about 625 miles yet to be built. In July the United States Government came to an agreement with the governments of the Central American states for the completion of a 'pioneer road' at the earliest possible date. The work is to be financed by the United States Government, and American contractors have been engaged to take charge of part or all of the work, but it is believed that local labor will be used as far as possible. Possibly some United States Army engineer units will be used, as in the case of the highway to Alaska.

The proposed road is to be made passable in all weathers. It will have a width of from 10 to 16 ft., with an 8-in. gravel surface. Grades will be held to 10 per cent and curvatures to a radius of not less than 66 ft.

Mexico has built hard-surfaced roads from the United States border to Mexico City and south to a point near Oxaca. It is actively engaged on completion of a road from that point to the Guatemala border.

Construction of a highway across the Isthmus of Panama to connect the two ends of Panama Canal, begun in 1941, was completed in the spring of 1942. It extends from the end of the highway built some years ago from the city of Panama to Madden Dam, about half-way across the Isthmus, through virgin territory to Colon, a distance of about 25 miles.

Connecticut put into service during the year additional sections of the Wilbur Cross Parkway, the principal one being the Connecticut River Crossing below Hartford.

Driving the twin tubes for a vehicle tunnel from the lower end of Manhattan Island under the East River to Brooklyn was continued until late in 1942 when the WPB ordered the work shut down to conserve critical materials. Work on the second tube for the Lincoln vehicle tunnel under the Hudson River at New York also was continued, including the approach plaza in New York. Approaches for both tubes on the New Jersey side were built when the first tube was constructed.

Because of the scarcity of steel, state highway departments in 1941 began to build concrete pavements without reinforcing steel and without steel load-transfer devices at expansion joints. That trend gained acceptance in 1942, being formalized by the issue of tentative designs for such pavements by the Highway Research Board. Slabs are thickened, expansion joints are spaced farther apart, and planes of weakness to concentrate cracking and reduce slab movement at expansion joints are formed in the pavement at close intervals.

Highway maintenance operations increased in 1942, especially in areas where there are many war industries. This increase is due in part to heavier truck loadings and to a sustained truck traffic despite restrictions on the use of gasoline and rubber, and in part to inability to replace old highways that call for a large amount of maintenance. These operations were handicapped by loss of men to the armed forces and war industries and by inability to replace equipment and difficulties in getting repair parts. Also, due to the transportation situation, use of asphalt oils was restricted, first in the Eastern States, then as far west as the Rocky Mountains, and finally for the whole country. This shortage of asphalt oils resulted in a further limitation on highway construction and maintenance. It also expanded the use of tars in areas within reasonable distance of the producing centers.

Looking ahead, all highway work except that directly connected with the war effort such as access roads to new war industries will be further curtailed in 1943. Maintenance operations on the roadway itself will increase, through such maintenance work as is normally done to keep the right-of-way in condition will be largely eliminated due to the manpower situation. About half the states expect to increase their maintenance expenditures above those of last year. This trend may be expected to increase as the war period lengthens. Many secondary roads with light surfacing may have to be permitted to revert to earth roads if road oils and labor continue to be scarce.

The volume of highway construction in 1942 was lower than any since 1938, but still totaled above $530,000,000 due in large part to Federal expenditures for access roads.

Water Supply.

Construction of new water supplies and expansion of existing facilities continued at a high rate during 1942 due to the increasing demands of war industries, the growth of new communities around those industries and military bases and the construction of army camps and training centers. In some communities curtailment of normal water use was called for to make it possible for existing facilities to meet expanding domestic or industrial requirements.

Although all work not directly connected with the war was ordered to be drastically curtailed, a great amount of work generated by war activities raised the total of water-supply contracts for 1942 to $151,000,000, practically twice the work done in 1941.

Most notable of the war-generated projects is that serving the Norfolk-Portsmouth-Newport News area in Virginia where expansion of military facilities brought an increase of 300 per cent in water demands. Major items of that undertaking were the construction of 19 miles of 42-in, reinforced concrete pipe, 32 mi. of 34- and 39-in. pipe and 14 mi. of auxiliary lines in the 34- and 39-in. sizes. To do this job that normally would have taken two to three years in less than a year, required the construction of the largest concrete pipe-casting yard ever built.

Work on Chicago's South District water purification plant, the largest in the world, having a capacity of 320,000,000 gal. per day, was brought to a near standstill by shortage of critical materials. The plant is about half complete.

Construction of the tunnels for New York's new Delaware System continued during the year, but other work was held up due to inability to obtain critical materials and equipment.

A new development in water softening is the 'Spirator' process, the first municipal installation of which was made at Teutopolic, Ill. Outstanding features are use of a short detention period — 5 to 10 min. — and the production of a granular waste instead of the large quantity of lime sludge that characterizes most municipal softening plants. Size of the plant also is smaller than plants of similar capacity built heretofore. This process involves the principle of catalytic precipitation, granular material acting as the nuclei around which deposits of calcium and magnesium are built up.

The need for emergency sterilization of water supplies in case of damage to existing domestic systems by bombing raids as well as the need for mobile units for military purposes led during the year to considerable development of mobile chlorinator units by manufacturers of such products.

Sewage Disposal.

As in the case of water supply, sewage disposal operations during 1942 were devoted chiefly to treatment of waste from military camps, from housing developments for war workers and from new war industries. Here again the total of work put under contract, $118,400,000, was considerably in excess of the 1941 work, $88,700,000.

New problems were introduced by the war industries, many of which have waste with characteristics differing from the waste of more normal industrial plants.

Because of the shortage of materials, traditional designs were modified considerably, heavy unreinforced concrete being used in place of reinforced concrete, wood being substituted for steel, and concrete or asbestos-cement pipe for metal pipe. Notable work was done by the army in the design of wooden Imhoff tanks, some of very large size. Manufacturers also made similar changes in equipment for sewage disposal plants, one company substituting wood for 62 per cent of the steel formerly required for its equipment.

The army made 25 installations of the Hays process for sewage disposal, a process little known heretofore in this country and only used for populations under 5,000. Army installations have raised the population load to as high as 40,000. This process consists essentially of preliminary sedimentation followed by successive stages of treatment by means of a submerged contact aeration and final clarification.

The army also has undertaken to reclaim laundry waste to conserve water at points where the supply is costly.

A new process for removing grease, scum and oil has been installed in a sewage treatment plant at San Diego, Calif.; it was developed by the Dorr Company and is known as the 'Vacuator.'

1941: Civil Engineering

Defense construction dominated the civil engineering field in 1941 as in 1940, but to a much greater degree. Due to defense work, the total construction volume exceeded $11,000,000,000, as compared to $8,000,000,000 in 1940, which in turn had broken the all-time record set in 1928 and 1929.

Defense Contracts.

Contract awards for engineering construction for the year as compiled by Engineering News-Record totaled $5,868,700,000 as against $3,987,000,000 for 1940 (these figures do not include small house construction, nor any waterworks, drainage or irrigation work below $15,000, other public works below $25,000, industrial buildings below $40,000, and other buildings below $150,000). The principal classifications covered in the above totals are as follows: Waterworks, $76,698,000; sewers, $88,719,000; bridges, $111,628,000; earthwork, $245,221,000; streets and roads, $582,847,000; industrial buildings, $496,176,000; commercial buildings, $485,683,000; public buildings, $2,785,585,000; unclassified, $996,142,000.

Predictions as to the construction prospects in 1942 are difficult to make. The Department of Commerce, before the start of war with Japan, estimated that construction would decline from $10,500,000,000 to $8,500,000,000, due to priorities on defense material and curtailment of non-defense construction. However, before the year closed the Government had inaugurated a speed-up of defense work that is expected to produce a further increase in defense construction that will more than offset the cut in non-defense work. The Office of Production Management now estimates the 1942 total at $11,250,000,000, slightly more than 1941. Early in December, a few days after war was declared, Congress passed a $10,000,000,000 appropriation act to speed up the nation's war effort and is expected to appropriate more money for further expansion of war activities early in the new year. That will further curtail both men and materials available for nondefense work and will mean almost complete stoppage of all building work not directly connected with defense or the housing of defense workers, drastic curtailment of street, highway and bridge building except to serve war industries and military bases and elimination of all water supply and sewage disposal operations except those made necessary by new communities of war workers. Power projects that can be brought into service this year or next will be speeded up but most other power work will be stopped. Similarly, flood control projects other than those protecting essential industries are expected to be postponed. Over against these curtailments there is to be an expansion of civil airport construction because a large number of high-grade airports is essential to air defense of the nation and both military and civil needs can be met by one airport in most instances.

Building Construction.

Building construction during 1941 centered mainly in defense activities, and it is in structures erected for such purposes that most of the noteworthy developments occurred. The industrial type of building dominated this work, with high one-story structures for the manufacture of airplanes, engines, tanks and trucks making up the larger group. These buildings, covering as much as 20 acres in area in some instances, were simply framed except in the case of plants for the manufacture of airplanes where wide unobstructed areas were called for. They are notable chiefly for the improvements in wall design that they produced and for the greater use of basements and underground ducts and passages to facilitate the movement of men and materials free of the manufacturing operations on the main floor.

Wall types vary widely, some being solid and some being provided with sash or panels of glass brick. Wall materials may be brick, concrete, plywood, asbestos, cement, fiberboard or steel, frequently faced on the inside with layers of insulating and sound absorbing materials. Much attention was given to insulating both walls and roof areas, primarily because air conditioning was accepted almost as an essential element of such structures to increase the efficiency and add to the comfort of the workmen.

Improved lighting also is an outstanding characteristic of these new factories, fluorescent lighting being most commonly used.

A few plants were designed for blackout, and some were designed specifically to afford a large measure of protection to employees in bombings. The more extensive use of basements and underground passages was due in part to recognition of the protection they would afford in air raids.

Airplane plants are notable chiefly for their large roof spans designed to give wide, unobstructed floor areas, the largest being the 300-ft. roof trusses of the Boeing plant addition at Seattle. In that plant production advances longitudinally through the 300-ft. wide bays to end doors having a clear opening 295 ft. wide and 35 ft. high.

At the Boeing plant in Vancouver, bc, columns and roof trusses are of timber, the trusses having a span of 128 ft., and side walls are of plywood panels treated to be weather resistant.

A distinct departure from past practice in factory design is the 400 x 1,000-ft. airplane plant for the Glenn L. Martin Company near Baltimore. Its 400-ft. width is made up of two 200-ft. trusses, the heavy columns at midspan being designed to carry the lateral force of a wind on a 100-ft. section of 66-ft. high wall. The 200-ft. trusses are pin connected to the wall columns, supplemented by welding after the dead load is in position. Longitudinal trusses are of cantilever design and 100-ft. span.

Other unusual structures built for war purposes include a variety of special buildings at munitions plants designed to limit the effect of explosions to a single building or to a cell where the explosion occurs. Generally, these buildings are characterized by heavy walls and light roofs that blow off easily. Other structures are large warehouses with roofs of thin reinforced concrete barrels carried by overhead concrete beams, and large concrete hangars in which deep arch ribs over the roof support a thin arch roof of 294-ft. span and 84-ft. rise.

Unrelated to war work are two notable structures of steel, both experiments in applying designs developed for industrial purposes to other uses. One is a recreation center for the Chicago Bridge & Iron Co. consisting of an elliptical welded steel plate dome, 80 ft. in diameter, supported only on steel plate side walls. An annular lean-to of welded plate accommodates the air conditioning plant, kitchens and other services. The interior surface is lined with an insulating and acoustical material sprayed directly on the steel and built up to a thickness of 2 in. The other structure is a recreation hotel in north Georgia, completed by the R. G. LeTourneau Company late in 1940, consisting of a 100-ft. diameter domed lobby with radiating wings one story high, the whole structure being frameless and built of welded cellular units made of rust-resisting steel.

Housing.

Defense housing took a dominant position in the house-building field in 1941. In all, the Federal Government allocated over $1,000,000,000 to such work and by giving encouragement to those with sound ideas as to how speed and economy could be obtained, produced some quite radical innovations. Private house building, except units costing at or below $6,000 in defense areas, which could get priorities, was badly checked toward the latter part of the year.

The Government insisted that all Federally financed defense housing built near military bases or to serve workers in defense industries be demountable. This stimulated prefabrication and encouraged the use of materials not common to house building. Prefabrication ranged from simple precutting and notching of lumber to factory fabrication of wall units, assembly line methods being applied to some of the larger operations. The Tennessee Valley Authority carried prefabrication to the point of building complete sections of one-story houses on an assembly line and shipping them to the site on trucks where the only remaining operation was bolting the units together on foundations built in advance of delivery.

The Public Buildings Administration set up a housing project at Indian Head, Md., as a sort of laboratory and gave ten fabricators an opportunity to show what they could do in the construction of prefabricated houses, including a demonstration of demountability through the transfer of 168 houses to Quantico. Va.

In addition to lumber, materials used included steel, plywood, compressed fiber, repulped newspapers, combinations of plaster and asbestos, and a small amount of concrete. Some units were made with wall panels of a single slab of insulating material having a weather-resisting exterior surface and an appropriate material for interior finish on the other face.

Bridges.

Defense work resulted in little curtailment of bridge construction in 1941 as compared with 1940, primarily because most bridge projects were on the strategic highway network and so were entitled to high priorities. Contracts totaled $120,000,000, only slightly below the 15-year average. Considerable curtailment is in prospect for 1942.

Progress in design centered chiefly in steel arches, three notable structures being the new Rainbow Arch at Niagara Falls, replacing the old bridge that was wrecked by an ice shove in 1938; a new bridge over the Chesapeake & Delaware Canal at St. Georges, Del.: and a bridge over the Mississippi River at Dubuque, Iowa. The Niagara bridge is a 950-ft. hingeless arch, longest of its type in the world. The bridges at St. Georges and Dubuque are tied arches, 540 and 845 ft. long, respectively. Simplicity of detail and ease of erection are the major advantages of the tied arch, which is relatively new to American practice.

Long plate girder spans continue to gain in popularity with American bridge builders. Most conspicuous among those started in 1941 is the Connecticut River crossing at Hartford where the three main river spans are to be formed as a continuous plate girder composed of a central 300-ft. span flanked by 270-ft. spans on each side, making it the longest continuous plate girder in this country. This bridge met with a serious accident on Dec. 4 when collapse of falsework under the first 270-ft. span as it was nearing completion dropped the erected steel and the large erector derrick into the river, killing 16 men.

Erection of the Pitt River bridge in California, conspicuous chiefly for its 350-ft. high piers, which are to be almost entirely submerged in the reservoir behind Shasta Dam, was substantially complete in 1941. Another bridge conspicuous for its piers is the new toll bridge over the Thames River at New London, Conn. The bridge has a clear height of 137.5 ft. above mean low water and the deepest piles under the piers are 155 ft. below water level. Use of steel H-column piles, a relatively new development, greatly simplified this bridge job.

Plans for reconstruction of the Tacoma Narrows bridge that collapsed in November 1940, have progressed to the point of applying to the War Department for a permit to build a new bridge having a wider deck and higher towers but somewhat less clearance over the navigable channel. Its design will incorporate the latest developments in knowledge of aerodynamic stability.

Three large lift bridges were completed during the year, a 365-ft. span at Jacksonville, Fla., a 332-ft. span over the Passaic River near Newark, N.J., and a 224-ft. double-deck bridge over the Piscataqua River at Portsmouth, N.H. Work is well along on the double-leaf bascule bridge on State St. in Chicago, 120-ft. wide and of 245-ft. span.

One leaf of the 27-year-old double-leaf bascule bridge of the Canadian Pacific Railway over the navigation canal at Sault Ste. Marie, Mich., longest of its kind in the world, collapsed under a locomotive in September, due, it is believed, to failure of the interlocking system. The bridge was not seriously damaged and is back in service.

Highways.

Highway building in 1941 fell below the all-time record for new construction set in 1940, due chiefly to delays growing out of priorities on war materials. Reinforcing steel was especially difficult to get, and as a result some state highway departments abandoned its use in concrete pavements, increasing the thickness of the concrete somewhat to offset the lack of steel.

Highway legislation passed in 1940 called for expenditure of federal-road funds as far as possible on the strategic highway network, a nation-wide system totaling 75,000 miles and designated by the War Department as important to the defense of the nation. Early in 1941 the Public Roads Administration reported to the President that about 14,000 miles of this system needed strengthening, that 2,436 bridges were substandard and that 2,830 miles of access roads to military camps were needed. This was expected to increase road building, but the President did not ask Congress for money for the work until July, and because of a disagreement between Congress and the President as to the handling of the money, legislation was not finally approved until November. No money for defense highway work was appropriated until after war was declared in December. Work under the normal Federal-aid appropriations continued at a reduced scale.

Further curtailment of new highway construction is anticipated in 1942 due to war work, but as the war effort is expected to add greatly to the heavy trucking on highways, maintenance expenditures will have to be materially increased.

Specifications for highways of the strategic network were issued by the Public Roads Administration in March to aid in insuring that road surfacing and bridges will be adequate to carry Army tanks and heavy motorized equipment. These specifications call for almost no precautionary measures on highways built to meet the H-20 loading of the American Association of State Highway Officials, now used in New York and in some metropolitan districts in other states, and few precautionary measures are needed on roads built to the H-15 loading, now standard for new construction in most states. Notable in the specifications was the recommendation that 8-ft. wide shoulders be built on all highways carrying more than 1,800 vehicles per hour, to permit mechanized military units to clear the traveled road when not in motion.

The Pennsylvania Turnpike, first major toll road to be built to modern standards, completed its first year of operation in November. The total income was close to the preliminary estimate but operating costs were about double the estimate. Despite this increase, the road earned enough to pay interest and amortization charges on the bonds issued by the state, but when the Federal grant of 45 per cent of the cost is included, the road is far from being a self-liquidating undertaking. Extension of the Turnpike west to the Ohio or West Virginia line was authorized by legislation passed in Pennsylvania in June but no work has been undertaken.

Connecticut continued work on Wilbur Cross Parkway, an extension of the Merritt Parkway which, with that parkway, when completed will give a superhighway across Connecticut about on an airline between New York and Boston.

Additional sections of New York's great East River Drive were opened during the year, but some of the more difficult work remains to be done before the whole drive can be opened. Work was begun on twin vehicle tunnels from the lower end of Manhattan Island to Brooklyn following completion of construction shaft started in 1940, but completion of the project, originally scheduled for 1944, will be delayed by the war. Work on the second tube of the Lincoln Tunnel at New York was resumed during the year due to rapid increase in traffic passing through the single tube that was opened in 1937.

A vehicle tunnel 3,400 ft. long having a two-way roadway 21-ft. wide under the Mobile River at Mobile, Ala., was opened on Feb. 20 as a toll facility.

Philadelphia has begun work on a system of express highways across the city on lines of major through travel to relieve congestion on existing streets, the state sharing in the cost.

Completion of a highway across the Isthmus of Panama, beginning and ending in the Canal Zone but largely in the Republic of Panama, is actively under way with the object of completing the work before the spring rains.

Water Supply.

Construction of water supply and sewage disposal facilities in 1941 continued at the high record of previous years despite the curtailment of normal public works that came with the defense effort. This was due to the establishment of new communities to house defense workers or the expansion of old communities for a like purpose, and also to meeting the need for water supply and sewage disposal facilities at the many cantonments being built by the Government.

A major addition to the nation's water-supply facilities is the 100-mgd. water softening and filtration plant at the western end of the 280-mile aqueduct that brings Colorado River water to the Los Angeles metropolitan area. Tunnel driving on the aqueduct for New York's new Delaware supply lacked only one half mile of completion of the 85-mile total at the end of 1941, and lining is in progress. Late in the year a start was made on the 145-mile steel pipeline across the Florida Keys to reinforce the limited supply at Key West, now the site of a great naval base.

The largest installation yet made of so-called radial well water collectors was that made at the big smokeless powder plant at Charlestown, Ind., 16 units of 10 mgd. capacity. In this system, underground sources are tapped by pipes projected radially from a large central well.

Technical progress in water purification was noteworthy. Rapid advances were made in adoption of break-point chlorination (briefly noted in 1941) for the control of tastes and odors, and two installations of 'potential chlorination' were made. This is a method of electro-chemical control of the application of chlorine which automatically regulates the supply of chlorine to the correct amount regardless of changes in flow or in chlorine demand. Further developments in the use of ozone also were reported, including the demonstration of a mobile ozonator for use of troops in the field.

Sewage Disposal.

Much sewage disposal work found its origin in defense, meeting the needs of new defense housing or serving military camps. In this latter field, the relatively new method of high-capacity filtration recorded the most extensive use it has yet attained, due doubtless to its flexibility, ruggedness under varying loads and lower construction and operation costs as compared with standard trickling filters.

New developments include perfection of equipment for automatic control of chlorination which uses a new principle involving electrical potential measurement of the sewage as a direct indicator of its chlorine demand.

Important improvements in settling tank design are being included in the new Bowery Bay plant for New York City; at Springfield, Mo., the first installation was made of multiple-tray clarifiers, a new device in sewage treatment.

Recovery of by-products from sewage disposal was advanced during the year by studies at Atlanta relating to use of compressed sludge gas to drive motor vehicles. Estimates showed a possible saving of $8,000 annually to the city, but the war stopped plans for putting the proposal into effect. The gas is now being used as fuel in a nearby pumping plant.

In Baltimore, the Bethlehem Steel Company is using 40 mgd. of the highly purified effluent from the city's disposal plant for industrial purposes to replace a depleted ground-water supply. See also ARCHITECTURE.

1940: Civil Engineering

Trite but true is the phrase that 'Construction is the spearhead of our defense effort.' As a result of defense work, 1940 was the biggest year in history for construction of the heavier civil engineering type, bigger even than 1929. Residential work exceeded that of any year since 1929, but fell considerably short of a record. Total construction for the year was about $8,000,000,000 compared with $7,000,000,000 in 1939. More than $2,500,000,000 in new construction reached the contract stage in the last half of the year, largely as a result of the speed-up of defense construction.

Private and public construction awards both participated in the gains over 1939. Public volume set a new high mark, exceeding by 34 per cent the record established in 1939; the tremendous Federal total, nearly $1,500,000,000, also a new all-time high, was responsible for the public gain, and topped the preceding year by 311 per cent. Private awards climbed to the highest point reached in 1930 and increased 31 per cent over 1939.

Industrial building construction was the important factor in the private gains. The total, $594,000,000, eclipsed the record of 1929 and more than doubled the volume of 1939. Industrial building included factories for aircraft, engines, machines and machine parts, all products closely allied to defense.

The gains in the public construction field were more widely distributed, and three new high marks were established in individual classes of work. Public buildings rose to unprecedented heights, topping the previous high of 1939 by 102 per cent. Some of this was due to cantonment work and some to Government-owned manufacturing plants which, if they had been financed by private funds, would have been in the industrial building total. Air-base, airport and shipyard construction aided materially in boosting unclassified public construction to a new pinnacle, 52 per cent over 1939. The third record established in the public field was in streets and roads, which increased 5 per cent over the record high of 1939.

There were losses. But in view of the great emphasis placed on national defense construction, only one of these is surprising, namely, bridges, which attained only 80 per cent of the 1939 total. The other two drops were in waterworks, which registered 43 per cent of the 1939 total, and in sewerage, which registered 57 per cent.

Not for a decade have construction prospects been so promising as they are for 1941, though they result in the main from a war boom and are liable to the hazards succeeding such activity. The tempo is already established, and only such an unexpected event as Germany's sudden and complete collapse could slow down our defense preparations, which in their present stages are predominantly construction. Of the $2,000,000,000 for construction in the Federal defense appropriations, nearly one-half remains as a backlog for 1941 contracts. Additional Congressional appropriations for shipyards and industrial plants are certain. More money for airfields may reasonably be expected. Highway building will not decline in amount and could increase. Steel mill expansion, already begun, may be greatly extended. Though predicting trends is risky, it seems reasonable upon the best available information to expect about an 11 per cent increase in construction for 1941.

Civil engineering and construction activities are most easily considered if divided into the various types of work involved, namely, buildings, highways, bridges, sewage disposal, water supply, etc. These are considered in turn below.

Building Construction.

The year 1940 was dominated by building construction of the factory type. Huge plants for the manufacture of powder, shells, tanks, airplanes and ships got under way and are supplemented by Army and Navy warehouses, ammunition depots, airplane hangars and cantonments. Technically, there were few important advances recorded because the objective was speed, which leaves little time for innovation.

Both the Army and Navy tried out thin concrete shell roofs for a few hangars, but for the most part such structures used steel frames. These steel-framed hangars, however, reflect great advances since World War days. For one thing, the maximum 110-ft. hangar width of the World War has been replaced by openings up to 250 ft. wide. The Army is building three types of hangars, the most common being the tied steel arch of 275-ft. span, 200 or 250 ft. long, and having unobstructed door openings 250 x 37 ft. And to accommodate the tail of the planes, which in the largest machines reaches a 45-ft. height, a lift door 15 ft. square is placed over the center of the main door openings. In Alaska the interior of the hangars is vestibuled by placing sliding doors similar to the main door at mid-length so that the inner or working compartments can be kept at a reasonable temperature.

The Navy uses simple trusses of long span rather than arches to support the roofs of its hangars. The standard seaplane hangar has a net floor area 240 x 320 ft. in plan, with two 160-ft.-wide door openings. Land-plane hangars are 200 x 220 ft. in plan with two 110-ft. door openings. Concealed or protected hangars are not favored as yet. The principle is that the place for planes is on the field ready for instant service. Accordingly, the hangar enclosure is built for weather protection only and not to resist bombs.

Most spectacular of the buildings at Navy air stations are the huge assembly and repair shops. These are being built initially with such plan dimensions as 640 x 580 ft., and all are so laid out that floor area can be doubled if needed. The Army also uses huge buildings particularly at supply and repair depots at one depot, for example, an engineering shop is 770 x 640 ft. in plan, and there is a supply building 480 x 860 ft.

Permanent barracks are of all types and utilize every conceivable material. Not only are they well built but considerable attention is being paid to make their appearance attractive.

Housing at naval shore stations utilizes many of the advances incorporated in the best of low-cost housing projects developed over the past few years, including insulation, acoustic ceiling and poured concrete foundations. Even the Army cantonments, which are of more temporary nature, are many times more convenient and livable than the 1917 variety.

Following closely on the changes in the New York City building code to permit welding, several buildings of this type were constructed. Most notable is the airlines terminal on East 42nd Street containing five stories and three basements in which all of the framing is arc welded. Several trusses of 70-ft. span weigh as much as 30 tons each. Because buses, which take passengers to the airports, are handled within the building by means of ramps and elevators, there is much complicated framing which required the development of many ingenious welded details.

Several important office buildings were completed during the year. In Des Moines, Iowa, the Bankers Life Co. moved into a new seven-story building notable for its 55-ft. clear span working area, enameled steel interior finish, radiation from pipes in the walls, ventilation through perforated metal ceilings and an exterior of granite and limestone. In Houston, Texas, the 16-story Mellie Esperson building was given a complete air conditioning installation; to fit the ducts into the building with greatest economy and least damage to architectural appearance, a special shallow beam framing was developed for the corridor buys down which the ducts were laid. Most notable reinforced concrete building of the year was Wesley Memorial Hospital on the Northwestern University downtown campus in Chicago. The central unit is a 21-story steel frame building; radiating from it are four 16-story wings of reinforced concrete.

Auditorium buildings were not so numerous as previously, but Buffalo completed one with a seating capacity of about 15,000 persons. Covering an entire block, the roof is supported by pin-connected trusses of 258-ft. span weighing 62 tons each. Numerous office buildings were built in Washington, D. C., one of the largest being the War Department building. Seven stories high and of steel frame construction the new building has 310,000 sq. ft. of floor space, which it is planned to increase to 1,200,000 sq. ft.

Great emphasis was placed upon defense housing toward the end of the year, the most interesting phase being the decision to utilize pre-fabricated units on some of the projects. The USHA slum clearance program continued to turn out well-planned and permanent quarters in a number of cities. Most spectacular of all housing during the year was the Parkchester development of the Metropolitan Life Insurance Co. in the Bronx, New York City. Consisting of 51 buildings ranging up to 12 stories in height, it is a self-contained community for about 40,000 residents. Apparently as a result of the success of this initial venture, the company awarded contracts late in the year for a similar though smaller housing development in San Francisco.

Aircraft factories turned in the best record of rapid construction, many of them doubling and tripling their floor space in a matter of months. Most notable of technical developments was the wide utilization of basement corridors in the Boeing plant at Seattle to take workmen from the factory gates to the point in the building where their job was located. Also, a number of windowless aircraft factories, given the wartime name of 'blackout' factories, were started, notably North American Aviation at Dallas and Grumman Aircraft at Bethpage, L. I. Such factories require controlled conditions of lighting and ventilation and are claimed by their proponents to promote the efficiency of the workmen. Because most aircraft factories have large expanses of glass in roof and side walls and thus would make prominent bombing targets at night, there was some talk of installing masking devices to shut in the light, but nothing of note in this direction has yet been done. (See also HOUSING DEVELOPMENTS.)

Highways.

More money was spent for roads in 1940 than in any other year in history; this same statement was true for 1939, so that the road building tempo is gradually being increased. The 33,000 miles of roads built in 1940 (in 45 states reporting) is an 11 per cent gain over the 1939 mileage. Some 52 per cent of the total is 'dustless' and only 11½ per cent is real 'pavement.' 'Non-dustless' surfaces accounted for 17½ per cent of the mileage while the balance of the 1940 total was merely 'graded and drained' and not surfaced.

Per capita spending for roads was $6.60 west of the Mississippi, $6.25 in the Far West, $6 in the South, $4.54 in the Middle West, $5.24 in New England, and $3.54 in the Middle Atlantic States. In New England 43 per cent of the highway money is spent on maintenance, in the Far West 38 per cent, in the Middle West 33.6, in the Middle Atlantic States, 31.5, west of the Mississippi 29, and in the Southern States 29.

Despite much talk about defense roads, little was done in 1940 to implement some of the plans that had been developed. Three major road problems raised by the preparedness program still need to be solved; how to finance the construction of access roads to the new Army camps; how to prevent serious congestion around plants engaged in military orders; and how to bring the system of strategic highways up to military requirements without neglect of normal commercial needs. Most urgent and simplest is that of camp access roads. It requires, however, funds from Congress and these have not been appropriated. The strategic road system will probably be taken care of in the normal course of highway development, but congested roads in industrial areas will need special attention.

Completion of the Pennsylvania Turnpike between Harrisburg and Pittsburgh, a toll road of the super-highway type incorporating every modern development for the rapid movement of traffic, was the outstanding highway event of the year. After three months of operating experience, the road is considered a distinct success, and plans are under way to extend it to Philadelphia when and if financing can be arranged. The most unusual operating result is that few automobiles can stand the sustained high speeds that are possible on the Turnpike; mechanical failures have been high and tires have been seriously damaged. The Turnpike consists of four 12-ft. lanes, two in each direction separated by a 10-ft. median strip in which shrubs are to be planted to form a separating barrier. Through the mountain tunnels, of which there are seven aggregating a total length of 6.8 miles, there are but two lanes 11 ft. wide. Experience to date has shown that the two-lane tunnels do not delay passenger vehicles by requiring them to merge with truck traffic because the trucks travel at the maximum speed permitted, which is 50 miles per hour approaching a tunnel and 35 within the tunnel. The 161-mi. road cost about $67,000,000.

Another great road-building job of the year was New York City's Belt Parkway. A little over 31 miles long, it cost about $28,000,000. Both highways give some indication of the tremendous cost of providing highway facilities that adequately meet traffic requirements. The Belt Parkway is being extended from its western terminus in Brooklyn to a connection with the Battery-Brooklyn tunnel now under construction under the upper bay at New York City. With the completion of this link the entire city of New York can be circled on a grade-separated highway.

Bridges.

The most important bridge development of 1940 was not bridge building but a bridge collapse. On Nov. 7, wind wrecked the 2,800-ft. main span of the Tacoma Narrows suspension bridge which had been in service less than six months. The bridge had been one of the achievements of the previous year, notable for its extreme slenderness and shallow stiffening members which were of plate girder type. From the time it was opened the bridge had exhibited disturbing lengthwise oscillations in its deck, and these were being studied by models when the collapse occurred. The collapse, however, resulted not from these up-and-down oscillations but from the fact that they suddenly changed to a twisting and sidewise rolling motion under aerodynamic influences. This twisting and rolling eventually tore the suspended deck loose from its suspender cables, dropping it 200 ft. into the waters of Puget Sound.

The failure has been likened to the failure of airplane wings under a type of vibration known as flutter. This vibration, not previously encountered in engineering structures, raised important new problems. Until studies now under way are complete, little can be said as to the cause of the collapse other than that the bridge was too flexible. The solid stiffening girders may have played a part in building up the irresistible forces, but on other bridges where they have been used — Bronx-Whitestone in New York City, Thousand Islands across the St. Lawrence River, and Deer Isle in Maine — and where vertical oscillations have also occurred, such oscillations have been reduced or eliminated by installing inclined stay cables at the towers. Plans are under way to rebuild the Tacoma Narrows bridge, salvaging, if possible, the tower, main cables and side spans which are still standing.

The Washington Toll Bridge Authority, owner of the Tacoma Narrows Bridge, is also the owner of the Lake Washington floating concrete bridge which was opened to traffic during the year. This novel structure consists of large concrete boats 350 ft. long and 60 ft. wide, placed end to end and carrying a four-lane roadway nearly 7,000 ft. long. At the shipping channel two of the pontoons are built to telescope providing an opening through which the boats can pass. Also on the Pacific Coast the great Pit River bridge on the railroad and highway line around Shasta Dam progressed to the point where steel erection began. This bridge contains the tallest concrete piers in the country, two of which exceed 350 ft. in height. It will carry the highway on the top deck and the railway on the bottom deck of a truss bridge having spans varying from 140 to 650 ft.

Four bridges were completed across the Mississippi River during the year, one each at Baton Rouge, La., at Natchez, Miss., at Greenville, Miss., and at Rock Island, Ill. The Natchez bridge with an 875-ft cantilever span contains the longest span of any Mississippi River bridge. The Rock Island Bridge is notable because it consists of a series of steel tied arches, varying in length from 394 to 539 ft. Such spans are uncommon, but the year witnessed start of construction of another bridge utilizing them, located on the DuPont Highway over the Chesapeake & Delaware canal at St. Georges, Del. This structure, which will have a span of 540 ft., replaces an old lift span.

Plate girder bridges continued to increase in length of span. The record at present belongs to a 271-ft. span in the lakefront approach to Cleveland's new Main Avenue viaduct. Work, however, has begun on a new bridge at Hartford, Conn, across the Connecticut River in which plate girder spans up to 300 ft. will be used. The most extensive use of plate girders and one of the most unusual occurred in the Thomas A. Edison Bridge built by the New Jersey Highway Department over the Raritan River at Perth Amboy. Opened during the year, this bridge contains eight 200-ft. spans and one 250-ft. span raised to a height of 135 ft. over the shipping channel. The 250-ft. span girder is 21 ft. deep over the supports, a maximum for this country.

In Lorain, Ohio, the country's longest double-leaf highway bascule bridge, 333 ft. between trunnion pins, was finished late in the fall. The other notable movable bridge of the year was built over the Piscataqua River at Portsmouth, N. H. A 224-ft. lift span, it is notable for the fine architectural appearance of the towers. It is a double deck structure with a highway on the upper deck and a railway on the lower.

Another New England bridge that deserves important mention is the Merritt Parkway crossing of the Housatonic River. Two unusual features characterize this bridge — the use of one-leg bents and of 1,824 ft. of open steel grid flooring, the largest installation of this type of flooring to date. The bridge is of plate girder type and the one-leg bents were adopted to give increased width in the shipping channel where conventional two-leg bents would have formed an obstruction or made it necessary to increase the span length unduly.

Sewage Disposal.

Following a decade of great activity, sanitary engineering dropped back to more nearly normal dimensions. Instead of an expenditure of $150,000,000 for sewage disposal as in 1939, the year 1940 witnessed only $91,000,000 worth of new facilities. Technical advance, however, kept up a reasonable pace. The high rate shallow filtration process — a novelty just a few years ago — received great impetus by forty new installations said to be 30 per cent lower in construction cost and as much as 40 per cent lower in operating cost than the standard trickling filter system.

Combined disposal of garbage with sewage, talked of for many years and experimented with for several, came into prominence with the completion of major plants at Rock Island, Ill., and Gary, Ind. The pioneer installation was made in Lansing, Mich. in 1938. Other plants are at Goshen, N. Y., Findlay, Ohio, and Marion, Ind.

Considerable controversy arose during the year over the utilization of sludge for fertilizer. Many new converts were obtained by those favoring sale of sludge as fertilizer; but experience at Milwaukee, one of the biggest and oldest producers of fertilizer from sludge, dispels the thought of profit. In Milwaukee it costs $23 to produce a ton of fertilizer, while the net return is about $15. Chicago, however, has been shipping sludge to Florida, and this has captured the imagination of some major cities.

Not much progress was made in stream pollution abatement but a step forward was registered when Congress approved the formation of interstate compacts for the control of pollution in the Ohio and Potomac Rivers. An extensive study of river uses and abuses is being made of the Ohio River, looking forward to a program of remedial measures for stream cleanup in a 14-state area involving 200,000 sq. mi.

Progress in sewage disposal as measured by new plant construction will continue to be slow because sewage disposal is not a prime national defense need. Several of the larger cities, notably Philadelphia, Boston, Louisville and Los Angeles, have plans for major expenditures but these will not materialize this year. The biggest jobs under way are the $10,000,000 addition to Chicago's Southwest plant and the $6,000,000 program for several plants in New York City.

Water Supply.

Outstanding among the new technical developments in the field of water supply in 1940 was the introduction of break-point chlorination for the elimination of taste and odor. The new technique involves the application of chlorine to a predetermined dose, at which point a change of condition will occur resulting in a sudden drop of residual chlorine. If more chlorine is applied this is followed by a breakdown of taste producing substances. A different form of attack on taste and odor problems, using ozone, was launched at Denver, Pa., where a 300,000 gal. filter plant was built and provisions made to apply ozone gas to the water.

Big water supply undertakings included the Baltimore tunnel, the Boston aqueduct, the Chicago filter plant, the Delaware aqueduct for New York City, and the softening plant for Colorado River aqueduct water in southern California. Also Toledo, Ohio completed a 108-in. intake conduit three miles long into Lake Erie, which is supplemented by 9 miles of 78-in. pressure main to a new 80,000,000 gal. daily purification plant. Wichita, Kans., draws water from a new prairie well field to its new plant through a 48-in., cast-iron pipeline. Work on the 320,000,000 gal. South District filtration plant in Chicago has progressed rapidly, and the substructure of the plant is substantially complete.

1939: Civil Engineering

New Records.

Construction volume, the dollar measure of civil engineering activity, was 8 per cent greater in 1939 than in the previous year. Including about $1,600,000,000 of residential building, the year's total was $6,974,000,000. Excluding the residential work, the remainder was divided about two-thirds for public construction and one-third for private.

New all-time records were made in the fields of roads (by 1 per cent); sewage disposal (by 17 per cent); waterworks (by 24 per cent); and public buildings (by 18 per cent). Bridge construction, at the second highest volume ever reported, was 12 per cent above a year ago. Industrial building after a poor showing in the first half of the year picked up to top the 1938 figure by 86 per cent. Commercial building and large-scale housing were the only classes of work that failed to exceed last year's totals.

Predicting what volume 1940 will produce is more precarious than usual, considering war abroad and a presidential election on the home front. All indications are for a considerable letdown in public works construction as Federal purse strings are pulled together. National defense needs may, however, be reflected in enough construction to cushion the drop. Substantial improvement in private construction — industrial plants, utilities and housing — is possible, so that 1940 can be expected to produce about the same amount of construction work as did 1939. Along such a trend, from a predominance of public works to an excess of private over public, is the road to normalcy as it existed before the depression.

Civil engineering activity is most easily considered if divided into the various types of work involved, namely, bridges, dams, irrigation, buildings, highways, sewage disposal, water supply, and flood control.

Building Construction.

The year in building construction was marked by a substantial increase in housing and a great rise in factory construction during the last half of the year. Technically, advance was marked by a wider use of structural welding for steel frame buildings. New York City approved this type of construction, permitting an apartment house and several schools with arc-welded frames to be built. Other large arc-welded buildings were 16- and 23-story structures for the Jersey City Medical Center, a 14-story office building for the State of Kentucky, at Frankfort, and a 14-story addition to the 13-story Chamber of Commerce Building in Houston, Tex.

The public housing program of the USHA made large strides during the year, as 19 low-rent projects in 13 cities were opened to tenants. A total of 145 projects, designed to provide over 58,000 dwellings, have gone into construction. By late spring all of the USHA's $800,000,000 appropriation will have been expended on 90 per cent loans to local housing authorities. A bill asking an additional $800,000,000 is pending in Congress. An important achievement has been the reduction of construction costs of the dwelling units in the program, the average now being $2,831; the average total development cost, including land and non-dwelling facilities such as stores, is $4,867. Cracked walls found in some of the housing projects called attention to the difficulty of combining brick bearing walls with concrete slab floors and roofs, and has resulted in much discussion and a test program that should benefit the entire building industry.

The privately owned and financed Parkchester housing development in the Bronx, N. Y., in a class by itself as to size and completeness, was brought to a stage of about 75 per cent completion. It is estimated to have cost the Metropolitan Life Insurance Co. $35,000,000 and will house over 12,000 families on its 129-acre site.

One of the fastest building jobs on record was chalked up by the Glenn L. Martin Co. at Baltimore, in constructing a two-story $1,800,000 assembly building for airplanes in a period of eleven weeks from the time the design contract was let; foreign and United States military orders were the incentive. About the most striking and unusual industrial building of the year was that built by Church & Dwight, Inc., manufacturers of baking soda, at Syracuse, N. Y. The equivalent of about 8 stories in height, the building is inclosed in solid walls of brick and glass block and presents striking effects in both mass and façade. Its steel framework is entirely welded and some of the connections are among the largest ever attempted by this method of joining steel together, carrying in several instances as much as 250,000 lb. each.

Another notable industrial plant was that of the E. I. du Pont de Nemours & Co. at Seaport, Del., where a one-story building 270 ft. wide and over 1,000 ft. long was completed for the manufacture of Nylon yarn and similar products destined for use in women's hose and toothbrushes, among other articles. Large-scale food terminal facilities were built in both Denver and Kansas City, Kan. Involving cold storage warehouses, grain elevators, farmers' markets and large railway trackage, these terminals represented some of the outstanding construction operations in the building field of the year. The thin-shell concrete barrel roof construction, previously used in this country on large skating arenas, made its appearance in the industrial field in a new factory for the Armstrong Tire Co. at Natchez, Miss. Another significant development was the use of enameled steel sheets for the exterior walls of a high school at Girardsville, Pa.

Highways.

More money was spent for roads in 1939 than in any other year in history. Tax revenues from gasoline sales and license fees mounted at an even faster pace, indicating increasing use of the highways. The year marked the beginning of a planned development of a national super-highway grid, with a master plan of an interregional system of 30,000 miles being drawn up by the Public Roads Administration. The year also recorded official recognition by the Federal Government of the problem presented by the high cost of rights-of-way for express highways into and through our cities. Such facilities are major needs of our highway program, and a bill was introduced into Congress providing for Federal loans for rights-of-way purchase, thus leaving existing highway money for actual construction work.

During the year the 48 states spent $735,000,000 to improve 28,000 miles of highway, of which 12 per cent was hard pavement, 53 per cent bituminous types of surfacing, and 35 per cent was graded and drained and given a low type surfacing. Increasing use of bituminous types of surfacing and a larger proportion of highway money assigned to maintenance were the principal trends of the year. On the basis of the $735,000,000 expenditure each American in 1939 spent through the various state highway departments an average of $5.98; the maximum expenditure was $8.18 in the Far West and the minimum expenditure $4.52 in the Middle West. In New England 46 per cent of the highway money is spent for maintenance, while the Middle West spends 36 per cent, the Far West 31 per cent and the South 25 per cent.

Most notable development of the year was the increasing use of divided highways, largely dictated by their safety values. Most of the other highway improvements were also allied with safety such as the use of accelerating and decelerating lanes at entrances to express highways, a continued high tempo of grade-separation construction work, the use of white reflecting curbs and the extension of highway lighting.

The smoldering subject of toll highways versus free highways was touched off when Connecticut placed tolls on its Merritt Parkway beginning in June. In retaliation, Westchester County, N. Y., placed tolls on its Hutchison River Parkway, which connects with the Merritt Parkway. Motorists paid the ten cent tolls with apparent willingness but opponents of the idea maintained that the motorist is already taxed far beyond the service that he gets and that until all highway tax money is used to build highways, toll roads can be justified only under very exceptional circumstances. In the meantime there is rapidly nearing completion a 200-mile road between Harrisburg and Pittsburgh that was planned and financed as a toll highway. Cost will be in the neighborhood of $70,000,000. Involving heavy grading and the reconstruction of a half dozen old tunnels, driven 50 years ago for the proposed South Penn Railway, the job represents one of the largest and fastest road building operations ever undertaken. It is without question the greatest road construction job of the whole year.

Running it a close second is the 31-mile Belt Parkway being built around the southern and eastern borders of New York City, a lane-separated express highway with 77 grade separation structures and costing a total of about $28,000,000. At its eastern end it connects with the Bronx-Whitestone Bridge across the entrance to Long Island Sound and leading to the Westchester County parkways, while at its western end it is proposed to connect it with a crossing of the upper bay from Brooklyn to lower Manhattan at the Battery. Such a crossing, now planned as a tunnel because the War Department refused to issue a permit for a suspension bridge, would provide direct connection with New York City's West Side elevated highway, which runs as an express road to a connection with the Westchester County parkway system. Except for the Brooklyn-Battery link, 1940 will see this road live up to its name of Belt Parkway.

Sewage Disposal.

The urge to clean up streams and the demands of governmental authorities are the principal factors behind two years of record-breaking activity in the sewage disposal field. Mechanization of sewage treatment processes continues. More and more cities are installing facilities for utilizing the by-product sludge gas to produce electric power. The subject of a Federal stream pollution abatement bill is still in Congress. Outstanding plants opened during the year were the Tallmans Island plant in New York City and the Southwest plant at Chicago. New York has two other large plants under way — at Bowery Bay, west of the Tallmans Island project, and a 65,000,000 gal.-daily activated sludge plant in Jamaica.

An inventory of sewage disposal facilities made by Engineering News-Record at the beginning of the year showed that more than half of the urban population in the United States is served by treatment plants; this is a gain of 52 per cent since a similar survey was made in 1938.

Water Supply.

At opposite ends of the country, the world's two largest supply developments continued in construction. The first water flowed through the 231-mile Colorado River Aqueduct to the distributing reservoir near Los Angeles during the year, and the distribution system which will carry the water to 13 nearby communities is rapidly nearing completion. Work also started on a mammoth softening plant to condition the water for the convenience of the consumer. In New York the Delaware Aqueduct, tapping new sources of water in the Delaware River watershed, celebrated the holing-through of the first section of the 85-mile tunnel. Work also began on Merriman Dam, to create a storage reservoir on this system. Chicago, last of our large cities to undertake filtration, began work on its 225,000,000-gallon-daily plant in south Chicago. The job involves, in addition to the plant, 115 acres of land filling along the shore of Lake Michigan, some 11,000 ft. of 16-ft. rock tunnels, a breakwater, bulkheads and the installation of 50,000 meters, first to be used in Chicago.

Boston continued improvements to its water supply system by substituting an 18-mile concrete pressure aqueduct for the existing open channels and grade-line aqueducts from the Wachusett Reservoir. The new aqueduct will carry the Quabbin Aqueduct supply of Swift and Ware River water together with Wachusett Reservoir water directly to the city distribution system without danger of contamination. The capacity of the line is 200,000,000 gallons daily. Precast pipes in sizes up to 12½ ft. in diameter are a notable feature of the work.

According to a nationwide survey made by Engineering News-Record, two-thirds of the total population of the United States is served by community water systems, of which there are 12,750. Three-quarters of the water systems are publicly owned and, on a population-served basis, private water utilities deal with only 11 per cent of the business. Some 85 per cent of the 81,000,000 people served by public and private systems receive water that has been given treatment for health protection, quality improvement or both. It is interesting to note that chlorination is practiced at only 4,000 of the plants, and filtration facilities are found in only 2,188. The only similar survey of recent years was made by Engineering News-Record in 1928 and much of the data then had to be based on estimates. These showed 10,679 waterworks systems. In 11 years, therefore, waterworks systems have increased about 20 per cent in number.

Typhoid fever fatalities as a result of contaminated water supply, once very common, have seldom been heard of in recent years. The 500 cases of typhoid fever and 53 deaths at the Marteno (Ill.) State Insane Hospital during the year were therefore an exceptional tragedy. The cause was traced to sewage seeping into wells.

1938: Civil Engineering

High Peaks and Low.

Five branches of civil engineering activity registered all-time peaks in 1938 in volume of work done. Despite this unusual record, total construction volume for the past year was only about 10 per cent above the 1937 figure. Industrial building construction was a disappointment, dropping from $480,000,000 to $150,000,000; this group and other private construction work pulled the year's total down.

All of the star performers were in the public works class, the five record breakers being waterworks, sewerage, earthwork and waterways, streets and roads, and public buildings. A new PWA program of $2,000,000,000 was put into operation in the last half of the year, and work from this fund will continue through all of 1939. A new public housing program was also launched, and about $600,000,000 committed for projects in about 150 cities; some $45,000,000 of this sum was actually put into construction work in 1938.

Bridges.

No single bridge dominated 1938 as the Golden Gate and San Francisco Bay bridges had dominated the previous year. On the other hand, the Bronx-Whitestone suspension bridge in New York City, with a main span of 2,300 ft., will be the fourth largest in the world: and to the bridge engineer it offers several new developments (which are also apparent to the layman), notably the use of plate girders instead of trusses for the stiffening members and the use of towers devoid of cross-bracing above the roadway, except for a strut at the top. The smooth lines and the simplicity of the design are distinctly different from most previous suspension bridges.

At Vancouver, a 1,550-ft.-span suspension bridge, the longest in the British Empire, was opened across the entrance to the harbor, known as Lion's Gate.

Other important bridges of the year include: the Thousand Islands bridge, in reality a series of five bridges and connecting highways traversing 8 miles of route across the island-studded St. Lawrence River; a multiple-cantilever layout of three through-truss spans of 800 ft., 650 ft., and 650 ft. across the Ohio River at Cairo, III.; the Connecticut River bridge at Middletown, Conn., consisting of two 600-ft. tied arches; the Neches River bridge near Port Arthur. Texas, 7,750 ft. long, with a main cantilever span of 680 ft. that provides 176 ft. of vertical shipping clearance; the Deer Isle 1,080 ft. span suspension bridge on the Maine coast; and an 871-ft.-span arched-cantilever bridge (8,120 ft. long) connecting the United States and Canada at Port Huron, Mich.

Important bridges still under construction are located at Baton Rouge, La., Natchez and Greensville, Miss., all crossing the Mississippi River; at New York City, where the Meeker Ave, bridge is being built across Newtown Creek; and at Tacoma, Wash., where a 2,600-ft. span-suspension bridge is just getting under way. One of the most unusual bridges, for which a contract was awarded late in the year, is a Lake Washington crossing at Seattle built of concrete pontoons for a length of 7,100 ft. and including a telescoping pontoon which will open to permit the passage of boats.

Important trends in bridge design are noted in a tendency toward wider decks, in extensive use of rigid frames and continuous girder layouts, in the extension of concrete flat slab design to longer spans, and in the incorporation of high curbs and sturdy handrails for safety's sake. One of the important developments in medium-sized bridges has been the growing tendency to use longer plate-girder spans. These are used on continuous girder layouts, and in the past two years have been built in span lengths of from 200 to 250 ft. Most notable is the Raritan River bridge at Perth Amboy, N. J., a $4,000,000 structure of plate-girder type in which the main span is 250 ft. long and the eight approach spans each 200 ft. The bridge is 135 ft. above the water. Only a few years ago such a crossing would have been bridged by a truss-type structure.

Several bridge failures marred the record of the year. The most disastrous was the collapse of an old plate-girder railroad bridge in Montana, which wrecked a passenger train and took 47 lives. The most spectacular failure was that of the Niagara Falls arch, a 50-year old structure over the gorge, which was knocked off its foundations by an unprecedented ice jam. Finally, the collapse of a welded bridge in Belgium marked the first major failure of a welded structure. It was determined, however, that the principal cause of the disaster was the use of steel unsuitable for welding, so that the failure did not reflect upon the safety of structural welding.

Dam Building.

In the field of dams, the Grand Coulee power and irrigation structure, on the Columbia River in Washington, continued to dominate the scene, as concrete was steadily poured into it at unprecedented rates. However, Shasta Dam on the Sacramento River in California, put under construction about the middle of the year, runs Grand Coulee a good second in magnitude and interest. As against Grand Coulee's 10,000,000 cu. yd. of concrete, Shasta will contain only 5,4,000 cu. yd.; but this is 70 per cent more concrete than was required for Boulder Dam, and the height of Shasta is greater than that of Grand Coulee. Furthermore, Shasta will be of overflow type; and with the water dropping a record distance of 488 ft. over its spillway, it will present a spectacular picture. While Shasta is being built, the Southern Pacific Railroad, which runs up the valley, will be placed in a tunnel beneath the dam foundation and then shifted to a relocated line on higher ground as soon as this location is ready; the tunnel will then be used to carry the Sacramento River past the dam site while construction proceeds.

The year witnessed the completion of Bonneville Dam on the Columbia River, and the start of power generation; the completion of Imperial Dam on the lower Colorado River and the diversion of water by it into the amazing settling works that take out the sediment before the water is discharged into the All-American Canal; the completion of Caballo Dam on the upper Rio Grande, a combination flood control and irrigation structure; and the virtual completion of Bartlett Dam on the Verde River in Arizona, whose height of 286 ft. makes it the highest multiple-arch dam in the world.

Seattle began construction of Ruby Dam on the Skagit River, to augment its public power sources; and work was begun on the $44,000,000 Colorado-Big Thompson project in the state of Colorado, whereby irrigation water will be brought across the continental divide to be used on the eastern slope. Preliminary work for the latter requires the building of the Green Mountain Dam on a tributary of the Colorado River.

The Tennessee Valley Authority continued construction of five dams — Gilbertsville, Guntersville, Chickamauga, Pickwick Landing, and Hiwassee. Gilbertsville and Hiwassee are farthest from completion.

Two earth-dam failures, one a relatively small structure near Kansas City, Kan., and the other at the great Fort Peck Dam on the upper Missouri River in Montana, were dramatic happenings of the year. Fort Peck, entering its sixth year of construction, suffered a slump of the embankment at its east abutment on Sept. 22, which seriously delayed operations. Some 20,000,000 cu. yd. of fill were placed in this dam in 1938, bringing the total since the start of dredging in 1934 to 97,000,000 cu. yd.

Irrigation.

The most notable irrigation happenings of the year were the virtual completion of the first 22-mile section of the All-American Canal in the Imperial Valley of Southern California, and secondly the start of work on the Central Valley project in California, by which Sacramento River water will be impounded by Shasta Dam and released to water-depleted lands in the San Joaquin valley. Estimated to cost $170,000,000, this irrigation project is already under way with contracts worth $40,000,000 outstanding. The Colorado-Big Thompson project has already been mentioned. In addition to these notable works, a dozen or more irrigation projects involving substantial dams and lengthy canal systems are under way in the intermountain region of the West.

In Nebraska, the Central Nebraska Power and Irrigation District has awarded 60 contracts amounting to about $20,000,000 out of an estimated $36,000,000 cost. The largest item, Kingsley Dam, is under way, as is the relocation of 33 miles of the Union Pacific Railroad. The 75-mile supply canal is about 30 per cent complete.

Buildings.

Compared with other years, building developments, measured either by number of structures or technical advance, were not notable. Rockefeller Center added the twelfth unit to its three-block group in New York City and began work on the thirteenth. New, tall office buildings were non-existent elsewhere. In the field of industrial building, the Carnegie-Illinois Steel Corporation completed its huge Irvin Works near Pittsburgh, Pa., one of the largest steel plants in the world and notable because of its location on a hill instead of in bottomland along a river. The Ford Motor Company built a press shop in which the presses, instead of being set in pits at ground level, are raised to the second floor to permit conveyors to operate beneath. This location of presses required the construction of a floor capable of carrying a load of 2,000 lb. per sq. ft.

The trend toward municipal approval of welding continued, with New York City and Chicago the most important recruits to an already numerous company. A half-dozen medium-size buildings were erected in New York City under the new code. Windowless buildings with glass block walls continued to multiply. In industrial structures, monitors enclosed on all four sides with glass block are finding favor. The extensive construction programs of the New York and San Francisco World Fairs have given opportunity to try many innovations in the use of timber, and some of these no doubt will find reflection in permanent structures later.

In the field of public housing, the United States Housing Authority got 12 projects under way in its present 150-project program. A notable characteristic of this program, as distinguished from those which have preceded it, is that, apparently, costs have been brought down to a reasonable figure for 'low-cost' housing. Thus living units in the 6-story concrete apartments of the Red Hook project in New York City have been estimated to cost less than $5,000, while single-story row houses in some of the projects in the south are being built for $2,500. These large-scale housing projects are having an important effect on city planning, in such matters as street layout, school facilities and playground spaces. The most notable housing development of the year was in the Bronx, New York City, the start of a private operation, owned and financed by the Metropolitan Life Insurance Company. Estimated to cost $35,000,000, and to house from 12,000 to 20,000 families, the project is spread over a 129-acre site.

Highways.

Highway construction was carried on at a faster pace than ever before, as measured by money expended. Following New York City's example, many other cities have begun the development of arterial parkway systems; and during the year, in addition to New York City's work, such projects could be noted in Cincinnati, Chicago, San Francisco, and Los Angeles. Much discussion has arisen concerning the possibilities of toll roads for special services. The subject has been given some study by the United States Bureau of Public Roads, but there has been no crystallization of policy as yet. In the meantime, however, Pennsylvania has begun construction of a 200-mile toll road from Harrisburg to Pittsburgh, utilizing the old right-of-way and the partly completed tunnels of the South Penn Railroad, begun and abandoned a half-century ago by the New Central Railroad in its historic fight with the Pennsylvania Railroad.

Modern highways in 1938 were designed for higher speeds than ever before. Wider lanes, 12 and 13 ft. instead of 10, were utilized. Traffic going in opposite directions was separated by a center island. Outside shoulders were made flat and wider. Concrete and bituminous surfaces continued to predominate, although brick showed new signs of life. Brick roads appeared with the brick laid lengthwise, with brick laid on a fresh concrete base, and with brick reinforced with steel rods similar to reinforced concrete. Earth roads made definite progress, firm and weather-resistant surfaces being obtained by scientifically combining and processing the soils with cement or bituminous binders. In most cases the mixing was done in place on the road, although in several cases traveling machines picked up the earth, mixed it with the binder, and re-spread it.

In the field of refuse disposal, acrimonious discussion arose. Land-fill methods of disposal in New York were criticized by those urging incineration; while in Detroit incinerators were declared a nuisance, and land fill was substituted. Enclosed and mechanized collection trucks were put in service in many cities.

Sewage Disposal.

In the sewage disposal field, the trend toward mechanization of processes is very marked. Elutriation of sludge has been started in several cities, including Washington. Baltimore, and Hartford. Equipment in many of the new plants favors alloy steels. Statistics indicate that although investment in sewage-disposal facilities has been at a high peak for several years and recorded an all-time record this year, only about half the country's population is served. An important development is the growth of the sewer rental plan, by which sewers are paid for by definite charges, as is water supply.

A number of important sewage-disposal plants were under way or completed in 1938. At Buffalo a $13,500,000 intercepting sewer and treatment works project was placed in operation in July, the plant having a capacity of 150,000,000 gal, a day. In Chicago, the $60,000,000 program started in 1933 is rapidly nearing completion; early this year the 400,000,000-gal. southwest treatment works will go into operation. Thus, Chicago will no longer dump untreated sewage into the Chicago River: and, looking toward this end, control works have been built at the mouth of the Chicago River to limit the outflow of Lake Michigan water to 1,500 cu. ft. a second. When Chicago's program is completed, 99 per cent of the sewage and industrial waste of this area, equivalent to a six-and-a-half-million population, will be treated.

Great as is Chicago's sewage-treatment plan, it does not approach that of New York City, where the largest single sewage-disposal program ever undertaken anywhere is under way. The city now has three treatment plants under construction, and designs are being prepared for three others. The program contemplates thirty-two plants, only two of which. Wards Island and Coney Island, are ready and in operation. The Taliman's Island job, a 40,000,000-gal, activated-sludge plant, will be completed in time for the World's Fair. Other cities having extensive sewage-treatment programs under way are Columbus. Niagara Falls, Atlanta, Detroit, Baltimore, Cleveland, Cincinnati, Minneapolis, St. Paul, Denver, and Memphis. The principal problem at Denver is to get more water into the stream which flows by the new sewage plant, so that the effluent can be carried away more easily and diluted more readily. Water is being brought in a tunnel from across the continental divide for this purpose.

Water Supply.

There were no outstanding developments in water-treatment methods during 1938. However, it is becoming more and more evident that large cities must go farther from their environs to get additional supplies, as witness New York, Los Angeles, Boston, and Little Rock. Much detailed improvement has been made in city distribution systems, particularly through leak surveys. Chicago, for example, reduced its consumption 5,000,000 gal, a day by such a survey. Also, after long discussion and planning. Chicago is about ready to spend $12,000,000 for new filters. The fears of a number of cities that air-conditioning installations would require great quantities of water have proved unfounded as a result of developments that permit the re-use of the cooling water.

Among notable water supply undertakings of the year, the most important was the completion of the Colorado River Aqueduct, bringing water 240 miles across the desert to a dozen cities in the Los Angeles area. The last operation to bring the work to completion was the holing-through of a tunnel under Mr. San Jancinto behind Palm Springs, Calif., a tunnel unequaled for difficulty of construction. The first water is expected to arrive at the distribution reservoir at the Los Angeles end about the middle of 1939.

Across the continent. New York City is getting under way another great aqueduct project, tapping new sources in the Delaware River watershed, 100 miles northwest of the city: some 85 miles of rock tunnel as well as one dam are under construction. By completing the hydraulic fill on the 4,000,000. cu. yd. Quabbin Dam on the Swift River, Boston brings its new water supply near completion. Little Rock put in operation its 32-mile concrete pipe line and filter plant. In Cincinnati, one of the largest water-softening plants in the world, 200,000,000 gal. daily capacity, was completed in 1938 at a cost of $3,300,000. And in Milwaukee, tuning up of the new $5,000,000-filter-plant was an activity of the late months of 1938. This plant also has a rated capacity of 200,000,000 gal. daily, and treats water taken from Lake Michigan.

Flood Control.

With memories and reminders of flood damage still present, various sections of the country have been the scene of intense flood-control operations. On the Susquchanna River in New York, two rolled-fill earth dams were started to impound the headwaters of this stream. In the Ohio valley, many local projects are under way to protect cities from a recurrence of the recent disastrous inundation. At Johnstown, Pa., for example, channel improvements are under way in the Conemaugh River. A concrete wall and earth-level project has been completed at Wellsville, Ohio; and a concrete wall at Huntington, W. Va. Extensive levees and walls are under construction at Ironton, Ohio. In the upper Ohio valley, the 14 dams of the Muskingum flood-control project in southeastern Ohio are complete. Tygart Dam on the Tygart River in West Virginia was also completed early in the year. In the Allegheny River valley two reservoir dams, Tionesta and Crooked Creek, were started during the year. All of these dams are designed to hold back tributary flood waters until the main river has receded to a low stage.

In California, and particularly in the Los Angeles region, work continues on dams designed to hold d‚bris from being washed down from the mountainsides. One such dam on the north fork of the American River is an arch structure 155 ft. high, designed to store 27,700,000 cu. yd. In the Los Angeles area, some $18,000,000 have been spent on channel protection along 13 miles of the Los Angeles River. Work also has started on Hansen Dam, a $6,000,000 rolled-earth fill on Big Tujunga Creek.

In northeastern Oklahoma, Pensacola Dam is the main feature of an extensive flood-control project under construction on the Grand River; providing flood protection for the Arkansas River valley, it will also furnish power. In New England, the floods and hurricane which struck in September brought to a head the long delayed flood-control plans for this region. One project, the Pittsburgh Dam on the headwaters of the Connecticut River had already been placed under contract by the New Hampshire Water Resources Board. In addition, the U. S. Army Engineers are making plans for a 2 million cu. yd. rolled-fill earth dam at Franklin Falls, N. H., and for five others of less size on various tributaries of the Connecticut and the Merrimack.

The Rio Grande from El Paso to Fort Quitman has been shortened from 155 to 88 miles, and 167 miles of levees have been built. A dam has been built at El Paso, and immediately upstream a 100-mile canalization-project was put under construction. Levees and floodways were also built extensively in the Rio Grande delta region by both the United States and Mexico.