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.