Considered one of the world's most beautiful bridges, the Golden Gate Bridge began life as a strange looking combination of cantilever and suspe nsion bridge designed by Joseph Strauss, the chief engineer. The design was broadly despised and discarded. The bridge we know today was designed by Charles Ellis, chief assistant to Strauss.

The greatest construction obstacle was the Pacific Ocean, which rolls through the Golden Gate four times a day at the speed of 71Ž2 knots. Founding the north pier just off the Marin Peninsula was comparatively easy. It stood on a bedrock ledge only 20 ft below water. But the San Francisco pier site was 1,100 ft off shore with bedrock 65 ft down.

Strauss built a concrete fender around the pier site, an ellipse of 155 x 292 ft with a 30-ft-thick wall 90 ft down. The sea was too rough to work from barges, so a trestle was built out to the site. The trestle was wrecked twice, first by an errant freighter and then by a storm.

Ellis planned to float a 90 x 185-ft steel caisson through an opening in the fender and build the pier from that. A wild sea banged caisson against fender, wrecking the caisson. The fender was closed and treated as a cofferdam for pier construction. Concrete was tremied into it to a depth of 65 ft and it was pumped dry and the pier built up (ENR 8/22/35).

The two 746-ft-high towers were riveted assemblies of hollow steel cells that were 31Ž2 ft square and ranged in height from 22 to 45 ft. Spinning began August 1935 and was refined as the job progressed. The use of triple spinning wheels placed 24 wires on each trip, six times the number on the George Washington Bridge. Spinning by John A. Roebling Sons Co., Trenton, N. J., was completed May 1936, almost two months early.

Deck work moved out in both directions from each tower. Workers were protected by safety nets that ran the length of the bridge. From the start of construction in January 1933 until Feb. 17, 1937, there had been only one fatality on the job. But that day a paving contractor's scaffold gave way, carrying 12 men and 2,100 ft of safety net down 220 ft to the ocean. Ten men died. There were no more deaths. The Golden Gate Bridge was the first large project where it was mandatory to wear a hard hat.

The Road-Building Years
(ENR Jan. 30, 1936, p. 163)—During the depression there were five years of prolific road-building, as the public importance of road construction increased and emergency funding was appropriated as a way of alleviating unemployment. An appraisal of the highway system calculated that, in a base period from 1925 to 1929, a total of 27,640 miles of roads were built. From 1930 to 1934, an average of 22,060 miles of roads were built using state funds. In addition, an average of 15,514 miles of roads a year were completed with federal funds from the Bureau of Public Roads. The total was 37,582 miles of roads built each year. By 1935, the average relative price for the new construction was 80% of the cost of work during the base period. ?

Modern Times and Windowless Offices
(ENR March 26, 1936, p. 457)—Along with the availability of improved lighting and air conditioning came the theory that an environment could be controlled within the realms of windowless walls. The Hershey Chocolate Corp. in Pennsylvania was one of the first companies to build a windowless office building and printing plant. They believed employees would work under the best weather and lighting conditions that science could supply. Hershey officials considered the theory scientifically sound in all but one respect—the psychological. Would people actually be content to work in a windowless office?

Building an Aqueduct to California
(ENR Nov. 24, 1938, p. 647)—Selection of the best route and whether to use a gravity or pump system were issues explored by engineers planning the Colorado River aqueduct, which would increase the water supply for Southern California. Hundreds of possiblities were considered and compared. Contour maps were made by doing topographic surveys of 25,000 sq miles of desert. Many schemes proposed gravity delivery. But the aqueducts could not follow wagon trails of the pioneers over the passes. One part-gravity-part-pumping scheme used a tunnel buried in alluvial fill that would pass under rather than through mountain ranges. Eventually, gravity proposals were seen as impractical, and engineers focused on how to pay for this approach.