И. А. Курбасова Е. И. Силантьева

TEXT 17. THE SALT LAKE BRIDGE
One of the most interesting railroad bridges of all is sure to be the twelve-mile trestle across the Great Salt Lake, the longest bridge in the United States. The erec­tion of the bridge was started in 1902 to cut off 140 miles of dangerous travelling through the mountains to the north.

The bridge was to be supported by timber piles. The job looked like an easy one — the lake was only about 30 ft (9 m) deep and the bottom was hard salt crust that could hold the great timber piles fast. What the bridge builders should have done was to give great care to soil conditions, but they did not. So when the first pile was being driven, it broke the salt crust and sank into soft ground under the salt crust, although having one hundred feet (30 m) in length. The failure with the first pile did not stop the workmen, and they drove another one in the same place, but it also disappeared. There was only one solution to the problem — more timber piles and more rock fill until they reached something stable to rest on. The enormous number of 40,000 piles and 75,000 carloads of rock fill went into the lake before the engineers thought the trestle was stable enough) to carry trains.

Needless to say, that this tremendous difficulty made all other troubles seem small, for example, bringing drink­ing water and food over a distance of nearly 80 miles every day. Besides, frequent storms turned the lake into an ocean, with waves so high that neither piles nor building equip­ment could withstand them. The Salt Lake Bridge being large, its maintaining has been expensive. Repair crews find it a full-time job. But no one knows how many accidents have been avoided by eliminating dangerous mountain travelling and how many hours have been saved. The bridge over Salt Lake has paid for itself many times over.