The Waterbury Democrat., 1931-03-30

Hartford, March 30 Althougi
 outdoor construction work during the winter months is difficult in the New England climate, that achleVe
 ment was accomplished by the Con neceicut Highway department during the winter just past in the continu' alton of concrete construction work on the new bridge which is being built over the Hockanum River or the Hartford New London highway just south of the center of East Hartford.
 Another notable feature in the construction of this new bridge, ac- cording to Highway Commissioner John A. Macdonald, is the use of the longest wooden piles ever driven in bridge construction in the history of the department.
 Both of these unusual features were made necessary by the charac- teristics of the particular Job. Ihe old bridge was habitually inundated under two or three feet of water during the annual spring thaws ana the resulting freshets which caused q marked rise in the river. In order to avoid any chance of having the river flood over the new contruc tion work. operations were rushed throughout the winter, so that now there is little possibility that trafhc will be forced into navigation in or der to cross the bridge this year. Winter concrete operations were made possible by completely cover ing and surrounding the site or the construction work with canvas. the improved housing being kept at con- stant temperature by means or steam heat. The concrete mixture, instead of being patched on the location as usuel. was made up at an indoor patching plant, not far distant, ana the mix carted to the scene or use on trucks equipped with mixers to keep it in circulation while an route All sand and water was heated So that the concrete when placed In the forms was 80 degrees Fahrenheit. By means of these two unusual onerat,ons the concrete work was conducted under artificial conditions which were the equivalent of sum- mer weather.
 Before the department undertook it's testing operations for the con, struction of the new bridge, It had been the belief that piles Of forty or forty-five feet in length would be sufficient to carry the weight or the spane and the maximum amount oi traffic that might pass over 1t. when the test pile was driven, however II was sunk into the river bed so rap idly that the necessity of greater length became obvious. A twenty foot addition was placed atop the pile and driven with almost equal ease, so that still another addition of the same length was added. when this had been driven home, 1t was tested to bear weight of twenty five tons, Since the maximum burd- en for each pile is only ten tons, a length of eighty to eighty-hve rect was determined as correct.
 Since piles of this length are ex- traordinarily rare, it was necessary to obtain them in Alabama and to transport them here. A special type of pile driver had to be used In the work. The bridge when completed will have about $50 miles.
 In order to insure a firm riveI bottom on which the concrete could be laid, a six inch layer of stone and gravel was laid on the river bed The accomplishment of this requir- ed the construction of dam of tenn porary piling which kept the parti. cuiar section of the bed where tht work was being condutced free o water. The river in this manne, was shunted around the constructor