The following is from the “Engineering and mining journal, Volume 96” published November 15, 1913.
Interesting .. eh?
In the reconstruction of the line of the Pennsylvania R.R. at Rahway, N. J., the Keystone State Construction Co. has a considerable length of timber trestle in which the stringers are made of old rails discarded by the railway. These trestles, states Engineering News, are of two types, one used as a construction railway and the other as a filling trestle which is covered by the fill as it progresses.
The construction railway trestle is the heavier of the two and is shown in the accompanying illustration. It is made up of the usual framed bents with round log uprights and sapling braces and a squared 6×8-in. cap.
On this cap run the stringers, four old 100-lb. rails, in groups of two, spanning the 12-ft. opening between bents. These rails are spiked with standard railway spikes to the cap and are spliced wherever the breaks come with the standard rail splices with bolts only in the end holes.
The 3-ft. gage construction track is built of old 70lb. rails spiked to 6×7-in. ties with an 8×9-in. tie dapped 2 in. over the stringer rails at the bents. These latter ties are bolted with 3/4-in. bolts to the bent caps, and this is the only fastening of the track to the bents or stringers.
In the filling trestle, the track rails also act as stringers. This track is of 3-ft. gage and is made up of old 100-lb. rails, spiked to 6×7-in. ties, which act merely as spacers between bents and as caps at the bents. The dirt train is backed onto the trestle and the cars are dumped at the edge of the fill so that no load but that of empty cars comes on the trestle. The ties and rails remain in the fill and form the construction track on the embankment.