“British bridges also remained popular with Railway Agency, which employed British bridge experts until almost 1900. The most famous one was C.A.W. Pownall, who designed and ordered British bridges for government lines like the Tokaido and did not retire until 1896.
“From the start, the British favored bridges with the Warren truss (diagonal web members, like triangles, between the top and bottom chords). For the Tokaido, Pownall increased the length of each span from 100- to 200-feet. These he linked into daringly long iron bridges across the broad Nagara, Ibi, and Kiso Rivers.
“In 1888 he designed his longest bridge of all across the Tenryu River near Hamamatsu: nineteen spans of British wrought iron and steel, each with 200-foot-long intersecting Warren trusses (forming double triangles, like rows of ‘X’s).”
– Meiji Revisted: The Sites of Victorian Japan, by Dallas Finn, 1995
“The work of double-tracking the three longest bridges on Tokaido line viz the Tenryu Oi and Kiso bridges was completed a few years ago. Recently the bridge girders for the first track built more than 25 years ago have shown weakness. As the load thereon increases year by year the railway board has decided to rebuild the bridge trusses at an estimated cost of 1,200,000 yen $600,000. The work of renewal on the Tenryu and Oi bridges was completed this March when the trial runs were made with satisfactory results. The new trusses have a carrying capacity three times that of the old ones and are strong enough to carry safely an engine as heavy as 90 tons. The work of truss renewal on the Kisogawa bridge (2032 ft. long) will be started shortly and be finished this year at an estimated cost of 400,000 yen $200,000.”
– The Railway and Engineering Review, Vol. 57, July 3, 1915