Three Concrete Bridges.

Progress, Volume III, Issue I, 1 November 1907, Page 26

Three Concrete Bridges.

Without entering upon the relative merits of different structural materials we refer here tr three railway bridges with spans rf IST feet 211 feet, and 21 1 feet, respectively A\hich ha\ c lately been erected in plain concrete on the three-hinged principle All of the structures were designed by Mr Beutel chief engineer to the Bavarian State railways One of them at T autrach cresses the river Tiler with a mam arch span of 187 feet and two smaller arches at the abutments. As the rise of the mam arch is only about one sixth of the span the threehinged system, is particularly advantageous The arch rib in this instance carries across walls connected by small arches surmounted by the road upon which the permanent way is laid. The ether two bridges cross the river Illei close to Kemptei. station, where there is a network of several branch lines One of these budges carries fcur railway tracks, and the othei only two, but their structural feature* are practically identical, the mam arch of each bridge having a clear span of 211 feet, with a use of about four-ninths of the span We are glad to say that all three bridges were fi nished without the castmp of stone or other veneer which some engineers seem to imogme is necessary for decorative effect It is stated that the cost of the Lautrach Bridge was 17% less, and the cost of the twoKempten 1 ridges was nearly twenty per cent less than the estimated cost of steel bridges The ultimate saving should be considerably more owing to the fact that practically no maintenance is necessary in the case ci concrete structures