Replacing Iron by Stone Bridges.

Te Aroha News, Volume V, Issue 242, 18 February 1888, Page 8 (Supplement)

Replacing Iron by Stone Bridges.

Notwithstanding their prodigious progress and advancement, the United States seem to be going backward in one Bense, and it is a fact that the retrogreiaion is from the iron to the stone ago. The " Railroad Gazette " states that the Pennsylvania Railroad Company is gradually replacing the existing road bridges cf short span on its lines by bridges of quarrystone or brickwork. It has been found, it is said, that the iron bridges were not only a constant source of anxiety, but a continual drain upon the income of the Company. It has been found necessary to regularly and carefully inspect them, and to repair or strengthen and sometimes even renew them. The fact, too, .that bho weights to bo carried by' railway 'bridges are steadily increasing, and that it is impossible to say' for a cdr.«tainty how great those- burdens may be in five or teif years' time has "also been taken into consideration in carrying' out the change. It is urged, further, In favour of masonry bridges that, although their initial cost is greater/they involve' little expense afterwards for inspection and maintenance ; that they sustain heavy weights j muoh mote efficiently, and are less exposed ! to injury or destruction by accidents than j iron or wooden 1 lattice bridges. — ' ' Iron. j