An account of the iron railway bridge across the Mississippe river, at Quincy, Illinois by Thomas Curtis Clarke; Illustrated by twenty-one lithographic plates

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1869 Excerpt: ...and the bottom levelled to an uniform depth of four feet below the heads of the piles, which were cut by the sawing-machine 13 feet below LW. Around these piles was sunk a crib 80 X 36 X 6 high, which were by it enclosed in a well of still water 50 X 19. The permanent crib was but six feet high, but it was carried above the then water level by oak posts, planked and filled with riprap. These were afterwards pulled down and the riprap allowed to fall below. (See Plate IX., Fig. 2.) These posts were capped and on them rested nine pairs of beams 12 X 15 inches, which carried the screws 18 in number 25 feet long and 2£ inches diameter. From these screws was suspended the grillage of four courses of timber, connected in the same manner as the other screws of the shoal water piers. After the space between the piles was filled with concrete, the grillage was floated into place and the masonry begun on November 28th. This was pushed on, and finally completed December 24th. During this time the glass fell as low as-J-16 Fahr. A shanty was built on a flat, and in this a kettle was placed on a stove and the cement mixed with hot water. During the coldest days each stone was, before being set, held over a brazier of charcoal to draw out the post. The mortar 9was carefully examined in the spring and found to be as hard and perfect as any on the work. Much of the masonry of this bridge was constructed during winter, although none in as cold weather as this pier, and there is apparently no difference in the quality of the mortar, whether built in winter or summer. The foundation of pier 2 differed from that of pier 4, in having its surrounding crib made of a single wall of timber, instead of double sides connected by ties and filled with riprap. The piles were driven...