THE KANSAS CITY BRIDGE. Al

braces and folding wedges. Under it were placed three shoes, which slid on
inclined launching ways, provided with guides for their whole length.

In October, the crib for the upper draw rest was rebuilt on the south bank
of the river, a third of a mile above the bridge ; it measured 31 feet wide, 73
feet long, and 10% feet high; was built of square timber, with cross walls and
bottom of round timber and planked on the outside ; the upper end was formed
like that of the piers and caissons, and the lower end square, though shelving
forwards—this form being thought favorable to a scour beneath ;* additional
buoyancy was secured by binding a number of empty coal oil barrels inside of it.
Karly in November an attempt was made to launch the crib, but its misfortunes
were not yet over, the ways breaking down under the weight and leaving it
lying on one side at the edge of the water; nothing could be done towards
raising it in consequence of the rapidity of the current in front of it ; and in this
position it remained till the following February. On the 9th of January the
ice jammed at the bridge site, and the river for several miles became closed ; a
channel was cut in the ice from the bank where the crib lay to its permanent
location above the pivot pier; on the 4th of February it was raised by means
of hand crabs, and successfully floated into position ; the water was very low,
the current only two miles an hour, and the crib was easily held by lines
attached to posts on the shore and to anchors put in the ice. It was sunk by
putting on additional courses of timber, and throwing in rubble stone ; the
current swept the sand, about 10 feet in depth, away from below, and allowed
it to settle firmly upon the rock. As this crib had to be placed in position
before the other works connected with the pivot pier could proceed, the diffi-
culties in the way of locating it accurately, with no neighboring anchorage, were
very great, and the misfortunes of the launch in October may have been more
than compensated by the advantages which the ice gave for handling the crib
when it was finally placed. On the 17th of February the ice gave way above
the bridge and went out, doing no further damage to the crib than to loosen
the upper course of timbers and fill it with ice. Before the close of the low-
water season the more exposed parts of the crib were filled with beton, and
additional stone was thrown into the central divisions.

 

* The shape of this crib appears on the plan of Draw Protection, Plate VII.
6