. St. Nicholas [serial]. THE CAISSON THAT CLOSES THE ENTRANCEOF THE DRY-DOCK. into the dock very slowly, many thick ropes,called hawsers, being carried over the side towinches on the dock. The ship is finally brought igie.] NATURE AND SCIENCE FOR YOUNG FOLKS 463 to a stop with the center line or keel of the shipexactly in the center line of the dock. The cais-son is then towed into place and water pumpedinto it until it settles down into the grooves in. A CONCRETE DRY-DOCK 750 FEET LONG the dock, thus making it water-tight. Then hugecentrifugal pumps begin to pump out the water,while the ship
. St. Nicholas [serial]. THE CAISSON THAT CLOSES THE ENTRANCEOF THE DRY-DOCK. into the dock very slowly, many thick ropes,called hawsers, being carried over the side towinches on the dock. The ship is finally brought igie.] NATURE AND SCIENCE FOR YOUNG FOLKS 463 to a stop with the center line or keel of the shipexactly in the center line of the dock. The cais-son is then towed into place and water pumpedinto it until it settles down into the grooves in. A CONCRETE DRY-DOCK 750 FEET LONG the dock, thus making it water-tight. Then hugecentrifugal pumps begin to pump out the water,while the ship slowly sinks into a sort of cradleprepared for her on the bottom of the dock. Eachship requires a different cradle. As the watergets lower and lower, workmen shore up thevessel by using timbers which keep it from top-pling over. When only a foot or so of water isleft in the bottom of the great concrete tub, itis great fun to watch the workmen trying to catchthe fish which were imprisoned when the caissonslipped into place, and which swim around tryingto escape. Undocking is a reversal of the process just de-scribed. The water is allowed to run into thedock through holes in the caisson, the ship gradu- ally rises, the caisson is floated away from theentrance, and the busy little tugs take the shipin tow and run her alongside of a near-by she is, safely out of dry-dock, and look-ing just as she did when shewent in. But the captain willc
Size: 2390px × 1046px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthordodgemar, bookcentury1800, bookdecade1870, bookyear1873
