The novel dry-dock here illustrated is the invention of an experienced builder of marine dry-docks and railways; and with his knowledge of this class of architecture he has endeavored to combine all possible good qualities, while avoiding the objectionable peculiarities of the various kinds now in use. The platform, A, on which the vessel rests, is supported by the cast iron pillars, B B B, which have joints at the top and bottom, so that they may ,be turned down horizontally, thus gradually lowering the platform, A, to the bottom of the dock. When thus lowered, the vessel is secured upon it in the l1sual manner, and power is then applied to haul the platform forward, tlm3 turning the pillars, B B B, up into a nrtical position amI mising the vessel into a position convenient for examination and repairs. The most suitable power for raising the platform i3 a hy-draulie press worked by steam— the cyIinder of the press of course to be hung llpon trunnions. In lowering the vessel into the water, the movement is completely under the control of the operator, who can, with one hand, entirely arrest its speed or increase or diminish it at pleasure. The whole operation of raising and lowering is accomplished with the greatest ease, steadiness and precision. Among the advantages claimed for this dock are : Its cbeapness of construction, its entire simplicity and conseqllent reliability, its economical operation, the uniform strain upon the vessel, and the superior facilitips for working on the vessel when raised from the water for repairs. Patents Rave been taken out in England, France, and the United States, through the Scientific American Patent Agency. Further information in regard to the invention or orders for the construction of docks may be obtained by addressing tbe patentee, H. I, Crandall, or Messrs. Taber & Grinnell, New Bedford, Mass The patent was issued on the 12th of June, 1860.
This article was originally published with the title "Improved Hydraulic Lifting Dry-Dock" in Scientific American 3, 26new, 406 (December 1860)