Volume Ten - Pre-Victorian to the present day - even more aspects - The Patent for the Penarth Slipway - 1881 . . .

Mr. T. B. Lightfoot cont'd :

but if the dock referred to would do that, there must have been some extraordinary and abnormal circumstances to account for the lowness of cost ; and of course under those circumstances, a slipway, if more expensive, would not have been recommended.

In relation to the cost of the Philadelphia dock, he could not do better than refer to “ The Naval Dry Docks of the United States,” by C. B. Stuart, in which might be found detailed accounts not only of that, but of many similar establishments. Those docks were certainly designed in a most extravagant manner. They consisted of a floating dock, a basin, and slips, and in America were considered at the time as extraordinary triumphs of engineering skill.

With regard to the straining of vessels when being placed on the cradle, some such action must take place; but it was obvious from experience that it was not attended with the slightest damage or injury to the vessel. He might mention the slipways on the Tyne belonging to the Wallsend Slipway Company, the general arrangement of which was shown in the diagrams. There were two ways, placed side by side, and each a little over 1,000 feet long. Since being put to work about nine years ago, nearly nine hundred vessels had been taken up on them without the slightest accident of any kind, the heaviest ship being her Majesty’s troopship “ Tyne.”

As additional and important testimony as to the safety and advantage of a slipway, he might perhaps be allowed to quote a few words from a letter he had received from one of the most successful ship-builders of the day, Mr. Charles Mitchell, of Newcastle-on-Tyne, who said : “Speaking generally, I consider a slipway better than a dry dock for all vessels up to 2,400 tons gross register, which represents a screw-steamer about 310 feet long by 36 feet beam, and there is nothing to prevent much larger vessels being slipped, but up to this time it has not been the custom to have stronger slips than corresponds with the above size.”

In reference to Mr. Redman’s observations, the tonnage and dimensions given in the Paper were those dealt with in actual operation, the tonnage being the gross weight of the vessel itself. In several cases the weight of vessels taken on the Author’s slip-ways had considerably exceeded that for which they were designed.