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XXXVI. Method of obviating the Nece.wtij of lifting 

 Ships. By Mr. Robert Seppings, of Chatham Yard*. 



X HE following is a description of an invention by Mr« 

 llobert Seppings, late master shipwright assistant in his 

 majesty's yard at Plymouth (now master shipwright at 

 his majesty's yard, Chatham), for suspending, instead of 

 lifting, ships, for the purpose of clearing them from their 

 blocks, by which a very great saving wil! accrue to the pub- 

 lic, and also two thirds of the time formerly used in this 

 operation. 



From the saving of time another very important advan- 

 tage is derived, namely, that of enabling large ships to be 

 docked^ suspended, and undocked, the same spring tides. 

 Without enumerating the inconvcniencies arising, and, 

 perhaps, injuries, which ships are liable to sustain, from the 

 former practice of lifting them, and which are removed by 

 the present plan ;. that which rektes to manual labour de- 

 serves particular attention ; twenty men being sufficient tO' 

 suspend a first-rate, whereas it would require upwards of 

 500 to lift her. The situation which Mr. Seppings held in 

 Plymouth-yard, attached to him, in a great degree, the 

 shoring and lifting of ships, as well as the other practical 

 part of the profession of a shipwright. Here he had an 

 opportunity of observing, and indeed it was a subject of 

 general regret, how much tirne, expense, and labour, were 

 required in lifting a ship, particularly ships of the line. This 

 induced him to consider whether some contrivance could 

 not be adopted to obviate these evils. And it occurred to' 

 him, that if he could so construct the blocks on which the 

 ship rests, that the weight of the ship might be applied ta 

 assist in the operation, he should accomplish this very de- 

 sirable end. In September ISOO, the shoring and lifting 

 the San Josef, a large Spanish first-rate, then in dock at 

 Plymouth, was committed to his directions ; to perform 

 which, the assistance of the principal part of tlie artificers 

 of the yard was requisite. In conducting this business, the 

 plan, which will be hereafter described, occurred to his 

 mind ; and from that time, he, by various experiments, 

 proved his theory to be correct: the blocks, constructed by 

 him, npon which the ship rests, being so contrived, that, 

 the facility in removing them, is proportionate to the quan- 

 tity of pressure ; and this circumstance is always absolutely 



• From the Traracctions of the Society of Arjs, who voted him the gold 

 medal, 1301. 



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