. Canadian Shipping and Marine Engineering January-December 1918. eans. The inclined track acts as abrake to the outboard movement and asan aid to the inboard movement. Thecompensating action of the link to-gether with the effect of the inclinedtrack greatly reduces the amount oftension in the operating screw. Theturning of the crank therefore requirescomparatively small effort and thedavit can be operated much faster thanwould otherwise be the case. With this type of davit the life boatscan be put overside and ready to loweraway even against a bad list of theship, but the great advantage lies
. Canadian Shipping and Marine Engineering January-December 1918. eans. The inclined track acts as abrake to the outboard movement and asan aid to the inboard movement. Thecompensating action of the link to-gether with the effect of the inclinedtrack greatly reduces the amount oftension in the operating screw. Theturning of the crank therefore requirescomparatively small effort and thedavit can be operated much faster thanwould otherwise be the case. With this type of davit the life boatscan be put overside and ready to loweraway even against a bad list of theship, but the great advantage lies inthe rapid and positive outboard move-ment of the boom, which enables theboats to be put overside, before thesinking ship has acquired a bad list,thus ensuring a safe lowering away ofall of the life boats. Where the boats are provided withhand falls, a stationery gypsy head isplaced on the side of the frame at aconvenient point and one man can con-trol the falls gear at each end of theboat with two or three turns of theline around this head. After the boat is. VIEW OF BOAT DECK EQUIPPED WITH COMPENSATING LIFEBOAT DAVITS. The Marten-Freeman davit, an m-stallation of which is shown in theaccompanying engraving has proved it-self, under service conditions, to besimple, reliable and fast operating. Itconsists of a cast steel frame whichforms both the track and supports, asteel truck of the tandem roller type, action obviously reduces the pull on theactuating screw very materially. A further reduction in the amount oftension in the screw is secured throughthe effect of the inclined track on whichthe truck rolls. The resultant force ofthe weight of the boat and the stressthrough the link is brought nearer to paced in her chocks, two or three turnsof the falls are taken around the gypsyhead and the line then belayed to thecleat. The gear is thus always in readi-ness to put the boat overside and tolower away immediately, the life boatin the foreground of the illustrationhaving been p
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Keywords: ., bookcentury1900, bookdecade1910, bookidc, booksubjectshipbuilding
