Fig. i. 

 Accumulator. Scale : ' /.,()■ 



To enable the rope to be taken 5 turns round the capstan it 

 had to be temporary gripped by the steel-stopper N which was fixed 

 to the boom; when winding in, the rope was led by a snatch block c. 



The dredge-rope was wound on the reel by means of an 

 electromotor C r , coupled by a leather belt. 



The wooden boom D, 20 centimetres in diameter, was attached 

 to the fore mast and provided with stays. It was slung by a steel 

 wire rope //, 27 millimetres in diameter, led through a block about 

 on a level with the fore-yard. The lower end of this rope was spliced 

 on to the upper part of the accumulator A, the lower end of which 

 was bolted to the deck. By means of this contrivance sudden shocks 

 and strains of the dredge-rope and the boom were avoided. 



The accumulator (Fig 1) consisted of 6 pairs of steel spiral 

 springs, having a combined length of 3.00 metres. Each pair consisted 

 of a heavy external spring with a lighter spring of smaller dimensions 

 insicle. The whole was constructed for a maxi- 

 mum load of 10000 kilograms. At this load 

 the compression was calculated to be about 

 one metre. 



The amount of compression on the 

 accumulator enabled the person on the bridge 

 who conducted the dredging operation, to judge 

 roughly the momentary tension of the dredge- 

 rope. A more accurate test however was 

 furnished by the hydraulic dynamometer D 

 of a well-known type, constructed for loads up 

 to 10000 kilograms, and attached to the star- 

 board anchor-chain bitt F by means of the 

 steelwire-strop E of 27 millimetres diameter. 



Since the two leads of the dredge-rope 

 durincr the windingf-in formeel an ano'le of about 

 6o°, round the sheave of the block, attached 

 to the dynamometer, the actual pull of the 

 dredge-rope was in round figures o. 6 times 

 that, indicated on the dynamometer. 



The block was slung from the fore 

 castle-deck to prevent the dynamometer falling 

 on the deck. The foremast was supported by 



tWO Stays I. s t«l block. Scale: '/ s . 



The sheaveblocks (Fig. 2) over which the dredge-rope passed 

 were of iron with brassbushed sheave and steel pin, the groove 



