UNIVERSAL DREDGES 135 



conditions. The boilers are arranged to act either together or 

 separately and their efficiency is such that one boiler can provide 

 enough power for both the dredging and propelling machinery 

 simultaneously. 



The pump for the hydraulic dredging is lined with steel through- 

 out. A special arrangement of the suction flowing above the 

 water level insures the floating of the vessel without the necessity 

 of sluices, as was previously required in this type of dredge. The 

 articulated joint of the suction pipe is located above the water 

 level, so that it can be easily inspected and not interfere with navi- 

 gating the vessel. 



The engine acting on the cutter at the end of the suction pipe 

 is located to starboard. The cutter will easily break up strata of 

 hard soils encountered in dredging, and in any case it will regulate 

 the proportion of water and materials so as to avoid any obstruction 

 both in the suction pipe and pump. 



The ladder supporting the bucket chain is very solid and permits 

 the excavation of soils at different depths varying from 6.5 ft. to 

 34.5 ft. The extreme end of the ladder is far in advance of the stern 

 in order to dredge its own way as stated above, and also to dredge 

 against the quay walls. 



The journals of the axle of the upper tumbler of the ladder are 

 provided with Belleville shock absorbers in order to eliminate 

 the shocks produced when the buckets meet with some extraordinary 

 obstacle. 



The 29 buckets of the ladder are entirely made of cast steel 

 reinforced at their cutting edge by a piece of hard steel easily renewed 

 when worn out. The links of the chain are made of cast-steel pieces 

 and the bolt holes are lined with soft steel so as to be easily renewed 

 when worn out. The axis connecting the links of the chain with the 

 buckets are made of hard steel. 



A steam crane of special design located at the stern is used for 

 the raising and lowering of the ladder and the lifting of large blocks 

 or rocks too large to be taken up by the buckets. This crane is 

 operated by a reversible engine located in one of the steamer com- 

 partments and moved by a belt connection placed on deck. 



All the various operations of the dredge are made by special 

 double-cylinder engines easily handled so as to have on board the 

 smallest possible crew. 



Telephones and electric bells afford communication between the 



