CHAPTER XL 



Pumping water from docks Vertical centrifugal-pumps Horizontal pumps at 

 Liverpool Docks Reciprocating plunger-pumps at Portsmouth Pumps ut the 

 Barry Docks Pumps at Bute Docks, Cardiff Pumps at the Hamilton Docks, 

 Malta Temporary pumping. 



FOR dock purposes, where large quantities of water have to 

 be rapidly raised to moderate heights, centrifugal pumping- 

 machinery is perhaps the best that can be adopted. Such 

 machinery is simple in construction, economical, and durable, 

 and has no complicated valves. In a dock, there is always a 

 considerable quantity of refuse, such as scrapings from ships' 

 bottoms, small chips, etc., much of which unavoidably passes 

 into the well. There being no valves, a considerable portion of 

 this refuse is drawn through the pumps without inconvenience, 

 anything, in fact, being discharged that will clear the water- 

 passages, which, in the case of large pumps, are of considerable 

 area. 



Special care must be taken, by the use of suitable gratings, to 

 stop all rope-ends, canvas waste, or anything that may be likely 

 to coil round the spindle or hang in the fan, and so choke the 

 pump. 



A further advantage attaching to centrifugal-pumps is the 

 absence of the incessant jar or pounding common to la 

 reciprocating-purnps, and which is so detrimental to the sur- 

 rounding masonry. 



A drawback to the use of vertical centrifugal-pumps and 

 directly connected driving machinery for dock purposes, is that 

 it is necessary to place it below the water level, in a water-tight 

 pit large enough to take both pumps and engine. With tip- 

 horizontal or turbine type of centrifugal or lifting-pumps, t 

 costly water-tight pit is not required, with the advantage that 

 the whole of the driving machinery is kept above the water 

 level 



