GENOA DOCKS. 



171 



SECTION ON LINE E F 

 FIG. 150. 



Sluice-ways for adjusting the level of the water in the lock 

 and scouring the gate floors are formed in the interior of the 

 side walls; they are 7 feet wide by 4 feet 6 inches high, con- 

 structed with stone 

 sides and brick-in- 

 cement arches and 

 inverts ; they are 

 placed parallel with 

 the line of the walls 

 with their outlets 

 within the locks. 

 Placed 50 feet from 

 the hollow quoins 

 within the gate re- 

 cesses there are seven 

 inlets 2 feet 4 inches wide by 1 foot 9 inches high, constructed 

 with granite cutwaters and lintels; each of the sluice-ways is 

 furnished with a strong cast-iron frame and valve, both being 

 fitted with brass faces. The upper sluice-ways are also fur- 

 nished with a pair of wooden paddles, fitted for the purpose of 

 allowing repairs being carried out to the iron penstock valves. 



The apron in front of the lock at the outer end extends 60 

 feet beyond the invert, and is 120 feet in width. It consists 

 of a mass of lime concrete 6 to 8 feet deep, with blocks of stone 

 from 2 to 3 tons weight embedded in it, and surrounded by 

 walls of Portland-cement concrete 5 feet in thickness, founded 

 at a depth of from 8 to 10 feet below low-water mark of 

 equinoctial spring tides, or about 2 feet lower than the hearting. 

 The top of the apron was pitched with heavy stonework rough 

 faced but dressed on the joints, and bedded in lias-lime mortar. 



Genoa Dry Docks. 1 These docks have the following dimen- 

 sions : 



No. 1. 

 Ft. in. 



Maximum length at coping, including entrance 588 6 



Effective length on the blocks 525 



Width at coping 96 



of entrance at water level 82 



Depth of sill below mean water level " 31 



Greatest depth in dock 32 



Maximum length of vessel between perpendiculars the docks 



can take in , 561 



Ko. 2. 

 Ft. in. 



721 7 



656 



81 8 



59 



28 



20 6 



695 



1 M.P.I.C.E., vol. xciii. p. 521; and Giomah dd Genio Cevi'e, Quinta Serie, 

 voL ii. p. 75. 



