TRANSACTIONS OF THE SECTIONS. 221 



north side of the docks ; but nothing was done till 1870, when the Clyde trustees 

 obtained an act for enlarged docks &c., and the railway company an act for the 

 renewal of the site of the station. 



Under their act the Clyde trustees purchased additional ground, to enable them 

 to carry out the works now authorized. The large cartoon plan showed the general 

 outline of the docks and the diversion of the I'ointhouse Koad &c. The road is 

 55 feet wide, and extends from Sandyford Street to Stobcross Street, or a length 

 of 980 yards ; it has been formed entirely in cutting, the average depth being 

 29^ feet, the greatest depth 43^ feet, and the total quantity removed was nearly 

 300,000 cubic yards, of which about a fourth was boulder-clay. Only the 

 immense power of dynamite enabled this to be removed. The cost of the road, 

 including land, was about £45,000. 



The docks will be tidal, and, when complete, will afford 33^ acres of water 

 space 20 feet deep at low water, and will comprise three basins. The entrance 

 from the river is at the west end of the docks, and is 100 feet in width, communi- 

 cating with an outer basin COS feet wide at its widest part, and two inner basins, 

 270 feet and 230 feet wide respectively, the pier between being 195 feet wide. The 

 total area of quay space will be 27^ acres, and the length of quays about .3342 yards. 



The entrance will be spanned by a swing bridge, worked by hydraulic power, 

 and capable of carrying a rolling load of 60 tons. There will also be four coaling- 

 cranes, each capable of lifting 20 tons, also worked by hydraulic power. The 

 bridge, cranes, and the necessary hydraulic machineiy are being constructed by 

 Sir W. G. Armstrong & Co. The quays will also be provided with sheds, grain- 

 stores, &c., and lines of rails. 



From the borings made on the line of the quay-walls, it was ascertained that 

 the strata were of the worst possible kind in which to construct such works, con- 

 sisting as they do (excepting at the north-west corner, where boulder-clay was 

 found) of water-bearing gravel and sand, interspersed with pockets of mud, and 

 that to reach the rock with the foundations, except along a portion of the north 

 quay, would be out of the question. A longitudinal and a cross section of the site 

 of tile docks, showing the strata as ascertained from the bores, were shown on the 

 cartoons. 



For the portion of north wall in the boidder-clay, and where the rock was within 

 a depth of about 40 feet under cope level, the usual section of wall has been 

 adopted ; but for the remainder of the walls and bridge-seat, where the sti-atum is of 

 sand and gravel &c., charged with an enormous quantity of water, especially imder 

 low-water level, and the rock at a depth of from 50 feet to 100 feet below cope- 

 level, the system of cyhnder substructure, recommended by INIr. Bateman and the 

 author of this paper in 18G9, and successfully carried into effect in the construction 

 of Plantation Quay wall and GO-ton crane-seat there, in 1870-75, was again fixed 

 upon. A small portion of the west wall of the dock is founded on sheet and bear- 

 ing piles where the boulder-clay suddenly dips, and a timber-wharf outside of the 

 dock-entrance, where the quay may be of a less permanent nature. 



The cartoons showed the general details of the whole of these walls, as well as of 

 the bridge-seat. 



The first contract, embracing the entrance and western portion of the docks' 

 walls, was let in August 1872, the amount being fuUy £100,000. 



The whole of the cyhnders are of concrete, composed of 5 of gravel or broken 

 stones and sharp sand to 1 of Portland cement of the strongest description, mixed 

 together by steam-power with the necessary water. The cyhnders for the quay- 

 waUs are about 27 feet 6 inches in height, made up of rings 2 feet G inches deep, 

 the thickness being 1 foot 11 inches. These rings are formed within wooden 

 moulds, on a platform, and, to facilitate hfting and break bond when built into the 

 cyhnder, they are divided into three pieces and fom' pieces alternately. The dividing 

 of the rings is effected by iron plates placed across the mould in the positions 

 required. The corbelling or bevelling of the bottom ring is done by placing con- 

 tracting pieces in the mould on which to shape the ring. The seat for the iron 

 washer on the top of the first, or " corbelled ring," and the holes for the bolts to 

 secure the same to the iron shoe are also formed in the moulding of the rings. 

 The concrete, as it is filled into the moulds, is well rammed with rammers weighing 



