A Treatise On The Principles And Practice Of Dock Engineering

200 DOCK ENGINEERING. The floor foundation consists of a bed of concrete, 14 inches thick at the centre and 4 feet 6 inches thick at the sides. On this was laid the brick invert, 5 feet 10 inches thick, with a radius of 177 feet, surmounted by a bed of concrete 6 feet 6 inches thick at the centre, diminishing to 12 inches at each side, with a cross-sectional camber of 6 inches on the upper surface. The surface finishing consists of a 6-inch granite causeway, with the excep- tion of a length of 103 feet at the head of the dock, which was paved with granite blocks. The side walls of the outer and inner entrances and the head of the dock are of brick and concrete. The walls of the outer entrance were faced with granite and those of the inner entrance and the head of the dock, with moulded granolithic-faced ashlar, all coped with granite. cuncret G Widrh of entrance 93.0 W/dth of dock at top 115.0 Are/age O.'gh nater spring tides firetage low water spring tides ■.■^ ocaie uur I _., ' Feet 10 soreet Fig. 502.—No. 3 Graving Dock, Glasgow. sut or. entrance c J^^^j^ Aere/ or entra nce walis > ---------------$-------- The side walls of the dock proper are of concrète, put in between movable frames, roughly stepped to receive the granolithic altar courses, fouiteen in number, ranging in dimensions from 45 by 20 inches to 18 by 14 inches. The altar courses, with the exception of the bottom course, were made in moulds on a platform and then built in position like ashlar; the bottom course was made in situ. The side walls are 4 feet 6 inches lower than the pierheads of entrance. Four double stairs of granite, with granite timber slides, are arranged in each of the two divisions of the dock. Near the outer entrance there is a rudder well, 10 feet long by 7 feet wide by 8 feet deep. The apron for the sill of gates of inner entrance is 6 inches below the floor of dock at the centre. The sill is 18 inches above the floor at its centre. The meeting faces and inner side of the sill are of granite. The upper surfaces of sill and apron are paved with granite, and in the apron are bedded