158
Albion loose flanges of Cast Steel. These long lengths were bolted together on the harbour bed by divers, a rubber packing 1/4" thick being inserted between the two flanges and the joint secured by ten 1" diameter steel bolts.
Flanged steel ball and socket joints of two kinds, having an angular deflection in any direction of 18 and 25° from centre line, were used to provide for any change of line and gradient of the pipe line and were spaced generally at intervals
of 300 feet.
Expansion joints of the Vulcan type, having a travel of 10′′, were used about every 600′ to provide for expansion and contraction of the pipe line.
To prevent lateral movement of the pipe line pairs of concrete piles 12′′ square were driven opposite every ball and socket joint lying at a depth not exceeding 35 feet. Below this depth concrete anchor blocks weighing 17 tons in air and of special shape were used for a similar purpose.
The bed of the harbour on the line of the pipe consisted generally of hard sand, shell and occasional boulders, but at the ends of the line for distances of 800 feet from the seawall at Kowloon and 400 feet from Queen's Pier the harbour bed consisted of mud. This was dredged to a depth of 4 feet and was replaced by a rubble mound 9 feet wide, on the top of which the pipe was laid.
At the Kowloon end a 12" Sluice Valve, 6" washout and an air cock were fixed, whilst at Queen's Pier an air cock, a 12′′ reflux valve, a 12′′ washout and a 12′′ Sluice Valve were provided.
As the 24′′ Trunk main, Hong Kong, and the Gardens Service Reservoir were not completed when the Harbour Pipe became available for use, water was first passed into the Hong Kong distribution system at the junction of Wardley Street and Queen's Road. On the completion of these two items of the scheme water was discharged into the Gardens Service Reservoir, on April 11th, 1933, the delivery re- corded fulfilling all expectations.
Under test the pipe line proved extremely satisfactory, only an infinitestimal amount of leakage being recorded.
The length of the pipe line from the seawall at Kowloon to the seawall at Hong Kong is 5,914 feet. The number of sections is 62; Albion loose flange joints, 66; ball and socket joints, 23; concrete anchor blocks, 15; and pairs of anchor piles, 15.
The best rate of laying over a period of 9 days was 178 lineal feet per day.
24′′ TRUNK AND 18" DISTRIBUTION MAINS, HONG KONG.
24" Trunk Main.
The 24" Trunk Main receives the discharge from the Cross Harbour Pipe and delivers the water into the Gardens Service Reservoir.
The route to the Gardens was originally intended to follow Jackson Road, Queen's Road and Garden Road, but owing to the change in the location of the Hong Kong terminal of the Cross Harbour Pipe, a more direct route was adopted from Queen's Pier via Wardley Street, Queen's Road to near the foot of Ice House Street, and thence across the Crown land behind the property on the East side of Ice House Street direct to the Gardens Service Reservoir.
The laying of the length of 800 lineal feet from Queen's Pier to Queen's Road, where a connection was made to the City distribution system, was completed by the end of 1929, enabling water from Kowloon, through the Cross Harbour Pipe, to be utilized on completion of the latter in February, 1930.