25
Before the pipes are put into position, the intermediate joints to be thoroughly protected, as previously specified for pipes, with Hessian Cloth saturated in Bitumen, and the whole so encased as to be thoroughly impervious to water and not likely to be damaged in laying on the floor of the excavated trench or by the filling afterwards.
22.
A provisional quantity of Concrete (1,000 cubic yards) to be allowed in Anchor Blocks. the Contract for Anchor Blocks or protecting works at such points as the Engineer may direct. The Anchor Blocks will be across the trench and be composed of concrete 1-2-3 deposited over and around the pipes, the probable cubic contents of each block to be about 20 cube yards or such other dimensions as the Engineer may direct, the rate in the Schedule to include all expenses for excavations, disposal of surplus, special plant and work for laying below the existing floor level of the Harbour.
23. The Contractors must be responsible for the method adopted for laying Method of Laying the pipe lines, and before proceeding with the work must disclose to and agree with Pipes. the Consulting Engineer the method of procedure proposed to be pursued. The suggested method of laying may be varied should a more reliable or simpler method be suggested. In laying the pipes as proposed it would be necessary to have ? connection made to the water supply mains of Kowloon to the first pipe laid from the Kowloon shore, and each successive length into the Harbour connected so as to be kept charged with fresh water, and as the pipe line progresses an approved test pressure to be applied from time to time to disclose any leakage that might arise before covering in the trench. The laying to be supervised and the adjustment made by skilled divers, and the whole of the pipes, ball and socket joints, etc., before being left, are to be tested and found to be tight, caulked where necessary, and amply covered with protective material other than the refill material specified for covering, if so directed by the Engineer.
24. During the laying of the pipes, the Contractors must act in accordance with Harbour the instructions of the Harbour Authorities and take the necessary steps that they Requirements.
or the Engineer may direct so that no obstruction to navigation in the Harbour is caused, and the navigation of shipping along the channel near Kowloon shore is not interfered with.
The Contractors must erect and maintain proper lights and guards, and such tugs and power boats as the Harbour Authorities may require to be supplied and maintained ready for use, so as to obviate damage to shipping in the Harbour or to Contractors' plant and the works herein specified and the contract sum shall be deemed to include all risks for which the Contractors may be liable under the Contract.
VALVE CHAMBERS, ETC.
25. Two valve chambers, Drawings Nos. 7 and 8, are to be erected on the line Valve Chambers. of the pipes one at Kowloon shore and one at Victoria shore. The chambers, valve houses over and connecting gangways are practically similar excepting as to depths of chambers and foundations. In both cases, the site of the chamber is to be surrounded by approved steel interlocking sheet piling driven well into the hard, so as to form a watertight coffer dam, and so constructed, strutted, protected against pressure, and maintained as to exclude any flow of water sand or soft silt from the surrounding strata. In the Victoria chamber, the foundation is to be constructed on the hard strata, properly levelled and stepped if necessary. It is intended that the steel piling shall remain in position permanently, and that afterwards, as the work proceeds, it shall be cut off at or about the level of low water, the level at which the granite facing begins and a protective timber fender cope provided and fixed.
At the Kowloon chamber, at or near the level of 20.00 below O.D., the space inside to have pitch pine or other approved timber piles with proper shoes and heads driven into the hard strata, the tops cut level, and a platform formed of two layers of pitch pine timbers framed and bolted to form a foundation for the works above, the space immediately below and around the heads of the piles being filled up with
concrete.
The chambers to be constructed of 5 to 1 concrete with a lining of brickwork in cement constructed with a collar joint. The bottom of each chamber to be inverted brickwork and skew blocks of approved stone, to be provided and built in at the
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