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THE DOCK AND HARBOUR AUTHORITY
Correspondence - continued
This question is fully dealt with in my report, the recommendation being the reclamation of an area of over 240,000 square feet oppo- site Kellett Island, for the purpose of deflecting from the refuge entrance heavy seas caused by a typhoon which may pass near and to the north of the Colony; typhoons in this position induce gales from a westerly direction, one of the worst experienced being that in 1908.
Ferries
Ferries across the harbour and the transport of passengers to and from Hong Kong by river steamboats is an important considera- tion which has to be taken into account in any scheme of develop-
ment.
Later on, I shall refer to one important reason for the great movement which goes on in Hong Kong. For the moment, suffice it to say that, apart from the considerable amount of passenger transport done by sampans, the number of passengers moving to and from Hong Kong Island and the Mainland, Canton, Macao, etc., is estimated to be about 175,000 per day. The Yaumati Ferry Co., organised and managed entirely by local Chinese, runs the vehicular ferries across the harbour and two other services to points on the mainland in British territory. In addition to the large number of vehicles ferried the company carries about 40 million passengers a year; i.c., about 100,000 per day. The Star Ferry Co., the oldest ferry service, crossing direct over the shortest width of the harbour to Kowloon Point, carries approximately 28,000 per day.
For the better regulation of this traffic and to relieve as far as possible congestion on Connaught Road, I recommend in the Scheme of Development which I advised should be put into im- mediate effect at Hong Kong Central, and to which I shall refer later on,
that the ferry piers be located at each end of the scheme from which Eastern and Western services respectively would
March, 1942
trance will no doubt be raised. In my opinion the effect will be beneficial, in that it will at least help to maintain, if it does not slightly increase, the depth of water outside the entrance.
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Regarding the extensive areas of reclamation proposed in Kowloon Bay: I see no objection to their being carried out when required. With the exception of that on the Eastern side which is shown extended to embrace Kun Tong foreshore, the limits are approximately those laid down by the Town Planning Committee. Foreshores inside Lye Mun: In my report I recommended that the foreshores immediately within Lye Mun (“ Mun in Chinese meaning an entrance passage or doorway ") viz.:-Chung Lui and Yau Tong Wan ("Wan" in Chinese meaning a "Bay") "should remain as far as possible in their natural state, so that seas entering the harbour through the Eastern entrance may dis- perse and expend their force rather than be propagated up the harbour." The proposal to construct boat-building yards in Yau Tong Wan is not an extensive reclamation, but this question will not arise unless the recommendation to construct the harbour of refuge at Cheung Sha Wan is adopted.
Limitation of space will, I am sure, preclude further comment on any more of the many adjuncts to shipping and trade: so I must now ask permission to proceed in my next and concluding letter to make some observations on what perhaps is the most important part of this subject, viz.:-The Provision of Wharfage. Westbury-on-Trym,
Yours faithfully,
Bristol.
4th February, 1942.
JOHN DUNCAN,
Concrete in Sea Water
Paper*
operate. By this arrangement the routes of ferry services would Continuation of Discussion on Mr. Homer Hadley's not pass through an area likely to be used extensively by other craft. The vehicular ferry service recommended was put into effect and, from what Sir David Owen says, the traffic has apparently already reached capacity. To provide for future increase in this traffic he suggests another service to operate between Marsh Road, Wanchai and Gillies Avenue, N.E. corner of Hung Hom Bay. This proposal was first mooted by the Director of Public Works in 1922 (the late Mr. T. L. Perkins, C.M.G.), and it was fully discussed in connection with Town Planning. Whilst I con- sidered the proposal, so far as the Hong Kong side was concerned, had much to commend it, by dissipating the traffic, and, if not relieving, at any rate not adding to the great congestion already existing at Hong Kong Central, I raised objection to the site pro- posed for the pier on the Kowloon side, that location, in my opinion, being eminently suited to the purpose of providing for the discharge, storage and bunkering of coal and oil fuel. For that reason the Town Planning Committee advised the Government not to alienate the area referred to or in fact any area of Hung Hom Bay pending the adoption of a complete scheme of Port Develop
ment.
Coal and Oil Fuel Bunkering
In 1923 import of coal amounted to 1,037,530 tons and the amount exported was only 205,140 tons. But the amount bunkered was 606,060 tons.
With the exception of that imported by the Admiralty, and by local industrial and shipping companies coal is handled by lighters and storage is located principally at Yaumati and Lai Chi Kok. Excepting Admiralty storage; oil installations are at Taikoktsui, Lai Chi Kok and North Point. As bunkering of coal and oil by lighters is so dependent on labour and costly (made more so by the fact that storage is located some distance from the shipping centre) I considered that, in any scheme of development, provision should be made in a convenient locality whereby more economic bunkering of vessels could be accomplished.
The locality I considered best suited is that referred to above, viz.: the N.E. corner of Hung Hom Bay. The design of the coal depôt and oil fuel installations recommended was suitable for the erection of mechanical conveyors and pipe lines whereby coal and oil fuel may be delivered direct from colliers and tankers to storage and loaded to ships at piers or to barges in a basin thus providing for the more economical handling of this trade. The scheme, which could be put into effect independent of the development of Hung Hom Bay, was estimated to cost $2,290,000 (in 1924, roughly £285,000).
Reclamation
This work is largely a matter of supply and demand; and the practicability of economic construction not only in regard to protec- tive works, but also to the cost of reconstructing drainage works in back areas such as over the thickly-populated area abutting on the Harbour of Refuge on the west side of Kowloon Peninsula. But there is, however, another consideration, viz.: the effect that re- clamation may possibly have on other sections of the harbour.
The bold scheme of reclamation, immediately to the West of the R.N. Dock Yard suggested by one of my former assistants, Mr. Andrew Nicol, is an excellent one. If/when its construction is contemplated the question of its effect on the R.N. Dock en-
Mr. E. C. Jack, Senior Civil Engineer at Puget Sound Navy Yard: Any viewpoint of the subject of concrete in sea water should be somewhat philosopnical, in that disintegration or deterioration may or may not be serious, depending upon the rate and keeping in mind the anticip..ed life of the structure. So many of the construction people win whom the writer does business consider 10 or 20 years a long time, and anything that might happen after that they believe is immaterial. However, one needs only to look back over the centuries to realise that this matter of ships is a long range, continuing one extending far into the future. The U.S. Navy is primarily interested in ships, and waterfront improve- ments to serve the ships should be provided with an eye to a life of at least 100 years. Thus, what to one person might negli- gible breaking up of the structure, to another would be a serious indication when a long life has been planned.
It has been noted that, in almost all cases where disintegration of one kind or another has taken place, there are contributing factors upon which the onus of the situation can be placed, thus clearing sulphate attack of the charge. Nevertheless, it is agreed with Mr. Hadley that the weakness of concrete toward sulphate attack has perhaps been over-stressed. Chemists have their cataly- tic agents and Metallurgists their eutectics; and, in a similar manner, is it not probable that the weakness of concrete toward sulphate and acid attacks makes possible the disintegration, by other means, such as wave and frost action, abrasion, and chemical action? In several places in Alaska, notably at Kodiak and at Dutch Harbour, concrete has met with progressive disin- tegration between tide lines, whereas the remainder of the struc- ture has withstood weathering very well for 25 years. Surely these cases must be a combination of sea-water attack plus frost and wave action.
Cement is a wonderful material that has been improved remark- ably through the years, and its comparatively low cost, together with the rather universal distribution of the mills throughout the United States, makes possible the building of many structures that would have been impracticable years ago. It is far from perfect, however, and it may be well to review the most well- known weakness of cement and concrete.
Aggregate. The quality and usefulness of concrete, with pre- sent-day cements, demand that aggregate be sound, chemically neutral or basic, and free of oil and other deteterious substances, in addition to being well graded. Thus, in some localities, con- crete is very costly because of the distance from which aggregate must be brought. On St. Paul Island, in Bering Sea, it was necessary, one time, to carry gravel by ship from San Francisco, California. If cement acted slightly different chemically, then a wider range of aggregate might be used.
Proportioning. The mixture must be a proper one with suffi- cient cement, and this item of cement, too, is relative: Witness the
*Published in the June, 1941, issue of "The Dock and Harbour Authority," reproduced from the Proceedings of the American Society of Civil Engineers.
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