TNAG-0273-FCO40-309-Scheme-for-development-of-container-terminal-at-Hong-Kong-1970 — Page 22

5.8

5.9

On the layout recommended these areas were shown as forming a rectangle with the marshalling area directly behind the working apron, the packing-station area directly behind the marshalling area with the lorry parks at the rear of each packing shed. Additional areas were provided for workshops, stores, offices and lighter berths.

In order to determine whether these areas should be revised because of developments since 1966 and whether there would be any objection to the layout being varied to give more flexibility, the Container Committee were approached in December 1968 for their advice. They were of the opinion that so far there was no indication that the areas recommended required alteration and they agreed that these should be aimed at in designing the 1st Stage of the Terminal; the areas to be provided for subsequent stages could then be assessed in the light of experience gained in the operation of the first berth.

In regard to the layout, they agreed that, if necessary, the packing stations could be sited at some distance from the marshalling areas but that this distance should be kept to a minimum for efficient operation. They did not agree that the same could be done with container-marshalling areas in relation to the working apron as this would result in inefficient operation of an unacceptable degree.

Road Access

5.10

Wind

5.11

5.12

5.13

5.14

5.15

5.16

Since the Terminal would be sited in close proximity to a limited-access 6-lane highway, a flyover would be necessary if as seems logical, access to the terminal is made from this road. The optimum siting of this flyover would be determined chiefly by the configuration of the hillside to the east of the main road and by the position of other interchanges. Once this access is fixed the layout for the Terminal must be planned to suit it. Although at present only small containers are allowed on the roads of Hong Kong without a special permit, the design of the flyover should be such that it would permit the larger types being transported between factories and the Terminal.

In choosing a site for, and designing a container terminal, consideration must be given to the effect of wind and waves. Wind in addition to creating waves is an important factor in deciding, inter alia, the design of buildings, the height to which containers can be stacked, the design of quaywall fender systems and in estimating the likely period during which the berthing facilities cannot be used.

In Hong Kong the winter monsoon blows from the north or north east and normally begins during September. It prevails from October until mid-March but can persist until May. The summer monsoon blows from the south or south west and although it can occur from mid-April until September, it is not as persistent as the winter monsoon and usually is predominant only from early June to the beginning of August.

On average five or six tropical cyclones threaten Hong Kong each year and one of these comes close enough to cause a gale of 40 m.p.h. or more. Gales due to tropical cyclones have been known in Hong Kong as early as May 19th and as late as November 23rd. About once in every 10 years the centre of a fully developed typhoon passes sufficiently close to cause winds of hurricane force i.e. of 74 m.p.h. or more. During the period from 1947 to 1968, a maximum hourly mean wind speed of 78 m.p.h. and gusts of up to 160 m.p.h. were recorded at the Royal Observatory during typhoons and the maximum hourly mean ever recorded from the south-west quadrant was 60 m.p.h.

At Kwai Chung, the proposed site for the Terminal is such that the winter monsoon will blow offshore and the summer or "south-west” monsoon onshore. The latter will thus have more effect in producing waves at the berths.

An analysis of winds at Cheung Chau Island during prolonged spells of south-west monsoon shows that in the period from 1961 to 1968, the south-west wind speeds rarely exceeded a maximum hourly mean of 25 m.p.h. and that the highest average daily-mean- wind speed over a period of 3 days was 17 m.p.h. The one exception to this comparative calm would be when Hong Kong experiences a direct hit from a typhoon when as mentioned previously winds of up to 60 m.p.h. from the south-west quadrant can occur. The frequency of surface winds recorded at Cheung Chau is shown as a "Wind Rose" at Appendix 4.

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