TNAG-0642-FCO40-790-Kowloon-Walled-City-and-aircraft-safety-in-Hong-Kong-1977 — Page 32

G.S. 84

XCR(77)248

RESTRICTED

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(b) The microwave links between the Observatory's radar

scanners at Tate's Cairn and other communication and telemetry facilities and equipment on the roof of the new building must remain unobstructed by existing and future building development.

(c) Because of the restricted area of the site a nine-storey

building has been designed to meet the Observatory's accommodation needs. If the height of the building were to be reduced, the shortfall of accommodation would have

provided in another new building which would be uneconomical in terms of construction and operation costs.

In addition, it has been found that a 81-metre high steel mast standing in the grounds of the Observatory, which is used to carry the equipment for displaying the visual symbols and lights for the tropical cyclones and strong monsoon warning signals and for other meteorological purposes, has not so far been exempted. The mast has been there since 1917 and it is proposed to take the opportunity presented by the need to exempt the new building to regularise the situation. The mast will be dismantled during construction of the new building and eventually replaced by a new one on its roof. As the mast must be at least as high as it is now if the tropical cyclone warning signals are to remain visible to shipping in the harbour, the new mast will also reach a height of 81-metres above Principal Datum.

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The Director of Civil Aviation has confirmed that he has no objection to the height of the new Observatory building, since it will permit standards of meteorological observation and aviation weather forecasting to be maintained and help ensure safety in aircraft opera- tions. Nor has he any objection to the height of the signal mast in view of its long existance. Exemption of the building and mast can be accepted only because they constitute an isolated obtrusion above the statutory height restriction. This can be tolerated, but general relaxation of the restriction in the area could have a marked effect on flight safety.

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Since exemption to the height of the mast will cover that for the proposed building as well, it is proposed to exempt the whole of the area covered by Government Land Allocation K107 to a height of 81-metres above Principal Datum. As the land is Crown Land, it will be possible to ensure that although the height limit is set at 81- metres above Principal Datum, this relates to the mast only and not to the building. A draft order on the lines proposed is annexed.

RESTRICTED