į
97
―
No. S. 50.
NOTICES TO MARINERS.
A DERELICT junk bottom up has been reported in Latitude 20° 9′ 30′′ N., Longitude 110° 38′ E., in the South Channel of the Hainan Straits. This junk when last seen at 4.30 p.m. on the 13th March was drifting in a Westerly direction, and constitutes a menace to vessels using this Channel.
HARBOUR DEPARTMENT,
HONGKONG, 16th March, 1916.
CIRCULAR, 1569.
C. W. BECKWITH, Commander, R.N., Harbour Master, &c.
BOARD OF TRADE,
Marine Department,
January, 1916.
Instructions to Surveyors.
Signalling Apparatus,
ON and after March 1st, 1916, every British ship of 500 tons gross or upwards going to sea from a port in the United Kingdom will be required, by Regulation 37A of the Defence of the Realm Regulations, to be provided with suitable hand flags for signalling by the semaphore code and with an efficient Morse flashing lamp.
The lamp should satisfy the following conditions :-
The body of the lamp should be so constructed as to be capable of withstanding the heat generated inside.
The light should be of such power as to be distinctly visible at a distance of three miles on a dark night in clear weather, and the full power of the light should be visible over a horizontal arc of at least 90 degrees.
If the lamp is fitted to burn oil there should be sufficient air space in the top and body of the lamp to ensure steady burning and the burner should be fitted with a chimney.
The shutter should work in exact unison with the key and should make a clean cut, so that the light is entirely obliterated when the shutter is closed and a full light is shown when the shutter is open.
In an electric lamp a make and break key is preferable, but a shutter may be accepted if it complies with the above requirements.
It is desirable that the means of signalling at night should not be solely dependent upon power derived from a dynamo which might accidentally fail at a critical moment. It is therefore recommended that, where an electric lamp is used for the purpose, a separate oil signalling lamp should also be carried.
In the case of a ship which is fitted with a fixed semaphore the provision of hand flags will not be required.
ERNEST G. MOGGRIDGE,
Assistant Secretary.