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Editors note:
The following
excerpt from "Engineering" magazine is from the collection
of TRMA member Cal Haines. This particular offering is from
the much sought after issue from Feb. 27th 1914, an article
on the Britannic. It would be difficult to transcribe the complete
article for this particular edition. However, In future editions
of the Docking Bridge, we will continue with sections of the
original writings.
The subjects
of telegraphs, wheels and the telemotor have been the center
of research for many of the trustees of the TRMA, especially
Mark Darrah. When it was all said and done, we hope to be able
to answer this once and for all. In this transcription, we will
visit the Britannic and "Appliances For Navigating and
Working the Ship".
Nowhere on the
ship are the lessons of experience so fully applied as in the
navigation and working of the vessel. The captain’s bridge
is 63 ft. above the water line, nearly 100 ft. above the keel,
and on the top of the "wheel house" is a standard
compass, isolated from everything which can magnetically affect
it. Not only can the navigating officer from the bridge receive
communication from the look-out forward and in the crows nest,
and issue orders to all parts of the ship by telephone or telegraph,
but by means of "tell tales" he has demonstration
that the orders have been executed. Thus the working of the
main propelling engines are indicated on the bridge by one of
McNab’s indicators-by the McNab Marine Appliance Company,
London. The angle of the rudder is electronically recorded.
There is an electric "sounding" machine, and by means
of electric submarine bells the proximity of light ships, &
etc., is indicated. The engine, steering and docking telegraphs,
by Messrs. J.W. Ray and Co., Liverpool, serve similar functions.
The bulkhead doors can be closed from the bridge, and there
is an indicator showing the position of each door…………
The three telegraphs
from the bridge to the engine room, made by Messrs. J. W. Ray
and Co., Liverpool, are of their triple-dial all-brass reply
and automatic reply transmitters, the clear glass of each dial
measuring 20" in diameter. Two of these are connected to
two 24" engine room indicators; the third is connected
to two extra engine-room indicators through an entirely different
route. The latter three instruments together form an entirely
separate emergency control should the ordinary telegraphs be
damaged. All the principle moving portions of the gear have
an enclosed type of ball bearing center, and all the sheaves
in the leads are fitted with Ray’s patent phosphor bronze
ball bearing pulleys, 6" in diameter, the result being
that, although there are no fewer than 312 of these sheaves
fitted at the various bends, the friction is so reduced that
the levers can be put over from full speed ahead, say, to full
speed astern by the easy effort of two fingers on the lever,
and the time occupied in moving over the complete range of orders
need not be any more than two seconds. The patent automatic
direction-indicator, which indicates the first stroke of any
change in the direction of the running of engines on the separate
third athwartship dial of all three bridge instruments, does
not take even this time, and the officers on the bridge are
practically aware of everything done in completing the orders
which they have transmitted. For the handling of the ship Messrs.
Ray have fitted between the forward bridge and the after docking-bridge
four 20" clear double-dial all-brass instruments and one
flange-back helm-indicator. Two of these instruments enable
any possible order to be given to the engine room to control
the engines via the bridge; the others enable a complete set
of docking and steering orders to be transmitted and replied
to between fore and aft. These instruments are connected by
the same 6" ball-bearing pulleys; delta metal chain of
heavy description is used instead of the usual copper sash-chain.
The steering control
of the ship is effected through the well-known telemotor gear
of Messrs. Brown Brothers and Co. Limited, of Edinburgh. The
installation consists of a standard mounted on the flying-bridge,
mechanically connected to the telemotor transmitter in the wheel-house,
but provided with a disconnecting clutch to permit of this gear
being disconnected when steering direct from the wheel-house.
The Britannic is
to carry five anchors-one 11-ton ands one 9-ton bower anchor
of the "Dreadnought" stockless type, a 16-ton Hall’s
patent stockless anchor, a "stream" anchor of 20cwt.,
and a kedge anchor of 10 cwt. These are arranged for 330 fathoms
of 3 3/8 in. stud-link chain made by Messrs. Hingley of Dudley.
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