Year: 1887

page_text: Date of Application, 24th Mar., 1887.
Specification Accepted, 26th Apr., 1887.
We, JAMES RODGER THOMSON, of the firm of James and George Thomson,
Engineers and Shipbuilders, and JOHN HARVARD BILES, Naval Architect, both of
Clydebank Shipyard, Dumbartonshire, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
Hitherto the locomotive type of steam generator which possesses advantages as
regards steam raising capacity, lightness and smaller dimensions over the marine
type of boiler has not been successfully employed on board large steam ships owing
to the impractibility of working such boilers for any length of time with sea water
and the undue increase of dead weight occasioned by carrying an adequate supply, for
long periods, of fresh water to replace the amount lost in working known as the
"make up" of feed water.
Our invention has for object while avoiding the difficulties incident to the use of
the locomotive type of boiler alone, to make provision whereby that type of boiler may
he employed to supply in part the power required for the propulsion of steam ships
and to that end it consists in arranging and combining together one or a series of
boilers of the locomotive type and one or a series of boilers of the marine type and
employing the latter in conjunction with the condenser of the ships engines or any
other condenser for the distillation from sea water of the necessary fresli feed water
or the "make up" of feed water for the locomotive boilers.
When the boilers and engines are regularly worked at full power a sufficient
quantity of sea water is fed into the marine boilers to replace from time to time the
amount lost in working and thereby permit of the feed water for the locomotive
boilers being taken solely from the hot well of the condenser. In the case of war
ships which are only occasionally propelled at full speed the range of locomotive
boilers provided may in general be kept idle, the engines being then supplied with
steam from the marine boilers which may be of power sufficient to propel the vessel
under ordinary conditions of cruising though quite inadequate for actuating the
engines for propelling the vessel at full speed, and when greater power is required
than can be obtained from the marine boilers alone the locomotive boilers are fired,
and the marine boilers connected direct to the condenser if necessary to provide

page_text: sufficient water of condensation for feeding the locomotive boilers, sea water being
used to feed the marine boilers.
In the accompanying drawings figures 1 and 2 are cross sections and figure 3 is a
longitudinal section of part of a steam ship showing in elevation a range of locomotive
boilers A, A, as employed in conjunction with a range of marine boilers B, B, to
supply steam to the ships engines C. Pumps D, D, are employed for feeding water
from the hot well of the condenser E, through the feed pipe d into the locomotive
boilers A, A, and a separate pump D, is used for supplying feed water to the marine
boilers B, B. The suction side of the pump D' is connected to the hot well by the
branch pipe, and to the sea by a separate pipe d², a valve or equivalent device
being provided whereby the supply of water drawn by the pump D, may be taken
either from the hot well or from the sea. Both ranges of boilers are connected to the
engines but the marine boilers B, have a separate connection direct to the condenser
by a pipe F, provided with a valve so that steam generated in such boilers may when
necessary be condensed without passing through the engines, to maintain a sufficiency
of fresh feed water in the hot well for feeding the locomotive boilers the feed for the
marine boilers being then taken from the sea.
Having now particularly described and ascertained the nature of our said invention,
and in what manner the same is to be performed, we declare that what we claim is
In a steam ship the combination of one or more boilers of the marine type with
one or more boilers of the locomotive type and suitable connections whereby the
marine boilers and condenser may be employed as means for distilling sea water to
supply the feed water for the locomotive boilers, substantially as described.
Dated this Twenty-third day of March 1887.
CRUIKSHANK & FAIRWEATHER,
63, Saint Vincent Street, Glasgow,
Agents.