202 THE PARSONS MARINE STEAM TURBINE AND ITS 
It is not my purpose in this paper to describe at any length the arrange- 
ments of the engine room bulkheads and the subdivision of the machinery 
space. 
In the three-shaft arrangements, both in merchant work, torpedo boats, 
destroyers, and including small cruisers of this type, the engine room is 
generally contained in one compartment having the turbines, condensers, 
and the various auxiliaries. 
In the first vessels of the Dreadnought type, including the United 
States ships, the turbines and auxiliaries are arranged in one athwartship 
compartment divided along the center line of ship by a fore and aft bulkhead. 
In the latest ships, the machinery is arranged in three compartments, in 
which both low pressure ahead and astern turbines are in one compartment, 
while the high pressure ahead and high pressure astern turbines are in sepa- 
rate compartments at the sides. The middle compartment contains the 
starting valves, condensing plant and various auxiliary machinery. 
Arrangements are also made so that in case the wing engine rooms are 
flooded, the high pressure turbines can be shut off and direct steam connec- 
tions used to each low pressure turbine, both ahead and astern. In the case 
of the Cunard liners Lusitania and Mauretania, the turbines are arranged in 
three compartments similar tothe foregoing installations, both condensers in a 
separate water-tight room aft of engines and air and circulating pumps 
farther aft in two compartments. 
As regards the steam consumption of turbine machinery, in the Turbinia 
the measurements figure out giving a water rate of about fifteen pounds per 
horse-power, all purposes at full power. In H. M. S. Amethyst the water 
rate in pounds per horse-power for all purposes at full power averaged 
13.60 pounds. ‘This agrees very closely with a figure of 14.0 pounds per 
shaft horse-power which was obtained with United States destroyers. | 
In battleships of the Dreadnought type, the water consumption in terms 
of shaft horse-power of main engines averages about 13.0 pounds for turbines 
only. 
In large cruisers of the Indomitable type, the consumption for turbines 
only averages about 12.0 pounds per shaft horse-power. 
In ships of the mercantile marine, the steam consumption of the turbine 
machinery for all purposes in terms of shaft horse-power of main engines 
averages about 15 pounds and in large installations such as the Mauretania 
about 14 pounds. 
In vessels fitted with a combination system of reciprocating engines and 
low pressure turbines, a saving in coal consumption of about 12 per cent. is 
made, compared with similar ships having quadruple expansion reciprocating 
engines only. 
