THE PARSONS MARINE STEAM TURBINE AND ITS APPLICA- 
TION TO VARIOUS CLASSES OF VESSELS. 
By E. H..B. AnpERson, Eso., MEMBER. 
[Read at the eighteenth general meeting of the Society of Naval Architects and Marine Engineers, held in 
New York, November 16 and 17, r911.] 
The object of this paper is to put before the members of this Society 
some of the various arrangements of turbine machinery in past and present 
vessels, which are fitted with Parsons turbines of the reaction type. Dealing 
with the well known pioneer vessel Turbinia it is of interest to note that in 
torpedo boats and small fast steam yachts of this type, a similar arrange- 
ment of machinery is still installed and there are about 40 such vessels at 
sea and in addition ro are under construction at the present time for the 
Spanish Navy. In the Turbinia, the astern turbine is in a separate casing 
and no cruising turbine was fitted. 
This arrangement combines simplicity with extreme lightness of parts 
and good economy over a very wide range of power. (Plate 95.) 
In the earliest turbine destroyers, Viper, Cobra and Velox, four shafts 
were fitted, having two sets of independent ahead turbines, consisting of two 
high pressure and two low pressure with astern turbines on inboard shafts 
only. 
This design was followed in the next destroyers by the standard three- 
shaft arrangement to which was added two cruising turbines in series, 
arranged at forward end of each low pressure turbine. (Plate 96.) 
There are about 100 vessels constructed with such an arrangement 
having shaft horse-powers varying from 7,000 to 20,000 and speeds from 26 
to 34 knots. 
In the United States Navy there are 15 of this type at sea and four being 
built, all of which have speeds of 29 knots and upward. 
In the French destroyers having the usual three shaft arrangement 
only one cruising turbine is fitted, and the machinery is arranged in two 
compartments. 
For small fast cruisers, the three-shaft arrangement has been found very 
satisfactory, and this design wasadopted in H. M. S. Amethyst and in the first 
turbine warship, Mogami, built for the Japanese Navy, and in two scouts 
completed for Brazil in 1909. No cruising turbines were installed in the ship 
built for Japan. 
