Source : Pacific marine Review, Volume 41, December 1944.
The function of the electric drive is primarily reduction of speed from turbine to propeller and it affords the added advantage that the ratio of speed reduction is variable to a conciderable degree by changes in the connection of motors without changing the speed of the prime mover.
Thus we can use one ratio of speed reduction for cruising conditions and another for high speed conditions and this makes possible a high expicieney in the turbines under both conditions. Efficiency at cruising speed gives increased cruising radius
without dependence upon sources of fuel supply. The electric drive also gives an interchangeability which is valuable in a warship. A plurality of turbine units can be used for high speed conditions where the power is large and a single unit for low speed cruising where the power required may be not more than a tenth of the
“About the year 1909 our turbines had reached a state of development which led me to the very positive belief that with the advantages above mentioned the turbo - electric drive if properly designed and handled would afford a very valuable improvement in warships, and I began a campaign of promotion which went on for several years and which finally resulted in the adoption of the electric drive for all of the new larger battleships and cruisers which were authorized after its adoption was decided upon.”
The first turbo - electric drive was installed on the U. S. Navy Collier Jupiter, built at Mare Island, California, and delivered in 1913. The first battleship so equipped was the New Mexico in 1917.
This 100th tanker at Swan Island is the first Maritime Commission tanker christened in honor of an individual and it is very fitting that she should be named W. L. R. Emmet for the man who, more than any other engineer, was responsible for the introduction of the electric drive for ships.
Left: Fore peak section of 16.800- ton Swan Island tanker is lifted into place.
Right: 104-ton prefabricated midship deck house is lifted while the signal man on the bow section in the background stands ready to direct the whirly operators as the section nears the ship.
Left: Forward pump room and coffer dams section weighing 78 tons about to be placed in the ways.
Right: The same forward pump room and coffer dam section almost lowered into place. Note fabrication details and piping and valves already installed.