The Republican journal. [volume] (Belfast, Me.) 1829-current, 1908-02-27
THE NEXT OCEAN LINERS.

The successors OF the great turbine
liners. Lusitania and Mauretania, which
only few months ago represented the
very last word of maritime engineering
skill, are already being planned. The
turbine method of propulsion, as at
present applied, is declared to be only
a compromise, makeshlft, and the
coming leviathans, which do not yet
exist, even on paper, will show some
radical departures from even the latest
Cunard ships. ...
The great defect of the existing sys-
tenn is the adjustment OF the turbine to
the screw propeller The steam turbine
does not manifest its greatest efficiency
at anything less than its highest speed.
The screw propeller, on the other hand,
reaches its maximum OF efhclency at a
certain fixed rate of speed. Ii it is o p
Grated at a higher rate the blades sim
ply churn up the water without getting
a grip on it, and the energy behind them
is lost. 1t is theoretically possible for
a propeller to turn SO fast that the YES
sci will not advance at all. In the Lusl
tania and her sister ship the propeller
blades are made very large in order to
utilize the power of the engines to the
uttermost In a small engine, instead
of attaching the turbines direct to the
propeller shaft, they can be geared
down to it, On the large ones, how
ever, such a device is mechanically I'M
practicable The problem will be solved
by using the turbines to generate cleo
tricity by means of dynamos, the cleo
tricity, transformed through motors, to
| be used to turn the propeilers at any
desired rate 1t is estimated that the
floss of power incurred in this double
nstormation of energy will be more
than compensated for by the increase
of mechanical efficiency gained.
This is by no means the only advan-
tage promised By placing the motors
far astern and transmitting the power
by cable, the shafts may be shortened
and the space now occupied by them
and the tunnels in which they run saved
for cargo or stores. The shorter shafts
will be far less liable to fracture than
those existing, and vibration will be
greatly diminished. There should be a
tremendous gain in control. 1t is estl-
mated that In an emergency the screws
can be stopped and reversed in four
seconds. 1t takes many precious min
utes to accomplish that result-noW.
The clumsy reversing turbine. SO
expensive in steam to keep heated and
occupying SO much valuable room, Will
be done away with altogether. >,
The system of signalling from the
bridge to the engine room will be done
away with, for the navigating officer
will have before him set of buttons,
! by manipulating which he can stop,
start and reverse his machinery at will,
without being obliged first to commu-
nicate his orders to the engineers.
With six ten thousand horse power
motors obedient to the pressure OF his
finger, five for use and one in reserve,
the captain of the new liner will have
his ship more perfectly under control
than a canoeist on the Charles river
has his frail craft. There is nothing
fanciful about this advantage, either.
The engine room telegraph now in use
is not infallible, and the accident to the
Deutschland, by which, through mis-
take in signals, she was driven at full
speed into a granite pier at Dover,
points the moral.-Boston Transcript.