The sun. [volume] (New York [N.Y.]) 1916-1920, 1919-08-31
States Merchant Mariners Need Watch the Still Engine
Has Met All Tests, and Promises To
Be Equally Valuable on Land
and on Sea.

.ure of $50 degrees-l3S degrees above
boiling point. This, of course, is $50
degrees lower than the compressed air
in the cylinder when the atomized oil
is ignited and for that reason serves
as a rcfrgerant while still keeping
the cylinder walls hotter than would
be the case ordinarily when cold water
is employed,
The steaming water in the duplex
engine passes from the jacket into a
small boiler where, by means of an
oil burner. a pressure is maintained
of 120 pounds to the square inoh-
Next, the exhaust gases from the COM
bustion cylinder are passed through a
water heater, which is also linked with
the boiler. These gases enter the
heater at 900 degrees Fahrenheit and
leave it at 400 degrees. The majority
Of the released 500 degrees is absorbed
by the water. as is evidenced by It's
temperature on flowing 20 the Jacket
space around the combustion cylinder.
The steam for power purposes, which
is tapped from the little auxiliary
boiler, first enters a steam jacket
which surrounds the steam cylinder.
placed directly below the combustion
cylinder, and is admitted by means OF
a suitable valve to the steam cylinder
when the piston reaches the limit OF
its oil driven stroke. This gives a
power impulse that effectually over
comes the dead load and the FRACTIONAL
losses which would otherwise repre-
sent a drain upon the energy devel-
oped at each operation of the combus-
ton cylinder.
Shows Well in All Tests,
The first experimental Still engine
developed $50 brake horsepower from
three cylinders when making 400
revolutions Il minute. At the start the
fuel was Illuminating gas. but this was
subsequently replaced by oil. While
the showing was not up TO expecta-
! tons, nevertheless an efficiency Of a1.8
| per cent. was obtained-an improves
ment of II per cent. upon the most
| efficient steam turbine and of nearly
20 per cent. upon the best OF Diesel
motors.
| Engines OF the Stin type have boon
| built and tested ashore and afloat and
. the results are extremely encouraging.
! Both In England and elsewhere the
| Still system is being worked out for
/ commercial marine service and two
J stroke single piston types, developing,
respectively, 100 and 400 horsepower
per cylinder, have been adopted. En-
| gines of this character with a 20 inch
| by sc inch cylinder at 40 revolutions
minute have given 1900 shaft
horsepower. With all auxiliaries and
water they weigh approximately 800
+, tons. 4 geared turbine plant In q
similar ship would weigh 20 per cent.
more, and would consume, 1t is esti-
mated, about 1900 tons more fuel for
q round-trip lasting 1000 hours.
Manifestly, Americans cannot afford
10 be Indifferent to this prime mover
OF British origin, used ashore or afloats
| because II means fuel economies
| which will be of considerable moment.
This applies equally to the factory.
the machine shop and any sort 81
power installation where units of thu
character would answer; but prob.
ably these motors will be of the most
conspicuous benefit in the realm of
shipping. We must give serious heed
to it's adaptation TO our own merchant
marine at the earliest moment when
motors of this nature can be en-
ployed without hesitation in our cargo
carriers.