Ma-rine′ steam-en′gine.
A form, or one of the forms, of
steam-engines adapted to use on shipboard.
The objects to be gained in the modification of the land engines to suit the change of circumstances are,—
Compactness, to save room on board and secure protection below decks.
A
low center of gravity, to increase the stability of the vessel.
Napier's side-beam engine is the form which has been extensively adopted in paddle-wheel vessels.
and is the one selected for illustration.
A modification of this is found in the
lever-engine.
An endeavor to dispense with the beam has originated a variety of
direct-action engines and
ascillating-cylinder engines.
The figure represents in section a
side-beam engine with a flue boiler as placed in a steam-vessel.
The sleepers supporting the engine are represented at
X, and the base of the engine is secured to these by
holding-down bolts passing through them.
S is the steam-pipe leading from the steam-chest in the boiler to the slides
c, by which it is admitted to the top and bottom of the cylinder.
The condenser is represented at
B, and the air-pump at
E. The hot-well is seen at
F, from which the feed is taken to the boiler.
L is the piston-rod connected with the beam
H, working on a center
K near the base of the engine.
The other end of the beam
H drives a connecting-rod
M, which extends upward to the crank on the paddle-shaft
O. a a are the rods of the parallel motion.
The framing by which the engine is supported is represented at
Q R.
The beam exhibited in the figure is shown in dotted lines, as being on the farther side of the engine.
A similar beam, similarly placed and moving on the same center, must be understood to be on the near side also, connected with the cross-head of the piston in like manner by a parallel motion, and with a cross-tail attached to the lower end of the connecting-rod and to the opposite beam.
The eccentric which works the slides is placed upon the paddleshaft
O, and the connecting arm which drives the slides may be easily detached when the engine requires to be stopped.
The section of the boiler, grate, and flues is represented at
W V. The safety-
[
1400]
valve
y is inclosed beneath a pipe carried up beside the chimney, and is inaccessible to the engineer.
The cocks for blowing off the salt-water from the boiler are represented at
h, and the feed-pipe at
I.
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|
Marine steam-engine. |
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|
Marine steam-engine. |
Fig. 3072 is a view of a similar engine, looking down the alley between the boilers and the working parts.
The side-beam engine is very compact compared with the elevated working-beam engine, such as the
Cornish, for instance, but the tendency of late years has been to direct action, dispensing with the beam.
The general adoption of the screw propeller has also much changed the general conditions required, and oscillating engines of large diameter and comparatively short stroke are now the order of the day.
The following list includes most of the varieties of engines specially adapted to marine purposes.
See under the respective heads:—
| Annular-cylinder steam-engine. | Oscillating-cylinder steam-engine. |
| Direct-action steam-engine. | Propeller steam-engine. |
| Double-cylinder steam-engine. | Screw-propeller steam-engine. |
| “Gorgon” steam-engine. | Side-beam steam-engine |
| Inclined-cylinder steam-engine. | Sliding-cover steam-engine. |
| Inverted-cylinder steam-engine. | Steeple steam-engine. |
| Inverted double-cylinder steam-engine. | Trunk steam-engine. |
| Lever steam-engine. |
