We give several illustrations of a sea going twin screw torpedo boat lately
built for the Italian government by Messrs. Yarrow & Co., of Poplar. The
vessel in question is 140 ft. long by 14 ft. wide, and her displacement
approaches close on 100 tons. The engines are of the compound surface
condensing type ordinarily fitted by this firm in their torpedo boats,
excepting where triple compounds are fitted. The general arrangement is
shown by the sectional plan. As will be noticed, there are two boilers, one
before and the other aft of the engines, and either boiler is arranged to
supply either or both the engines. Yarrow's patent water tight ash pans are
fitted to each boiler, to prevent the fire being extinguished by a sudden
influx of water into the stokehold. There is an independent centrifugal
pumping engine arranged to take its suction from any compartment of the
boat. There are also steam ejectors and hand pumps to each compartment.
These compartments are very numerous, as the space is much subdivided, both
from considerations of strength and safety. Bow and stern rudders are
fitted, each having independent steam steering gear, but both rudders can
be worked in unison, or they can be immediately changed to hand gear when
necessary. The accommodation is very good for a vessel of this class.
Officers' and petty officers' cabins are aft, while the crew is berthed
forward.
[Illustration: TWIN SCREW TORPEDO BOAT FOR THE ITALIAN GOVERNMENT.]
The armament consists of two bow tubes built in the boat. There are two
turntables, as shown in the illustrations, each fitted with two torpedo
tubes. These, it will be noticed, are not arranged parallel to each other,
but lie at a small angle, so that if both torpedoes are ejected at once,
they will take a somewhat divergent course. Messrs. Yarrow have introduced
this plan in order to give a better chance for one of the torpedoes to hit
the vessel attacked. There are two quick firing three pounder guns on deck,
and there is a powerful search light, the dynamo and engine being placed in
the galley compartment.
We believe, says _Engineering_, this torpedo boat, together with a sister
vessel, built also for the Italian government, are the fastest vessels of
their class yet tried, and it is certain that the British Navy does not yet
possess a craft to equal them. It is an extraordinary and lamentable fact
that Great Britain, which claims to be the foremost naval power in the
world, has always been behind the times in the matter of torpedo boats.
The official trial of this boat was recently made in the Lower Hope in
rough weather. The following is a copy of the official record of the six
runs on the measured mile:
Boiler | Receiver | |Revolutions | | |Second
Pressure.| Pressure.| Vacuum. | per Minute.| Speed.| Means.| Means.
-------------+----------+---------+------------+-------+-------+------
|lb. | lb. | in. | | | |
1 | 130 | 32 | 28 | 373 | 22.641| |
| | | | | | 24.956|
2 | 130 | 32 | 28 | 372.7 | 27.272| | 24.992
| | | | | | 25.028|
3 | 130 | 32 | 28 | 372 | 22.784| | 25.028
| | | | | | 25.028|
4 | 130 | 32 | 28 | 377 | 27.272| | 25.138
| | | | | | 25.248|
5 | 130 | 32 | 28 | 375 | 23.225| | 25.248
| | | | | | 25.248|
6 | 130 | 32 | 28 | 377 | 27.272| |
+------+----------+---------+------------+-------+-------+-------
Means.| 130 | 32 | 28 | 274½ | | | 25.101
| | | | | | knots
-------------+----------+---------+------------+-------+-------+-------
--_Engineering_.
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