The engines of Japanese warships are, save in the case of a few small
vessels, of British manufacture, and the same as those of British ships.
In boilers, the Belleville type was adopted with the Shikishima, and
several older vessels have been re-boilered with it. Almost the first
warship to be fitted with this type was the Chiyoda.
With some remarkable exceptions, Japanese naval engineers have not
succeeded very conspicuously in securing the very economical coal
results which have been obtained with Bellevilles in the British Fleet.
A remarkable instance to the contrary was the Idzumo; the Mikasa also
did well. The Asahi, when first commissioned, did badly, but, when the
art of coal spreading on scientific lines was mastered, suddenly became
very economical.
No trouble of any sort has been experienced, and the Japanese have
shown themselves singularly adapted to the management of water-tube
boilers.
[Illustration: THE LATEST PATTERN ELSWICK SUBMERGED TUBE.]
When the Yaeyama was re-boilered, Niclausse generators were fitted to
her, but with indifferent success. Consequently, in order to continue
experiments on the lines of the British Navy, this type was fitted to
the Niitaka and Tsushima, and ordered for one of the new battleships.
Apparently the experiment is to be continued to other types, following
the example of the British Navy, though the majority of the engineers
are averse to such a procedure, both on account of the success obtained
with the Belleville and because of the extreme difficulty involved when
many types exist, and many of the men sent to a ship are used to some
other type of boiler than the one that they are called on to work.
[Illustration: BELLEVILLE BOILER WITH ECONOMISERS.]
A water-tube boiler of Japanese design exists—a species of cross
between the Belleville and Yarrow, with a little Niclausse thrown in.
It does not appear to promise well, and though designed to possess the
virtues of each type, seems more likely to embody their weaker points
than their strong ones. Such, at least, appears to be the general
verdict.
There is also another water-tube boiler of Japanese origin, something
like the Thornycroft, which is in the hands of the Temperley
Transported Company; but I have not heard of any practical tests of it
as yet, its invention being quite recent.
In any case, neither is likely to oust existing types, as most of the
valuable points in a boiler are already patented all over the world.
The inventors of new types are, therefore, hampered much like inventors
of new systems of wireless telegraphy are—some one has been before
them. In addition, a water-tube boiler requires some years of practical
service before it can be classed as out of the experimental stage. The
great advantage possessed by the Belleville, which “in theory” is one
of the worst of boilers, lies in the numerous features introduced by
years of practical experience. In rough-sea work theory and practice
rarely go together; the thing that is ideal on paper is apt at sea to
fail unexpectedly. The water-tube boilers fitted in Japanese ships are
as follows:—