Marcu 17, 1906.] 
FOREST AND STREAM. 



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The Motor Boat for Naval Purposes. 
A paper read by Mr. M. M. Whitaker, at the annual 
meeting of the National Association of Engine and 
Boat Manufacturers. 
In considering the possibilities of the motor 
boat for naval purposes, it would probably be 
better to go over the ground already covered, 
and get some account of the work that has been 
done in this line, and also that projected. 
In March, 1904, John E. Thornycroft, of 
London, read a paper before the Institution of 
Naval Architects which brought the possibilities 
of the internal combustion motor officially be- 
fore the society. His paper was wide in its 
scope, covering broadly the different points of 
internal combustion motors which could be used 
in torpedo boats, with which his paper had to 
deal. He divided the possibilities into three. 
1. Engines which drew their combustible mix- 
ture at atmospheric pressure; in other words, 
gasolene. 2. Engines which vaporized their 
mixture through heat or spray; in other words, 
kerosene and heavy oil engines. 3. Engines 
furnished with gas from producers. In his paper 
he used for comparison a first-class torpedo boat 
and a boat of smaller dimensions and power, 
but with internal combustion motor. In dia- 
grams accompanying the paper he showed the 
motor torpedo boat driven by four six-cylinder 
gasolene motors actuating two propellers. The 
saving in space occupied about 20 per cent.— 
that is, the space devoted to machinery in the 
ordinary torpedo boat is about 50 per cent., 
while the gasolene engines with their reverse 
gear would take up about 50 per cent. Mr. 
Thornycroft’s paper only went into the subject 
tentatively, and showed possibilities without ad- 
vocating any specific motor or system. He 
seemed inclined, however, to favor either the 
gasolene engine or the producer gas engine. 
His firm last year constructed a 4oft. open boat 
with an engine working on kerosene. This boat 
was called the Dragon Fly, and was fitted with 
torpedo dropping gear, and attained a speed of 
about 18 knots per hour. The engine was 
placed forward, under a hood, with an open 
cockpit just abaft it. This was followed by the 
tank for fuel, and the torpedo was carried on 
the after deck. It would seem that boats of 
this type are too small for the service intended. 
and as they are open, are liable to be swamped 
when going in any kind of a sea. 
The firm of Yarrow & Co. have just produced 
a 6oft. Vidette boat equipped with triple screws, 
the two outside being driven by two four- 
cylinder, 61%4 x 6 motors, coupled direct to the 
shaft. The center screw is driven by one motor 
of similar dimensions, equipped with reverse 
gear. These motors are of light, high speed 
variety, running at about 1,000 revolutions per 
minute, and the form of the boat is similar to 
that of Napier II., that is, very shallow draft, 
and having a truncated bow and flat bottom. 
The forward compartment is covered with a 
hood, and is intended to shelter the crew. The 
second compartment contains the motors and 
is also covered by a-hood. The gasolene tank 
is located on the deck aft, the deck being 
dropped, and the tank fills out the form of the 
hull, so that its presence would hardly be 
noticed. At the same time any leak would drain 
directly overboard. It is intended to mount a 
torpedo tube on the after deck, and as the boat 
complete will only weigh about 13 tons, it will be 
possible to carry a number of them on the deck 
of a warship, to be launched, of course, at a 
suitable time. The boat has attained a speed 
of over 30 miles an hour, but the brief objections 
to her seem to be her shallow draft and flat 
bottom, which would make her a bad boat in a 
seaway, the opening of the engine room afford- 


ing inadequate protection for the motors. The 
type also being of high speed variety, would 
seem to be unsuitable. 
Mr. S. F. Edge, selling agent of the Napier 
motors, a couple of years ago placed the Napier 
Minor, a 35-footer, at the disposal of the Ad- 
miralty for experiments, and she was used in 
the fleet maneuvers of that season in carrying 
messages between ships and the shore. For 
this service she seemed to be well suited, and it 
is to a certain extent on her success that the 
other experiments have been carried out. 
The French government have just issued con- 
ditions for a competition for naval service boats 
propelled by internal combustion engines. They 
have laid down a series of rules governing the 
competition, and restricting the class of boat in 
many ways. The boats under the competition 
must be in the neighborhood of 6o0ft. long decked 
over which gives adequaate protection for the 
motor, quarters for officers and crew, must carry 
anchors, gear and several small rapid firing 
guns, with other ammunition. The speed must 
be at least 12 knots per hour, and the engines 
of the kerosene type, are to be supplied by the 
French government. They are of the heavy, 
slow speed variety, and under the conditions as 
outlined, very little room is left for the designer 
to exercise any discretion. 
The Russian government have probably more 
internal combustion engine boats than any other, 
several, as is well known, having been built in 
the United States, of the same type as Gregory, 
a go-footer, equipped with two 300-horsepower 
motors. They also have several built by Belgian 
and French firms for light dispatch service, as 
for instance, one 40-footer fitted with Germaine 
motor, and several built in Germany. 
Our own government has not gone into the 
matter very deep up to the present, although 
they made experiments at one time with the 
Standard, and have since placed orders with a 
number of firms for motors of different classes. 
One branch of the naval service, however, in 
which the gasolene motor has already made such 
headway is in submarine boats, those of Eng- 
land and our own government being supplied 
with this form of power for use on the surface. 
I would refer to another type of motor which, 
while it has not been as yet in naval service, is 
interesting as showing the possibilities for light- 
ness in motors. That is the motor of Antoinette 
III., an eight-cylinder, 5.9 x 5.9, made in V form, 
and giving on the brake somewhere between 
100 and 120 horse-power at a thousand revolu- 
tions. Antoinette III. is equipped with two of 
these motors, having a total weight of only 
750 pounds, and has shown a speed of over 30 
miles an hour over long distances. This motor 
is remarkable for its light weight, and through- 
out a season’s hard racing on the continent has 
never failed to function properly except on one 
occasion, at the last race of the season, held in 
the latter part of December. Here it is said 
that it failed to go because proper provisions 
had not been made for the cold weather. 
This covers about all that has been done so 
far in fitting gasolene motors for the naval 
service, but I believe that the future will see 
their adoption in larger numbers and for more 
varied uses. Taking these uses in the order 
of their probable adoption, I should say that 
the first form in which it would be generally 
adopted would be for the ship’s working boats. 
There are many motors on the market to-day 
suitable for this work, and they certainly can 
give no more trouble than the ordinary steam 
launch with which warships are generally 
equipped. From personal experience I know 
that these are constantly giving trouble and are 
a sore point with the officers of the engineer’s 
staff. For boats of this class it will require a 
motor of medium speed and weight, but the 
motor must have adequate protection. This is 
the particular point where all the racers and 
high speed boats have proved weak. In other 
words, the motor must be fitted in a compart- 
ment that is water-tight. I do not think that a 
boat of the small, high speed type can ever be 
used as a torpedo boat. In the first place, in 
order to get the requisite speed in so small a 
hull, it is necessary that the weight of hull and 
machinery both should be cut to the limit in 
order to provide carrying capacity for the weight 
of a torpedo and its launching gear. This seems 
to have been entirely forgotten in the calcula- 
tions of those who have dreamed of this class 
of boat, but aside from this, the light weight of 
the machinery and hull makes it unsuitable for 
the hard usage which it must undergo in the 
naval service. 
The next class in order of probable adoption 
would be the Vidette torpedo boat, ranging in 
length from 60 to ooft., and having motors of 
medium weight, medium speed variety of from 
300 to 600 or 700 horsepower. In this class it is 
possible to arrange weights on a practical basis 
and make a boat which would be useful and in 
many respects more economical than a similar 
boat propelled by steam, while its cost would not 
be high and a large fleet to operate from a base 
on shore or one or two carried by each vessel of 
a fleet, would make a formidable array for any 
enemy to meet. The form, however, must be that 
of a torpedo boat, strong and yet high, and freaky 
features must be cut out. The probability of car- 
rying internal combustion motors up to the tor- 
pedo boat class would seem to be possible only 
through the use of either heavy oil or alcohol 
motors or motors of the suction gas type, and for 
this reason: That the fuel consumption of the 
gasolene motor of large sizes becomes so large 
and extensive as to render its use improbable. Of 
course the Government can afford to do most 
anything it wants to, but, like the private indi- 
vidual, it does not want to go into any unneces- 
sary expense. With the increased use of gaso- 
lene in multitudes of small motors, the price will 
undoubtedly advance to limits which will make 
its use almost impossible. Anyway, the naval 
service of this and other countries seems to have 
a prejudice against the fuel as dangerous. They 
seem to forget that they carry all the time ex- 
plosives which are a thousand times more dan- 
gerous than gasolene could ever be, and experi- 
ences of the Government with it so far certainly 
do not justify their fear of it, as it is used in 
submarine boats, and the only instances of explo- 
sion have been through gross carelessness on the 
part of those handling it. If the handlers of the 
explosives had been as careless as those who had 
charge of the gasolene, the results would have 
been still worse. 
For torpedo boat service requiring powers well 
up in the thousands, it would seem that there 
are difficulties to be encountered with the use of 
gasolene as fuel, or with any internal combus- 
tion motor in fact, that will require engineering 
ability of high order to overcome. Still, they are 
by no means insurmountable, and if the same 
thought is given to those problems that has been 
given to the development of steam, I believe that 
there is no doubt that they can be successfully 
overcome. The use of internal combustion motors 
has so many advantages‘in the way of economy, 
saving of weight and hence increased speed, etc., 
that such difficulties as reversibility and ease of 
starting should not be considered. These can 
undoubtedly be overcome, in either case by the 
use of compressed air. As I stated a little while 
ago, the saving of space is about 20 per cent., and 
the saving in weight, even allowing that the pro- 
pelling motors themselves would weigh the same 
as a steam engine, is a big item, as the weight of 
the boiler is saved. - 
