How To Select A Launch-Engine

Some Useful Hints For Islands Residents

By An Islands Engineer—Copyright.

AFTER a number of years of practical experience and observation of marine engines in the Islands, a few comments on this class of engine may be acceptable.

Almost all interests on the coast-lines of the Islands depend upon launches or other craft for communication with the main ports; and for the execution of a great amount of their work, government departments, traders, planters, missionaries, and various occupations rely upon water transport.

It is surprising to see the different types of boats and engines used. In many cases both boat and engine are unsuitable for the purpose required. Many factors account for this, perhaps the chief being the lack of capital. It is imperative in many cases that a person must have a boat of some description, and being unable to finance, what he would desire, the alternative is the purchase of what his pocket will allow —in some cases, some old craft fitted with a motor-car engine, or engine that was originally intended for motor-car use, but with a certain amount of camouflage in the shape of reverse gear, pump, and other contraptions fitted is called a marine engine.

The writer came across one of these engines. After about two weeks of continual toil and grinding, mixed with a fair amount of un-parliamentary language, it was found that the magneto fitted was of the wrong rotation.

Take into consideration the cost of benzine in the Islands and one wonders how any person could be gulled into the purchase of an engine of this class.

Irrespective of heavy running costs for fuel, there is also the lack of access to any main working parts. When this class of engine is designed for motor cars the means of access is by removing the crankcase base. This can be done in a pit, with a motor car, but when fitted into a boat it means removing the engine from the beds. This aspect is never thought of until something occurs; it may be a bearing requires attention; it is then discovered that wood work requires to be cut away, pipes disconnected and the whole engine dismantled to carry out perhaps just a small renewal or adjustment. The result is that a job that should have cost only a small amount, runs into £20 or £30. In many cases these accidents happen in some isolated spot, and many days are wasted waiting for the means of get ting a tow to some place where the repair can be carried out.

Prospective purchasers of engines should show more judgment in the future than they have in the past, and save themselves both time and money. In the past semi-Diesel, kerosene, and benzine engines have been dominant in the Islands. With the advent of the full Diesel engine a new era opens up. The change over to this type of engine, under present financial condition, will not be too

quick. Still, by degrees, it will come.

Man’s great friend, money, kindest, truest, and best, will play a dominant part.

I am not a prospective purchaser of an engine. But, from past experience, I will explain the procedure I would follow be fore I made a final choice. Let me say this first. Do not be too impressed with any fine pictures you may see. My first procedure would be to procure the catalogues of marine engines. In doing so, I would ascertain the standing of each maker in this special class of work.

Catalogues are a work of art; and it is necessary to give them very careful consideration. Unless you are well up in the

business, you will find some catalogues and specifications misleading. Take the specifications of different makers with regard to equipment. Some quote for a complete equipment; some make you be lieve they are doing so; others don’t know what they are doing themselves. In all cases, the following information should be procured before coming to a decision.

What did the engine in itself consist of? What length of stern-tube supplied;

size; was it fitted with inside or outside bearings or stuffed box; what material?

Length, diameter and material of tail shaft? Details of propeller? Length of intermediate shaft, diameter and material?

Were couplings and intermediate bearings supplied? What tanks were supplied— material, capacity, and fuel-pipes and fittings supplied? Details of water intake; description of strainer and hull fittings and pipes supplied? Length, size and particulars of exhaust pipe and fittings?

To make comparisons it is necessary that all the above information be available.

Another important asset is the tool box.

With some engines a splendid kit of tools is supplied; with others, you could buy it for two shillings.

Having procured the above information, the first question is the matter of horse power. Remember, the chief factor in the purchase of an engine is, all other things being equal, the cost per horse power.

Any consulting engineer or naval architect makes horse power the deciding factor. Perhaps no subject throughout the engineering world causes more discussion than horse power of engines. You have only to pick up the various catalogues to see the diversity of rated horse power.

In 90 per cent, of cases, internal combustion engines have no rated horse power. If you buy an engine, and the rating is given as 12-60 h.p., you can be pretty certain the normal horse power is 12: the 60 horse power may be attained if you are game to run the engine about 5000 rev.

There is the maker who rates his engine in the catalogue at maximum horse power, but recommends they be run, under working conditions, at a lower horse power.

Then, again, there is the maker whose engine loses power through temperature.

Why these excuses should be made I fail to understand. The maker whose product would appeal to me is the one

who gives you the horse power straight out. If an engine is governed, I presume the setting is to the working horse-power.

This, therefore, becomes the normal horse power of the engine, and, as such should be sold. If the engine is capable of over load, no harm is done by giving this information.

The only sure way of being satisfied regarding horse power is to insist that Lloyd’s or other certificate be supplied with the engine, giving its normal working horse power under normal conditions. If this certificate is procured, and the engine complies with the Board of Trade requirements, the details of the engine construction can be left to the makers. If these precautions are taken, purchasers will not go far wrong and will be assured that the main factor, power, comes up to what is represented.

Regarding consumption of lubricating oil. This should be watched, and a guarantee received.

After horse power, we have to consider reliability. To a very great extent this must be left to reputation. An engine that is suitable for intermittent work and pleasure purposes is not always suitable for hard, constant and rough work.

You have only to study the accounts given in the press, at different times, of yachts, cruisers, and other craft. These craft, by the description given, are floating palaces. So far as the engine is concerned, too much is not said; these boats are the home of the derelict motor-car crock.

To find out the engine suitable for reliable and hard service you require to turn to another class of users, fishermen, launch proprietors, shipping service launches, pilot service, lifeboats, and other services. A study of engines used in these services suggest the engines which will give Islands service.

Simplicity is another factor overlooked

by many makers. It should be remembered that in the Islands hundreds of miles often separate the user from any avenue for repairs; therefore, it is necessary consideration should be given the design of the various working parts, subject to renewal or repairs.

Take, for instance, main bearings, crankpin bearings and other working parts. These should be designed in such a manner that the average person should be able to renew them. Anti-friction metal run into bearings which are a fixture should be avoided. Should an accident occur, it often means the dismantling of the whole engine—an expensive matter. Then, again, the metal used for renewal may not be suitable.

All main bearings and crankpins, also intermediate bearings, should have liners.

These can be carried as spares, and in cases of accident or renewal, the work can be carried out by the average person.

Another bad feature with many engines is the casting of the crankcase and cylinder block in one piece. Should the water jacket become cracked, or the cylinder damaged, it means the renewal of the whole cylinder block and crankcase — a most expensive operation. In some cases, a renewal of this kind would cost more than a new engine. The argument may be used that motor car engines are constructed this way. Motor car engines are not subjected to a continual flow of salt water through the water jacket, and exposure to salt air.

Accessibility is, perhaps, the most important point which requires consideration. Very few people consider this until something occurs. Any engine that lacks access for the examination of the main working parts should never be considered for marine work. Where life is at stake in cases of accident, too much care cannot be exercised, and regular examination of main bearings and working parts should be carried out. Working until some thing occurs is a very bad motto.

The cost of repairs in the Islands is a very heavy item, when it becomes necessary. In a great many cases, from 40 to 60 per cent, of expense in this respect could be saved, if makers took into consideration design and access to meet the situation.

Much more could be written on this subject. The idea of the writer is to point out to the prospective purchaser the necessity of giving consideration to the different points mentions. The makers of the many marine engines on the market may also find food for thought.

This article was prompted through many years’ experience of some very bad engines. There are many first-class engines used in the Islands—some of which could be greatly improved with a little thought.

In conclusion: Service is the chief consideration. This can only be accomplished by reliability, accessibility, and simplicity. Compactness should be studied, and, above all, the maker (or his agent), when asked to give a quotation, should be explicit, giving full details and specifications of what he offers for the price quoted. The average Island purchaser does not ask for either maximum or minimum performances, regarding horse power, fuel, or lubricating oil. What he wants to know is the average which will apply to the work to be accomplished.

Rev. A. J. Thompson, of the New Guinea Mission of Wanigela, Papua, recently arrived in Sydney from Port Moresby with his wife. They sailed from Melbourne for Europe on May 21, and after furlough in England will return to Melanesia for further mission work.