AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

• AGRIMOTOR NOTES.

23rd November 1920
Page 25
Page 26
Page 25, 23rd November 1920 — • AGRIMOTOR NOTES.
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

The Ministry of Agriculture's Report on the Lincoln Trials.

AN ACCOUNT of the Lincoln tractor trials appears in the Journal of the Ministry of Agriculture for November. The article containing the report was written for the Ministry by Mr. Thompson Close, Mr. B. K. Owen and Mr. H. G. Richardson.

So far as the general information goes concerning the trials, there is nothing in the account very different from that which appeared in The Commercial Motor, but the Ministry do raise a munbqr of points which it may be well worth our while to consider in some little detail.

In their weekly service for November 6th, it is pointed out by the Ministry that the only classes which could be properly regarded as being representative were Classes 1, 2, and 7, as, in certain other classes where the competitors numbered only 3, 2, or -1, the award of medals . had an air of unreality.

It is stated that, among competing tractors and motor ploughs, there was striking uniformity in design and construction, although two main types could be distinguished: (a) those in which the whole of themachinery is built up-in one unit, that is entirely without frame, and (b) those in which there are separate units on a, frame.

The Ministry state that, broadly speaking, there was very little difference observed between the machines which competed this year and last, and it would seem to the Ministry that, for the time being, manufacturers consider that design has attained finality and are content with minor improvements. ff one may be allowed to make a comment upon this, I should say that this opinion of the Ministry is wrong. Tractor design and construction certainly had arrived at a, stage when it was necessary to. attend closely to minor details with a view to effecting improvements, but manufacturers, alive to the present situation, do not imagine any such thing as having reached finality in design. In regard to the Ministry's statement as to the uniformity in design and construction, this is only true when applied to the American machines. In that country the tractor has become fairly well standardized, and almost any make can be depended upon to do a good day's work, but I think it will be agreed that there is not much approach to standard among the English machines, manufacturers not having yet discovered a standard at which they can aim in construction. It is urged that manufacturers and designers-, naturally enough, have been strongly influenced by the example of horse ploughing, and have regarded the tractor as a substitute for the horse, which may have led to the neglect of the possibilities of the conversion of power into rotary motion—a pro'blem engaging the attention of French manufacturers, and 'one that will require close investigation in this country.

In this problem, the question of the act of cultivation cannot be separated from the question of the tractor. We have before, in these columns, urged many times the need for breaking away from the • orthodox methods of cultivation.

The Ministry note that, in the more recent -designs of tractor, there has been a tendency to reduce 'weight per horse-power, pointing out that the Fordson tractor, the lightest of all, is only one cwt. per horse-power as compared with 3 and 4 cwt. per horse-power in the case of heavier machines.

The whole question, however, of weight in relation to horse-power Is at present little -understood. Weight per horse-power should be, and undoubtedly will be, universally regarded as a necessary element in the selection of a machine for any particular class of work. In actual practice; or in relation to their problems, farmers generally have no idea *hat it means. Another problem is that of the relative efficiency of wheels and chain tracks. The Ministry point out that no definite opinion can be stated, until a very protracted test is made under a wider range of conditions than those which obtained this year. Results so 'far, it is stated,' have demonstrated the superiority of the chain track tractor over the wheel tractor on wet soils, where the track machine, with its low intensity of pressure upon the soil, shows itself to greater advantage than on a dry, light soil. Wheel machines practically group themselves in efficiency in greater or less proportion to the weight per Square inch carried on the contact.with the ground. The Minis-try says that last year's trialli demonstrated clearly that heavy weight is not necessary -to provide tractive effort, and that with efficient forms. of grip, light ma,chines■are successful. As to:designs of chain tracks, there is ample scope for investigation and comparative tests at the hands of any research association or institute that may be established in connection with agricultural machinery. The Ministry note that a good deal of attention. has been given to points of detail in order to secure ease of handling and the saving of wear and tear. Nearly all machines haell brakes and attention aas been paid to springing. We are told that there were tew exposed gear drives, and in most cases vital parts were fully enclosed, although with due regard to the

need for accessibility. While most machines had been fitted to effect alteration ol. draw-bar connection. in a horizontal direction, Some had not been provided with easy adjustment in a vertical direction and suffered as a result.

Attention is called to the complicated nature of assay of the machines, and it is pointed out that the advice given last year by a well-known farmer that tractors should be made simply, to suit the simple folk in the country, may well be repeated. Complicated electric outfit, requiring an expert mechanic to correct the-slightest mishap is, the writers state, a glaring error of judgment. A machine so fitted would leave the ordinary farm hand helpless. While agreeing-with the Ministry reporters, that complicated tractors should be avoided., I cannot agree with them in their statement that many ether. machines were obviously too -complicated ; as a matter of fact, a large majority of the machines at,Lincoln were of simple. construction and easy to manage. Machines ,competing for the first time are commented upon, and it is pointed out that a well-known name is no evidence.that a maohine is designed on the same lines as a namesake of earlier years. In several instances, complete change of design has been adopted where the old names has been retained.

Of the four new machines in Class I, namely, the British Wallis, the Saunders.= Junior, the Case, and the Samson—two British and two American—it is stated of the Wallis that it is a modified and considerably .impreved pattern of the old three-wheel Ameridan Wallis, the most obvious alteration being that of the addition of another wheel, making it a four-wheeler, with many other detailed modifications which add to the usefulness of the tractor. The Saunderson. Junior is, it is. stated, in general principle, a replica on a smaller scale of the standard model G tractor of the Saunderson Co. 'It has the same twocylinder vertical engine and arrangement of clutch, gearbox and.final drive. Of the Case, it is said that this machine is very original in detailed design from. front to rear. One-piece cast frames have never before been used in the design of this machine, in which

an extremely strong east-iron member runs from treat to. rear, carrying the radiator on its front end. The engine is disposed midway across the frame which, at the rear, serves also to support a gearbox and axle ease, The Sylphone thermostat is a useful feature of the Case. The Semeou is stated to resemble the Fordson externally. An interesting feature of this tractor is the lubricating system, there being only a couple of holes through which oil need be poured occasionally, no other attention of that kind being necessary.

In Class 2, besides the British Wallis again there was the Peterborough and the Pick. Of the 'Peterborough it is stated that the machine is constructed on excellent lines, but, if I may interpolate a personal comment here, I should say that the Peterborough will have to secure a stronger frame for so powerful an engine, otherwise the wear andtear item, will go very much against it. The Pick is stated to resemble, on geeteral lines, the Austin,and Fordeon types, the most noticeable feature being the over-lapping.etrakes which are embodied in the back wheel construction. The design avoids the choking of the machine even on sticky soil, The Canadian Chase is pointed to as being a threewheeler without the disadvantages usual in that type of machine, and has a. number of yery important features to recommend it.

The larger Case is referred to, and the Hart-Parr, the latter as an entirely new machine. The principal point of interest in the Hart-Parr seems to he in the engine, a two-cylinder slow running horizontal unit, transmitting through a clutch and series, on plain spur wheels, to the differential on the rear axle. It also has an extremely strong frame. . The Twin City is noted for its unusual engine. It has four valv.es to each cylinder, two for induction and two for exhaust. The frame is an interesting departure, and is made to serve as a base for the transmission gear, but does not actually form part of the engine, which is suspended within it. The attention which the Parrett tractor aroused, was mainly on account of its somewhat unusual appearance, due to the large -diametee and the wide spread of its wheels. The construction has a decided advantage at the headlands, since it facilitates considerably the turning or:oration. AGRIMOT.


comments powered by Disqus