Designing for Overseas
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DESPITE the fact that manufacturers of com mercial vehicles are so fully occupied in production for the war effort and in meeting other Nally urgent demands from operators, it is essential that the export market and its future should not be unduly neglected.
In catering for road-transport activities abroad it is of little use to base the requirements upon usage at home. It may be that, in some areas overseas, where there exist good roads and the climatic variations are not excessive, models practically akin to those marketed here will prove satisfactory. In fact, that has been shown already, particularly in relation to British-built buses, hundreds of which are giving eminently satisfactory service in foreign capitals and other large centres abroad. There are, however, countries in which, whilst it is urgently necessary to push the claims of the British vehicle, these must be substantiated by most careful attention to designing to meet the specific difficulties which have to be faced.by operators.
In an article published in our issue of July 20 we referred to some interesting and valuable comments made by an engineer in Nigeria, and although some of the points raised concern a particular make, they can be applied equally well in the construction of others, and in areas where conditions resembling those existing there may prevail.
Where the Oil Engine Scores He points out that, so far as his area of transport activity is concerned, fuel restrictions and the need for economy render the oil-engined vehicle almost the only type—at least, in the larger classes—which is practicable. At the same time, merely rugged strength, necessitating a chassis perhaps even heavier than that used on good roads for carrying an equivalent load, is not what should be aimed at. Strength must be combined with light weight, whilst the design must be such that maintenance and the possibilities of breakdown are reduced to the minimum.
Admittedly, in Uganda, the conditions may be particularly severe. The, road surfaces are usually uneven and rough in dry weather, and soft and possibly under water during the wet season ; after the rains, severe drying by the sun and winds may result in the forma. tion of corrugations, which severely stress both chassis and bodies, the position being often aggravated by inconsiderate driving and overloading.
Unless a vehicle be built to meet such conditions it proves almost impossibleto keep anything tight, and some chassis are apt to shake almost to pieces, whilst the fracture of engine bearers and chassis frames is frequent.
One of the major needs is good ground clearance, whilst any attachments, such as wings, must not be an afterthought, but considered in relation to the rest of the vehicle. Good ventilation, both for the working parts of the vehicle and for the cab, is a sine qu5. non.
Important Points in Design As to the power, this should be high in ratio to the weight, and preferably the engine should be insulated from the driving axle by some form of joint which will absorb the vibration and not require attention in respect of lubrication or replacement.
The choice of gearbox ratios and that for the final drive must receive careful consideration. Although this engineer does not refer to this point, at least one particularly low ratio is often required, and it might be advisable in some cases to employ a supplementary reduction gear doubling the ordinary range of ratios. We have to consider in this connection that certain foreign competitor§ allow for the provision of such a fitment.
Suspension is, naturally, a feature deserving more than ordinary care in design. The steering gear, also, is liable' to be subjected to unusual stressing and wear. Brakes should be powerful but progressive, and free, so far as possible, from cables, which are apt to seize when employed under tropical conditions. Naturally, effective cooling is required, with a system which cannot easily be choked when impure water is used.
It should always be remembered that skilled labour is not nearly so easily available as it is at home, so that it is even more essential to design for low maintenance and good accessibility. In Nigeria it has been found that bodywork is more durable if of the.composite steel and wood type, the wooden platforms being supported by an ample number of bearers, and preferably with a steel facing to take the wear. It may be necessary in certain parts of the world to make allowance for the ravages of the white ant, and the wood should be such as will not only resist these, either by its quality or treatment, but should also be reasonably unaffected by heat and moisture.
Retention of Summer-time Will Help Operators
TRANSPORT interests and the public in I general should be well pleased at the, albeit somewhat tardy, decision to retain summer-time during the winter months. We quite realize that there are certain difficulties in the way, chiefly with the agricultural community, due to the fact that some animals are averse to having their milking and rest times altered in any way.
However, the majority of the people will benefit, whilst retarding the black-out should ease the burden of those who provide public-transport facilities by road and enable workers to reach their homes, or shelters, as the case may be, in reasonable time.
Those who rise early may not feel quite so pleased at the commencement of the day, although they will gain the advantage at the end of it ; but, on the other hind, the average time of starting the day's labours is now somewhat later than was the case previous to the war of 1914-18.
Bound up with this question should be that of staggering the hours of work, so that the loading peaks become less apparent. The need for this policy is enhanced by the fact that so many shops and other places of business are closing much earlier.
The Law (1v1.0.T.) and the Profits
THE attention of area secretaries of haulage associations is respectfully directed to the two articles by our contributor S.T.R., on pages 252 and 256 of this issue. In the one ke deals with the implication of the new Ministry of Transport Order relating to the increases in haulage rates and shows how; from his own experience, data justifying such increases should be prepared for sIbmission to the Regional Transport Commissioners. In the other article he draws attention to a subject which deserves immediate entry on the agenda of area committee meetings—the assessment of fair profits on a haulage enterprise.
There is urgent need for immediate agreements as to what does constitute a real yet fair and legitimate percentage of profit. There are two aspects Of the subject. First, hauliers themselves are, in general, hazy on the matter, as might be expected, seeing that so few are aware of their costs, let alone the ratio of profit which they are earning. Secondly, there is undoubtedly a good deal of loose thinking in official quarters. What is not appreciated is 'that there is no parallel, but, indeed, a vast difference, between a haulage business and others. It comes somewhere midway between a trade and a profession; at any rate, in this way, that it is unfair to take, as a basis of comparison, a profit on turnover which would satisfy a shopkeeper or similar business man. That this is so, that it is essential that the profit from a haulage business must be more than that which is adequate for most other trades, is clearly shown, and figures for the profit are set out in the article. Even if the reader does not accept the figures, they do at least afford reasonable basis for discussion. The arguments in favour of the distinction between a haulage business and others are unanswerable.