In Your Opinion
Page 57
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Compulsory Anti-jack-knife Devices?
I SELDOM read an article more than once, but I did read those on artic braking in the July 22 issue several times.
The one by A. J. P. Wilding was of special interest, and to those who pin their faith on any one system of brakes I commend his last paragraph, especially the final line, in the article. It is for this very reason that I have proposed, through the appropriate road safety committees, the compulsory fitting of an anti-jack-knife device.
One basic fact so frequently overlooked is that in a variety of conditions, for which the braking system is not necessarily responsible, harsh brake application can cause a jack-knife.
The only way to meet these variables, therefore, is to incorporate a device which is also actuated by the brakes to counter any tendency for the outfit to become misaligned, and since the only component which is itself unaffected by the variables is the trailer kingpin; it is logical that this should be the medium by which the counter measure is applied. Without any intention of showing favour this requisite restricts the choice to one such device.
It is interesting to note that some criticism of this device has been made by drivers on the ground that it stiffens the steering. Any driver making such an allegation is convicted out of his own mouth for entering a roundabout or bend too fast and making a panic brake application while turning.
The fact that so many artics overturn on roundabouts proves that excessive speed is the cause, and in my borough further proof is provided by the fact that this has happened only on the east-bound carriageway following a downhill section. Also, they always overturn at the same point on the roundabout because this is where centrifugal force takes charge.
Thus the fitting of the device has the further advantage of encouraging drivers to brake on the straight and reduce speed before the hazard. No doubt these points are made by the York Trailer Co, Ltd. in its splendid plan to run a course of instruction for wide drivers, which should be compulsory anyway.
In view of the complications so well put by Mr. Wilding, plus the variables to which I referred in my previous letter, I would hate to be a new artic driver in a mixed fleet, and it would seem sensible to have a notice in every cab indicating at least the type of secondary system in use, whether the main system incorporates a light laden valve, and sundry other information. • Alternatively, if the trailers are known to be fitted with an antijack-knife device the driver knows that whatever else can happen, the outfit will at least maintain alignment.
It is not fair to expect any driver, least of all the fresh and young men in the industry, to know all that is involved, and the fact that the manufacturers cannot agree on a standardized brake system confirms that braking alone is not sufficient to prevent jack-knifing. If it is, will someone openly guarantee this? Because I and, I am sure, every driver are anxious to know.
R. B. DANIELL, Road Safety Officer, London Borough of Ealing.
Steering Device for Jack-knifing
I WOULD like to give my non-expert opinion on the subject of jack-knifing of articulated vehicles. It would appear that once the trailer has started to jack-knife it is already too late to apply the brakes, which surely only aggravates the situation. If the trailer could be prevented from ever starting to jack-knife it would help a lot in preventing accidents.
Consequently I invented and patented a device controlled by the steering rather than the brakes. Briefly, it consists of two interconnected hydraulic rams placed between the tractor and trailer. The steering wheel operates a valve which is closed in the straightahead position, the tractor and trailer then being virtually rigid. As the steering wheel is turned, the valve is progressively opened, which allows one ram to expand and the other to contract, and consequently the trailer pivots.
I do not suggest that this will entirely eliminate jack-knifing, hut then neither does any other device. I am now writing to various manufacturers of tractive units, and Armstrong Hydraulics, of Beverley, have already shown some interest in the device.
M. SANDERSON, Cottingham, Yorks.
'Not a True Picture' . WE HAVE just seen your brief notice about our activities in the July 22 edition of COMMERCIAL MOTOR and feel that it does not by any means present a true picture, as primarily the reason for ceasing manufacture as Reall Coachbuilders Ltd. was persistent and acute labour shortage.
Reall Designs Ltd. are continuing as consultants, and our association with the Eagle Engineering Co. Ltd., of Warwick, and Always Welding Ltd., of Aldershot, is not merely to take over existing commitments but to handle future new business initiated by Reall Designs Ltd., and a good deal of this is already in hand.
W. H. MALTBY, director, Reall Coachbuilders Ltd.
A World Beater?
I IMAGINE that The Hawk's story on "That Elusive Bus" in the July 1 issue was taken from a report I made to an enthusiasts' magazine to which I had supplied information on the exterior of the vehicle. I had seen it tucked away in the experimental depot of AEC, and not Park Royal, as an item during an "open day" Saturday morning visit to the Southall factory in late May and unfortunately could see only the outside of the bus.
During that visit workmen were also busy on "the line" manu facturing a new V8 engine, as yet unannounced. The engines were the first production run and were for stockpiling ready for the announcement. There was a lot of confidence among the men in the quality of the product they were making.
Apparently this engine had been developed at Southall and in competition trials with a Leyland-developed similar unit had won handsomely. A severe cost analysis followed for producing engines at Southall rather than at Leyland, and again the former factory won—if that is the correct word to use.
Extensive reorganization of production and labour facilities at the factory followed to provide space for what everyone concerned thinks is a "world beater". The initial production run of engines got under way only to stop completely at the recent LMC reorganization, the outcome of which was the shifting of this engine and key staff concerned in its development to Leyland. This is a bitter blow to the men at shop-floor level, who feel that AEC will not be identified with the development work and that the name of their company, in which they feel a measure of pride, will be identified only as badge engineering in the future.
They are quite rightly concerned at their (AEC's and their own; future within the Leyland group, particularly as at the time of thc merger it was stated that the two companies would retain identitie5 and remain competitive in the home market, the benefit to come ir rationalizing research, development and exports marketing.
All this seemed fair enough, but so far the "rationalizing" ha: involved the steady eroding of the AEC name and product. Witnes: the Ergomatic cab of the group, the demise of the Renown and no the disappearance of the V8 to Lancashire.
P. DAVIDSON, Blackwater, Hants