Heed the Americans...
Page 84
If you've noticed an error in this article please click here to report it so we can fix it.
HAVING JUST read your report on the second IRTE national conference, I am amazed to hear that neither Mr. Edbrooke nor Mr. Farrow can see the reasoning behind the American idea of applying little or no braking effort to the front wheels of tractive units.
Surely it is generally accepted that a freely rotating wheel cannot promote a skid, other than side-slip, which is rare with large section tyres.
The technique employed by many artic drivers, the writer included, as applied to vehicles with two-line air systems, is to use the hand-reaction valve when braking on slippery surfaces, keeping in a fairly high gear, and keeping a little throttle open, so that one is in fact still pulling the trailer as the outfit is slowing down.
Since we have had new vehicles with three-line braking, nobody ever uses the "deadman" for fear of locking the front wheels of the unit, so apart from its emergency properties, the third-line system is really wasted effort, and of course it is not possible partially to brake the trailer and pull it straight if it does start to come round, or slide down on a camber.
Any system which relies heavily on valves and complication in general, while it may be ideal in theory, is extremely unlikely to remain in adjustment for long; indeed, I know of one firm who had to disconnect all the load-sensing valves on their heavy artics, because front brake linings were wearing away in a matter of weeks, and the rears were doing nothing when running light, quite apart from the danger of front-wheel locking, which is one of the most unpleasant phenomena one can experience with a heavy, and one which can put a vehicle in the ditch before the driver can remove his foot from the brake.
The Americans have had a great deal more experience of articulation over a much longer period, than we have had in Europe, and personally, as an attic driver of many years' experience, I would be more inclined to listen to the ideas of American hauliers, evolved over millions of miles of interstate trunking in every conceivable weather condition, than trust my life to the theories of some of the learned gentlemen whose papers I so often read in the COMMERCIAL MOTOR.
E.G. CORKE, Ealing, London, W13