Suspensions for bulk vehicles
Page 44
If you've noticed an error in this article please click here to report it so we can fix it.
With reference to Mr Trevor Longcroft's statements in Commercial Motor, February 2, regarding suspensions for bulk vehicles. In view of my involvement in this field. I feel it necessary to make certain comments of my own.
Mr Longcroft states "The ultimate from a ride point of view is the air supsension''. Is this the view of the operator or the manufacturer, because this does not comply with reports received from operators of our tandem units?
We use an equalizing beam, and as most of us have at some time in our lives ridden a seesaw, we are aware that it is impossible for a person to bump his end on the ground without immediately sharing that bump with the partner at the other end. This is how an equalizing beam functions. It must also be remembered that whatever the height of the obstacle met by either of the axles, the lift on the frame is only half that height. •
I am rather at a loss to understand Mr Longcroft's views on the air supsensions because, as he states, the air bags are interconnected by air pipes, but as these pipes are only approximately kin. diameter, I fail to see how, when a vehicle is running at normal speeds over varying road conditions, or meeting with obstructions such as kerb stones, these small connecting pipes can transfer air from one bag to its opposite number, which may have diameters of 10in. or more, without compressing the air, and consequently passing son-le of that shock load directly to the frame in that area. Should this be possible, why fit a suspension, why not interconnect the tyres through the levelling valves from the air reservoir, and use these as the suspension medium?
I have one further comment regarding the statement of the " NOR DE" load capacity being 18 tons. They should read as follows:–
Single axle UK regulations : 10 tons.
Tandem equalizing beam type 4ft 1in. : 18 tons Aft bin. : 18.5 tons 5ft Oin. : 19.0 tons Wide spread 20.0 tons RON WRAGG, Inventor of "NORDE", North Derbyshire Engineering Co Ltd, Matlock, Derbys