No drawbar drawbacks
Page 18
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IN REPLY to Mr M. Spencer (CM, June 13) on the Fruehauf GLZ rigid/drawbar outfit, he, like a lot of people on their first viewing, has become confused, because it has a single pivot point at the turntable only.
Therefore, in reverse it can to go 900 tothe left and the right before it stops, also an acoustic warning device sounds in the cab at this point.
The point that is not generally grasped is that the Ackermann steering is a separate entity and is normally only active when the GLZ is moving forwards. Its selfsteering caster action improves the timing circle and when exceeding 35km/h its caster action locks automatically via an electro-pneumatic valve improving both stability and braking.
When reversing, the caster is locked up by remote control via a press-button in the cab. At all times the turntable is free to pivot.
One of the reasons for the drawbar extending is to allow it to be used as a conventional trailer with other rigids giving, as Mr Spencer described, "ordinary two-pivot geometry with its attendant awkwardness". PRESTON C. ALLEN Sales manager Crane Fruehauf Hayes, Middlesex