Peter W Jones MInstP
.
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University of Bath
School of Mechanical Engineering
THE DYNAMICS OF TOWEDVEHICLES
An experimental study into caravan snakingFinal year project
submitted by Christopher J Killer
for the degree of MEng
of the University of Bath
23 May 2003
Assessor RFN
Supervisor JD
Technician PC
*******************************************************************11 Conclusion
********************************************************************************************The performance of the Alko 2004 tow ball friction damper has been shown to be
very effective at smoothing down snaking oscillations and reducing settling time. But this does not necessarily mean that it makes the coupled combination any safer, i.e. increase the snaking speed. Theory states that this type of damping has little effect on the snaking speed, and tests have shown no evidence to suggest otherwise.
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11.1 Practical advice for caravan owners & designers
Nothing fundamentally new was discovered in this study, but theoretical factorssuggested in the past have been substantiated by road-tested evidence. The
theoretical advice that is now known to be significant in increasing stability includes
the following points.
For owners:
• Make sure car is suitable for the size of caravan
• Load heaviest items in the car if possible
• Locate other heavy items in the centre of the caravan, just forward of its axle
• Make sure tow ball load is adequately high
• Avoid sharp steer inputs at high speed
• Never exceed 60mph
for designers:
• Put the heaviest parts of the caravan, e.g. kitchen, in the centre
• Consider the distance h between the C.G. and the axle, and its significance in
terms of stability
• Calculate the new stability coefficient (incorporating h) for each design
and although not tested in this study, other recommendations from mathematicalanalysis include:
• Make distance from tow hook to axle as long as possible
• Move back the C.G. so as not to induce excessive tow ball load
• Maintain a high tyre pressure to keep lateral stiffness high
