Overhung Caravan Hitches - updated June 2019

When a side force hits a trailer attached by a hitch that is NOT overhung (top), there is NO consequential side force on the tow vehicle. When a side force affects a trailer with an overhung hitch (bottom), the resultant side forces on the tow vehicle are material
When a side force hits a trailer attached by a hitch that is NOT overhung (top), there is NO consequential side force on the tow vehicle. When a side force affects a trailer with an overhung hitch (bottom), the resultant side forces on the tow vehicle are material

Conventional caravans and camper trailers are towed via an overhung hitch attached to the extreme rear of the tow vehicle.

This overhung caravan hitch transfers the necessary nose weight of the caravan to the rear of its tow vehicle. This overhung caravan hitch is also subject to strong side forces due to the caravan yawing (swaying sideways). As the caravan yaws clockwise, that overhung hitch forces the tow vehicle to yaw anticlockwise - and vice versa. The greater that caravan hitch overhang, the worse the effect. It is undesirable at low levels and increasingly dangerous at high levels, particularly at high speeds.  

Described in Why Caravans Roll Over this interaction can escalate to a 'chaotic' jack-knife, 'fuelled' by the rig's critical momentum (e.g. effect of its weight and speed).

It is essential that the tow vehicle be steerable only by its driver at all times. But that overhung hitch can literally steer the tow vehicle out of line (by distorting its rear tyre's slip angles) - and overwhelming the rig.

Never use a tow hitch that extends that overhang. Safety is  more important than a minor easing of coupling and uncoupling. 

Overhung hitches are used for caravans and camper trailers because typical tow vehicles are used also for other than towing.

The adverse effects of an overhung hitch can be reduced, but never eliminated. The only truly stable caravan is the fifth-wheeler - that has the hitch directly above the tow vehicle's rear axle.

 A full explanation is in our Why Caravans Rollover - and how to prevent it . This book explains just why rollovers happen. It enables you to estimate the stability of your own rig - and how to improve its stability. That's good value for $19.95!



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