How long a caravan can I get behind my house?

This paper describes how a seemingly simple request from a reader of a magazine for caravan users led to an intriguing mathematical challenge in optimization. The problem was to find the longest trailer caravan that could be moved around a Z-bend bordered by walls. If one treats the caravan as a free moving block, an upper limit on its size may be obtained. The problem constraints become more important when the motion of the caravan is treated with greater realism, and a spreadsheet simulation is used to search for the optimum. This improved model appears to be far more restrictive on the length, but it is hard to demonstrate that it is optimal.