A truck recently drove under my local railway bridge, it managed to get about half way when it became stuck fast.
It was too tall, 12 foot and 1 inch to be precise. The bridge was exactly 12 foot high.
The truck driver was most unhappy as his monthly bonus was stake. He tried to move backwards and then forwards, but to no avail.
Eventually a clever old soul had a marvellous idea to release the stricken truck. What was his idea?