I recently came across the following extracts, in an old book titled 'Muck Shifting for King George', about a small band of plant equipment operators who had to make a retreat to Dunkirk along with their machinery. As you can see from the attached items it mentions that they had to go through a tunnel at Cassel. Now having visited the area a number of times I can only presume that they mean the very short entrance gates at the north and south of Cassel? Has anyone else come across this story before? Perhaps from the people mentioned within the text others may be able to shed even more light, along with some pictures?