A few suggestions were that it has something to do with coal trucks/trains, possibly a prison cell? I don't know..... any info is appreciated

http://img38.imageshack.us/img38/821/cimg7919.jpg
http://img842.imageshack.us/img842/6802/cimg7920.jpg
http://img21.imageshack.us/img21/3476/cimg7922t.jpg
Thanks
