Road-rail mower vacuum truck.
Fullsize image: https://s3-us-west-1.amazonaws.com/h...r_fullsize.jpg
https://s3-us-west-1.amazonaws.com/h...il_cleaner.jpg
Previously:
https://www.homemadetools.net/forum/...917#post119761
https://www.homemadetools.net/forum/...488#post131989
https://www.homemadetools.net/forum/...710#post108194
https://www.homemadetools.net/forum/...097#post138108
https://www.homemadetools.net/forum/...075#post134237
https://www.homemadetools.net/forum/...613#post166933