The first element. A truckwash.
I used to install these in a former life. Trucks would drive through them and water would squirt up to wash the mud/ coal dust/ iron ore dust/ shit* from the underside of the trucks. When I say "water squirts" I mean 3000-5000 litres/minute. Designing one to wash 100 Ton Haulpaks was an interesting exercise. Imagine a Supersoaker that could shoot an 80mm wide stream at a target 50 metres away, with minimal spreadage.
*we installed one at a effuent treatment plant. That was the first time I had to wash my hands before I went to the toilet.