What's this?

Does anyone know what this is? It's located on the eastern side of what was Wrotham Camp which was a pre-OCTU training unit. The chap who showed me the rest of the camp (nissen hut bases, water tower, etc) would like to know as well.

Thanks, Lee

 

well they look like clay gullies. some kind of grease/oil interceptors??

 

Could be, the two horizontal clay collars have inserts to take smaller gauge pipe ,from sink? or as it seems it was once a brick build structure may be smaller pipe from washbasin with toilets beyond.
Only thing against that vertical pipes seem to have had something attached with screws.

 

Probably sewage system from a toilet block.