These tools are really tough

CP hydraulic submersibles are a range of rugged pumps for continuous pumping of water on building sites, in flooded excavations and cellars, and similar situations. Performance is impressive in relation to size and weight.

The 2 inch pump handles dirty water containing small stones and debris up to 10 mm.  The 3 inch CP submersible trash pump can handle rocks of up to 2½ inch diameter!

Cooled and lubricated by the hydraulic oil, they can be left to run dry without damage.