Although D series were often configured as water tenders, as well as a wide array of specials, relatively few were built as pump escapes or water tender escapes.
This example seems to have a rear mounted pump with side plumbing and controls, but these are behind a roller shutter locker, which is rather unusual. By the date this was built, this configuration was quite popular, but enclosing everything was not.
Added by Rob Johnson on 17 May 2020.