Unknown Lincolnshire Structure

We were contacted by a member of the public to the location of this underground structure and after seeking permission from the landowner we attended to carry out a full report. It is a little strange to say the least, with its steel lined shaft, hooks hanging from virtually everywhere and that the structure is very small. No Aux Unit can be attributed to this bunker except that of Kirmington, however we feel that it could be a either a Ammunition/Explosive Store or a Forward Operating base for observing the Airfield whch is now Humberside Airport.