Fort Purbrook - Tunnel No3

 Created 06-03-2004    Last update 08-08-2004

During February 2004 a work party was clearing scrub from the north ditch of Fort Purbrook. As they stripped away Ivy growing on the counterscarp an opening best described as a cavern was revealed. The purpose of this excavation was not known so it featured in the 'Legends and Mysteries' section of this website. The following ideas were put forward as to its origins:

  • a WWII dugout for the 3 Royal Signals Radio Operators

  • a practice countermine adit header from WWI

  • a store for the 100 yards rifle range located in the ditch

The mystery continued until August 2004 when it was suggested by Peter Cobb that I should seek out an article which had appeared in an (unknown) edition of the Palmerston Forts Society journal - REDAN - titled "Fort Purbrook - 1940/41". I contacted David Moore, the copyright holder, with this very vague request asking for an electronic copy of text. What happened next is best described by David's reply: 

Hi Bob
Phew, that took a bit of ingenuity. It dates back to 1991 when I was using a now defunct early Acorn computer and had compressed the files using an obsolete piece of compression software to save space. But... here it is!
Attached as a PDF.

The article in the REDAN is an extract from the memoirs of a soldier, Mr AF Izett, who died of cancer in 1989. In 1940 he was in the 65th Chemical Warfare Company, 11th Chemical Warfare Training Battalion at Figsbury Camp, Winterbourne Dauntsey, near Salisbury. On 13 June 1940 he was moved to Cosham Portsmouth and billeted with civilians. Fort Purbrook was requisitioned for an equipment store and operational base.  

There were several miners from the Rhonda Valley in the Company and the Officer Commanding decided to put these men to good use by having them dig a tunnel (no3 tunnel) in the counterscarp (the outer bank of the ditch surrounding the fort) to create an Observation Post (O.P.). Mr Izett suggested that a railway for the spoil be made using pipe as rails and took the pulleys from the ready-use ammunition stores of the fort's gun sites. The Company's Blacksmith made a truck and the track was pipe spiked to wooden sleepers. The tunnel was dug and the O.P. built all from within with only a slot for vision visible from the outside.

 Contributors: Peter Cobb, David Moore

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Plan of Fort Purbrook

Lower plan of Fort Purbrook with the arrow showing the location of tunnel No3.

Cavern location

The north ditch of Fort Purbrook looking east. The location of the Observation Post in the counterscarp (centre left) can be seen in relation to the north east Caponier where tunnel no 1 is located.

opening in the counterscarp

The partly blocked opening in the counterscarp. The Observation Post was constructed in such a way that only an observation slot was visible from the outside. It is not known how access to the O.P. was achieved.

inside the cavern

A cut has been made in the 4 feet thick counterscarp brickwork and then has proceeded into the chalk to a distance of some 15 feet. The tunnel has been partly backfilled at a later date with a surprisingly wide date-range of objects - from an original fort ventilation grille to plastic bottles. 

insdie the cavern

This close up shows that the back-filling is present up to the roof which made me suspect that this tunnel may go further back into the chalk. On removing some of the backfill however a dead-end was found. The back of the tunnel narrows to 1 foot across and further mining would have be impractical.