Mystery Colchester Bunker

In 2010, Catherine Pearson published EJ Rudsdale’s Journals of Wartime Colchester (ISBN 978 0 7524 5821 2), the account of a museum curator, air raid warden and “War Ag” inspector in Colchester in World War Two. Having grown up in Colchester, I received a copy as a Christmas present and was immediately drawn to the accounts in April 1941, relating to his view of events in Colchester’s Castle Park from his office in Hollytrees House [my explanatory notes in brackets];

April 8th
Hull went down the Park today with two Army officers and Inspector Barricoat of the police, to examine Duncan's Gate to see if a safe, secret hiding place can be found do Army purposes, I suspect for a secret wireless transmitter to be used in case the town falls into enemy hands.

April 21st
“Work began today on the ‘secret’ dug out at the North Eastern Postern. This has been arranged in a blaze of ‘secrecy’. First Hull [Curator of Colchester Castle Museum] walked up and down the field on several days with Inspector Barricoat and Army Officers. Then it was decided that the men doing the actual work should be disguised. The result is that four men arrived today ‘disguised’ in blue ARP dungarees but, unfortunately, they were brought into the Park in a large Army lorry, which rather gave the game away.”

Then there were additional details noted in 1944

May 23
Called to see Poulter [Curator of Hollytrees Museum in Castle Park]. He told me that there had been an amusing set-to about the 'secret' place at the North-Eastern Postern [also known as Duncan’s Gate]. Duncan Clark [a member of the Museum Committee] had brought up the matter of repairs to the Roman Gate fabric and Poulter told him that nothing could be done there owing to the existence of the 'secret chamber'. Duncan Clark calmly brings this forward in the Museum Committee today and after much enquiry found an officer in the garrison who knew about it. He, poor man, is now shaken to the roots to find that his 'secret' is known to dozens of people and is, in fact, no secret at all. Apparently the real purpose of the place is as a store of explosives, to be used by 'saboteurs' Colchester has been occupied by the Germans. The Army were going to leave some picked men behind to do this work. The fact that each subsequent explosion would result in the summary execution of several of the inhabitants of the town would worry no one (except the persons executed).

Sept 21
Poulter told me with much laughing that the famous secret place which the Army dug 3 years ago by Duncan's Gate had been found , broken into and some hand-grenades stolen.
Poulter told the police, who had forgotten all about the place, and they told the Army, who had never heard of it - the people who dug it and stocked it with explosives having long since disappeared. Apparently it was full of bombs and ammunition, to be used by saboteurs after the Germans had occupied the town but nobody knows how much there was, nor how much is stolen. A heap of Army blankets shows that somebody has been sleeping there.

I had heard rumours of an underground in Castle Park since the mid 1990s, so this seemed to confirm things. I made contact with the editor, Catherine Pearson, just in time to be invited on a visit to Castle Park in Colchester in May 2011, accompanied by staff from Colchester Castle museum and Fred Nash, Essex County Council’s Military Archaeologist. It had been thought that the bunker had been discovered, but the truth was even more complicated. Catherine was also able to provide some additional excerpts that hadn’t made the final cut of the book.

April 8th
Hull mentioned this to me some time ago.

April 16th
Hull went down to Duncan’s Gate again today, with two officers and two soldiers. There is certainly some plot being hatched down there. I only hope it will not involve damage to either the Gate or the [Roman] Drain.

April 21st
I have known for some time that Hull had been consulted as to the whereabouts of a “very safe place”, in which a certain amount of material could be kept, and from which “two men could get in and out”, after the Germans have occupied the town. Hull has given them the Gate, to do as they like with, alter or change as suitable for their purpose. If I see the slightest damage to any of the original work I shall send a telegram to the Office of Works.

1944
May 23rd
Duncan Clark calmly brings this forward in Committee today, and wants to know whether or not the military paid any acknowledgement for this place? This was taken up with the Claims people, who denied all knowledge of the place, and it was only after much enquiry that it was found that only one officer in the whole garrison knew about it.

View inside the surviving structure looking back to entrance ladder.

The Northeast Postern gate (also know as Duncan’s gate) is one of the gates through the Roman walls surrounding Colchester and lies halfway down the hill from the Castle to the River Colne, which was a fortified defence line during the war. Pillboxes and concrete anti-tank obstacles remain in the Park today. The gate has been sealed since before the war by metal railings and this corner is sealed off from the public areas of the Park. With official permission we were able to enter this area and explore what remained. There certainly was an underground bunker and it even seemed to have an escape tunnel, but the answer came from EJ Rudsdale himself. Before the war, the gateway had been the subject of an extensive archaeological excavation, with the excavations being photographed at the time. Rudsdale had been passionate to ensure they were preserved for display. Of particular note was a Roman drain, with a precisely constructed brick arch roof. Rudsdale helped ensure that in 1929 a viewing chamber was constructed in order to display the remains, and tours were organised to explain the findings. This was a concrete rectangle, centred along the drain, which can be see leaving one end of the chamber. Once upon a time this would have drained down to the river, but the end is now bricked up. The chamber was roofed with metal grilles to allow viewing inside. The museum has photos of this in place prior to the war.

Not a Roman escape tunnel! The concrete slabs on the top of the narrow Roman brick walls had been arranged by Rudsdale after initial suggestions the drain be demolished. The original Roman arch can be seen further into the tunnel.

The initial photos had certainly looked very much like an OB – concrete rectangular walls, and a long tunnel exiting downhill, the far side of the Roman walls and out of view – but this obviously wasn’t one, given the open roof! However, it is important to remember that EJ Rudsdale had taken part in the excavations and was passionate about the preservation of the ruins and instrumental in the construction of this viewing chamber. He knew exactly where and what the currently surviving structure was, but was talking about something new and different. Fred Nash had brought along an extract from the “contraventions” list, drawn up at the end of the war to plan the destruction or disposal of wartime works that were no longer required. This listed an “ammunition dump” in the approximate location we were investigating. This would be a reasonable explanation, but it seems unlikely that this would have been buried in a public location, not given the large number of existing stores spread around Colchester. Nor would it explain Rudsdale’s description. He gives a contemporary and extremely accurate description of an Auxiliary Units Patrol, even down to the Intelligence Officer, not immediately to be found (because he was based in Earls Colne). Reading carefully what Rudsdale wrote, he talks about the structure being dug on more than one occasion, indicating that was additional to the structure over the drain.

Duncans Gate as it appears today. The 1920s excavation photos show that these ruins were dug out to the height of a man, leaving plenty space to bury a hidden structure.

It seems likely that there was an Auxiliary Units structure built here, possibly just a small ammunition store (of Anderson shelter size), but possibly a larger OB. It is likely that this was near to the surviving structure and used the age old principle of hiding things in plain site – why look for a hidden underground bunker when there is an obvious one staring you in the face. It seems that this was not a Special Duties outstation, which remarkably Rudsdale also seemed familiar with, perhaps from one of the farms he had visited, given the presence of explosives and ammunition. It seems likely that the structure was completely removed at the end of the war, in order to restore the historic monument to its former condition. At the time, the thought that the structure might itself be considered a historic monument probably never occurred. Thanks to this journal, we are left with a rare contemporary account of the construction of an Auxiliary Units structure, complete with disguise. What is interesting to note is that the senior Police Officer was aware of the location as was a member of the museum staff, a surprising degree of compromise for the Patrol. It is also unlikely that they would have been involved for a simple regular Army ammunition store.

Colchester was home to several Auxiliary Units Patrols, as was the surrounding area. However, we don’t have any details to link this structure to one Patrol in particular, though perhaps the best candidate would be the Patrol largely made up of men from Paxman’s works, which was within walking distance. We would be pleased to hear from anyone with additional information about this structure or the men involved. Presumably its removal would have been a far more open process than its construction. Examination of Duncan’s Gate today reveals no sign of any structure or where it may have been. But then the diary indicates that there were plans to restore the fabric of the gate by 1944, so it probably disappeared soon after the end of the war.