My phone rang one day last March. I didn’t seem to recognize the number. These days, I tend to communicate via email, social media and a multitude of internet messengers, so receiving a direct call is a bit unexpected. And when I do, it’s usually wrong numbers, cold automated calls, or bad news…
But I was soon delighted to find out it was none of that – at all. The caller was Mr Miles Gillman of Northwood, a Friend of Ruislip Woods and trustee of the Ruislip Woods Trust. Having just read through a recent article of mine about the Battle of Britain House that went out with the RWT Newsletter, he went on to congratulate me about the write, and the renewed interest it has sparked over the history of the ruined mansion in Ruislip Woods. He also seemed eager to share his own experience of the site, as well as a very interesting theory about the mansion : for he had reasons to suspect that an underground Cold War bunker may have existed nearby.
“Will you show me?!” I asked, instantly hooked on the prospect of peeling back more layers of the history of the mansion. We promptly set up a meetup at the woods for late April.

The meetup
I met Mr Gillman, Miles, at the mansion’s steps on a sunny Saturday morning. He was in great spirits, and happy to be back to Ruislip Woods after quite some time. I was equally delighted with the opportunity to meet him and record his story. I was in for a treat !
We proceeded to a clearing next to the mansion and its car park. It is an area as big as an average garden, and reasonably flat. Miles remembers the existence of a hut there : he describes it as a cabin with a lower and an upper level, and perhaps a balcony. I am instantly reminded of the Annexe, an outhouse which used to accommodate the students, au-pairs and other guests that lodged at the Battle of Britain House :
“There still remained another newer building in the grounds which had been used as a
Colin Bowlt
dormitory and not touched by the fire, but in spite of being boarded up it was eventuallyvandalised and had to be demolished”
Ruislip, Northwood & Eastcote Local History Society 2011 Journal

This Annexe was clearly a later building, possibly post-war. It would have been erected during a time when the mansion was transitioning to its new utility as a residential college. And then Miles dropped a proverbial bomb : he maintains that the Annexe might have been a cover for a Cold-War era ROTOR Station.
ROTOR and the Cold War
A few words about ROTOR (which as far as I’m aware is a code name, rather than an acronym). In the early days of the Cold war, one of the the greatest threats posed to Britain was from Soviet bombers performing a potential sneak nuclear attack. The Soviets had acquired U.S. long range bomber technology since 1945, when on four separate occasions, B-29 Superfortress bombers crash landed in Siberia on their return from bombing raids over Japan. The Soviets surveyed the wrecks and proceeded to reverse engineer an exact clone of the B29 into what would become their own Tupolev Tu-4 in 1947. By 1951, the Soviets had also being successful in detonating an air dropped nuclear device, code named RDS-3. It was nearly 3 times as powerful as the Hiroshima bomb.


This was the threat the ROTOR system was meant to counter. It utilized elements of the existing Chain Home early warning system, consolidated and upgraded with the latest Radar technology, a new command and communications structure, and all new, nuclear bomb-proof installations that comprised an underground bunker with a distinctive bungalow on top to serve as living quarters for the operators. The ROTOR bunker hut’s design was very distinctive, probably the outcome of a common blueprint.


There certainly are differences and similarities here, but it’s difficult to establish a match as the Ruslip Woods hut is now long gone. What remains, however, is the wide flat area where the Annexe once stood, which still remains mysteriously clear from the large trees and thick foliage of the area immediately surrounding it. So could there be something underneath?
It’s difficult to tell. Miles has visited the site a number of times with friends from Subterranea Brittanica , a well known project that have been charting Britain’s underground heritage for decades. They also speculate that the Annexe may have resembled a typical ROTOR hut. Yet there should have been other visible clues, like ventilation shafts or solid bases for Radar dishes and other above ground elements – but there are none visible. Although maybe these are still around, somewhere out of sight. Or maybe they have been removed, or covered by nature over the years.

Today, the location of every ROTOR site in Britain is public domain, but as you might expect, Ruislip Woods doesn’t feature. So was there ever anything there, after all? Miles suggests that metal detectors or a ground penetrating radar might be the only way to answer that question. And I have some eyebrow-raising questions of my own. For someone has told me in confidence how there has been top secret training taking place at the Battle of Britain House well into the 60s, and it had to do with radar technology… And another testimony has emerged, vividly describing the gruff looking military men who attended courses at the mansion during the same period… I will be relating these stories in detail on future posts. All will be revealed !
In the end, the post-war technology race saw the Soviets and the Western Allies constantly vying to top each other. Faster, jet powered nuclear bombers were being built, prompting the need for earlier warning and better radars to upgrade ROTOR with. By 1959 the Soviets had successfully launched their first intercontinental ballistic missile, soon to be armed with nuclear weapons. This new technology, and the proliferation of nuclear armed missiles that came with it changed the strategic defense outlook dramatically. There was no point in maintaining a complex system to warn about a bomber – or ten – entering one’s airspace. If there was an attack, the Soviets would do well to throw everything at it, every bomber and every missile, eventually overwhelming the defenses. So the new doctrine aimed to detect missiles at launch, and hopefully prompt an immediate retaliatory response within the 15 to 25 minutes it’d take for the Soviet blow to land. So in the 60s, the ROTOR system was abandoned in favour of airborne and over-the-horizon radar systems that could detect a missile launch thousands of miles away.
The Ice House
We now found ourselves walking along the old driveway towards the Ducks Hill road gatehouse, talking excitedly about rumours and possibilities. I felt compelled to ask Miles whether he might know what those mysterious stone walls built against and earth bank were, so close to the old gatehouse and driveway? He believes those are the remains of an Ice House that may have existed here. (I regret that for all the times I’ve seen the remains of those stone walls, I couldn’t find a single picture in my collection – but I promise I will as soon as I visit the site again).

Before the invention of refrigeration, people depended on ice houses to preserve perishables. Those were underground stone or brick chambers packed with ice brought in from frozen lakes or rivers in the winter, or sometimes imported from as far as Scandinavia. The thick walls of the structure coupled with the lower underground temperature meant that ice could last from winter to winter before it needed replenishment, providing businesses and important households with adequate refrigeration all year around. There are still many surviving examples in the UK.

So could these indeed the remains of an Ice House? Perhaps. The mansion was a stately home, and a farmhouse before that. Ruislip Woods were famed for the game that could once be hunted there, particularly pheasants, that may have been hunted there up to the 1930’s. So it is possible that a cold storage might have once existed, at least until there wasn’t a need for one anymore. At any case, it is great to finally have a working theory about the mysterious stone wall next to the driveway.

The Shooting Range
Our next stop is the part of the woods adjacent to the Battle of Britain House, roughly between the ruin and Poor’s Field. Soon, we come across a sizable horseshoe-shaped mound. It looks like what it might have been : a firing range for the agents who trained in Ruislip Woods during the war.

I’d seen photos of it through the years, but never got to see it in person before today. And it is surprising that I’ve missed it, having unknowingly walked next to it several times ! Firearms training would have been integral to the agents’ preparation for para-dropping into enemy territory. Their weapons of choice would be the British Sten gun or its US counterpart M3 (often referred to as the Grease Gun). Miles showed me one of the spent cartridge cases that have been found in the vicinity of the range.

It is an amazing find that demonstrates the possible use of this area for discharging firearms. I’ve read that metal detectorists have found a fake hand grenade that would have been used for throw training in the same vicinity a few years back.

I am not an expert, but at first glance it looks like a rimmed cartridge case (meaning without a characteristic flange around its base). This fact might limit the search for the weapon type drastically, but corrosion didn’t help in this case, since the cap markings are totally illegible. If you know of an expert who can identify the cartridge case, please do ask them to get in touch.
The Pumping House
And there were yet more discoveries to be made. In the near distance, past a picture-perfect bluebell clearing, I could see the outline of a brick structure. Getting closer, it was evident that this wasn’t a living space : it looked rather like a workshop or machine room. Miles believes that this used to be a Pumping House, possibly to mechanically draw water from a nearby source.

And there is mention of such a venture in local history groups – one that has led to misadventure, so to speak. In 1942, the Colne Valley Water Company (the precursor to Three Valleys Water) committed to establish a water well in this part of the woods. The drilling was successful, but didn’t yield the expected amount of water. Towards the end of the war, it was decided to bore an additional tunnel which roughly followed the contour of the Northern side of the Ruislip Lido reservoir into Poor’s Field. A pumping station was built to aid in the extraction of water from the well.

However, the water yield from the well remained unsatisfactory, despite the mechanical aid. And to make things worse, mysterious swallow holes began appearing close to the Ruislip Lido. According to geologists, these dangerous holes were a result of the collapse of the layers of chalk under Poor’s Field. There were 6 or more such collapses between 1944 and the early 1960s’, all in connection to the operation of the well and the changes it brought about to the geology of the woods. That fact and the low yield eventually led to the well being abandoned.

Today, the abandoned pumping station is testament to this failed effort to extract water at Ruislip Woods. It is an interesting ruin, especially once one becomes aware of what it represents. It is quite possible that the underground opening may lead to a tunnel under Poor’s Field – however I would absolutely not recommend trying to explore it. No-one knows what dangers may lie down there, not least the danger of collapse which I have already mentioned.
The way back
Our one-hour was up, and we started making our way back to the car park. But Miles Gillman’s storytelling didn’t abate. Inspired by the stories of bunkers and tunnels under the woods, we discussed about other local rumours and landmarks, such as the (now permanently closed) Pinner Chalk Mines as well as other known or suspected tunneling and mining efforts under our feet here in Hillingdon. It’ll suffice to say that some of us might have tunnels running under our gardens – about which we have no idea about ! It was a great discussion that certainly merits its own dedicated post and research.

As we went past the mansion on our way to the car park, Miles produced another interesting item : fragments of china recovered from the woods near the Battle of Britain House. These were probably part of a platter or dining plate, but otherwise difficult to tell how significant they were, or even whether these belonged to the crockery of Battle of Britain House. Miles remembers how in the days before recycling, it wasn’t uncommon for households to dispose of broken household items near their gardens. It is another interesting theory, and if it’s true, then there must be a potential treasure trove of fragments and other items close to where these were found! It’s yet another fascinating avenue of exploration that may yield more insights into the past of the ruined mansion at Ruislip Woods.

I am grateful to Mr Miles Gillman for being generous with his time, and for the interesting stories, artifacts and locations he shared.
For those interested in further detail, the story of the Ruislip Woods water well and pumping house has been described in great depth on the 1998 Ruislip, Northwood & Eascote Local Hisotry Society journal.