A Super Connected City below a City
The Kingsway Tunnels
A few years ago, I had the great good fortune to visit the Kingsway Tunnels. I recently learned that they are unlikely to be opened again for visitors so I thought I would resurrect an article I wrote some time ago for another blog.
I wish I could say it was a rare cold and wet day in July, but… Having left the office later than expected I was now rushing down the escalator at St Pancras International and across the road to grab the first cab. “Fulwood Place please.” “Yeah ‘op in.” In I ‘opped, relieved that I wasn’t going to be late as I would have been left standing at the door. “Look at this wevver… It’s getting on me nerves. I ’ope you ain’t come ‘ere expecting to get a sun tan!” My cab driver must have thought I had just got off of Eurostar. The weather didn’t bother me because I was heading for another world… or another city at least… underground.
I’ve walked past Fulwood Place more times than I can remember. I spent a lot of time in the Holborn area when I worked for Cable & Wireless and a previous business accountant of ours was based in Warwick Court only a one minute walk away. No matter how many times I passed by I would never have guessed where the steel door in this small alley would lead.
”Now I was handing over my signed site induction form… before passing through the door and back in time.”
Only two weeks before I was offered an opportunity by the Institute of Telecommunications Professionals (The ITP) to visit the Kingsway Tunnels. Having worked in similar tunnel complexes in the past I jumped at the chance. The Kingsway Tunnels are a significant part of telecommunications history for me having lived in London for the majority of my life and spent a lot of time working in London (as well as across the UK and well beyond). Now I was handing over my signed site induction form for health and safety compliance before passing through the door and back in time.
We headed down the first flight of concrete stairs to a lift lobby adjacent to what looked like a bottomless emergency escape shaft with a vertical ladder and queued for the lifts. After a quick descent in a small lift we were in the tunnels. I hadn’t been into a deep level tunnel for nearly 40 years but immediately recognised the atmosphere. The temperature is comfortable and stable all year round and the air quality is good, just as it was so many years before. As we assembled with our guide you could hear the constant loud rumble of tube trains passing overhead. They sounded so close they could have been in the same tunnels.
The tunnels were originally constructed in 1940 as an air-raid shelter for up to 8,000 people as well as providing a possible home for our Government in the event of a land invasion. The construction was completed in one year – anyone visiting the site will realise that was an incredible engineering achievement, especially with the frequent bombing raids at the time.
”The tunnels were… used by the Inter Services Research Bureau… think Q branch in James Bond!”
The tunnels were constructed by foreign workers who were not given any indication as to where they were working. This ensured the tunnels remained a secret. However, that doesn’t really fit with the original plans to use the tunnels as an air-raid shelter in my mind. The tunnels were never actually used as a shelter but towards the end of the war they were used by the Inter Services Research Bureau, part of the Special Operations Executive – think Q branch in James Bond! The tunnels then moved over to the Post Office who further developed them by adding larger tunnel sections. The tunnels then passed on to their current owner British Telecom.
The tunnels really were a self-contained, self-supporting, city below a city with power generators, backup power generators and air handling units, as well as a goods lift capable of carrying a 10 ton load. There was even an artesian well to maintain a water supply. As I walked around the tunnel complex I couldn’t help becoming more and more impressed at the scale of the construction. When I saw the generators I had many questions in my mind. The scale of the operation to get them in situ, the logistics of delivery and storage of fuel and then routing the exhaust 50m back to the surface.
”…just like getting out of a time machine back in the 1970s.”
The tunnels were well equipped to support the 200 staff that worked in the tunnels with a restaurant, bar and games room. The restaurant had windows with images of exotic beaches and mountain views to make the area appear less claustrophobic for the staff. The tunnels even had some bunk rooms for the MI5 operators and telecommunications engineers based in the tunnels. The tunnels had street names to aid navigation. However, I’m not convinced they would have been very effective when leaving the bar at closing time. At one point, we saw a stair case leading down to another area of the tunnels that is as yet uncharted by the current owners.
You rarely get the chance to step back into a building like this that was just, vacated. It is just like getting out of a time machine back in the 1970s. Many of the telephone exchanges I worked in had bars and social clubs and it was common to spend lunchtime in the bar having a few beers before going back to work for the afternoon. It was interesting seeing signs as you exit the Kingsway Tunnel bar warning customers to extinguish cigarettes, cigars and pipes when leaving the bar. Drinking and smoking at work – how times have changed!
When I joined the Post Office as a Telecommunications Technician Apprentice back in the early 70s, the UK was still entrenched in the Cold War. I knew very little about it but I knew it was a national threat with frequently changing alert levels. Part of my training including vivid government education films detailing the impact and implications of a nuclear attack on the UK and what would be expected of us as telecommunications engineers to restore and maintain what is now referred to as the critical national infrastructure – for those of us selected for these duties, most of us would not be.
Although I never had the opportunity to work in the Kingsway Tunnels, I did have the great privilege of working in some fascinating locations. Some of the locations I worked in were part of our defence against a potential attack, including some of the hidden underground telecommunications facilities across London. I remember one place I worked where the entrance was through a door of a Portakabin style public car park office. The door opened onto a staircase down to a double steel doorway leading to a reinforced concrete lift lobby. The lift descended to a depth of about 30m to an underground telephone exchange.
The concrete slab above the telephone exchange must have been three metres thick. The telephone exchange was part of the CBX or Central Branch Exchange network. The CBX network comprised a number of exchanges providing connectivity between the government offices including Whitehall and a number of public telephone exchanges. This preceded the Government Telecommunications Network. I am relying on my memory so it may have faded a little but I remember one of the exchanges I worked in was one of the first Crossbar exchanges I had seen. I distinctly remember the pushbutton phones as the only phones I had seen before had rotary dials. The dial keypad even pre-dated DTMF as (again from memory) it used diode arrays to convey each digit to the exchange. If I didn’t store all of this information I would probably be better at remembering birthdays and anniversaries.
”My excitement had to be contained at the time as I wasn’t allowed to tell anyone about it.”
I offer no apologies for taking a minute to share the excitement I was experiencing at that time. I was buzzing! In June 1973 I was the product of a comprehensive school where I really should have paid more attention. Two months later I signed The Official Secrets Act. The following year I was working in relatively secret facilities under London. My excitement had to be contained at the time as I wasn’t allowed to tell anyone about it. The Portakabin is long gone and the land has been redeveloped, but there is still an air vent where the Portakabin once stood – an indication that the underground complex is still there. I have to add that once underground I had no idea where I was in relation to the surface so the secret – if there still is one – is safe with me. Another part of this network has already appeared on TV so I am sure what I witnessed has little relevance now. Fortunately, that was the first of many exciting experiences in my long career in telecommunications.
There are many tunnels under London but not too long after the Second World War it was realised that tunnels like Kingsway would not survive a nuclear attack, and with London being a prime target, alternatives were sought. In the 50s the government built a massive underground city at Corsham referred to as the ‘Burlington Bunker’. Burlington was a totally self-sufficient, 240 acre site with 60 miles of roads. In the event of a Soviet nuclear attack the bunker would support up to 4,000 people including a skeleton government. It even had a secret railway platform, a branch off of the main London to Bristol line specifically to extract the Royal Family from London. At the time, it had the second largest telephone exchange in the UK. Back in 2004 Astro were involved in decommissioning some of the systems in the bunker. Burlington was never actually used and in reality, was never likely to be with only a four minute warning of impending doom.
”At the time of the Cuban missile crisis TAT1 carried the Moscow to Washington hotline”
Even though the life expectancy the Kingsway Tunnels was severely limited, they certainly played their part during one of the most historical incidents of the Cold War. The tunnels were home to a telecommunications facility which included a large Strowger electro-mechanical telephone exchange with connections to other parts of the UK telephone network. This telecommunications facility was also the termination point for the first transatlantic telephone cable TAT1. At the time of the Cuban missile crisis, TAT1 carried the Moscow to Washington hotline between the American and Soviet heads of state. During the crisis the Kingsway Tunnels were fully staffed and locked down preparing for the worst. Although the lock down only lasted two weeks, the tunnels could support their staff for at least three months. Taking all of this into consideration, I believe it is safe to say that in their day, the Kingsway Tunnels were an early example of a super connected city – albeit subterranean.
The tunnels were still in operation as a Trunk Switching Centre and Repeater Station until the early 80s when large quantities of blue asbestos were found. There have been a number of suggestions as to their future use including a night club, ghost train and a firing range. Whoever owns the tunnels will be taking on a huge responsibility as they must keep up the maintenance. The tunnels have to be regularly structurally checked as they lie beneath the tube network and all of the buildings above ground. The tunnels cannot be filled with concrete because the weight would cause the tunnel infrastructure to sink in the London clay presenting a significant risk to the buildings above. Whatever the tunnels are used for, I feel privileged to have been able to visit them before they are stripped of their remaining history. It was certainly a stark reminder as to what life was like in the Cold War era.
Coincidentally, one of the BT Properties staff handed me an old copy of the Post Office Gazette as I was leaving. The Gazette had been found in perfect condition in the tunnels. It was dated 22 August 1973 and would have been the first copy I received shortly after I joined the Post Office on 6 August 1973 – the icing on the cake for me!
