Catesby Tunnel, Northamptonshire

Abandoned railway tunnels can be a bit dull after you’ve done a few, as a rule they are dark, straight and mostly featurless. I’ve had my fill I suppose and they don’t really ‘blow up my skirt’ anymore, however Catesby presented itself as an opportunity and it was rude to say no…

Catesby Tunnel is a little more interesting than your average tunnel, mainly ‘cos its a big boy. I believe it’s somewhere around the fifth longest, behind stuff like Rhondda, both Woodhead’s, and Standedge.

Interesting features that also set this tunnel aside from many are the culvert that runs the entire length of the tunnel under the tunnel floor, accessed by catchpits (yes I stupidly crawled in there with no waders, up to my waist in freezing water to get the shot below), the three large Rest Cabins built into the up-side wall (one found to contain a sadly ransacked GeoCache) and the five air-shafts that these days spectacularly pour water down into the already flooded tunnel (the north end was knee hight on this visit).

Not many photo’s as I managed to flood my 40D and it packed up for a few hours….

Some history, copyright © Graeme Bickerdike/Forgotten Relics

The 2,997-yard structure was cut by T Oliver & Son of Horsham as part of the Great Central’s ‘London Extension’ construction contract No.4. It passes through the upper beds of the lower Lias and the lower beds of the middle Lias. 27 feet wide and 25 feet 6 inches high, Catesby is straight throughout and on a rising gradient of 1:176 to the south, with the summit of this section reached as daylight resumes.

Its creation demanded round 290,000 cubic yards of mining. Work to sink the first shaft began on 18th February 1895 and the last length was keyed in on 22nd May 1897 – a remarkably quick average rate of 110 yards per month. Progress was greatly accelerated by the use of Ruston steam navvies (cranes).

The tunnel was mostly driven from nine construction shafts, each equipped with wooden headgear which was used to lower materials to the men working beneath. None though was permitted within 500 yards of the north portal due to the landowner’s wish that the privacy of his residence, close to the workings, be maintained. As a result, 264 yards through very heavy ground had to be constructed by means of a 12x10ft bottom heading and break-ups. This proved liable to breakages and one part completely collapsed. The surrounding strata was under significant pressure which resulted in a heavy lining of seven rings in the arch and side walls, with six rings in the invert. These were divided into 10-foot sections.

Cut-and-cover was used for the first 44 yards from the north portal. The length adjoining this had so little ground above it that the two crown bars were laid from a trench on the surface.

The remainder of the tunnel proved relatively light work and was driven full-sized without headings. Here the lining is mostly five rings thick with a four-ring invert, all faced with Staffordshire brindle and built in lime mortar. Around 30 million bricks were swallowed up by the structure.

Very little water ingress was experienced, amounting to around 80 gallons per minute. Chases were built into the back of the brickwork at intervals, leading to pipes built through the side wall at rail level. Water was then discharged into a culvert in the six-foot, accessed via deep catchpits.

Ventilation is provided by five shafts. Four of these are 10 feet in diameter but the northernmost – 1,250 yards from the entrance – is 15 feet wide to provide greater air flow. The landowner did not want his view blighted by rising smoke either! The first belch from coal traffic occurred on 25th July 1898.

Trackworkers were relatively well served with regular refuges provided on both sides and three rest cabins built into the Up side wall. One is located directly opposite the tablet that marks the “half way” point.

Both lines through the tunnel were inspected by the local ganger twice each day. In the winter of 1906, this role was carried out by Joseph Turner, as it had been for the previous 18 months. At about 4:20pm on 4th January he completed an examination of the Down line.

Half-an-hour later, a London-Manchester express with upwards of 50 passengers on board entered the south end of the tunnel at around 60mph. As it approached the fifth shaft, a rail broke beneath the locomotive and all five coaches behind it derailed, ripping up 450 yards of track. The last carriage became detached and came to a stand foul of the adjacent Up line as a goods train was approaching. Only prompt action by the driver, who put down a detonator, and the guard, who sounded the whistle, prevented a collision.

Catesby Tunnel retired from operational service on 3rd September 1966 since which time the permanent way has been removed. Water ingress compounded by a blocked drain just north of the fifth shaft means that, in places, it is flooded to a depth of a foot or more. Calcite makes it presence felt with some extraordinary formations.

Brixworth ROC Post – Northamptonshire Group

Opened – February 1962
Closed – September 1991

Brixworth forms part of the Bedford 30 Cluster and is the Master Post, with Crick 31 and Duston 32 and came under ROC Group HQ No 7 Bedford

This was only a quick visit so no underground shots on this occasion (we will be back for these another day). In the compound are what looks like the concrete steps for a Visual Reporting Post (Aircraft Observation), there are also some of the poles from this laying on the ground.

Cantilever ‘Mushroom’ Pillboxes

Straying from the Cold War theme slightly here is my attraction to old airfields, I’m not big on WW2 stuff but these places provide a certain draw to me and I’m lucky to have many old RAF/USAF sites very near to my house. A full report on one of these sites will follow in the near future but for now here’s a small article on Cantilever Pillboxes.

Cantilever Pillboxes, more commonly known as Mushroom Pillboxes are found only on airfields and mainly in the East of England, they are of a circular design, partially sunken into the ground and have a 360 degree embrasure (opening) to allow weapon fire to be layed down in any direction. Just inside the embrasure and attached to the brickwork is a circular gun rail so a machine gun could be moved almost anywhere in the pillbox to lay down fire.

The construction of these two are of a circular brick built base with a central cruciform wall which in turn supports a poured concrete dome. The example in the photo’s below is from RAF Grafton Underwood and was in a defensive position at the north end of the No.1 Runway.  A second Mushroom Pillbox is also present on this site but the roof has sadly collapsed.

The airfield was opened in 1941 and was first used by the RAF  Bomber Command 1653 Heavy Conversion Unit with Liberators. The original runways were approximately 1,600 yards and 1,100 yards in length. The runways were not suitable for the operation of heavy, four-engined bombers so the airfield was upgraded to Class A, including the lengthening of the runways to the required 2,000 yards for the main and 1,400 yards for each of the others, started in late 1942.

As a result of this Grafton Underwood was assigned United States Army Air Force Eighth Air Force in 1942. Its designation was USAAF Station 106. The airfield became a major base for the USAF and many squadrons were based there during WW2 – 15th Bombardment Squadron (Light), 97th Bombardment Group (Heavy), 305th Bombardment Group (Heavy), 96th Bombardment Group (Heavy) and 384th Bombardment Group (Heavy).


Duston ROC Post – Northamptonshire Group

Opened – February 1962
Closed – September 1991

Duston forms part of the Bedford 30 Cluster – Brixworth 30 (Master Post), Crick 31 and Duston 32 and came under ROC Group HQ No 7 Bedford

With the fast rate things were being removed from here and more importantly the imminent demolition of this entire site to make way for a major urban development plan (the ROC Post is the little grey square in sector O) we decided now was the time to visit before the post is gone forever.

Expecting a stripped post we were pleasantly surprised by what we found. If anyone is interested there is also the lower half an Orlit Post in the same compound.

Earls Barton ROC Post – Northamptonshire Group

Opened – Unknown (gotta cross reference it in Attack Warning Red)
Closed – September 1991

It’s been a ROC Post Fest this last few days across several counties, I’ve hit up 8 posts in 6 days and the 9th planned for tonight but this one wins the FUBAR award so far, not only has it been stripped bare inside, its now Fly Tipping Central with the shaft totally full of refuse/junk/detritus

I was on my own and also short on time so I didn’t attempt to start removing the trash, plus I wasn’t sure of the contents of the black bin bags

The compound itself is chest high in stinging nettles so I’m not sure what original items might be laying around, I suspect none though.

Benefield ROC Post 22 (Bedford 20 Cluster)

Opened – June 1958
Closed – September 1991

RAF Deenethorpe was constructed in 1943 and was allocated to the United States Army Air Force Eighth Air Force. It was assigned USAAF designation Station 128. The 401st Bombardment Group (Heavy) were stationed here. They operated chiefly against strategic targets, bombing industries, submarine facilities, shipyards, missile sites, marshalling yards, and airfields; beginning in October 1944, concentrated on oil reserves. The Group received a Distinguished Unit Citation for striking telling blows against German aircraft production on 11 January and 20 February 1944.

After the war, Deenethorpe was used as a RAF Recruiting Center, and later for several years the control tower was used as a lookout post by the local Royal Observer Corps. It was finally sold in 1963 and largely returned to agriculture. Part of the old main runway is now used as a private airstrip.

Its possible this site won’t be around much longer as the Deenthorpe Control Tower has been demolished and the whole site is being taken back by nature. Inside the post was very untidy but many original items remain, however lots of items have sadly been removed.

Yet another sad example of a ROC Post being stripped bare

Cold Overton ROC Post 10 (Master – Bedford 10 Cluster)

Explored with Winch It In

Opened – April 1959
Closed – September 1991

This ROC Post has declined steadlily over the years, the top of the vents have been off for a long while and some time ago an attempt to chop away at the concrete on top of the hatch has left a nasty mess.

Below ground many items seem to have been stolen, even since April of this year, sadly there will be nothing left in this post soon. We visited this post as part of an objective to take in all three of the Bedford 10 Cluster with Sutton Bassett 11 and Clipston 12 making up the rest of the cluster.

As suggested by the cluster name this ROC Post came under ROC Group HQ No 7 Bedford

Sutton Bassett ROC Post 11 (Bedford 10 Cluster) – Part 2

Here are the underground shots that were taken on a second visit to this ROC Post – Explored with Winch It In.


Sutton Bassett ROC Post 11 (Bedford 10 Cluster)

The Royal Observer Corps (ROC) was a civil defence organisation operating in the United Kingdom between 29 October 1925 and 31 December 1995, when the Corps’ civilian volunteers were stood down.Comprised mainly of civilian spare-time volunteers, ROC personnel wore a Royal Air Force (RAF) style uniform and latterly came under the administrative control of RAF Strike Command and the operational control of the Home Office.

Originally there were some 200 observation posts throughout the country and their role was to provide visual detection, identification, tracking and reporting of aircraft over Great Britain during the World Wars. Early Observation Posts were often crude and un-fortified but during the war many were rebuilt from brick and had sandbag defences.

On 12 May 1945 when the German Luftwaffe had ceased combat operations the ROC stood down, however it wasn’t long before the threat of Cold War arose and the ROC were reinstated.

In 1957, the United Kingdom Warning and Monitoring Organisation (UKWMO) was established under Home Office control to provide essential information about impending nuclear attacks to both civilian and military authorities.So that the ROC could work with the new type of threat the old monitoring posts were replaced with something that had protection from nuclear blasts.

Between 1958 and 1968 a countrywide building programme resulted in a network of 1,563 underground monitoring posts, approximately eight miles apart, distributed throughout England, Scotland, Wales and Northern Ireland, at an estimated cost of almost £5,000 each.The bunkers were built by digging a 25 feet deep hole, placing a reinforced concrete bunker in the hole and then burying it under compacted soil.A single hatch to the surface was the only entrance/exit with a 20 ft vertical ladder that lead to an underground chamber 7ft x 16ft x 7ft high.Posts were typically grouped together in threes or sometimes four, to form a cluster. One post in each cluster was a master post and could communicate directly back to ROC Control using a Tele-Talk device connected to ROC Group HQ and the Carrier Warning Receiver.

No telephones were provided. Each ROC Post was manned by 2 to 3 people who ate and slept in very primitive conditions as there was no electricity or running water in the bunkers, toilet facilities were by way of an Elsan Chemical Toilet located at one end of the bunker.

The ROC Post had a variety of external equipment fitted as standard:Bomb Power Indicator (BPI) – This would register the pressure wave from a nuclear explosion passing over it and the results were read on a dial inside the ROC Post.

Ground Zero Indicator (GZI)– Basically a crude pinhole camera that could ‘photograph’ the fireball of a nuclear explosion.
Radiac Meter – Used to count radioactive particles
Fixed Survey Meter (FSM)– Replaced the Radiac Meters and used to detect nuclear fallout. (The FSM could be safely operated without leaving the bunker)
Cross section of a ROC Post

After bomb a detonation, the direction, elevation and spot size of the fireball and reading of the pressure wave on the BPI would be passed to ROC Group HQ using the Tele-Talk unit or Radio. Group HQ would use the direction information from two or more posts to determine the exact point of detonation by using triangulation.

The end of the cold war and advances in technology eventually brought the end of the ROC and the monitoring post and group control personnel were stood down on 30 September 1991.

Amazingly hundreds and hundreds of these ROC Posts still exist (although some have been demolished) and even more amazing is that many still have the original equipment and supplies intact inside, it seems many ROC volunteers just climbed up the hatch and left everything where it was. Sadly there are also many existing ROC Posts that have been burnt out or heavily vandalised by kids.

A brighter end to this story is the emergence of ROC posts being restored for posterity, perhaps the most famous of these is 23 Post Skelmorlie in Ayrshire, Scotland. 23 Post has been totally restored and is open as a museum on certain days in the year

This is Sutton Bassett Post 11, part of the Bedford 10 Cluster.

10 Post (Cold Overton) was the Master Post with Sutton Bassett 11 and Clipston 12 making up the cluster.