Some time in early 1935 there was a knock at the door of the bungalow stables near Chilton. Leonard Cundall opened the door to two uniformed men, with only one thing to say. “Mr Cundall there’s going to be a war”. Within 6 months the Air Ministry had compulsory purchased the land for £11,6500. The land would be used for one of many new airfields being built as part of a national war effort. The John Laing engineering company won the contract to build 66 airfields for the RAF expansion period prior to World War Two. Reportedly the area south of Harwell village had been used as an emergency landing ground for night flying since WW1. There has also been talk of the area being used as a glider training ground around this time as well. The ground is surprisingly flat, and a big open space, perfect for air training. The John Laing engineering company was also famous for building the Mulberry Harbour system, which was the artificial harbour built for the Normandy landings. They also build the Royal Ordinance factory in Sellafield, Windscale nuclear power plant, the M1, and the reconstruction of Coventry cathedral. Of the 66 airfields Laings company built, Harwell was the first to be constructed. The work started on the airfield in June of 1935.
In RAF tradition all airfields have pretty much the same layout. This makes sense when you think about it as if a new pilot flies in from another group they know where to go to find the mess hall or where to get paid or where to find the Commanding Officer. Another tradition is that every building is numbered in the order of construction. No. 1 was the guardroom at the entrance to the site. After initial construction the site had 202 individually numbered buildings, and then almost another 100 houses on top of this for people to live. The hangars had a slightly different numbering system, the four hangars were originally named H1-H4, but at the outbreak of war they were renamed H7-H10. At the other end of the numbering B199 was a Gymnasium that doubled up as a chapel. There were no buildings west of Hangar 10 when the site was built. There was a gunnery range in this area that was there to realign the aircraft guns, but this was subsequently occupied by the B220 radio chemical facility, the first major building built by Chivers post war. Two civilian houses were demolished to make way for a a deep underground fuel store, building B3. It contained 6 large cylindrical tanks, with excavated dirt piled on top to produce bomb proof mounds. The second building was pulled down to become the main runway, which is now Frome Road. Aldfield farm to the north and Upper farm to the south escaped demolition. Upper farm stables were requisitioned though. The long building with large doors was perfectly sized to be turned into an aircraft cleaning shed. Go in one side dirty, come out the other side clean!
The naming of the airfield comes with an interesting story. The 800 acre site sits mainly in the parish of Chilton. A third of the site is in East Hendred parish, with the smallest section being in Harwell. Up until the Commanding Officer got there, it likely had some sort of code name or number. When the CO arrived the subject of the name had to be handled. He lived in the largest of the houses in the northern end of the site in South Drive. He declared that the airfield should be named after whichever parish his house resided in. That parish happened to be Harwell, therefore RAF Harwell it was. As it was a very early airfield it had many flaws. Even worse, it was a bomber training station, with new and inexperienced pilots everywhere. The first big issue was that the three runways intersected in the middle (almost). This is a huge issue, as it would only take a single bomb to take out all three runways. Plus there is a much larger risk of the new pilots crashing in the centre when trying to launch at the same time. There was also a hugely complex system of taxi tracks. There were also over 120 dispersal pads for the planes/gliders scatted around the site. These pads are there to disperse parked aircraft, so if there is an air raid it will minimise the damaged caused overall. Also called hardstands, they also stopped damage to other planes if there was an accident while “bombing up”. These pads tended to be 150 ft (46 m) in diameter and at least 150 ft from the funnel track, this was actually a rule for all buildings on the site.
One big thing that they overlooked in the design was the location of the munitions dump. They placed it at the end of the shortest runway, now known as Severn Road. The other issue with this particular runway is that it had a slight hill. When going along the runway you couldn’t actually see the other end over the brow of the hill. There are many stories of young pilots with huge bomb payloads barreling down the runway to then realise they did’t have enough speed to make it. They would have to ‘prang’ the aircraft into the field between the end of the runway and the bomb store fence. There was no reports of any explosions caused by this though. One other notable point is the building materials used in the construction of many of these buildings and tracks. The runway of a bomber station was often up to 9 inches (23 cm) thick, and took 18,000 tons of dry cement and 90,000 tons of aggregate, then covered with a layer of asphalt. In later airfields the hardcore used was often from destroyed buildings, and were carried by train to the sites. Harwell initially opened in February 1937 with a grass airfield but got replaced with concrete runways between July and August 1941.
The buildings themselves were made from the classic red brick but the food preparation and storage areas were made from a brick named ‘grano’. Short for granolithic stone it was a mixture of sand cement and granite dust. The resulting stone was hard wearing and was perfect for the constant cleaning and wiping of food storage areas. The issue found later was that the high granite content meant measurable amounts of natural uranium/thorium. The food areas were slightly radioactive. They were also found in the walls of offices in the aircraft hangers and in the BISO, the aimens mess! Plus most dials on compasses and equipment were painted with radium, another radioactive material. Turns out Harwell always had some radioactive heritage.
By the end of the war over 500 airfields had been built, and most of these issues were ironed out in later designs. The original site was only designed to last 10 years, but even today a huge amount of buildings on that Harwell site still remain in some state. There are a few sections of runway still left, and even a few of the dispersal pads are still visible underneath the undergrowth.
Thank You for reading, take a look at my other posts if you are interested in space, electronics, or any other sort of history. Alternatively follow me on Twitter to get updates on projects I am currently working on.