# RAF Coolham

Royal Air Force Coolham, or more simply RAF Coolham, also known as Coolham Advanced Landing Ground (ALG), is a former Second World War Royal Air Force Advanced Landing Ground located in Coolham, West Sussex, England, United Kingdom.

## Background

During June and July 1942, Southern England was combed by Air Ministry surveyors attempting to identify suitable sites for the construction of Advanced Landing Grounds (ALGs). The main purpose of the Southern England ALGs was, owing to their close proximity to Nazi-occupied Europe, to provide air support to allied forces prior to, during, and after an anticipated future liberation of the European mainland, which later manifested on 6 June 1944 as the Normandy Landings (Operation Neptune, AKA D-Day) and the Battle of Normandy (Operation Overlord). In total, 72 such sites were located, although this figure was considerably whittled down to just 23 sites which were eventually used to construct ALGs upon, this being mainly due to the war agricultural executive committees' fierce opposition to such large swathes of agricultural land being requisitioned and thus no longer being agriculturally productive. One of these sites was located on land near the small village of Coolham, West Sussex, England. A top-level Air Ministry conference was held at Coolham on 8 October 1942 when it was at last agreed that an ALG would indeed be constructed on the previously identified site at Coolham.
The site consisted of land accessed by, and to the east of, the B2139 Thakeham Road, and just south east of Coolham crossroad, with Saucelands Lane itself adjoining the southern perimeter. This ALG, which would be known as Royal Air Force Coolham, or more simply, RAF Coolham, was situated roughly 6 miles (9.7 km) southwest of Horsham and would be one of 7 ALGs eventually constructed in Sussex for use by RAF Fighter Command along with its allies. The other 6 Sussex ALGs constructed were RAF Appledram, RAF Bognor, RAF Chailey, RAF Deanland, RAF Funtington, and RAF Selsey. On account of the Coolham site's level terrain and the area's excellent transport infrastructure connections via road and rail, specifically Billingshurst, Christ's Hospital, Southwater, and Horsham, it was considered to be an ideal location.

## Construction
### Preparation

In total, 113 acres (46 ha) of both wooded and agricultural land was requisitioned by the Air Ministry at Coolham. Original estimates were that 700–800 hedgerow trees would need to be cleared, and approximately 8,400 feet (2,600 m) of high-tension electrical cable would need to be laid and buried, along with wiring for telex and PBX telephone facilities. The area's natural flatness, although partly why it was chosen as an ALG site, also meant that, in conjunction with the heavy topsoil of Weald Clay present in the area, under-drainage would be required to prevent the strip area becoming boggy after rainfall, and this initially made planners believe preparation of the site would be slow.
The 10-month-long construction of the airfield commenced during August 1943 with 156 personnel of Nos. 4661 and 4663 AC Flight, of 5004 Airfield Construction Squadron, Airfield Construction Branch RAF, commanded by Squadron Leader J.K. Lancaster. 5004 Squadron utilised a large arsenal of plant to carry out construction including (but not limited to) bulldozers, tractors, dump trucks, road rollers, a paint sprayer, and a concrete mixer. A number of airmen constructing the ALG at Coolham were billeted at the prisoner-of-war camp at Barn House Farm, Shipley, (POW Camp 658) at the southern end of the airfield, while others were billeted in numerous farm buildings along Saucelands Lane. Those who happened to live nearby could apply for a 'living out' pass and cycle/commute to and from RAF Coolham. H. Kay, a local Horsham contractors, were also employed in the initial ground clearance and levelling and Ronald Coleman, a civil engineer who had been seconded to the War Office, worked with both civilians and RAF personnel in constructing RAF Coolham from the very beginning.
The north-south runway's southern end was initially obstructed by buildings. Five Mile Ash, situated on the south side of Saucelands Lane, was demolished as it directly obstructed the southern end of the north-south runway. An adjacent historic property, Saucelands, was saved from destruction after West Sussex County Council objected to its demolition. Bridge Hill House, situated on the B2139 Thakeham Road at the western end of the main east-west runway, had its roof removed due to safety concerns about its height possibly hindering clearance at the end of the runway, making it uninhabitable until the roof was restored after the end of the war.

### Runways

Two runways were constructed in total, along with 36 aircraft dispersal hardstandings which were intended to space aircraft apart from each other when not in use in order to mitigate aircraft losses if the airfield suffered enemy bombing. The larger main runway running east-west for 4,500 feet (1,372 m) and the smaller second runway running north-south for 3,600 feet (1,097 m) with both runways constructed using Sommerfeld tracking. Sommerfeld tracking was a relatively light weight, inexpensive, quick, and easily assemblable method of reinforcing a ground bearing surface for use by heavy vehicles and high volumes of traffic, preventing the bearing surface from wearing away and becoming uneven, and preventing vehicles from sinking and becoming bogged down or stuck, and thus was ideal for constructing ALGs' runways which were only intended to be used temporarily, had to be built quickly, and would see heavy aeroplanes taking off and landing regularly. It consisted of rolls, 23 metres (75 ft) long and 3.25 metres (11 ft) wide, of metal wire mesh, similar to chicken wire or chainlink fencing, with round iron bars at regular intervals all along its length running widthways and looped at either end. It was then rolled out flat on the ground like a mat, and flat iron bars were then threaded through the loops to physically anchor each track together, before it was all anchored to the ground using 2ft and 3ft iron pickets.
At RAF Coolham, 5004 Airfield Construction Squadron laid most of the Sommerfeld tracking down. A mobile crane was used to move the rolls into place as the weight of each roll, although lighter than other alternatives, meant that it would otherwise take 6 personnel to move each roll into position. One row of tracking was laid along the entire length of each of Coolham's runways and secured by a group of 3 personnel with sledgehammers driving the 2ft and 3ft iron pickets into the ground one at a time, swinging in harmony on the same picket. Once this initial length of tracking was laid, other rolls of tracking were laid next to, and adjoined with, the side of the initial length, until the required width of the runway was completed, followed by a tractor being used to stretch the width of the tracking while it was then secured in place with further pickets until the whole length was taut. Although the Sommerfeld tracking patent states that asphalt or a similar material should then be added onto the mesh to cover it, at Coolham this was not the case as grass seed was sown over the area instead, so that the grass roots would help consolidate the soil together and to help with drainage.
Barriers were erected on Saucelands Lane because the lane crossed the north-south runway's southern end. The barriers were to be brought down to close the lane off to the public when the runway was in use in order to prevent traffic from crossing the north-south runway which could otherwise cause a collision with aircraft during take offs and landings. The control tower at RAF Coolham was a moveable caravan and the ALG was designated by the airfield identification letters XQ. There was no instrument landing system to aid aircraft in landing at night or bad weather and sorties were monitored by the personnel of ROC Group No. 2, Royal Observer Corps, based nearby at Denne Road, Horsham.

## Based Units

It is believed that c. 700 personnel served at RAF Coolham at some point, 15 of whom were killed whilst carrying out their duties at or from RAF Coolham (each denotated below with a †).
The following order of battle shows all units which were stationed at RAF Coolham at any point during its construction and its operational history (August 1943 – July 1944) as well as deconstruction efforts as the aerodrome was reverted back to agricultural land (September 1945 – October 1945):

### Second Tactical Air Force, Royal Air Force
#### No. 84 Group
##### — No. 18 (Fighter) Sector
###### —— No. 133 (Polish) (Fighter) Wing

* No. 129 (Mysore) (Fighter) Squadron †††††
* No. 6129 Servicing Echelon
* No. 306 (Polish) (Fighter) Squadron ††††
* No. 6306 Servicing Echelon
* No. 315 (Polish) (Fighter) Squadron ††††
* No. 6315 Servicing Echelon
* No. 411 (Polish) Repair and Salvage Unit †

###### —— No. 135 (Fighter) Wing

* No. 222 (Natal) (Fighter) Squadron
* No. 6222 Servicing Echelon
* No. 349 (Belgian) (Fighter) Squadron
* No. 6349 Servicing Echelon
* No. 485 (New Zealand) (Fighter) Squadron
* No. 6485 Servicing Echelon

##### — No. 84 Group Signals

* No. 5090 (Polish) Type C Mobile Signals Unit
* No. 16 Advanced Landing Ground Signals Section

#### Royal Air Force Regiment

* No. 1314 Mobile Wing RAF Regiment
* No. 2701 (Light Anti-Aircraft) Squadron RAF Regiment
* No. 2722 (Light Anti-Aircraft) Squadron RAF Regiment
* No. 2800 (Light Anti-Aircraft) Squadron RAF Regiment
* No. 2829 (Field) Squadron RAF Regiment

#### Airfield Construction Service

* No. 5003 Airfield Construction Squadron
* No. 5004 Airfield Construction Squadron
* No. 5018 Airfield Construction Squadron †
* No. 5027 Airfield Construction Squadron
* No. 5206 Airfield Construction Squadron

### Maintenance Command
#### No. 40 Group

* No. 49 (Faygate) Maintenance Unit

#### No. 42 Group

* No. 422 Aviation Fuel and Ammunition Park
** No. 8 Section