Airfield Buildings and Site Info.

R.A.F. Harrowbeer was constructed in 1941.

The rubble from Plymouth after the Blitz of March / April 1941 was transported to Yelverton to be used as hardcore for runways and some of the buildings.

On the main airfield one hundred and eighteen buildings were constructed according to the official site map. Of these one hundred and ten have been located, all that remains today of the buildings are the Dispersal Bays, concrete bases and foundations or remnants of odd brickwork.

There are also a number of associated buildings that are not shown on the official site plan of R.A.F. Harrowbeer.

                     

                                   Airfield Defence

 

Policy and Procedures

 

In 1939 there was a policy of dispersing aircraft on around and sometimes beyond the perimeter of the airfield, but this would make defence very difficult. Defence was confined to a limited number of light machine-gun posts for anti-aircraft use in protecting the airfield against enemy attack. Certain operational stations would have additional guns of a higher calibre:- two pounders and three inch guns, but no further works were constructed for them.

 

In 1940 with the threat of invasion there was an initiation to construct pill-boxes, rifle pits and very extensive wire entanglements ( barbed wire ) as additional airfield defence. Some pill-boxes were constructed with anti-aircraft positions on the flat roof for twin Browning or Lewis machine-guns, thus giving an elevated all round view and protection of the surrounding area.

There was no laid down procedure or standard for the defence of an sirfield due to the fact that owing to variations and topography it was impracticable.

A procedure that was adopted required the Local Military Authority, usually acting through the Local Defence Commander, who was the Defence Advisor to the Station Commander and would plan the defences and produce designs and drawings for the structural work. These were then sent to the Air Ministry Works Area Heasquarters who prepared detailed drawings for contractors to work from.

 

In 1940 the R.A.F. Regiment had not been formed, but in the Autumn of 1940 there was created a new trade of " Ground Gunner " for airfield defence within the R.A.F.

Light anti-aircraft defence was the responsibility of the Royal Artillery with Bofors Guns. These were supported by the R.A.F. Gunners with light machine-guns.

 

In 1941 the location of defences of an airfield was considered a priority second only to the runway layout and above the requirements for accommodation. It was an important issue that the defences were completed in readiness of the opening of an airfield. There was also a requirement for inward facing defences in the event of the enemy landing on the airfield itself by parachute.

 

In August 1941 after R.A.F. Harrowbeer opened the Local Defence Adviser was Major Gaywood  MC.

As far as is known at present R.A.F. Harrowbeer defence consisted of:-

            Three Alan William Gun Turrets

            Four anti-aircraft machine-gun posts on top of four of the Dispersal Bays

            One anti-aircraft machine-gun post on the ground close to the Leg O'Mutton facing Princetown

            Two pill-boxes, one definitely with provision for twin machine-guns on top

            Various slit trenches ( straight and half moon ) and fox-holes

 

Royal Engineers

 

With the evacuation of the British Forces from France in June 1940 a body of men became available who could maintain vital airfields under the worst conditions. This body of men were the Royal Engineer Units. Detachments of sixty six to one hundred men each were located on approximately one hundred and ten airfields. A total of seven thousand Royal Engineers were available during the Battle of Britain and carried out repair work of the utmost importance.

 

Gunnery School

 

Gunners trained at No.1 Ground Defence Gunnery School at North Coates, Lincolnshire in December 1939.

The Gunnery School moved to Ronaldsway on the Isle of Man during March 1940.

In March 1943 the School was absorbed by the R.A.F. Regimant.

 

The R.A.F. Regiment

 

In November 1941 the Committee on Airfield Defence recommended that the R.A.F. should have it's own defence force under Air Ministry control.

The " R.A.F. Regiment " was formed from all existing R.A.F. Ground Defence Squadrons and Flights on the 1st February 1942 and soon relieved the Army of it's unwanted responsibilty for defending R.A.F. installations in the U.K.

 

The R.A.F. Regiment ( the next stage )

 

On the 18th April 1944 Winston Churcill wrote:-

" I do not think we can afford to continue to maintain a special body of troops purely for the defence of aerodromes. The R.A.F. Regiment was established at a time when the invasion of this Country was likely. and when our life depended on the security of our Fighter Aerodromes. Since then it has been reduced, but the time has now come to consider whether the greater part of it should not be taken to reinforce the field formations of the Army. I consider that at least twenty five thousand men should be tranferred. They will be much better employed there than loafing around overcrowded airfields warding off dangers which have ceased to threaten. "

 

The suggestion was taken up and two thousand men were transferred to the Guards in June 1944. In October 1944 all defence work was abandoned apart from half a dozen airfields in the South East of England and the Shetlands which kept limited light anti-aircraft facilities.

 

                                               Air Raid Sirens / Shelters

 

Air Raid Sirens

 

Airfields were equipped with air raid sirens to give prior warning of an enemy attack

The R.A.F. adopted the signals:-

            Alert                       =     A wailing, undulating tone

            Raiders passed         =     A steady, constant note ( also known as " the all clear " )

The sirens were usually activated from the Operation Block. Alternatively it was from the Guard Room after notification by telephone from the Operations Block.

There were two forms of sirens. There was the large pole or top of a building electronically operated version. Another type was a small portable, mobile siren which was operated by cranking a handle, the audible tone could be altered by twisting the hand hold on the top of the siren.

 

Air Raid Shelters

 

There were many forms of Air Raid Shelters. The early type being a crude covered slit trench. These were soon superseded by pre-cast concrete shelters ( Stanton type ) each holding twenty five to fifty persons. Concrete pre-cast sections were bolted together to form the required length, then covered with earth for bomb splinter protection. At one end was an entrance, shielded by a blast wall. At the other end was a wall mounted ladder leading up to an escape hatch.

The Stanton type shelter was often incorporated into some of the Dispersal Bay designs. Where the three earth banked sections joined together a shelter would be constructed which was capable of giveng shelter to twenty five persons. At the back of each of the aircraft bays there was an entrance into the shelter. Instead of a blast wall to protect the entrance you would enter a short dog-legged passage, then through a door into the shelter. At the back of one of the short passages there an emergency exit

 

R.A.F. Harrowbeer had a large number of the Stanton type air raid shelters close to the airfield defence accommodation huts and also on the dispersed sites for the airmen.

On the main airfield close to the two bay Bomb Stores there are three underground re-inforced air raid shelters which are not shown on the official site plan.

Each of Harrowbeer's twelve Dispersal  Bays had a Stanton type shelter built into them.

 

                                          Buildings

 

Windows in buildings on an airfield were a great liability. The reason for this was that in the event of an enemy gas attack the windows could have the glass shattered or blown out therefore creating an opening for the gas to penetrate and render the occupants inoperable.

 

Battle Headquarters

 

R.A.F. Harrowbeer was in a unique position of having two Battle Headquarters, it is not clearly understood as to why this was.

One was situated on the Technical Site in accordance with the official site plan of the Station Airfield Site. The second Battle Headquarters was built in 1942 and is not on the main airfield site, it is to the south and commands an excellent view of the airfield.

The defence of an airfield was co-ordinated from the Battle Headquarters.

A purpose built stronghold which was standardized as drawing No.1108/41 for Operational Stations ( usually an underground building ) ( Harrowbeer's second one ). Another type of Battle Headquarters was to drawing No.3329/41 normally for R.A.F. Fighter Stations, Satellite Stations and Training Fields, ( Harrowbeer's original one ). This design again was normally built underground, but Harrowbeer's was above ground!

As with other defence work the Battle Headquarters was not always included in the plans for an airfield but sited in agreement with the Local Army Authority, taking into account terrain and camouflage.The Battle Headquartes was normally built on high ground, in a hedge or close to farm buildings. A few were built close to the Watch Office.

 

The 1108/41 Battle Headquarters was recognized by a square observation block ( six foot square and three feet high ) standing above ground with a three hundred and sixty degree viewing slit. The rest of the building was usually underground, if not a substantial earth bank was placed on all exterior sides. The sunken section was entered by a stairway at the opposite end to the observation block. The observation block had it's own emergency escape hatch. The building measured approximately twenty on foot long by eight foot wide and comprised an office, sleeping accommodation and a latrine. A member of the personnel would be a ' runner ' for use if the telephone communication ceased to operate.

 

Bellman Hangar

 

R.A.F. Harrowbeer had two Bellman Hangars.

This design was at one time the most common steel hangar of which approximately four hundred were located on British Airfields between 1938 and 1940. The Bellman Hangar became obsolete during the 1940's when superseded by the " T - series " Hangars.

 

Blister Hangar

 

R.A.F. Harrowbeer had eight Over Blister Hangars.

Blister Hangars were produced by Messrs C. Miskin and Sons in 1939. There were basically three designs:-

          ( 1 ) The " Standard " which was constructed of wooded arched ribs, clad with corrugated iron and had a span of forty five feet.

          ( 2 ) The " Over Blister " constructed of steel arched ribs, clad with corrugated iron with a span of sixty five feet.

          ( 3 ) The " Extra Over Blister " constructed as ( 2 ) but with a span of sixty nine feet.

All three styles were manufactured in forty five foot length sections making it possible to construct a ninety foot long building if required.

It was usual to have canvas curtains at each end for protection against the weather, sometimes the canvas curtain at one end would be substituted for a brick wall.

An advantage of the Blister Hangar was that they did not require foundations or hard standing, therefore being flexible enough to be constructed on fairly uneven ground.

 

Blast Shelters

 

Within the Technical Area were constructed Blast Shelters which were traversed blast walls built above ground in a large rectangular shape with shielded entrances. These shelters were for personnel to use at the last minute, minimizing the disruption of their duties.

There were three standard sizes giving effective protection for 10, 20 or 30 personnel.

 

Bomb Dump / Store

 

On airfields built in the early stages of the Second World War bomb storage was of a simple and economical design. This comprised of open Bomb Dumps, each around 200 Tons capacity made up of four 50 Ton bays seperated by grass covered blast banks/walls. This was an easy way of manhandling and storing small capacity bombs, from unloading off delivery lorries to re-loading onto the Bombing-up trolleys. Efficient movement of vehicles was ensured by circulating roads from the Bomb Storage area, Component Stores, Pyrotechnic Stores and other ancilliary Explosive Buildings in hutted construction, onto the Fusing Shed and onto Aircraft Dispersal. 

 

R.A.F. Harrowbeer had a two bay Bomb Store. The earth blast banks/walls and unloading ramps are still visible. The area were the bombs were stored is a little harder to identify, but they are there, as are the tarmac roads leading too and from the Bomb Dump.

 

Broadcasting System

 

This is probably better known as the ' Tannoy '. It's general purpose was to enable operational instructions to be given clearly, rapidly and simultaneously to personnel at dispersal points and other distant parts of the airfield.

Microphones were placed in the main operational buildings eg:- Operations Block, Watch Office and Battle Headquarters and connected to a Speech Broadcasting Building which housed the amplifying equipment. This small blast-proof building was normally found close to the Watch Office. Cables ran to an average of 150 loudspeakers spaced around the airfield.

It was often found that the early type of Battle Headquarters on an airfield that was no longer required ( due to the building of new deisign Battle Headquarters ) was used for the Broadcasting and back-up System. It is not sure if Harrowbeer's original Battle Headquarters was used for this purpose. There are photographs that show loudspeakers on poles on the ends of the Dispersal Bay arms at Harrowbeer.

 

Cannon Test Butt

 

This was constructed as a robust brick and concrete wall with returns and sand piled up against it. A red flag would have been flown when firing was taking place at the test butt.

Another feature at the butt was usually a large grooved block which would contain a pulley wheel, this was used to enable the tail-wheel of an aeroplane to be raised in order that the aircraft's guns and cannon could be tested and re-aligned as required.

 

Compass Base

 

The Compass Base at R.A.F. Harrowbeer consists of a round concrete base thirty feet in diameter with a central bronze pin level with the top of the base. There would have been a circular ring fixed in the ground at sixty feet diameter to the bronze pin which would of had the points of the compass marked on or fixed to it.

The thirty feet concrete base and pin are in situ but the outer ring can only be located by a slight ridge where it should be.

 

The Compass Base was used fairly frequently to check the accuracy of an aircraft's compass. This was done by positioning the centre of gravity of the aircraft over the central pin in the centre of the concrete base. A trolley was normally placed under the tail wheel of the aeroplane so that it could be rotated easily. The aeroplane was moved in a circular movement to the main points of the compass on the fixed outer Compass Base ring and the aircraft's compass was checked for accuracy against this. There was also a field compass on a tripod close by that was used as a three way check for accuracy. If an inaccuracy was found it was marked on a variation card which was kept in the cockpit of the aeroplane alongside the compass.

Compass variations were often caused by an aircraft's armoury, the amount of ammunition on board, bomb loads and or other metallic additions to the aircrafts normal construction.

When an aircraft was in flight ( on an operation ) and the Flight Controller gave the pilot a course to fly the pilot would have to check the variation card against his compass and given course, make the necessary calculations ( in his head ) and fly in that direction. A miscalculation could result in the pilot missing the target or rendezvous point.

 

Dinghy Drill

 

This would usually be carried out at a local swimming pool, pond or reservoir, ( for R.A.F. Harrowbeer they used the Moorland Links Hotel outside swimming pool ).

The proceedure was that the aircrews were blindfolded ( to give the impression of night time conditions ) the thrown into the water. Each man had a whistle which he could blow, allowing them to come together as a group. An inflated dinghy was dropped upside down in the water and the aircrew had to locate it, right it and then climb on board.

 

Direction Finder

 

Also known as the ' Radar Directional Finder '. This was a building which contained instrumentation that could follow ( track ) aircraft by means of radio ' fixes ', these were obtained from the I.F.F., ( Identification Friend or Foe ) sometimes known as the ' pip squeak ' which was a small automatic transmitter fitted in the aircraft's cockpit.

The Direction Finder passed an aircraft's position onto the Stations Operations Room. From here it was calculated the aircraft's interception course and the information given to the Flight Controller. He could then direct the friendly aircraft to intercept a hostile aeroplane.                      

A code was used between the Flight Controller and the pilot of an aeroplane:-

            Scramble = Take off  

            Angels = Height in thousands of feet ( eg. Angels ten = ten thousand feet )

            Orbit = Circle a given point

            Vector = Steer a course of . . . . . degrees

            Buster = Use full throttle

            Tally ho = Enemy sighted

            Pancake = Return to base and land

R.A.F. Harrowbeer's Direction Finder was in the vicinity of the junction to the Moorland Links Hotel on the A386 road. On one side of the main road was the transmitter and on the other side was the receiver, all that remains today are the concrete bases.

 

Dispersal Bays / Pens

 

Dispersal Bays were constructed as substantial earth banked areas with small retaining walls on the inner edges in the rough shape of a letter " E " if viewed from above. Harrowbeer's Dispersal Bays were designed for Hurricane and Blenheim sized aircraft.

These bays would offer blast protection for two aircraft and their ground-crew. At the intersection of the three banked fingers most bays housed a Stanton type Air-raid Shelter for up to twenty five persons. This was entered from each aircraft standing area by an entrance with a short tunnel with a dog-leg built into the earth banking, next was a door into the shelter. Within the shelter was sometimes an emergency exit which consisted of a ladder fixed to a wall leading up to an escape hatch through the top of the shelter. There was also an emergency exit built into the rear of the Dispersal Bay leading off from one of the short entrance tunnels.

Some of the aircraft standing areas had concrete pads for the aircraft to be positioned on, this was because various types of aeroplanes ( the Typhoon in particular ) were notorious for leaking oil and fuel which broke up the tarmac standing area making it unstable. Around the edges and in the centre of the concrete pad were metal loops set in the ground for securing the aircraft in strong windy and gale force conditions.

Another feature on some of the earth banked fingers of the Dispersal Bays was a defence, anti aircraft gun position. R.A.F. Harrowbeer had twelve Dispersal Bays of which four had these gun positions for either Browning or Lewis guns.

On the central earth banked finger, towards the extremity on the ground in each of the aircraft standing areas is a small brick rectangle. It's purpose is not clear, but was possibly used for standing fire fighting equipment on ( fire buckets with sand and a fire extinguisher ).

 

Fencing

 

Barbed Wire     The best use of barbed wire as a means of defence during the Second World War was in rolls. This normally took the form of two rolls on the bottom layer stretched out and interlocking, with one balanced on the top stretched out. The barbed wire would have been held upright by the use of looped metal screw-picket stakes.

Basic Picket Fencing     Airfield perimeter fencing ( as in the type used for R.A.F. Harrowbeer ) and specific defence areas were often encompassed by a waist-high barbed wire fence. This would usually comprise of several straight lines of barbed wire stretched taught and fastened to upright metal angle iron posts. The bases of these posts were concreted into the ground for stability.

 

Flying Control Caravan

 

During the Summer of 1942 to reduce the number of accidents on the airfield, especially on the runways it was decided to position a caravan alongside the touchdown area. Where an airfield had a hard runway the caravan had it's own hard-standing and access track at each end of each runway. The caravan was manned by an Aerodrome Control Pilot who had an Aldis Signalling Lamp and a Very Pistol to warn pilots of danger.

An access track for a Flying Control Caravan can be found at R.A.F. Harrowbeer at the South Eastern end of runway two not far from the large granite rock outcrop.

 

Lighting / Signals / Emergency Landing Systems

 

Aldis Lamps     This was a small moveable trolley which was pointed into the wind, on it were mounted four powerful Aldis Lamps. As the aircraft descended on landing the lamps were switched on, shining a beam of light over the runway surface it was to land on. The aircraft would land into the beam, the lamps being switched off after the aeroplane had touched down on the runway.

Aldis Signaling Lamp     The Aldis Signaling Lamp was a hand held lamp that was used for communicating messages by morse code. There were also provisions for changing filters from clear to red, yellow, blue, green, etc. for use in transmitting the colours of the day when required.

The Darky System     If an aeroplane was in an emergency situation regarding it's condition and position to an airfield it was due to land at the pilot could use the basic life-saver ' DARKY '. This was a system where the pilot could call for a ' Homing ' using the call-sign Darky. Most R.A.F. Stations operated a permanent Darky Watch on a common frequency with a transmitter / receiver of limited range to avoid possible overlap with other Stations. By taking bearings and comparing them by telephone they could rapidly fix a lost aircrafts position and guide it to safety.

Where R.A.F. coverage was poor the Royal Observer Corp Posts could be contacted to assist as they were also equipped with the Darky sets.

 

Gooseneck Flares     The Gooseneck Flare was so called because of the long-necked spout on the container that resembled a large watering can. The main body contained paraffin, or other flammable liquid with a wick travelling up the spout and extending by a small amount. The Gooseneck Flare would be positioned with the spout pointing downwind to prevent flaring when it was alight. It produced a bright light that was extremely difficult to extinguish in the event of enemy aircraft approaching the airfield. The Gooseneck Flares were positioned at intervals along both edges of the runway being used at night to assist the pilots in taking off and landing their aeroplane. On the end of the spout there was a metal hinged flap that could be used to cover the wick to extinguish the flame when no longer requird. When not in use the Gooseneck Flare would be stored in the Night Flying Equipment Building. 

R.A.F. Harrowbeer did not have any form of electrical runway lighting, it was dependant on the Gooseneck Flare system.

 

Landing Foodlights     These were improvised from floodlight units surplas to other services. The floodlights were mounted on three wheeled trolleys for ease of movement around the airfield. One floodlight unit would be placed on the left-hand side on the end of the runway edge and twenty five yards in from the G.P.I.'s so as to shine down the runway length in the same direction as the landing aircraft.

 

Pundit Beacon     This was a mobile beacon which would flash the airfield's Pundit Code ( identity call sign ) high into the sky at night using Morse Code by way of a red light.

R.A.F. Harrowbeer's Pundit Code was ' Q. B. ' = Quebec Bravo.

 

The Royal Observer Corps     Originally called the Observer Corps but later their job was recognised as being of national importance and they were renamed the Royal Observer Corps. Their function was to plot aircraft movements both visually and by sound. All information was then passed on to their respective Group Operations Room by telephone where a complete picture was built up on an Operations Plotting Table of aircraft ( friendly and hostile ) in the area. This information was then forwarded onto Fighter and Bomber Command to be dealt with in the appropriate manner.

R.A.F. Harrowbeer in 1941 had a Royal Observer Corps Post ( a wooded hut ) on the airfield in the area of the Leg O'Mutton. The personnel at that time had no official uniform, they wore an armband. It was not long before they received a uniform very similar to the Royal Air Force, a black beret was worn instead of the R.A.F. forage cap. After a short time the Observer Post was moved off the airfield and set up in an area by the Walkhampton road junction between the Princetown road and the railway line.

 

Sandra Lights     This system comprised three search lights positioned around the airfield which could be directed skywards to form a cone. In the case of low cloud-base when the system was switched on a glow could be seen from above thereby guiding aircraft to the safety of an airfield.

 

Signals Square     The Signals Square was a black area sixty feet by sixty feet edged with a white border and situated fairly close to the Watch Office. On this square was marked the runways in the correct orientation to the main airfield which could be visible by overflying aircraft. The Flight Controller would be responsible for keeping the symbols on the Signals Square up to date at all times.

For instance:- On an airfield, the runway in use for landing and take off was dependant on wind direction. For aircraft coming into land a white ' Landing Tee ' would be positioned on the touchdown end of the appropriate runway showing the direction the aircraft was to land in. There would also be a second white ' Tee ' positioned at the downwind end of the runway. The crossbar was always nearest to the approaching wind. Other signs may include a white       ' Dumb-bell ' = airfield is unservicable except for runways and taxiways, a red ' G ' on a triangular white background = airfield has been subjected to a gass attack, etc. 

The Signals Square was of utmost importance for the reason being that if a pilot was returning from an operation and had lost radio contact he could fly over the airfield and read the signs on the Square.

R.A.F. Harrowbeer's Signals Square is still visible apart from it's markings of the border and runways. It can be found on the Southern side of where the main Watch Office was built. 

 

Signal Mortar     A Signal Mortar was a device built into the ground close to the Watch Office and controlled by the Flight Controller. It was used when visibility was very poor ( usually thick fog ) to guide them to safety.

A very large pyrotechnic flare would be fired from the Signal Flare vertically high into the air when the use of a Very Pistol would be useless. The flare would cut through the thick fog giving off a visual light which could assist the pilot of an aeroplane to either land or proceed to another airfield.

The Signal Mortar at R.A.F. Harrowbeer is still in it's original position, adjacent to the Signals Square and close to the Watch Office. It is three inches in diameter and is stamped around the rim with a date of 1943. We know from the Station Operation Record Book that the Signal Mortar was used on several occasions.

 

Very Pistol     A Very Pistol was a hand held device which fired flares of different colours depending on the situation into the air as a signal to pilots and personnel.

A flare was often fired to alert pilots, air-crew and ground-crew at dispersal of a scramble in the event of other methods failing, eg:- Tannoy or Telephone. A green flare would be fired for aircraft to take off when on the end of a runway awaiting take-off instructions. Flares were often used to warn air-borne pilots to fly round again if they were approaching with another aircraft in a blind spot or the aircraft was attempting to land with it's undercarriage retracted.

There were occasions at R.A.F. Harrowbeer when a red flare would be fired into the air when a squadron was about to return from an operation. This was to call personnel to the airfield from their Dispersed Sites ( around Crapstone ) to clear Dartmoor ponies from the runways and perimeter tracks so that the aircraft could land in safety.

 

Link Trainer     The Link Trainer was invented in 1920 by an American:- Edward Albert Link, it was the first electro-mechanical Flight Simulator.

This was a machine housed in a building which was a very basic representation of an aeroplane with cockpit controls and flight instruments. A bellows arrangement at the base of the cockpit would give the impression of movement. A hood could be placed over the top of the cockpit to give the impression of night so that night flying practice could be carried out.

 

Operations Room    

 

This was normally a windowlss building. The usual design was for the main Operations Room to be constructed similar to a small theatre with a raised dias for the controller. The rest of the building was a maze of rooms and corridors. 

 

Pundit Base and Code    

 

During the Second World War the R.A.F. adopted a system of airfield recognition which was visible from the air.

 

Runways and Taxiways

 

Due to the large number of aircraft at an airfield and the increase in activity there had to be regulation of vehicle movement, the clearance of obstructions and the control of taxiing aircraft. Taxi routes were devised and white lines were painted on perimeter track bends, this proved effective especially at night.

Runways had numbers ( compass bearings ) allocated to their extremities.

R.A.F. Harrowbeer had three runways, therefore they required six numbers. The numbering started from the runway end nearest to North and continued in a clockwise direction. Harrowbeer's numbers were:- 05 / 23      11 / 29      17 / 35. From March 1944 runways were referred to by their magnetic headings.

On an all grass airfield it was possible for a squadron of four aircraft to take-off at the same time in a line abreast, this had the advantage of the squadron to be in fighting formation immediately after lift off. It was also possible for all the aircraft to land at the same time. Another advantage of grass airfields was that take-offs and landings could be made directly into the wind. The disadvantages were that in continuous bad weather the airfield became waterlogged and therefore impossible for the aircraft to take-off or land effectively, this made them vulnerable in the event of an enemy attack. Another factor was that as aircraft were becoming larger and heavier they required a firmer surface to stand on and operate from.

Hard runways ( asphalt, tarmac or concrete ) had a few restrictions, mainly that aircraft could only take-off singly or in a staggered group of three down the runway. Landings had to be carried out one at a time with sufficient intervals between aircraft, a major danger being that if aircraft were landing too close together the following aeroplane ran the risk of being caught in a slipstream which caused it to be thrown out of control resulting in a crash.

The longest runway was normally in the direction of the prevailing wind, other runways used for landing due to unforseen circumstances could involve cross-wind landing which required expertise and handling skills which had to be learnt.  

A Spitfire MKI required 230 yards to take-off and 270 yards to land.

 

Sewage System

 

To minimise the amount of drawings for types of buildings and other site layouts, the R.A.F. standardised as much as possible in order that units could be made en-masse. The sewage system was one such area. By the end of 1939 most sewage layouts were the same comprising:- humus tanks and drying beds, sedimentation tanks and percolating filters.

R.A.F. Harrowbeer's sewage site was to the rear of the Station Sick Quarters and off Stokehill Lane ( Dispersed Site No.13 ), it is still in use today under the control of South West Water.

The Latrines on R.A.F. Harrowbeer were of the chemical toilet type ( commonly referred to as ' bucket and chuck it ' ) and the waste material would be collected at regular intervals and taken to the Sewage Site for processing. Dirty water and storm water was disposed of through a drainage network incorporated in the construction of the airfield.

 

Screw Pickets

 

Short Screw Pickets were commonly used for tying down aircraft.

Long Screw Pickets were used for staking out barbed wire. Barbed wire fencing was used as a method of enclosing an airfield around it's perimeter, airfield dispersed sites and also some anti aircraft gun positions.

 

Smoke Generators

 

This was a device that could indicate wind direction and if required lay a smoke screen. This usually consisted of a slotted metal cover over a pit, the smoke was produced by vaporizing oil or paraffin over a hot surface.

( It is not clear whether R.A.F. Harrowbeer had any on the airfield. )

 

Tactical Units

 

A Tactical Unit ( Squadron ) of twelve aircraft would normally be divided into four sections of three aircraft as follows:-

     Red and Yellow in  " A " Flight

     Blue and Green in  " B " Flight

The pilots in each flight were numbered 1,2 and 3.

Red 1 would lead Red Section followed by Red 2 and Red 3.

 

Watch Office    514/80

 

The Watch Office was considered the nerve centre of a Second World War Airfield second to the Operation Block.

The Watch Office was normally located on the first floor of a two storey building constructed with an internal starcase to the rear. The building also housed a Control Room, Meteorological Office and a Teleprinter Room.

 A Duty Pilot room was situated on the ground floor and it was one of his functions to book the aircraft in and out.

 In the Control Room which was situated on the first floor was a backless iron cabinet and used for storing Very Pistol Cartridges. The cabinet would be situated either infront of a window or an asbestos panel, the reason being that in the event of the contents being accidently ignited the contents would blow out into the open air.

 

R.A.F. Harrowbeer's original Watch Office was a three storey, square tower built alongside the existing house ( known as ' Knightstone House ') and thought to be built early in 1939. It was used for the duration of Harrowbeer's operational life and after the second Watch Office ( a 514/80 ) was built and opened in early 1942 close to the Technical Site operated as a Plotting Room.

The ground floor of Knightstone House comprised five rooms and a staircase to the first floor. The five rooms were:- a Flight Office, 2 Crew Rooms and 2 Workshops ( one of which was used for repairing wireless transmitters and radios ). On the first floor of Knightstone House were a number of rooms used by Squadron Officers and Intelligence Rooms ( as debriefing was carried out within the building ).

It was in this building that on 21st October 1941 No.276 Air Sea Rescue Squadron was formed and used part of it as their Squadron Headquarters until moving across the road to Ravenscroft in February 1943.