Details

The monument includes the defensive structures situated around the perimeter
of the former World War II airbase known as RAF Sawbridgeworth. The airfield
dates back to the First World War when it was built as an emergency night
landing ground for pilots experiencing difficulties returning to their home
bases. In 1937 the airfield, known as Mathams Wood, was designated as an
advanced landing ground (ALG) providing the RAF with a training facility for
the squadrons in 22 Group, Army Co-operation Command. From 1940 onwards
Mathams Wood ALG was extended and upgraded ready for full-time operations
during World War II. The flying field was extended into a three runway layout,
constructed using Sommerfeld wire mesh, encircled within a concrete perimeter
road complete with dispersed aircraft pens and hardstandings. Other associated
buildings constructed at the time included sleep shelters, pillboxes,
ammunition stores, Blister hangars, operations rooms, barracks and a watch
office. Following the cessation of RAF operations here in the late 1940s many
of these were removed.

The monument is in eight separate areas of protection. The first area encloses
a large brick and concrete pillbox sited in the corner of a field 200m south
east of Blount's Farm and some 250m north of the southern perimeter road of
the airfield. The square pillbox has a diameter of 7m and a wall thickness of
1.5m. Each gun aperture (six in all) measures 250 sq mm at its interior wall
and fans out to 1.4m by 0.9m at its exterior wall. Two of the apertures have
Turnbull machine-gun mounting pivots.

The second protected area encloses a large brick and concrete hexagonal
pillbox and an adjacent road barrier stanchion situated near Fiddlers Brook,
on the northern side of Parsonage Lane. The pillbox has a diameter of 7m, a
wall thickness of 1.5m and an entrance on its south eastern face. The pillbox
has two gun apertures, facing north west and south east along the road. The
road barrier stanchion, originally set closer to the road, would have
supported a wooden barrier designed to block unauthorised traffic to the
airbase.

The third protected area encloses a brick and concrete hexagonal pillbox at
the south western corner of Matham's Wood. The pillbox has a diameter of 6m, a
wall thickness of 1.5m and a covered entrance with anti-ricochet walling. Two
gun apertures afforded a good view over the open ground to the south and south
west.

In the north west corner of Matham's Wood a fourth protected area encloses a
hexagonal pillbox of the same design as that at the south western corner,
except that it has three gun apertures, facing to the north, north east and
north west. A covered entrance in the south eastern side gives access to the
pillbox from the direction of the airfield.

Further to the south east, along the northern edge of Matham's Wood, a fifth
protected area encloses two infantry firing trenches and a hexagonal pillbox.
The pillbox is of a similar design to the others in Matham's Wood: 6m in
diameter with a covered entrance faced with anti-ricochet walling. As with the
others it has only limited apertures to enable views north and north east over
open land, and a single entrace facing towards the airfield. The trenches lie
to either side of the pillbox forming a line of defence approximately 40m in
length which would have defended the airfield from attack from the north. The
trench to the north west of the pillbox is crescent-shaped in plan providing a
wide field of fire to the north. The inner face of the trench is lined with
corrugated iron sheeting held in place by 13 vertical angle-iron stakes.
Remains of concrete-filled sandbags survive along the trench's front parapet,
and to the rear is an earthen bank. The trench to the south east is also
crescent-shaped in plan, brick-lined and with a brick-built ammunition recess
at its western end. As with the western trench, the remains of concrete-filled
sandbags are in place along the northern edge.

The fifth area of protection includes part of the northern circuit of the
airfield perimeter road, forming a 600m long arc around the north west corner
of Mathams Wood, complete with three aircraft dispersal pens (set
approximately 200m apart) two further pillboxes, a sleep shelter, a small arms
ammunition store and the Battle Headquarters. All three dispersal pens have
the same design and means of construction: a banked earth enclosure, partially
supported by brick retaining walls, 3m in height and built in a crescented
E-shape, incorporating an air raid shelter built into the central junction of
the arms. The outer arms of each pen enclose an area with a maximum width of
approximately 25m and have a light tarmac surface, strengthened in the centre
where the aircraft would have stood. Each pen would have accommodated two
aircraft within the shelter of its three arms. The air raid shelters could
accommodate up to 25 men during an attack. They each have a central room made
from concrete `Stanton' parabolic shelter panels bolted together and set into
a concrete base slab. Two brick-built passageways gave access from the two
aircraft bays and a third provided an emergency exit leading out of the pen.
The pens are linked to the outer perimeter road by concrete aprons. In between
the first two pens, set back approximately 70m from the airfield perimeter
fence, is a brick and concrete hexagonal pillbox measuring 7m in diameter. It
has four gun apertures and covered entrance. An inscription on the internal
face of the door lintel reads `APL.11.1940'.

To the south of the south eastern dispersal pen is a rectangular brick and
concrete sleep shelter - effectively an air raid shelter with fixed bunks for
overnight accommodation. The building is approximately 7m long by 3m wide with
a flat roof. Internally it is divided into a series of sleeping bays and could
accommodate up to 33 men. Lacking windows, ventilation was afforded by air
bricks and an air extractor system.

To the south of the sleep shelter is the final group of structures within
Matham's Wood: a pillbox with associated small arms ammunition store and the
airfield Battle Headquarters. The pillbox is of brick and concrete
construction, 7m in diameter with three gun apertures and a covered entrance
with internal anti-ricochet walling. Approximately 4m to the north are the
brick foundations of the small arms ammunition store. The Battle Headquarters
lies to the south of these two structures. This is a largely subterranean
structure with only the look-out post projecting above-ground. The entry
stairs give access down to a further five rooms: sleeping quarters; mess room;
office; lobby and latrine. A small escape hatch with an iron ladder provides a
secondary (emergency) exit adjacent to the look-out post. The look-out post
has a 360 degree observation slit and a signal mortar tube in its roof.

The last two protected areas each enclose a hexagonal pillbox. Both are 6m in
diameter and each has only two gun apertures. The first is located on a field
boundary 200m to the east of Matham's Wood. The second is positioned on the
same field boundary a further 100m east.

All modern fences, fence posts and metalled-surface trackways are excluded
from the scheduling, although the ground beneath them is included.

MAP EXTRACT
The site of the monument is shown on the attached map extract.

Source: Historic England

Reasons for Scheduling

The importance of defending airfields against attack was realised before the
outbreak of World War II and a strategy evolved as the war went on.
Initially based on the principle of defence against air attack, anti-aircraft
guns, air raid shelters and dispersed layouts, with fighter or `blast' pens to
protect dispersed aircraft, are characteristics of this early phase. With
time, however, the capture of the airfield became a more significant threat,
and it was in this phase that the majority of surviving defence structures
were constructed, mostly in the form of pillboxes and other types of machine
gun post.
The scale of airfield defence depended on the likelihood of attack, with those
airfields in south or east England, and those close to navigable rivers, ports
and dockyards being more heavily defended. But the types of structure used
were fairly standard. For defence against air attack there were anti-aircraft
gun positions, either small machine gun posts or more substantial towers for
Bofors guns; air raid shelters were common, with many examples on each
airfield; and for aircraft, widely dispersed to reduce the potential effects
of attack, fighter pens were provided. These were groups together, usually in
threes, and took the form of `E' shaped earthworks with shelter for ground
crew. Night fighter stations also had sleep shelters where the crew could
rest.
For defence against capture, pillboxes were provided. These fortified gun
positions took many forms, from standard ministry designs used throughout
Britain and in all contexts, to designs specifically for airfield defence.
Three Pickett-Hamilton forts were issued to many airfields and located on the
flying field itself. Normally level with the ground, these forts were occupied
by two persons who entered through the roof before raising the structure by a
pneumatic mechanism to bring fire on the invading force. Other types of gun
position include the Seagull trench, a complex linear defensive position, and
rounded `Mushroom' pillboxes, while fighter pens were often protected by
defended walls. Finally, airfield defence was co-ordinated from a Battle
Headquarters, a heavily built structure of which under and above ground
examples are known.
Defences survive on a number of airfields, though few in anything like the
original form or configuration, or with their Battle Headquarters. Examples
are considered to be of particular importance where the defence provision is
near complete, or where a portion of the airfield represents the nature of
airfield defence that existed more widely across the site. Surviving
structures will often be given coherence and context by surviving lengths of
perimeter track and the concrete dispersal pads. In addition, some types of
defence structure are rare survivals nationally, and all examples of Pickett-
Hamilton forts, fighter pens and their associated sleep shelters, gun
positions and Battle Headquarters closely associated with defence structures,
are of national importance.

The remains of the north western sector of the former airfield RAF
Sawbridgeworth centred on Matham's Wood survive very well with three of the
five fighter pens constructed in this sector surviving in a near complete
state, along with an associated sleep shelter and sections of the perimeter
roadway. Fighter pens are now rare survivals in England, and with their
associated structures they provide a valuable illustration of the measures
taken to protect fighter planes during World War II.

The provision for defence against capture at RAF Sawbridgeworth also survives
exceptionally well with nine pillboxes remaining in the northern and western
sectors of the airfield, one associated with infantry firing trenches. The
associated Battle Headquarters - the nerve centre of the defensive operations
is a rare and particularly important structure.

Source: Historic England

Sources

Books and journals
Dobinson, C S, Twentieth Century Fortifications in England: Volume X Airfield Defences in WWII, (2000)
Dobinson, C S, Twentieth Century Fortifications in England: Volume X Airfield Defences in WWII, (2000), 60-1
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995)
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995)
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995)
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995)
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995), 17
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995), 75
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995), 32-3
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995)
Doyle, PA, Where The Lysanders Were: The Story Of Sawbridgeworth's Airfields, (1995)
Buchan Innes, G, 'Aviation Pocket Guide' in Aviation Pocket Guide 1: British Airfield Buildings of the Second World War, (1995)
Buchan Innes, G, 'Aviation Pocket Guide' in Aviation Pocket Guide 1: British Airfield Buildings of the Second World War, (1995), 46
Buchan Innes, G, 'Aviation Pocket Guide' in Aviation Pocket Guide 1: British Airfield Buildings of the Second World War, (1995), 40-1
Buchan Innes, G, 'Aviation Pocket Guide' in Aviation Pocket Guide 1: British Airfield Buildings of the Second World War, (1995)
Other
10.4.73, Ordnance Survey, OS-73-066-479, (1973)
10.4.73, OS, OS-73-066-479, (1942)
10.4.73, OS, OS-73-066-479, (1973)
10.4.73, RAF, OS-73-066-479, (1973)
11.10.46, RAF, CPE-UK-1788-3403, (1946)
16.8.61, RAF, 58-RAF-4627-0169, (1961)
18.5.48, RAF, 58-36-Pt I-5090, 1, (1948)
18.5.48, RAF, 58-36-Pt. I 5090, 1, (1948)
18.5.48, RAF, 58-36-Pt.I-5090, (1948)
18.5.48, RAF, 58-36-Pt.I-5090, 1, (1948)
18.5.48, RAF, FNO-68-1096 and 2096, (1942)
21.5.52, Ordnance Survey, OS-2R21-0111, (1952)
21.5.52, Ordnance Survey, OS-2R21-0111, (1952)
21.5.52, RAF, OS-2R1-0111, (1952)
21.5.52, RAF, OS-2R21-0111, (1952)
26.7.42, RAF, FNO-681096 and 2096, (1942)
26.7.42, RAF, FNO-68-1096 and 2096, (1942)
26.7.42, RAF, FNO-68-1096, (1942)
26.7.42, RAF, FNO-68-2096, (1942)
RAF Hendon Museum, RAF, RAF Sawbridgeworth, (1944)
RAF Museum Hendon, Air Ministry, RAF Sawbridgeworth, (1944)
RAF Museum Hendon, Air Ministry, RAF Sawbridgeworth, (1944)

Source: Historic England