Conserving military airfields
The author puts the subject of military airfields in a broad historical context and explains the approach followed in selecting sites and buildings for protection.
RAF Bicester is the best preserved of the bomber bases built in East Anglia and Oxfordshire as part of Trenchard's expansion of the RAF (the Home Defence Expansion Scheme), under development from late 1923. The technical buildings, which include hangars and a control tower, front onto the grass flying field which retains a portion of its defensive perimeter and its bomb stores. It is more strongly representative of Bomber Command airfields prior to the adoption of the Strategic Bomber Offensive than any other site in Britain. The Domestic Site has a splendid group of both original buildings, primarily of 1926, and those of the later phase of the 1930s Expansion Period, with developed Art Deco characteristics.
1 Andrew Saint, 'How Listing Happened', in Michael Hunter (Ed), Preserving the Past (London, 1996), pp. 115-134
2 See David Uzzell, 'The hot interpretation of the Cold War', in English Heritage, 1998.
3 Andrew Sounders, 'The Defence of Britain Project, in English Heritage, 1998, pp. 79, For a characterisation of field remains ' see Bernard Lowry (editor), 20th Century Defences in Britain: an introductory guide, York (Council for British Archaeology), 1995
4 Examples of recording in progress are Johannes Bruns's work on ai eld sites in Germany, the completion of survey work in Brandenburg having underpinned the selection of concrete hangars and barracks buildings at Werneuchen, which functioned as a nightfighter station during the Battle Of Berlin and later as a Soviet fighter airfield close to the NATO border.
5 For a summary of the English Heritage approach, see C.S. Dobinson, J. Lake and A.J. Schofield, 'Monuments of War: defining England's 20th-century defence heritage', Antiquity, 71, Number 272 (1997), pp. 288-299; also English Heritage, Monuments of War The evaluation, recording and assessment of 20th century military sites, 1998. The categories of site covered by the Monuments Protection Programme are as follows: Anti-aircraft artillery, 1914-46; Anti-invasion defences, 1939-45; Bombing decoys, 1939-45; Operation Diver sites, 1944-45; Operation Overlord embarkation sites, 1942-45; Coast artillery, 1900-56; Civil defence, 193945; Airfield ground defences, 1939-45; Radar (with acoustic detection), 1937-45; Cold War sites, 1947-69. The scope and methodology of the survey is summarised in Colin Dobinson, '20th-century fortifications in England: the MPP approach', in English Heritage, 1998, pp. 26. The Listing Team survey of airfields has assessed surviving sites and the documentation for certain themes and sites: see Jeremy Lake and Paul Francis, 'Thematic reviews: military aviation sites and structures', in English Heritage, 1998, pp. 13-17.
6 The Operations Records Book for the fighter airfield at Kenley, for example, states that its permanent buildings accommodated 334 personnel in December 1939, which excludes the hutments then in the course of erection for an additional 320 (Public Records Office, AIR 281419).
7 Lutyens was deputed to deal with the Air Ministry, although the exact nature of his involvement is still unclear.. Dobinson, 1997,pp.136-137.
Our study of military aviation is the third, after barracks and naval dockyards up to 1914, in a series of thematic surveys undertaken in consultation with the Ministry of Defence and other owners. The timing of these surveys has been prompted by the Ministry of Defence's reassessment of its estate and the historic buildings in its ownership and care. As military airfields have formed one of the categories of the defence heritage which have been least understood and potentially most threatened by the processes of disposal and redevelopment, there is now a pressing need to identify the most significant sites and structures.

Mastery of the air touches on some of the essential paradoxes of the 20th century, for despite an awareness of the liberating and even peacemaking potential of air technology, there was a growing realisation throughout the inter-war period that air power had removed the immunity of civilians as well as combatants well away from the battle zone, a point embodied in prime minister Baldwin's dictum 'the bomber will always get through'.

Furthermore, the image in the mind's eye of the mass destruction of civilian populations, and of names such as Guernica, Dresden and Hiroshima, challenge our very notion of heritage. The protection of historic buildings through listing was, indeed, propelled into reality (by the Town and Country .Planning Act of 1944) out of an awareness of the potential destruction of a nation's culture which
aerial bombing brought in its wake, the need to identify what could be saved and the awareness of the opportunities presented to architects and planners by the tabula rasa of devastated city centres.1

Our own attitudes towards this heritage are, of course, inextricably linked to its complexity and associations. There has been a recognition that the horror and 'hot emotions' associated with some sites of the more recent past should not preclude their preservation for future generations, and indeed that they embody society's 'duty of memory'.2 In contrast, however, to the popular interest in the materiel of 20th-century conflict, including the military aircraft which attract thousands to museum sites in Britain and elsewhere, it has only recently been possible to more dispassionately consider the historical role and importance of the sites and buildings which made up its defensive and operational infrastructure. The range and variety of structures involved is enormous, a direct reflection of the changing nature of external threats and the new and varied counter measures built in response to them.

These have had a profound effect on the landscape, from the construction of airfields, radar sites and anti-aircraft batteries, to the thousands of structures and earthworks associated with the anti-invasion defences erected throughout Britain in the summer of 1940. Whilst heritage and amenity has superseded the uncomfortable associations enshrined in fortifications and other building types whose historic and archaeological importance has been recognised for generations, it is only recently that a 'paradigm shift' has enabled us to more coolly assess 20th century sites and buildings.

Volunteers working for the Defence of Britain Project, initiated by the Fortress Study Group and the Council for British Archaeology and launched in 1995, have been undertaking a leading role in the systematic survey and recording of certain types of site.3 This work is now matched throughout Europe, both in terms of recording and an objective historical analysis of sites ranging from the defences of the Atlantic Wall to airfields.4

English Heritage's survey of 20th century military remains embraces all its statutory functions, though with more emphasis on the securing and preservation of historic sites and buildings and the promotion, through publication and other work, our knowledge to the general public. In modern conservation practice sustainability is the key, and this requires a sound understanding and characterisation of the historic resource to underpin decisions regarding management and protection. Despite their recent date, our understanding of the rates of survival and historical context of recent military sites has been surprisingly poor. Prior to our national survey there had been no systematic review of sites, their typology, national distributions, rates of survival, vulnerability and so on; there had been no attempt to characterise the resource. And without that information decisions about the preservation of individual structures could not be made on the basis of informed judgement.

In 1994 English Heritage's Monuments Protection Programme commissioned a survey from the Council for British Archaeology (undertaken by Dr Colin Dobinson) which aimed to provide this overview for eleven classes of monument, and a further study of military airfields for English Heritage's Listing Team, using material held in the Public Records Office.5 This material survives in staggering quantities, ranging from Cabinet papers to the daily records of military units, and service and civilian departments. These records have been used to create full national site distributions (where possible) as well as the dating and typology based on original type drawings. This is the first time that this archive has been used for such a study, and it has enabled us to gain a fresh overview of the subject at a strategic level and understand the rationale and forces which determined the typology, distribution and development of military sites.

After the first ascents of the 1780s, the military potential of balloons for aerial observation was quickly recognised. All the major powers in Europe and elsewhere, notably the Japan and the United States, became aware of the potential of powered flight in the first decade of the 20th century. Development was remarkably rapid, from the setting of the duration record to one mile in May 1909 to the introduction of aerial manoeuvres over the Home Fleet in July and the army in Salisbury Plain in September 1910. Air power was thus conceived as an adjunct of the army and navy, and the first military airfields were built for the army around Salisbury Plain and for the navy's Royal Naval Air Service around the coast.

In April 1910 the War Office's Air Battalion was formed, absorbing the Royal Engineers' Balloon School, and an increasingly serious level of interest from government and the military culminated in April 1912 in the foundation of the Royal Flying Corps, accompanied by an explicit linkage and collaboration at the research and development level with the government's Royal Aircraft Factory at Farnborough. During the course of the First World War, its potential as an independent arm of the armed forces became increasingly clear. When the RAF was formed as the world's first independent airforce in April 1918, and during the period of retrenchment which lasted from the Armistice until the early 1920s, its founding father and first Chief of Air Service, General Sir Hugh Trenchard, concentrated on its strategic role as an offensive bomber force. Trenchard ranks, along with America's Billy Mitchell and Italy's General Douliet, as the most important advocate of the doctrine of offensive de terrence in the inter-war period. Having laid the foundations for a technology-based service - through the training of officers at Cranwell and technicians at Halton Trenchard's expansion of the air force from 1923 was centred upon the building of offensive bomber bases in East Anglia and Oxfordshire, behind an 'aircraft fighting zone' some 15 miles deep and extending round London from Duxford in Cambridgeshire to Salisbury Plain. This principle continued to guide the siting and layout of stations after 1933, when Hitler's rise to power and the collapse of the Geneva disarmament talks forced the British government to engage in a massive programme of rearmament. The deployment of new bases was characterised by the establishment of training and maintenance bases behind an eastern front line extending from Yorkshire to East Anglia - facing Germany. It was the latter bases which provided both the backbone of the RAF's infrastructure during the Strategic Bomber Offensive, augmented by the construction of many new bases on highly dispersed sites, and throughout the Cold War period.

Dispersal against attack
Military airfields have had a considerable impact upon the landscape, and were built in great numbers: 301 air bases at the end of 1918, most of which were subsequently abandoned, more than 100 built in permanent fabric between 1923 and 1939, and the country's total of 150 expanded to 740 - mostly in temporary materials and on dispersed sites - during the Second World War. In addition to their number, typological range and deployment, airfields were divided into the separate functional areas of flying field, domestic and technical sites, with, in the Second World War, provision for close defence in the form of pillboxes and battle headquarters. All of these stations were planned in accordance with Trenchard's requirements that fabric must be dispersed against attack, and airfield building types can be broken down into many different groups, such as barracks, hangers, control towers and synthetic training buildings: all of these can vary in their planning and other features, according to their date and precise function. Like the barracks and particularly naval dockyards which the British state had been constructing since the late 17th century, these new airfield communities also had a considerable social and economic impact on their immediate hinterland,6 although the marked improvement in the quality of design of stations built under the post1934 schemes reflected government and Air Ministry reaction to public concerns over the issues of rearmament and the pace of environmental change. It was in this context that Ramsey MeDonald, as Prime Minister, had instructed that the Royal Fine Arts Commission to be involved in airfield design, and that a process of consultation with the Air Ministry was initiated with visits by commissioners - three distinguished architects (Sir Edwin Lutyens, Sir Reginald Blomfield and Giles Gilbert Scott) and the planning authority Professor S D Adshead - to Upper Heyford and Abingdon in 193 1. This resulted in the creation of the new post of architectural advisor to the Director of Works and Buildings, first occupied by A Bulloch in 1934, with many of the early (1934-35) building designs being specifically approved by the commissioners; afterwards, liaison over layout and other matters was personally handled by Lutyens.7 The buildings erected for much of the 1930s Expansion Period were, as a consequence, more carefully proportioned than their predecessors, a clear distinction being made between neo-Georgian for domestic buildings and more modern styles for technical buildings.

The Officers' Mess and Chalets at Netheravon, one of the most outstanding military aviation sites in Britain, having the bestpreserved suite of domestic buildings of any of the 301 military airfields in existence by the end of 1918. Most of its surviving fabric dates from a crucial formative phase in the development of military aviation in Europe, prior to the First World War. It was the second new site built by the Royal Flying Corps as a whole, the first being the Central Flying School at Upavon, and it was the first new squadron station selected and developed by the RFC's Military Wing, which concentrated here before going to France with the Expeditionary Force in August 1914.

Faced with this level of complexity, the Listing Team survey has pursued a two-pronged approach of fieldwork and documentary investigation. A complete inventory of building and site types, enabling our selection to rest upon a thorough statistical analysis of what has survived, comparison with original populations and a critical analysis of importance or otherwise in a typological and national context, has been compiled by Paul Francis, author of Military Airfield Architecture and the acknowledged national expert on the subject. Colin Dobinson has undertaken archival research, exploring certain themes relating to airfield planning and architecture, particularly from 1923: this study, entitled Airfield Themes, has been published as Volume IX of the '20th Century Fortifications in England' series, otherwise commissioned by the Monuments Protection Programme as a key element in its evaluation of defence sites of this period.

There has been a decisive move away from the provisional list of recommendations drafted by Temple and Francis in 1994, which were clearly aimed at the selection of a broad selection of building types characteristic of military airfields between 1910 and 1945. As a high level of standardisation can rarely be associated with intrinsic merit, on the grounds of either their rarity or architectural virtuosity, it became clear at an early stage that the identification of the most important sites will constitute the most effective method of protecting building types which are otherwise wellrepresented in other, more altered or less significant, contexts. The taxonomic approach, whilst valid to the establishment of a buildings typology, is not considered to be the most effective method of recognising the historical development and character of military aviation in its broad context, one which the identification of key sites can reflect. Outside these key sites, it is only structures which are remarkable for their intrinsic architectural and/or historic merit (such as the Fulton Block at Cosford) or their rarity and importance in an international context (the 1910 hangars at Eastchurch and Larkhill) which will be recommended for listing.

It has to be accepted, as part of this philosophy of approach, that many building types cannot achieve statutory protection as they are not within sites considered to be of national importance on account of their historical interest and completeness: for the latter, awareness of their potential interest for future generations must rest upon the body of research and publication which this thematic survey has generated. Appropriate levels of record must be considered for all categories of site, as a precondition to future management, alteration or demolition.

Historic interest and rarity
In determining our policy for selection, there are obvious factors such as completeness, condition, rarity and the weight of supporting documentation. Factors such as standardisation, however, mean that airfield buildings can rarely be judged to be of intrinsic merit: while early hangars, which in their use of Belfast trusses are closely related to civil dock warehousing from the 1890s, can be recommended for listing on the grounds of historic interest and rarity, the same cannot be said of their interwar successors - there is no English equivalent of either Nervi's or Freyssinet's remarkable experiments in concrete construction in Italy and France. In Britain, the most advanced hangar design were based on Continental prototypes, such as the Junkers-Corporation- designed Lamella sheds and the segmental concrete hangars used for Aircraft Storage Units.

It is clear that the identification of the most important sites will constitute the most effective method of protecting building types which are otherwise wellrepresented in other, more altered or less significant, contexts. These are remarkably few in number. Of all the airfields built up to 1918, only eight have retained suites of buildings which allow a reasonable appreciation of the site's function and importance: hangars at two of these sites - Calshot and Yatesbury - have already been listed at grade II*. The great mass of buildings erected in this period - of temporary materials expected to last for the conflict only - were either cleared after 1918 or have since decayed. The layout and fabric of inter war permanent bases is generally better preserved, although the completeness or otherwise of original detailing is closely linked to the nature and intensity of post-war use. Thus, while Upper Heyford became a key USAF site in the Cold War, less intensive use has ensured that Bicester is the most complete bomber airfield to have survived from the period up to 1939. The fighter airfield at Duxford, now the site of a world-famous air museum, survives as the pre-eminent example of a multiperiod site. It has buildings dating from both world wars and the two inter-war phases of expansion: its most recent addition is Foster and Partners' elegant HeritageLottery funded hangar, housing the museum's fine collection of American aircraft.

The officers' mess at Hullavington, one of the first stations planned under the post-1934 expansion of the RAF and - with Manby in Lincolnshire - the best preserved and most architecturally distinguished.
Duxford's distinguished wartime associations, both in the context of the Battle of Britain and the US Air Force's involvement in the European theatre, introduces the important criterion of historical association. During the Second World War Britain's entire layout of military airfields was involved in the war effort, although some can be more readily identified with key events than others. Association with the Battle of Britain has already formed a basis for the conservation area designations and listings of the officers' messes at Biggin Hill and Hornehurch, and there are additional sites and structures associated with this vital battle - most notably the control room at Uxbridge, preserved exactly as it was described by Churchill in 1940 - which merit protection.

In contrast, the strategic bomber offensive of 1942-45 was longer, less focused, and involved a much larger number of bases, mostly 1930s Expansion Period stock, plus many wartime temporary airfields. Arguing for the preservation of single bases solely on the grounds of their association with the campaign is too generalised, but prime among the stations holding associations with famous raids is Scampton, which in 1943 became the home of the newly-formed 617 Squadron.

During the Second World War, the Air Ministry had been forced to abandon its dislike of temporary butting, and the materials used during the acute timber shortage, such as Maycrete, Laing and Thorn huts, were all far below its desired standards. Nissen huts were reintroduced in 1941, and manufacturers of the more successful prefabricated huts such as the Seco Curved Asbestos, BCF and Orlit looked ahead to the post-war housing shortage. Moreover, and in contrast to the permanent structures and tightly-defined sites characteristic of the inter-war period, the temporary structures of the stations built during the Second World War are spread across many square miles of land. Whilst the inter-war 'permanent' stations were retained for use by the Royal and US air forces during the Cold War period, the great majority of the latter were disposed of after the war. Many surviving groups are now in agricultural use, with consequent adaptations, and others are in an advanced state of decay, leaving only the remains of runway strips and ruinous control towers. Those currently in good repair, invariably those used for light industrial purposes, have needed, for example, more durable systems of cladding, and none have retained their full complement of technical and domestic buildings.

The character of airfield sites and structures, and the sheer range of standardised types, demand a multidisciplinary approach to their protection. Airfield buildings are structures which fall most easily within the framework for listing, a system of managing change which is most suitably applied to buildings which are in use or capable of some form of reuse (PPG 15, 3.8). The earthworks and pillboxes - both concrete and hydraulic associated with airfield defence in the Second World War can be most suitably managed as monuments through the scheduling legislation: airfield defences are the subjects of reports by Dobinson and Francis, commissioned by the Monuments Protection Programme. However, a component-orientated process such as listing (or scheduling for a small number of airfield defences) cannot in themselves provide the means to protect the character of extensive areas.

Conservation areas can also have a significant role, alongside the drafting of local plans, in maintaining the character of what we consider to be the sites most strongly representative of their type and period. Conservation area designation has its precedents: Hornehurch was designated in 1989, followed by Hullavington in 1992 and Biggin Hill in 1993. The local plan process is also a vital part of recognising the importance of flying fields.

The identification of key sites also brings with it the need to work with owners and occupiers in order to compile guidelines for management, which have been successfully applied to buildings affected by the post-war listing programme and are currently being piloted on the domestic site at Bicester, currently occupied by the Defence Clothing and Textiles Agency and shortly due for a greater intensity of use. Their value to all parties centre on the elucidation of precisely what are the restraints imposed by listed status, including the identification of buildings which are not of listable merit but merit protection, internal features and paint colour, and the role of tree planting and spatial ordering in the planning of sites. Where statutory protection is not appropriate, non-statutory planning guidance has a significant role.

CONTEXT 66 : JUNE 2000