American Air Museum, including 'Counting the Cost' war memorial, Thriplow, Cambridgeshire

Summary

Museum exhibition hall, built in 1995-1997 to the designs of Sir Norman Foster and Partners, with Ove Arup and Partners as consulting engineers and John Sisk and Son as main contractor. A contemporary war memorial sculpture entitled ‘Counting the Cost’ by Renato Niemis lines the ramped walkway leading to the main entrance.

Description

MATERIALS: the building's roof is constructed from precast concrete panels stitched together with in-situ reinforced concrete and covered with a waterproof membrane. Its foundations, floor slab, A-frame abutments and retaining walls, the latter covered by a grassed, earthen bank, are all of in-situ reinforced concrete. A glazed curtain wall forms its principal façade.

PLAN: the building, which stands on a north-west to south-east axis, is a half-ellipse on plan, rising from its narrow north-west end, where a low entrance way is cut into the grassed, earthen bank, to a tall, glass curtain wall that cuts off the ellipse just before its mid-point.

STRUCTURE: the form of the American Air Museum is that of a giant concrete shell partly buried in a raised landscape. Its curved roof, which spans a distance of 90m, consists of a single composite system made from two precast concrete shells measuring 100mm thick and spaced 900mm apart. Adopting the geometry of a torus (see HISTORY section), it consists of a total of 924 precast panels, with the lower shell being formed of 274 curved panels with an inverted T-shaped cross-section (10m long by 2m wide). These panels support 650 curved rectangular panels (3m long by 1.9m wide) forming the top section. Forces from the roof are collected into an in-situ curved upper concrete ring beam and are then passed through an aluminium-framed clerestory, which varies in width from 500mm at the front (south-east) of the shell to 3000mm at the rear (north-west), via 34 steel arms spaced at 4m intervals to a lower in-situ concrete ring beam at abutment level and then to the concrete abutment walls and foundations. A grassed, earthen bank covers the retaining walls up to clerestory level, while the roof above is covered with a waterproof membrane.

EXTERIOR: at the front of the building, which faces south-east across the airfield, the arched opening is closed by a glazed curtain wall with a circular sector of 63m radius, 90m width and 18m maximum height. The glazing is supported by a series of steel-plate twin mullions 25mm thick and 40mm apart (clamped together with studs), spaced at 3m intervals. Every mullion is of a different height and shape to match the bending diagram, with the taller mullions being deeper and the shorter mullions shallower, all with a curved profile. It is stabilised out-of-plane by the roof, but is otherwise self supporting, using 19mm sheets glass (with an ultraviolet film applied in the early C21), the largest of which are 3m wide and 5.5m high. To ensure overall stability of the façade in its own plane, the mullions are linked into vierendeel frames, each with two mullions and one set of transoms. Double-leaf glazed doors are positioned at the centre and at each end of the façade.

At the narrow north-east end is the building's main entrance. Placed below the clerestory, it comprises plate glass doors with sidelights flanked by reinforced-concrete wing walls.

INTERIOR: the main entrance leads directly onto a mezzanine floor overlooking the ground-floor display area, with recesses to its left and right-hand side accommodating a café and a small exhibition space respectively. From the mezzanine two cantilevered, ramped walkways, which are lit from above by the clerestory, descend to the ground-floor display area. The walkways have tempered glass balustrades embedded at the base and surmounted by a stainless steel tubular handrail on the display area side, while the opposing side has a double-line stainless steel tubular handrail fixed to the perimeter walls (which are angled at 30 degrees from vertical) by projecting steel brackets.

At the rear of the ground floor, immediately below the entrance, is a small exhibition room known as the Georgia Frontiere Gallery (named after one of the major US Appeal Board members).

Flanking the left- and right-hand side of the entrance to the Georgia Frontiere Gallery, at around the quarter-way point from the rear, there are recessed doorways with double-leaf wooden fire doors through which toilets, plant rooms and storage rooms are accessed.

To the underside of the roof, which is comprised of the underside of the inverted T-units of the lower shell, each panel has two aircraft suspension points of cast-in steel sockets.

The floors are of reinforced concrete with an epoxy-resin finish. Several, contemporary, concrete benches are dispersed throughout the display area.

SUBSIDIARY FEATURES: a contemporary glass war memorial sculpture entitled ‘Counting the Cost’ by the artist Renato Niemis lines the raised walkway leading to the museum’s main entrance. It comprises 52 glass panels engraved, in 1:240 scale, the plan-view silhouettes of the 7,031 Eighth and Ninth Air Forces and US Navy aircraft lost while operating out of British bases during the Second World War. Each panel bears the outlines of the exact number and type of aircraft lost by specific USAAF groups and US Navy squadrons. Stainless steel inscription panels read: COUNTING / THE / COST // DEDICATED / TO ALL THE / AIRMEN / WHO FLEW / IN THE / SECOND / WORLD WAR // US AIRCRAFT / LOST / FLYING FROM / UK BASES // USAAF / 8TH AF / 6346 / 9th AF / 692 // US NAVY / 24 // Supported / Henry Moore / Foundation // Friends of the / Imperial War // Simon Gibson // artist / Renato / Niemis.

History

RAF Duxford, which represents the finest and best-preserved example of a fighter base typical of the period up to 1945 in Britain, formerly closed in 1968, although its last operational flight took place in July 1961. With the airfield not being large enough to accommodate the new generation of fighter jets, the Ministry of Defence declared its intention to dispose of the site in 1969. Although various schemes were put forward, including a prison and a sports centre, none came to fruition. In 1976 the airfield finally received a new lease of life, when the Imperial War Museum (IWM) obtained permission to use it for the storage, restoration and eventual display of exhibits that were too large for its headquarters at Lambeth Road, London. The following year the IWM joined forces with Cambridgeshire County Council to purchase the runway and thus restore the airfield to operational use, an arrangement which continued until the IWM acquired the site outright in 2009.

In 1975, the year before the IWM took over the airfield, Lieutenant Colonel John Woolnough, a B-24 Liberator pilot during the Second World War, formed a veteran’s association in the United States, the 8th Air Force Historical Society. As Duxford had become 'Station 357' of the United States Army Air Forces (USAAF) Eighth Air Force 78th Fighter Group on 1 April 1943, Woolnough was keen to support Duxford's emerging plans for a tribute to all the American servicemen who served out of British bases during the Second World War along with a memorial to the 30,000 servicemen who lost their lives. To this end, in 1977, the 8th Air Force Memorial and Museum Foundation (8AFMMF) was formed as an adjunct to the 8th Air Force Historical Society to support activities perpetuating the memory of the Eighth Air Force, with Duxford considered the obvious site on which to concentrate their representation in Europe.

An important aspect in the growth of the IWM Duxford collection was the acquisition of many historic American combat aircraft. Following the restoration of a P-51 Mustang, now on display at the museum's headquarters in London, several important American aircraft were acquired from the late 1970s, including a B-17G Flying Fortress in 1978, a B-29 Superfortress in 1980 and a B-52 Stratofortress in 1983. Much of the restoration work was financed by the 8AFMMF, who also donated memorabilia for a permanent Eight Air Force exhibition housed in an annex to one of the existing hangars where the American aircraft were displayed. As the collection and visitor numbers grew, however, it became obvious that there was not only scope but also a need for something more ambitious than the existing exhibition. Plans were subsequently developed in favour of a scheme which would not only embrace the Second World War USAAF connection, but one that incorporated all American military aviation connections with the United Kingdom. To attract donations from the United States, particularly as the estimated cost of a purpose-built exhibition hall was estimated to be in the region of £700,000, the appeal was widened to include First World War and Cold War elements, thus transforming it into a tribute to US air power.

In 1985, at around the same time the project for what would become the 'American Air Museum in Britain' was being initiated, the architect Norman Foster visited Duxford at the request of two Cambridge-based friends who were unhappy with the design of a new hangar about to be built on the east side of the airfield. Although Foster's offer to design a more aesthetically-pleasing building was too late, Edward Inman, Duxford's then director, was so impressed with his ideas, along with his passion for aviation, that he proposed to the Trustees of the USAAF Collection that Foster should be approached to design the new exhibition hall. With the Trustees having already decided that a building of inspirational design would help significantly with their fund-raising campaign, they subsequently provided Foster with a brief requesting a museum that was large enough to accommodate 21 aircraft whilst providing optimum enclosure, in terms of humidity levels and ultra violet protection, for their conservation. As well as highlighting the take-off and landings during air shows and maximising the use of natural light, the trustees also requested that the building should provide the exhibits with a neutral backdrop and be of a restrained appearance due to its rural location. Further key aims were low capital costs, low costs in use and ease of construction. In due course, in co-operation with Ove Arup and Partners as engineer consultants, Foster designed an elliptical-shaped building whose width and height was informed by the dimensions of the B-52 Stratofortress (a 16m high tail and a 61m wingspan). Costs were to be controlled by suspending some of the aircraft from the roof while a vertical glass wall on the runway (south-east) side would provide the main natural light. To achieve a dramatic visual experience, the visitor entrance at the north-west end was to be at a raised level confronting the nose of the B-52 and providing a panorama of the whole collection.

While Foster's concept was met with unanimous approval, its proposed £10 million cost, which rose to a daunting £15 million when the proposed IMAX cinema, all interior fitting-out and three years inflation were factored in, necessitated a substantial fundraising campaign on both sides of the Atlantic. This began in England in 1987, where Sir John Granby was appointed as Co-Chairman of the UK Appeal, and in the United States in 1989, where Texas Senator John Tower was named US Co-Chairman (both were later replaced, with the actor Charlton Heston taking over in the US in June 1991 and Field Marshall Lord Bramhall in the UK in December 1992). Among others, Lieutenant General James ‘Jimmy’ Doolittle, commander of the Eighth Air Force over Europe during the Second World War, and the actor James Stewart, a former Eighth Air Force B-24 pilot, spearheaded the campaign in the US, while British support was provided by HRH the Duke of Kent and HRH the Duke of York. The project was widely supported with 60,000 individual donations, of which some 50,000 came from the US, aided by high-profile fundraising events in Washington DC (1989), Los Angeles (1992 and 1994), and Houston (1995). In 1991 the Saudi Arabian government donated $1 million in gratitude to the US and British forces for their efforts in the Gulf War.

Planning permission for the American Air Museum was approved in August 1991, by which time Ove Arup and Partners had refined the roof structure. This, along with the decision to eliminate the cinema and postpone the retail fixtures, reduced the estimated cost to £8 million. Further refinements established the building cost at £7.5 million and the design was completed in early 1993. With great foresight, most of the money raised from the fundraising campaign was used to finance detailed design work, meaning that the project was well placed to receive the first ever grant, of £6.5 million, from the Heritage Lottery Fund in 1995, which finally allowed construction to start.

A ceremonial groundbreaking ceremony was conducted on 8 September 1995, attended by 500 guests, of whom 300 were USAAF veterans. Building work commenced 21 days later with the site excavated to a depth of 3m to accommodate reinforced-concrete foundations followed by retaining walls. Work on the curved roof, the building's single biggest element, began in February 1996 and utilised pre-cast concrete panels made off-site. As the building’s affordability was dependent upon an efficient roof structure that was both simple to manufacture and construct, the choice of a rational construction geometry was key to it being made from high-quality, factory-produced components. This was solved by designing a double-shell roof based on the rationalisation of the geometry of a torus (or doughnut) in which a small fragment was used, the surface of which being defined by two constant radii. In this way, with all the elements of the roof having the same curvature, namely a 278m principal radius and a minor radius of 64m, its 924 precast panels were made from just six sets of standard concrete components rather than the 1000 or so one-off components that would be required for a doubly-curved roof of constantly changing radius. When the roof was completed in the summer of 1996 it was the largest precast concrete structure in Europe. Installation of the aircraft began on 2 September 1996, with the first placements being those suspended from the roof. After the final aircraft was installed on 16 September, though some later additions were taken into the building in sections and reassembled inside, work commenced on the demountable curtain wall. While this was completed in December, work on the internal finishes along with the installation of mechanical plant and exhibits continued until the official opening. This took place on 1 August 1997 by Her Majesty Queen Elizabeth II and was attended by some 4,000 USAAF veterans. Critical acclaim for the building arrived in 1998 when it won both the Royal Institute of British Architect's premier award, the Stirling Prize, over the favourite, Colin St John Wilson’s British Library, and the Royal Fine Art Commission/British Sky Broadcasting Building of the Year award.

On the same day the American Air Museum was opened, the Queen also unveiled a war memorial to the 30,000 US servicemen who lost their lives on active service in the United Kingdom during the Second World War. Entitled ‘Counting the Cost’ by the London-based artist Renato Niemis, it lines the approach ramp to the museum’s entrance and comprises 52 glass panels engraved with the plan-view silhouettes of the 7,031 Eighth and Ninth Air Forces and US Navy aircraft lost while operating from British bases.

In March 2016 the American Air Museum was re-launched following a five-year development project (with the museum being closed for one year of that time) which, undertaken by Redman Design, re-imagined the exhibition to tell the stories of not just the aircraft but also the people connected with them. A third of the £3 million cost went towards removing the building's curtain wall and then putting it back up again so the aircraft, with the exception of the B-52, could be temporarily removed for safety checks and restoration. To preserve the restored aircraft an ultraviolet film was applied to the curtain wall to minimise the risk of sun damage.

Reasons for Listing

The American Air Museum, built in 1995-1997 to the designs of Sir Norman Foster and Partners, with Ove Arup and Partners as consulting engineers, and the contemporary ‘Counting the Cost’ war memorial sculpture by Renato Niemis, are listed at Grade II* for the following principal reasons:

Architectural interest

* Architect: as an outstanding, later-C20 building by one of England’s most significant and internationally acclaimed modern architects, one which illustrates how the practice put aside the exposed structural framing of its earlier work in favour of a curvilinear form which anticipates some of its later buildings;

* Technological innovation: its simple form belies the fact that it deploys an innovative construction geometry which, based on the rationalisation of a torus, allowed for the creation of a very efficient structure which was simple to manufacture and build;

* Design: as a powerful and striking design which illustrates Foster’s devotion to the principles of architecture as an art form and his passion for flight; the curved concrete roof derived from the stressed skin structure commonly employed in aircraft construction, its toroidal geometry resembling the cockpit of a modern fighter jet and its buried form reminiscent of a Second World War blister hangar truly encapsulate his aeronautical metaphors in a dramatic but refined symbolic quality;

* Skilful planning: its internal planning and effective layout illustrates how Foster revolutionised the building’s function to maximise the space available for exhibits and allow for a unique user experience;

* Landscape relationship: the use of the Second World War blister hangar metaphor is a significant contextual design feature for this historic airfield site, creating a wholly new yet recognisable building form that successfully connects the museum to its landscape setting.

Historic interest:

* for successfully combining an acknowledgement of the emergence and dominance of United States air power during the C20 with a powerful and evocative tribute to all the American servicemen who served out of British bases during the Second World War along with the 30,000 airmen who lost their lives, as exemplified by Renato Niemis’ ‘Counting the Cost’ war memorial;

* as a purpose-built museum which was designed to accommodate the Imperial War Museum’s collection of American combat aircraft, regarded as the most impressive group outside the United States;

* for Duxford’s important association with the United States Army Air Forces Eighth Air Force 78th Fighter Group.

Group value:

* for its strong group value with the buildings and structures at former RAF Duxford, recognised as the finest and best-preserved example of a fighter base representative of the period up to 1945 in Britain, with four buildings listed at Grade II* and 38 at Grade II.

External Links

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