Summary
The Wing Test Hangar at the Rolls-Royce site, Watnall Road, Hucknall, comprising a brick building, H-shaped in plan with concrete de-tuner supports to the west.
Reasons for Designation
The Wing Test Hangar at the Rolls Royce site, Watnall Road, Hucknall, erected by Rolls-Royce in 1944, is listed at Grade II for the following principal reasons:
Historic interest:
* For its connection with aviation engine developments of national and international importance in the mid C20, notably the testing and continued war-time development of the iconic Merlin engine, and of Frank Whittle’s turbojet engine, the first commercially viable jet engine.
Architectural interest:
* As a largely intact and rare building type used for the testing and development of aviation engines. It illustrates the technological and design needs for its function with surviving fixtures and fittings for that purpose dating to construction in 1944, and to the mid C20: notably an engine-testing control panel, observation windows, wing spar mount assembly, roller doors, pierced metal sheet lining, as well as fittings and support for a detuner.
Group value:
* The Wing Test Hangar has strong group value with two pairs of aircraft hangars constructed in 1916 and listed at Grade ll, which stand on the Rolls-Royce site to the south (List entries: 1234854, 1275906)
History
An airfield was established at Hucknall in 1917 for the Royal Flying Corp. In 1934 Rolls-Royce leased two hangars at the site and established a testing programme there for aero engines and ancillary equipment (Rolls-Royce Flight Establishment). At this time the site was confined to the south of the current site, alongside the Watnall Road. Over the following years the site expanded northwards driven for the most part by the demands of the war and the development of the turbojet. The wing test hangar building was built in 1944. Both the south (no.1) and the north (no. 2) hangars were designed for piston engine testing, but the north hangar was then used for jet engine testing.
Amongst many world-leading developments at Hucknall, it is worth noting that the Merlin Engine was tested through the early 1940s and developed from a 650 horse power (HP) to a 2000 HP engine, and was adapted for the American Mustang fighter aircraft there. The flight testing and further development of Frank Whittle’s jet engine was undertaken at Hucknall in the mid 1940s. The world’s first commercial turboprop engine, the Dart, was tested in the wing-test hangar, and the world’s first flight of a commercial jet aircraft flew from Hucknall to the Paris Airshow in the late 1940s.
Air photos show the Wing Test Hangar from above, in 1944-48 and in 1948 (Rolls-Royce Heritage Trust and the Historic England Archive respectively), when it was H shaped in plan, as now. The image of 1944-48 shows test enclosures had been constructed at the east end of both the north and south hangars, but by 1948 enclosures had been added to the west ends also. These enclosures provided blast protection and mitigated against the effect of excessive noise on personnel in the surrounding buildings. Only the enclosure at the east end of the north hangar, and that at the west end of the south hangar (much altered) survive. The enclosure at the west end of the south hangar contains three phases of masonry. It is possible that a fragment of an early brick enclosure (shown in the 1944-48 aerial photo) survives as fragmentary red-brick components in the concrete-block walls. The lower courses of concrete blocks appear to be the enclosure of the 1948 image, while the upper courses are for a modern roofing over.
It is notable that the brick bonding of the central range is different to the brick bonding of the hangar ranges and that the bricks do not at the upper levels consistently course through from one to the other. This may indicate that the hangar ranges were added in 1944 to the core of an earlier structure. Whatever, the building as it is now (2018) is largely as it was in 1944.
The Wing Test Hangar is shown, still in its 1948 form, in an aerial photo of April 1953 (Historic England Archive), but it was later altered. By the time an air photo was taken in June 1968 (Historic England Archive) the form of the roof covering had changed to the present covering and a detuner (now lost except for concrete plinths) is shown in an air photo of that year at the west end of the north hangar, replacing the test enclosure there. The metal collar for the detuner (still in-situ in the west wall of the north hangar), is contained within a panel of secondary brickwork that has replaced a full height roller door. The brickwork panel and metal collar were added in 1958 for the Conway engine development. The Conway was the world's first dual shaft bypass turbine engine and required a detuning arrangement to mitigate against the considerably greater noise generated during testing. The wing spar in the north (no. 2) hangar was removed at this time and replaced with a purpose-built thrust measuring bed, of which the concrete plinths survive.
In the late 1960s, the south hangar was converted to house a wind tunnel and the test enclosure at the west end was roofed over (shown in the aerial photo of June 1968) and used as an adjoining workshop where models for testing in the wind tunnel were constructed. The test enclosure at the east end of the south hangar was demolished in 1985 for ease of access to the hangar.
The Wing Test Hangar is now occupied by the Hucknall branch of the Rolls-Royce Heritage Trust and used as an engine museum.
Details
A former wing-test hangar constructed in 1944 by Rolls-Royce for the testing of aeroplane engines, and concrete supports for a 1958 detuner to the west; now a museum.
MATERIALS
The building is constructed of red brick, laid to English and Flemish bond, with concrete lintels, steel small-pane windows, and a flat, metal-covered roof.
PLAN
The building is H-shaped on plan, comprising the south (no.1) hangar and north (no.2) hangar, with concrete block enclosures at the east end of the north hangar and the west end of the south hangar. Beyond the footprint of the building to the west there is an external area for engine exhaust de-tuning: the de-tuner no longer survives but concrete supports remain.
EXTERIOR
The building is of pier and panel construction, given additional support by internal steelwork, with a flat roof (lead covered?), edged by a shallow brick parapet with blue engineering brick coping. Rainwater goods comprise metal down pipes with rectangular heads supplied through portals in the brickwork. The hangar ranges are blind in the main, both with full-height, central sliding doors (timber in a steel frame and metal lined) for vehicular loading access, and small side lights, as well as a pedestrian doorway to one side. Various electrical equipment, conduits, pipes and other gear is attached to the exterior face of the building. The main elevation is to the east from where both hangars are accessed by full-height, full width, metal roller doors, under a full span concrete lintel. Access to the roller-door mechanism is gained via small metal doors at the top corner of the side elevations. The south lintel carries the painted sign, in faded black letters on white, ‘HUCKNALL TEST OPERATIONS INVENTORY STORE J1’. Over the north roller door, the lintel carries the painted sign, ‘2’. The north roller door is fronted by a single-storey concrete-block perimeter wall, with a doorway to the north, which contains a small enclosure area for noise and blast containment. This is the most intact of similar enclosures which stood at each end of both hangar ranges. That at the west end of the south hangar is altered and is of two phases of concrete block construction with a cat-slide roof. It incorporates a fragment of brick walling in its west elevation. The other concrete-block enclosures have been lost.
Concrete plinths and supports for external de-tuning equipment, now lost, are located to the west of the north range, the site of a former concrete-block enclosure. A circular metal collar is housed in the brickwork panel of the west wall of the north range through which the engine exhaust was vented and to its left is an entrance door (timber in a steel frame with a sheet steel lining.) The brick panel here is secondary (1958) and replaced a metal roller door.
The central range has a full-height central section contained within a single-story section to front and a low, two-story section to the rear. Its brickwork is laid to an extended Flemish bond (three stretchers to a header). Windows sit below concrete lintels and on sloping, two-course blue-brick cills. The single-storey section to the east, its brickwork now painted white, forms the entrance way via modern doors. Access to its flat roof is gained by metal fire-escape stairs to the right. The upper level of the two-storey section of the central range is lit from the east by a full width, small-paned metal-frame window, with two-pane opening lights (this window is currently (2018) boarded over internally). Beneath the window are three doorways. The rear, west elevation of the central range is of two storeys, lit by three bays of small, square windows to the upper storey (containing modern timber frames) and two, similarly proportioned windows at ground-floor level, containing 3 over 3 metal window frames, either side of a timber sliding door.
INTERIOR
The interior comprises two engine-testing laboratories in the north and south hangar ranges, and office and monitoring accommodation in the central range. The building contains numerous engines and other equipment, artefacts and signs that form the museum exhibits. Only fixed equipment and fixed signs that were used when the building was functioning for engine and wind-tunnel testing are included in the listing.
The interior comprises two engine-testing laboratories in the north and south hangar ranges, and office and monitoring accommodation in the central range. The hangar ranges are of a single, open space with concrete floors. The walls and ceilings are lined with steel sheets, those on the walls pierced. Square steel-framed, viewing windows of the upper floor of the central range look down into the engine testing hangars. Lights attached to the side walls of each range lit the room in test conditions. Electrical switches and dials of various dates survive throughout the building.
The roller door survives at the west end of the south hangar, the partner to that at the east end, up and unused at the junction of the original building and the concrete block, roofed over, test enclosure. Located approximately central to the north wall of the south hangar is a wing spar mount assembly, with a gantry crane over this area of the range. The wing spar helped in supporting a wing section to which engines were fitted for testing. Wing sections (now lost) were a permanent fixture in both hangars.
The north hangar is an open space. Its gantry crane has greater range of travel than that of the south hangar; almost the full length of the room. A tall concrete plinth each side of the room formerly supported a steel framed carriage (installed in 1958 for testing the Conway engine but now lost), from which engines were suspended during testing. Marks on the metal, ceiling sheeting show the location of former full height sound baffles.
The ground-floor of the central range contains office accommodation at the east entrance end (a suspended ceiling here) and a doorway gives access to the north hangar. Access to the south hangar is via a centrally located doorway. Stairs at the west end, with a tubular hand rail, give access to the upper floor. At the upper level a small partitioned office, with a mid-C20, four-panelled door, stands at the top of the stairs, against the south wall. Located centrally on the north side there is a panel of controls and test monitoring equipment on each side of the north hangar observation window. At least the base panel and throttle levers date to 1944. There are small rooms in the corners at the east end, which appear to be secondary, and steps up to a central east exit door.
