Hangar No.2 and Hangar No.3 RNZAF Base Ohakea

Kororareka Avenue, Rnzaf Base Ohakea, Ohakea

  • Hangar No.3 at Ohakea Air Base.
    Copyright: NZ Historic Places Trust. Taken By: Blyss Wagstaff. Date: 15/07/2009.
  • Interior of Hangar No.2.
    Copyright: NZ Historic Places Trust. Taken By: Blyss Wagstaff. Date: 15/07/2009.

List Entry Information

List Entry Status Listed List Entry Type Historic Place Category 1 Public Access Private/No Public Access
List Number 9009 Date Entered 26th August 2011

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Extent of List Entry

Extent includes part of the land described in Sec 57 Blk XV Rangitoto SD (No.2 Hangar) & Sec 58 Blk XV Rangitoto SD (No.3 Hangar), (NZ Gazette, 1937, p 1462), Wellington Land District, the buildings known as Hangar No.2 and Hangar No.3 RNZAF Base Ohakea thereon, and their fittings and fixtures. (Refer to map in Appendix 1 of the registration report for further information).

City/District Council

Manawatu District

Region

Horizons (Manawatu-Wanganui) Region

Legal description

Sec 57 Blk XV Rangitoto SD (No.2 Hangar) & Sec 58 Blk XV Rangitoto SD (No.3 Hangar), (NZ Gazette, 1937, p 1462), Wellington Land District

Location description

The RNZAF Base Ohakea is located 22 km west of Palmerston North on State Highway 1 between the towns of Bulls and Sanson.

Summaryopen/close

Royal New Zealand Air Force Base Ohakea’s No.2 and No.3 Hangars have been recognised as two of New Zealand’s great engineering achievements of the twentieth century.

Designed during the lead-up to World War Two, the hangars were to accommodate one of the two bomb squadrons of 12 medium bombers. This was recommendation by Sir Ralph Cochrane (1895-1977) in 1936, for the Department of Defence. The Cochrane report stated that the security of New Zealand, the United Kingdom and their shipping routes required air defence. The squadrons were intended to locate and attack enemy raiders before they reached New Zealand, supported by a reserve of personnel, an army co-operation squadron, and a territorial air force. By 1937 the Ohakea settlement had been selected as an appropriate site for an airbase within which one of these squadrons would be accommodated.

Among the first of the structures to be built on this air base were the monolithic concrete hangars. Built by McMillan Bros Limited at the cost of £76,750 per hangar, the availability of construction materials for the buildings had prompted the use of a unique design that used reinforced arch concrete construction. Due to the imminent threat of war, steel structuring was difficult to obtain within the 15 month time period allocated. The hangars were completed by the beginning of 1940 and measured 94.5 metres by 64 metres. A further two hangars of the same design were subsequently built at Whenuapai, another new airforce base located in West Auckland. When war was declared in September 1939, the plans for the Ohakea base as a whole were rapidly enlarged; this included the rapid construction of further hangars, however this time using steel structuring.

Following World War Two, the two hangars continued to play a key role in the Ohakea Base. In 1948 the numbering of the hangars was changed with No.1 being changed to No.2 and No.2 Hangar being allocated the number 3. Following the reorganisation of the RNZAF in the late 1950s, changes were made to No.2 Hangar to accommodate the strike aircraft squadrons No.14 (Canberra) and later No.75 (Vampire). Changes were also made to No.3 Hangar to accommodate the RNZAF’s communication squadron No.42. From 1970 the Vampire jets were replaced by Skyhawks. In November 2001 following a review of New Zealand’s defence capabilities and funding strategies the Air Combat Force was disbanded and the Skyhawks put up for sale. No.3 Squadron, which currently operates the Iroquois and Sioux helicopters, moved to Ohakea in January 2002, and are currently housed in No. 3 Hangar. No. 2 Hangar currently houses the No.75 Squadron of fixed wing aircraft.

The Ohakea Hangar’s No. 2 and No. 3, with their then rare reinforced arch concrete construction, are of outstanding technological significance within the engineering heritage of New Zealand. Their rapid construction also reflects the increased importance placed on aeroplanes leading up to and during World War Two. As part of a wider landscape of buildings related to the history of New Zealand’s air force, the hangars are two of the original structures built at Ohakea and as such have historical significance. With only minor changes made to the hangars in their lifetime, they continue to be used for the purpose for which they were constructed.

Assessment criteriaopen/close

Historical Significance or Value

The two hangars are of considerable historical importance, both nationally and locally, due to their association with the early phase of the operations of the New Zealand Air Force. Their impact nationally was to provide a centre for the development of New Zealand’s air defence through the housing and maintenance of aircraft and the men who flew and serviced them. The hangars are therefore representative of the increased importance placed on aeroplanes in World War Two. They have played a long and important role in the history of the RNZAF and its operations.

Aesthetic Significance or Value

Royal New Zealand Air Force Base Ohakea’s No. 2 and No. 3 Hangars have special aesthetic significance, derived from their massive size and presence, their design, and the manner of their construction, which allows for awe-inspiring interior spaces. They loom large over the rest of the air base and are easily visible by traffic travelling northbound on State Highway One.

Architectural Significance or Value

The hangars are of high architectural significance due to their innovative design. Furthermore when designing the hangars, Turner was unaware of structures of similar design so these were essentially created in a design vacuum. The design, thought to be more splinter proof than other designs, was the first of its kind to appear within the British Empire.

Technological Significance or Value

The Ohakea hangars used materials that reflected the difficulties posed by World War Two. The shift from steel to concrete gives the structures added significance, as the adaptation made the design that much more difficult. The hangars were completed largely without the aid of the kind of large machinery available today.

Social Significance or Value

Ohakea’s No. 2 and No. 3 Hangars have a close association with the main squadrons and generations of airmen and maintenance crew who worked and socialised in the building. With the end of the strike force a plaque was placed on the outside of No.3 Hangar in recognition of the contribution made by 75 Squadron from 1946 to 2001.

(a) The extent to which the place reflects important or representative aspects of New Zealand history

The unprecedented large size of Ohakea’s No.2 and No.3 hangars represents the increased importance placed on the Air Force in World War Two. Aeroplanes formed a significant part of the war effort and this was recognised through dramatically increasing the size and capacity of the RNZAF and making it a separate entity from the defence force.

(b) The association of the place with events, persons, or ideas of importance in New Zealand history

An initial important association for the Ohakea Air Base was with Robert Cochrane, and this relates directly to the report he wrote for the Department of Defence. This initiated the construction of the base, as part of the larger plan to improve the air defence of New Zealand and protect its shipping lines with Britain. The base was designed by the Public Works Design Department who were also responsible for the design of the Whenuapai Air Base. The Hangars were designed by Charles Turner, Chief Designing Engineer of the Public Works Department, who had extensive experience with reinforced concrete through the construction of the bridges on the Napier – Gisborne railway line.

(e) The community association with, or public esteem for the place.

There is a strong community association with No. 2 and No. 3 Hangars at the Ohakea Air Base due to the huge impact that their presence, and that of the entire base, has had on local communities. The base itself is a community in which the two hangars are well-regarded and important functional buildings. The RNZAF and local Ohakea personnel are strongly aware of the heritage importance of the buildings.

(g) The technical accomplishment or value, or design of the place

The outstanding technical accomplishment of the hangars can be easily understood when the adaptation of reinforced arch concrete construction is taken into consideration. The use of these materials is illustrative of how compromises were made when building structures during the war as a result of the difficulty of obtaining materials such as structural steel.

The mobile steel frame that was used during construction of the hangars was an important technical aspect of their construction. Utilising his experience with bridge construction Turner essentially created the interior space of the hangars by enclosing space between arches that are reminiscent of the traditional bridge arch. For a structure of this scale ten large arches were aligned to create the extensive floor area required. This type of construction was proven to be more bomb proof than other designs and was the first of its kind to appear within the British Empire.

In 1990 Hangars No.2 and 3 were recognised by the Institute of Professional Engineers (IPENZ) as part of the ‘Engineering to 1990’ awards.

(h) The symbolic or commemorative value of the place

Royal New Zealand Air Force Base Ohakea’s No. 2 and No. 3 Hangars have commemorative value. Following the end of the strike force in 2001 a plaque was placed on the outside of No.3 Hangar in recognition of the contribution made by 75 Squadron from 1946 to 2001.

(j) The importance of identifying rare types of historic places

The concrete hangars are rare in New Zealand; the only other examples are the two identically designed hangars at the Whenuapai Air Base.

(k) The extent to which the place forms part of a wider historical and cultural complex or historical and cultural landscape

The hangars are part of the original Ohakea Air Base complex, which was established in accordance with the recommendations made by Sir Ralph Cochrane and the provisions of the Air Force Act 1937 to ensure that air defence was available to protect New Zealand during what became World War Two. The establishment of the base reflects the increased importance placed on air defence during this period and the hangars serve as physical evidence of this. They were the principal buildings on the base, which then included a flying field, a 1.6 kilometre (mile) long runway, and accommodation for the air force personnel.

Conclusion

It is considered that this place qualifies as a Category I historic place.

Royal New Zealand Air Force Base Ohakea’s No.2 and 3 Hangars have been recognised as two of New Zealand’s outstanding engineering achievements of the twentieth century. Ohakea Air Base’s No.2 and 3 Hangars were amongst the first air defence structures to be purpose built for the Royal New Zealand Air Force and can be considered special for their technical importance and the role they have played since. Their construction was part of an overall plan to improve the air defence of New Zealand and its shipping lines with Britain at a time when a second world war appeared imminent. The design of the hangars was a significant engineering feat at a time when construction materials were sparse and time was critical. The use of concrete reinforcing meant the hangars could be constructed within 15 months, without requiring expensive steel structuring to be imported from Britain.

Both hangars have played a long and important role in the history of the RNZAF and its operations, and retain a large degree of integrity despite ongoing maintenance issues. The sheer size and scale of the hangars has major significance in aesthetic terms but also in its relationship with the wider historical landscape of the Ohakea Air Base.

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Construction Professionalsopen/close

Public Works Department

No biography is currently available for this construction professional

McMillan Bros Limited

Builder J L McMillan originated in Dunedin and later moved to Wellington. In the early 1900s he won the contract to build the Miramar Gas Works and a Wellington tramway building, most likely the 1908 Corporation Tramways head office formerly at the corner of Lambton Quay and Thorndon Quay. In the mid twentieth century McMillan’s sons James and Lloyd established McMillan Brothers. This firm was responsible for the construction of a number of North Island freezing works and buildings particularly in the Manawatu. In World War Two the firm was co-opted by the government to construct the Ohakea Hangars. The firm is now part of McMillan and Lockwood Group.

Additional informationopen/close

Historical Narrative

Introduction

Construction of the RNZAF Base Ohakea began in 1938 with the express purpose of strengthening the newly christened Royal New Zealand Air Force. The timing would prove invaluable when, along with other allies, New Zealand was declared at war with Germany on the 3 September 1939. Hangars No.2 and No.3 were built as part of the overall construction plan that was quickly extended at the outbreak of war.

Early advent of New Zealand’s air defence

New Zealand’s role in World War One was a reflection of its close ties with Great Britain. Over 100,000 New Zealanders were sent overseas, many for the first time, and fulfilled a variety of positions. Included in this were nearly 300 airmen who served with the Royal Flying Corps. They received training at two commercial flying schools, the Canterbury Aviation Company at Sockburn and the New Zealand Flying School in Hobsonville, Auckland. Henry Wigram, the establisher of the Canterbury school and a politically influential figure, insisted that the Government take notice of the importance of air defence. At the end of the war he gifted Sockburn Airfield expressly for the purpose of establishing military aviation.

It was not until 1923 that the Government established the New Zealand Permanent Air Force (renamed the Royal New Zealand Air Force (RNZAF) in 1934), as a division of the army. Initially, attention was given to the establishment of aerodromes, and as early as September 1930 a scheme had been advanced for the establishment of a chain of landing grounds. The Public Works Department (PWD) was to undertake the work, using unemployed labour wherever possible.

In 1935 the Labour Government decided that the air force should become a separate arm, and Tom Wilkes, Director of Air Services, was approached to prepare a scheme. He recommended that an expert from the United Kingdom be asked to draw up a report. Wing Commander the Honourable Ralph Cochrane (1895-1977), AFC, of the Royal Air Force was selected for the task. His report, entitled 'Air aspect of the defence problems of New Zealand' and known as the Cochrane report, took the view that the security of New Zealand, the United Kingdom and their shipping routes required air defence. Cochrane recommended that the air force operate as a separate service controlled by an air board under the Minister of Defence. It would comprise two permanent squadrons of 12 medium bombers capable of locating and attacking enemy raiders before they reached New Zealand; a reserve of personnel to support these squadrons; an army co-operation squadron in time of war; and a territorial air force.

This report was accepted and Cochrane was promoted to the rank of Group Captain and asked to stay on for two years to implement his proposals. The first stage was for the RNZAF to establish two permanent squadrons equipped with medium bombers. This immediately heralded the need for the construction of bomb storage, repair facilities and accommodation for the two squadrons. As the first appointed Chief of Air Staff of the RNZAF, Cochrane selected two aerodrome sites, one at Whenuapai, near Auckland and the other at Ohakea, near Palmerston North. The construction of these bases and the other proposals in his report was begun in earnest on 1 April 1937 under the legislative authority of the Royal New Zealand Air Force Act.

RNZAF Base Ohakea – its beginnings

The escalating tension that was stirring in Europe at this time made it apparent that a second world war was imminent. It was also clear that should war be declared, the aeroplane was going to have a significant role in the defence of the Empire. This gave added impetus to the construction of the RNZAF Base Ohakea, the chosen location of which was considered an ideal site due to its sheltered position and an absence of hills for around 48 kilometres (30 miles).

The properties taken for the Ohakea base were all situated in Block XV Rangitoto Survey District. Previously known as Pukenui, the 700 hectare (1732 acres) tract of land had been sold by James Bull to the Crown in 1899 under the provisions of the Land for Settlements Act. Renamed Ohakea Settlement, it was subdivided into 16 sections and sold for dairy and agricultural farms under the Lease in Perpetuity system.

The previous Maori landowners were Ngati Apa who had been negotiating a number of informal lease arrangements with European settlers from the mid-1840s. These leases and the subsequent Crown purchases became the focus of a recent settlement as part of a claim to the Waitangi Tribunal, which sees Ngati Apa (North Island) as having right of first refusal should the Crown dispose of the land upon which the RNZAF Base Ohakea is located. The RNZAF base at Ohakea is located on the traditional lands of the Kurahaupo people. The area was originally occupied by Rangitane, whose influence in the region had decreased towards the mid 1800’s. Ngati Apa then established themselves in the region, an iwi formed out of circumstances during the early and mid 1800s. Ngati Apa is an old name for these people, signifying that they are the descendants of Apahapaitaketake and Nga Wairiki, the eponymous ancestors of Ngati Apa. Nearby Parewanui is a Ngati Apa centre and is located 8km south-west of Bulls. Two pa sites belonging to Ngati Apa are located almost immediately to the west of Ohakea. One pa (S23/4) is recorded as a gunfighter pa dating to about 1868, the other (S23/75) known only as Mangamahoe Pa.

The area of is also acknowledged to be of significance to Ngati Kauwhata and other iwi including Rangitane o Manawatu. As part of the Deed of Settlement with the Crown, Ngati Apa have agreed to provide Rangitikei-based iwi an opportunity to jointly purchase this property if the right of first refusal is exercised.

Construction of the Ohakea base was also aided by the flat nature of the land and the relatively small amount of earthworks required. Five properties, covering a total area of nearly 200 hectares (491 acres, 3 rods and 33 perches) were taken under Section 254 of the Public Works Act and comprehensive plans were prepared by the design office of the Public Works Department. The base was to include a flying field, 1.6 kilometre (a mile) long runway, two hangars and what would amount to a self-contained township to accommodate the air force personnel. The plans also made allowances for more hangars to be built should they be required. The initial two hangars were to be identical and among the first of the structures to be built. They were designed by Charles William Oakey Turner (1901-1994), Chief Designing Engineer of the PWD.

Turner was born in Cardiff, Wales in 1901 and immigrated to New Zealand in 1925. He had been travelling between the United Kingdom (UK) and New Zealand working as a marine engineer on coal-fired sailing ships when the 1925 British seamens’ strike occurred. He decided not to return to the UK and with his experience and degree in mechanical engineering he was able to secure a job in the PWD design office in Wellington, where he spent the next seven years. During his time at PWD Turner became involved in a number of projects, a significant example of which was the construction of the Mohaka Viaduct (Category I historic place, Reg. No. 4418, built 1930-1937). Following the Hawke’s Bay earthquake in 1931 Turner was seconded to the Hastings, Napier, Wairoa and Gisborne Borough Councils. In this role Turner was responsible for approving construction work and issuing permits. As a result of this work, he made important contributions to the establishment of seismic design principles. These principles were to form the basis of the first earthquake design code for New Zealand.

After winning a Commonwealth scholarship Turner completed his Masters in Engineering, studying at both Stanford University and the University of Illinois. On his return to New Zealand Turner was appointed deputy to William Langston Newnham (1888-1974), PWD’s Chief Designing Engineer (1929-1936), and eventually succeeded Newnham in 1937. During this time Turner played a key role in the design of concrete road and rail bridges. This work included designing arch bridges on the Napier to Gisborne railway line. The construction technique of arch-bridge falsework was to be used again by Turner in the design of the hangars at Ohakea and later Whenuapai.

Monolithic designs

The two hangars that Turner designed were the major buildings to be built on the base. The layout and orientation of the hangars was carefully considered concurrently with the whole aerodrome development, and with close involvement of the Air Department. Each hangar was 67 metres in width and 58 metres in depth, with a door opening 7.6 metres high. The total floor area of each was 3475 square metres. This would allow for ‘a considerable number of modern bombing machines of a wide wing-spread’. The floor area was established by arranging cardboard models of aeroplanes and determining the most economic use of the space. The hangar space was also to be surrounded by annexe accommodation making the total floor space of each building 5333 square metres. The annexe accommodation included space for instrument and repair shops; carpenter’s shop; flight workshop; machine room; fabric and dope room; parachute room; armoury; wireless rooms; navigator room; lecture room; library; and an area for photographic work.

Several options with varying types of construction were put forward by Turner, along with estimates. These options varied in the location of where the arches were to be tied and the position of the openings. There was some debate over whether a rear-ended opening would be more suitable. However, for the Wellington bombers to be housed in the hangars, front openings were adopted. The choice of construction material was debated extensively by the PWD, as the large size of the hangars meant that their weight would not allow normal construction methods of boxing and concreting to be used. Despite the use of structural steel being a cheaper and much preferred option it had to be abandoned as delivery took a minimum of 20 months and such a delay was unacceptably long. So an innovative plan to use reinforced arch construction was devised. The construction process was sped up by the use of readily available reinforcing bars. Turner stated that the choice between ferro-concrete and structural steel was one of ‘economics and expediency’.

Taut string of the bow

The design adopted utilised two-hinged arch ribs. For a structure of this size 10 great arches of reinforced concrete were required, the feet of which would sweep down far outside the outer walls. This ‘shell’ type of structure also allowed for the roof itself to act as part of the stress-carrying structure. The weight of this roof was a major design consideration as it would bring about a large outward thrust from the base of the arches, thus requiring a very strong force to join them together. Instead of the usual method of thrusting up the bases of the arches by heavy concrete foundations, ten rolled steel joists were placed in pairs – end to end – in order to connect the extremities of the arches at ground level. The hangars were believed to have been more resistant ‘… to destruction by bombing than one embodying a structural steel roof.’

However, once in place the joists were found to be out by 2.5 centimetres, so oil burners were then ‘played’ on them until the joists expanded enough to be locked together. Once the joists began to cool, the contractions caused a tension of an estimated 150 tons, which helped to counter the thrust of each arch, ‘providing, in effect, the taut string of the bow’. The buttresses of each arch were poured from the ground up, allowing for the huge steel frames required to support the remainder of the arch to only need to support the clear middle span. This made them mobile and through continuously pouring the concrete arches, three bays at once, the hangars were rapidly erected. Using a system of pulleys and winches each arch was adjusted into position using the back wall as a base. Upon completion of the first hangar, the steel frames could be shifted to the next without being dismantled, despite being constructed of 138 tonnes of steel.

Tenders for the construction of the hangars were advertised for on 11 January 1938, with the successful contractors being McMillan Brothers Limited with a tender of £105,127. Not included in the price was the fabrication of the steelwork by Cable and Co. Wellington, and other structural and reinforcing steel and its transport. The construction phase presented several challenges, as the chosen design was unusual at this time. The standard form adopted in the Royal Air Force stations in Great Britain used heavy structural steel, which as aforementioned was difficult to obtain within the 15-month time frame. However the use of this reinforced concrete ‘shell’ type of construction was gaining favour and there were at the time several examples to study, although these examples were mostly of a smaller size. However, unbeknown to Turner until after his design was completed, this particular method on this scale had previously been used by the French and German Air Forces.

New Zealand at War

New Zealand declared itself at war with Germany on 3 September 1939, and the Ohakea Air Base was officially commissioned on 18 September 1939. No.1 Hangar was completed shortly after the opening, with No.2 Hangar opened later, early in the following year. The hangars, which in the end cost £76,750 each, attracted much attention for their size and for the engineering difficulties that were overcome during construction.

The base’s first role was to train observers and air gunners, and new recruits, the first intake arriving on 20 September 1939. Most were to receive their final training through the Empire Air Training Scheme, based in Canada, before being posted to the Royal Air Force or an RNZAF unit. However, by October 1940 the main role of the base had shifted to pilot training with the establishment of the 3rd Service Flying Training School. In late 1940 the Recruit Training School was closed and relocated to Levin. For a short period in 1940 the Auckland Ground Reconnaissance Squadron, normally based at Whenuapai, was moved to Ohakea for convoy escort duties out of Wellington. By mid-1940, De Havilland Dragon aircraft were operating from Ohakea searching for German commerce raiders off the New Zealand coast.

Japan’s entry into the war in December 1941 initiated further expansion of the base, including the replacement of the hardened earth runways with concrete in 1942. Additional squadrons were created, mostly fighters with a Fighter Training Unit formed at the base in 1942. No.17 (Fighter) Squadron was formed in 1942. In 1943 No.2 (Bomber-Reconnaissance) Squadron was transferred from Nelson to Ohakea, before being deployed to the Solomon Islands.

Post World War Two

After World War Two the RNZAF struggled to find a role. Following demobilisation the Air Force was reshaped into a smaller force designed for peace-time operations whose capability could be increased considerably in times of war. The territorial Air Force was reformed and an Air Force Reserve constituted. The Auckland bases of Hobsonville and Whenuapai (established 1937) became the main bases for RNZAF transport and maritime squadrons, and, from 1949, Woodbourne (established in 1939) became the principal aircraft repair depot and Wigram developed into the main training facility.

Ohakea became the base for the reformed No.’s 14, 42 and 75 Squadrons. Squadron 75 was a Royal Airforce (RAF) squadron initially formed during World War One as 75 Squadron Royal Flying Corps. During World War Two the squadron became part of the New Zealand Squadrons in RAF Bomber Command. In 1946 the RAF presented the squadron title and standard to the RNZAF in recognition of the service of New Zealanders during the war. It is apparently the only time the RAF has ever gifted a squadron title to a Commonwealth Airforce.

The hangars continued to serve the purpose for which they were built. In 1948 the numbering of the hangars was changed with No.1 being changed to No.2 and No.2 Hangar being allocated the number 3.

In the late 1950s the RNZAF underwent a substantial reorganisation. Changes in weapons technology, including the development of nuclear weaponry resulted in a reconsideration of the role of the airforce as a ‘force-in-being’. As a result five territorial squadrons were disbanded. Ohakea became the main base for the RNZAF’s squadrons of strike aircraft – No.14 (Canberra) and later No.75 (Vampire). To accommodate these changes, work was undertaken on the aircrew room, change room, briefing room and ablution area of No.2 Hangar. Changes were also made to No.3 Hangar to accommodate the RNZAF’s communication squadron No.42. Other work undertaken at this time included repairs to the roofing. The waterproof covering of the flat roofs of the annexes was replaced, and in 1959 the decision was made to replace all metal flashings. Another issue remedied at this time was that of the hangar doors. Problems had arisen with the main doors soon after completion. Each door weighed a total of 27 tonnes, being made of 250 millimetre thick reinforced concrete, and were supported on two wheels with guide rollers placed in the upper corners. Their weight made opening difficult. In 1961 they were replaced with lighter corrugated metal doors. 1964 also saw a significant response from the public with large numbers attending an Air Force open day at the RNZAF Ohakea Base, at which visiting aircraft from the Royal Air Force, United States Air Force, Royal Canadian Air Force, Royal Australian Air Force and United States Navy performed flying and static displays, including a supersonic flight by Phantom 4 Bombers.

In the 1970s further problems with the structures arose due to spalling. The concrete that was used in the original construction is believed to have contained beach sand. The consequent spalling from decaying reinforcing necessitated considerable and costly repairs. Since this was identified the buildings have been painted to help reduce water ingress.

In 1970 the RNZAF replaced its ageing Vampire jets with Skyhawks. The Skyhawk fleet was augmented in 1984 with another 10 aircraft acquired from Australia. These aircraft were assigned to a reformed No.2 Squadron, which was also based at Ohakea alongside No.75 Squadron. To accommodate the new squadron No.42 Squadron was relocated to Whenuapai.

During the 1980s the concrete floors of the hangar were relaid and in 1989 the hangars were clad with long-run corrugated iron. Some of the arched buttresses on the sides of the hangars were also enclosed at this time. Both these changes significantly altered the original appearance of the hangars. In 1990 the No.2 and 3 Hangars were recognised by the Institute of Professional Engineers (IPENZ) as part of the ‘Engineering to 1990’ awards.

No.2 Squadron was relocated to Nowra (NSW Australia) in 1991, but remained under the command of Base Commander Ohakea. In 1993 the Pilot Training Squadron and the RNZAF’s Flying Training School returned to Ohakea from Wigram. In 1996 a mezzanine development in No.2 Hangar saw the provision of new bathroom facilities, a lobby, locker room and staircase. The work was carried out by Works Consultancy. In November 2001 following a review of New Zealand’s defence capabilities and funding strategies the Air Combat Force was disbanded. A plaque was placed on the outside of No.3 Hangar in recognition of the contribution of 75 Squadron from 1946 to 2001.

In 2004 one of the hangars was proposed to be demolished to make way for a larger hangar as part of an overall redistribution of RNZAF personnel and craft. However, this did not go ahead. No.3 Squadron, which currently operates the Iroquois and Sioux helicopters, moved to Ohakea in January 2002, and are currently housed in No.3 Hangar. No.2 Hangar currently houses the No.75 Squadron of fixed wing aircraft.

The development of the Base had an economic impact on the adjacent township of Bulls, swelling its population and generating more business from the people connected with the Ohakea air force base. By 1977, there were an estimated 1200 people (including the families of personnel) connected with the air base, with around 400 of these living on the base itself and a large remainder residing in Bulls. During the time of construction many of those working on the base moved their families into the district, swelling the local population significantly. This connection remained strong as was evident by the ‘community criticism’ of the closure in 2007 of the Ohakea Air Force Museum. By 1993, locals had invested more than $500,000 in the museum, which had opened in 1976, and many were therefore dismayed at the loss to the community caused by the closure.

Physical Description

Environs

The No.2 and 3 Hangars are situated on flat countryside, several hundred metres from State Highway One. The aerodrome is visible from the road and the hangars can be easily seen as the road swings around the site. The hangars are critically sited to face out towards the airfield: to the runway oriented north to south (approximately), and the other nearly east to west. Eastwards lies State Highway One; westwards lies farmland; and north of the hangars is the working and living settlement of Ohakea. Between the two hangars are a large landscaped area of lawn and Phoenix palms and a collection of smaller buildings adjacent to the tarmac.

The Hangars face the tarmac at a 60 degree askew orientation to each other, a relative angular displacement which is only completely understood when viewed aerially. The hangars – along with the runways, roads and other buildings – are part of a carefully planned small purpose-built township. Regular rectangularly-aligned streets, and the large and small buildings of the aerodrome and its resident community, are bounded by the airfield, State Highway One and adjacent irregularly-shaped rural plots. The Hangars are sited specifically with respect this planning. The airfield spreads out to the south; the township behind is laid out in reference to their presence; the landscaped space between Hangar No.2 and Hangar No.3 is formal and precise; axes (taken through the ridges of the hangars) intersect at an important physical focal point of the town; and symmetry is apparent. The siting of the Hangars No.2 and 3 (and town behind) indicates attention to purpose and (less importantly perhaps) aesthetics.

Hangars No.2 and 3 are the largest and most impressively-singular buildings on the site. They are visually sculptural (rather than four facades enclosing space), and bestow a presence and orientation to the landscape. Other high or broad structures can be glimpsed however it is the graceful and complete curving forms of the No.2 and No.3 Hangars which stand out on approach from the east.

The similarities between the two hangars are clear. Both are arched forms built for immense enclosure. The regular arches appear to form a parabolic drum or shell; the middle high section of the arches is a gentle curve; the ends of the arches straighten as they meet the ground and join to the joist (taut bow-string) structure beneath the ground surface. The building ends are infill: the south face ‘ends’ open out with large doors onto the airfield; the north ‘ends’ have rectangular–framed annexes built to house the offices, stores, administration and staffing rooms that are associated with the aerodrome.

Hangar No.2 and Hangar No.3

Exterior

Hangar No.3 is the more eastern of the two almost identical hangars and the first that the visitor moves around. Both buildings are vast and graceful, with the structure and material unconcealed and undecorated. Yet the curving form of the two structures has an impressive elegance. The materials retain a raw utility that speak of a time and purpose.

Reinforced concrete arches are equally spaced the length of each hangar and their rectangular-section lengths can only be imagined from the outside until they protrude from the building along its long sides where they straighten, extend and plunge into the ground. Hangar space is enclosed beneath as the arch broadly spans the ground in what appears to be a graceful parabolic curve, visually reinforced by smaller tighter curves built into the structure. Corrugated metal roofing is laid over each array of arches, forming a shell and visually reinforcing the curving form of some 20 metres height. A lower section of corrugated translucent sheeting runs the length of the arches on both sides.

The northern annexe to each hangar is a long low concrete section of building with an overhanging flat roof, rhythmical steel windows with their horizontally paned divisions, and a central taller section. An annexe sits symmetrically in front of the north end of each hangar: doors vary in their size, spacing and authenticity. The annexes have an exterior finish and presentation with the rawness of concrete and a display lacking any pretension. Windows of various sizes open out from various functions and activities within. The raw utility of the annexe reflects the activities and passage of people and vehicles associated with the hangars. The ‘end’ of the hangar shells is concrete columns and infill, propping the arches. The concrete shows the boxing imprint of construction. High steel windows allow for light.

The south ends of the arched shells are much less solid in their infill. The full width is a series of immense sliding metal and glass doors set beneath a windowed lintel and corrugated metal cladding. Either side are smaller formal annexes with horizontal detailing of the Modern style and commemorative plaques - as well as later concrete block additions.

On all long sides, in between arches, original steel windows or later newer windows give light to various infill sections or to small structures that have been added. The rooms have a haphazard nature and vary from the original or early building-in of the arched space, to concrete exterior additions, glazed porches and portable cubicles.

Also, of note around the building are: staircases formed into one of the arches closest to the runway; an exterior access stair to the arch pinnacle at the north end; and a myriad of aerials and hardware associated with the operation of the buildings.

Interior

The interiors of Hangar No.2 and Hangar No.3 are vast spaces where the lofty curving arches remain exposed and enclose a volume as breathtakingly large as imagined. The hangar doors slide back to create an extended opening and substantial steel framing supports the doors to enable the lintel to be raised to allow a large fixed-wing aircraft to be housed. Daylight pours through high windows on all sides and, with the internal roof sheathing painted white, the interior spaces are soaring. The wall-to-wall painted concrete floor is broken from time to time by expansion joints, drainage channels and hardware. At the peripheral edges, doors lead to the smaller side-wall spaces created in the wings of the arched building at the sides and to larger rooms in the annexes. Hardware, storage and service reticulations necessary for the aerodrome to function are located both at the perimeters and within the hangar space. Side spaces cater for storage of servicing equipment and materials, ablutions and changing rooms, staffing rooms, communications rooms and offices. Mezzanine walkways lead between side rooms and levels.

Generally the interior of rooms and their corridors are painted boxing-imprint concrete. In some of the original rooms and through the steel windows beyond, the structural arches can be glimpsed. Where rooms have had a desired degree of comfort added, walls have been lined, suspended ceilings hung, and glazing installed as skylights or walkways.

Construction Dates

Designed
1937 -
Design using arch concrete construction accepted

Other
1938 -
Tenders called for and contract let to McMillan Bros. Ltd to construct the hangars.

Original Construction
1939 -

Modification
1958 - 1958
Numerous alterations and additions: Sealing of expansion joints in the roof using “Mulseal”, a bituminous compound; minor alterations to the aircrew accommodations.

Modification
1959 - 1960
Flashings on expansion joints are replaced on both hangars.

Modification
1961 -
Concrete doors on both hangars replaced

Modification
1963 - 1964
Access to Hangar No.3 improved

Modification
1968 -
Accommodation changes are made to No.2 Hangar.

Modification
1978 -
The annexe of Hangar No.2 is waterproofed

Other
1985 - 1986
Floor repairs made to both hangars

Modification
1986 -
Addition of cable braces to improve seismic resistance

Modification
1989 -
Roof replaced on both hangars

Modification
1996 -
Work carried out on mezzanine floor of Hangar No.2

Modification
1996 - 1999
Work undertaken on repair of concrete due to spalling.

Construction Details

Steel reinforcing, concrete and corrugated iron.

Completion Date

27th June 2011

Report Written By

L Hawthorne, A Dangerfield, with L Fair, H McCracken

Information Sources

Appendices to the Journals of the House of Representatives (AJHR)

Appendices to the Journals of the House of Representatives

1937-1938, D-1

Archives New Zealand (Wgtn)

Archives New Zealand (Wellington)

AIR 1, 3/5/111, Hangarage 1pt (11/37-12/51); Defence Works and Buildings - Ohakea - Hangars No 1 and 2 1938 - 1940

Dictionary of New Zealand Biography

Dictionary of New Zealand Biography

Aspden, Rob, 'Turner, Charles William Oakey 1901 - 1994', updated 22 June 2007; Harrison, Paul, 'Cochrane, Ralph Alexander 1895 - 1977', updated 16 December 2003

New Zealand Defence Force

New Zealand Defence Force

Kelly, Michael, Air Force Base – Draft Heritage Inventory, Wellington: Land and Facilities Management, NZDF, 2001

Thornton, 1996

Geoffrey Thornton, Cast in Concrete: Concrete Construction in New Zealand 1850-1939, Auckland, 1996

Institute of Professional Engineers in NZ (IPENZ)

Institute of Professional Engineers in NZ

Turner, C.W.O. ‘Reinforced concrete hangars for air force stations in New Zealand’, Proceedings of the New Zealand Institution of Engineers, Vol XXXIV, pp. 465-488, 1948

Bentley, 1987

Bentley, Geoffrey & Maurice Conly, Portrait of an air force: the Royal New Zealand Air Force 1937-1987, Wellington, Grantham House Publishing, 1987

Franks, 1991

N. Franks, Forever Strong, the story of 75 Squadron RNZAF 1916-1990, Random Century, Auckland, 1991

Griffin, 1977

R. H. Griffin, and G. Krishnan, BNZ Bulls: A century of service 1877-1977, Wellington, BNZ Bulls, 1977

Hales, 1990

D. Hales, and R. Salmon ed., “The Royal New Zealand Air Force: yesterday and today’, Wellington: RNZAF Public Relations, 1990

Keyte, 1978

R. Keyte, Ohakea Open Day: Celebrating the 41st Anniversary of Formation of the Royal NZ Air Force, Bulls: Bulls Rotary Club, 1978.

Royal New Zealand Air Force

Royal New Zealand Air Force

RNZAF Golden Anniversary Souvenir Booklet: Ohakea Air Pageant 4th & 5th April 1987, Wellington, RNZAF, 1987

Salmond Reed Architects, 2005

Salmond Reed, Ohakea Heritage Management Plan, NZDF, 2005

Other Information

This place is included on the Institution of Professional Engineers New Zealand (IPENZ) Engineering Heritage Record.

This place is included in Annex J Defence Buildings Assessed for Heritage Value of the Heritage Policy for NZDF, Land & Facilities Management, 26 May 2005.

Please note that entry on the New Zealand Heritage List/Rarangi Korero identifies only the heritage values of the property concerned, and should not be construed as advice on the state of the property, or as a comment of its soundness or safety, including in regard to earthquake risk, safety in the event of fire, or insanitary conditions.