Although Gloucestershire Transport History focuses on Gloucestershire and its rich transport heritage it has never been parochial or afraid to explore relevant national or international topics. As such – following the kindness of Sean Edwards of Florida in sharing pictures and descriptions of his wind tunnel models – it was no blow at all to hear from Paul Kidder of Los Angeles, California with his own fascinating collection of wind and water tunnel and display models. As he points out:
“My collection of models spans from 1936 through the late 1980’s. Many of these models are one off, hand built without the aid of computers or C & C machines. These models are truly a lost art form that we will never see the likes of again.”
If you would like to contact Paul he would be happy to receive your emails about wind tunnel or presentational models at firstname.lastname@example.org
Starting with one of the oldest types in the collection, Paul accidentally stumbled upon and acquired this very rare 1/50 scale walnut presentation model of the Model 39 (R2Y) Liberator-Liner manufactured by Consolidated Aircraft in Air Force Plant 4, Fort Worth, Texas. As acquired – and pictured above – the model was missing the stand, all four engines and propellers, although it was clear that four engines were attached at one time because there were four faint nacelle outlines on the wings.
The superb quality model measures 21.5″ long with a wingspan of 26.75″ and if it were not for the cut out windows could almost pass for a wind tunnel model. New engines, propellers, and a stand were replicated by a retired Beechcraft master model maker while Paul finished the job himself, staining the new wood and applying coats of varnish.
In early 1943 Consolidated foresaw a market for a large civil and military transport and started design work on the Model 39. Later that year Consolidated and Vultee Aircraft merged and the type was continued as the Convair Model 104, combining the wings, engines, single vertical tail and landing gear of the PB4Y-2 Privateer (the ultimate US Navy version of the B-24 Liberator) with an entirely new circular-section fuselage.
The US Navy became interested and signed a letter of intent for 253 aircraft in March 1944. The first prototype NX30039 (constructor’s number 1) was flown for the first time on 15 April 1944 piloted by Phil Prophett and his crew. Due to design deficiencies the Navy cancelled its order but Convair received permission to purchase and complete the second prototype in Navy colors.
Thus the second aircraft was completed as the Convair 104 XR2Y-1 and fitted with R-1830-65 engines. NX3939 (c/n 2) made it first flight on 29 September 1944 and was eventually given the US Navy registration 09803.
American Airlines operated the first aircraft, named City of Salinas, with the support of Convair for three month transporting fresh fruit between Salinas and El Centro, California and Boston, New York and other eastern cities.
In airline service the Liberator-Liner would have carried 48 seated passengers or 24 in sleeping berths and a cargo of 18,500 lb (8,392 kg) could have been loaded straight from flat trucks into the aircraft through large fuselage doors. However, the type could not compete in performance with other much more powerful aircraft of the era and as there was no other interest in the design both aircraft were scrapped in 1945.
These models are believed to be Marquardt ramjet centre-bodies (possibly full size) and came from the estate of Charles Faust, a famous wood carver/artist in the San Diego area. It is also not known if Mr Faust was given the items or if he made them himself, but Marquardt was located not far away in Van Nuys and they were very likely tested at the California Institute of Technology wind tunnel.
Marquardt ramjets eventually ranged in size from 6″ to 6′ diameter and the first 20 ” example was delivered from Marquardt Aircraft to the US Navy for flight testing by the end of 1945. By the summer of 1946 this had begun manned flights on a twin-engined Grumman F7F Tigercat.
The Army Air Force, not to be outdone, also took delivery of a 20″ ramjet at the end of 1945 and began flight-testing at Wright field. In early 1946 two Marquardt ramjets were installed on the wing tips of a P-51 Mustang and created an increase in maximum speed of 40 miles per hour. Although this was not phenomenal, the 20″ Marquardt engine, which weighed slightly more than 100 pounds, could provide as much thrust as a turbojet engine that weighed 10 times more. In 1947 a modified XP-80 Shooting Star also became the first aircraft to fly on ramjet power alone.
Continued testing in the 20-foot wind tunnel at Wright Field further advanced the knowledge and design of ramjets, which allowed larger and more powerful models to be built, with Roy Marquardt quickly becoming known around Washington D.C. as “Mr. Ramjet”. However, the Marquardt M-14 or “Whirlajet” (N4107K), a one person, open cockpit, experimental pulsejet-powered helicopter with 29’ blades first flown in 1948 was never commercially built, although a similar concept – obviating the need for a tail rotor – was pursued by the British Fairey Rotodyne.
Although uninhabited reconnaissance vehicles are seldom out of the news in the early 21st Century, Paul has a particular connection with this 1960s example with unusually strong provenance and takes up the story:
“This is a Fairchild AN/USD-5 Osprey drone wind tunnel model. Much to my surprise, it is made of solid balsa wood. My Dad worked for Cornell Aeronautical (Flight Research) and was involved with the design and flight testing of this drone. We lived in Yuma, Arizona, from 1959-1961 while he worked on this program.
The amazing thing is the model is still in its original shipping wood box (including multiple elevons). The Drone is 20 inches long with a 15 inch wingspan. The box measures 23.5 Inches x 17.5 Inches x 7 inches. I found a date on the box indicating that the model had been returned from Washington State University’s Wind Tunnel Facility and received by Fairchild on 4 February 1960 (three months prior to the Drone’s first flight in May 1960). The green USD-5 model in the photo immediately above was my Dad’s desk model from that program.”
The Fairchild USD-5 was a subsonic delta-wing aircraft powered by a single Pratt & Whitney J60 turbojet. It was zero-length launched with the help of a single solid-propellant rocket booster – yielding 178 kN (40000 lb) of thrust for 3 seconds – and recovered by parachute. The drone had an operational radius of 1 600 km (1 000 miles) and could fly at altitudes between a few hundred feet and 10 700 m (35 000 ft).
Projected payloads were infrared scanners, side-looking radar and optical mapping systems. The sensor data could either be transmitted by radio or stored for examination after drone recovery. The Army had planned to have the AN/USD-5 system operational by 1964 but in November 1962 the program was cancelled because of budget constraints.
The slim fuselage and delta wings of the Fairchild Osprey drone were echoed in one of this set of Supersonic Transport (SST) wing design models from Ames Research Center, which also have interchangeable noses to effectively change the centre of gravity of the aircraft.
Indeed, similar models would have been tested at the Royal Aircraft Establishment at Farnborough from 1956 in support of what would become the Anglo-French Concorde, itself a step beyond such established aircraft as the Fairey Delta 2 and Gloster Javelin.
However, America’s response to Concorde in 1966 was the Boeing 2707 – the most advanced aircraft ever to have reached the advanced planning stage – which combined a similar slender delta wing with variable geometry outer sections and a more conventional horizontal tailplane. This 300 ton Mach 2.7 concept was cancelled in 1968 after a full scale mock-up had been constructed but it is interesting to see from these wind tunnel models what other options were being explored.
On the left of the picture, for example, was perhaps the most conservative of the four designs – combining the short, straight wing of the Lockheed F-104 Starfighter with a swept leading edge. Could this perhaps have influenced the design of the Pan American operated Orion space shuttle from the 1968 Stanley Kubrick film “2001: A Space Odyssey” if not the NASA Space Shuttle orbiter itself?
Much more radical however was the W wing model, effectively like two swept-forward plan forms on either side of the fuselage and combining the proven advantages of a swept or delta wing with aerofoils closer to the front of the fuselage to enhance low speed handling. A similar effect is nowadays achieved by the use of canard foreplanes such as those found on the Eurofighter Typhoon, although back in the 1950s the W wing was seriously considered by the Bristol Aeroplane Company.
Notice the very small cockpit windscreens on this drawing combined with a short, pointed nose as well as the swept back T-tail. The British and French Concorde prototypes had similarly limited pilot vision – replaced by a full width windscreen on the production models – behind a much longer nose which drooped to provide improved forward vision on take off and landing. The tail, meanwhile, is very similar to the one fitted to the Vickers VC-10, first flown in 1962 and from the side the Bristol W wing appeared to have similar rear-mounted engines.
In fact Vickers had their own Project X concept with engines fitted to the rear fuselage and fuel tanks where Bristol draughtsmen had placed their gas turbines while Armstrong Whitworth’s P.13003 (pictured above) envisaged an M rather than W wing but with mid-wing engine nacelles like the Bristol design. This layout was further refined into the Armstrong Whitworth P.22001 with a T-tail although the P.13003 offered a spike mounted on a Bristol Britannia type nose as a sonic boom diffuser rather than Concorde’s droop snoot and visor combination. However, despite these and possibly other design studies no M or W wing aircraft have ever been built or flown.
Perhaps the most intriguing of the set of ex Ames SST models however was the one evaluating the circular – or lenticular – planform and Paul was also kind enough to send me this artist’s concept drawing of several variants of lenticular winged aircraft flying in formation. The triple-boom example at the top certainly puts me in mind of Star Trek’s USS Enterprise and I wonder if any of them were built as “black projects” and passed off as extraterrestrial flying saucers? Paul also quoted from an article describing this design:
The lenticular or saucer shaped spacecraft by virtue of its circular cross section houses more “internals” per square foot than the circular cross-section and tubular design of rockets and intra-atmospheric aircraft. ”
In fact, but for an accident of history, saucer shape aircraft could have been a common sight in our skies decades ago – thanks to the experimental work of Charles H. Zimmerman in association with the Vought company in Connecticut. “Zimmer’s Skimmers” grew from radio controlled experiments such as the Vought V-162 in the late 1930s to wind tunnel tests of full size models sponsored by the US Navy in 1940-41.
The piloted Vought V-173 “Flying Pancake”, pictured above, first flew on 23 November 1942 powered by a pair of 80 bhp Continental A-80 piston engines buried in the disc body turning 16′ 6″ diameter three-bladed propellers through drive shafts. To accommodate these large propellers, the V-173 had a tall fixed main undercarriage and small tail wheel giving the aircraft a 22 degree nose-high angle as compared to the 12.5 degrees of a Supermarine Spitfire.
The disc wing design featured a low aspect ratio that overcame the built-in disadvantages of induced drag created at the wingtips with the large propellers actively cancelling the drag-causing tip vortices. The propellers were arranged to rotate in the opposite direction to the tip vortices, allowing the aircraft to fly with a much smaller wing area. The small wing provided high manoeuvrability – especially at low speed – with greater structural strength and the potential for high maximum speeds.
However both the V-173, now preserved, and the Vought XF5U “Flying Flapjack” developed from it suffered greatly from gearbox vibration problems and as a result the US Navy chose to invest in more conventional aircraft powered by jet engines – such as the Grumman Panther– at the end of the 1940s. Since then, no more similar discoidal aircraft have been officially built or flown.
Paul’s 24 inch long 5 pound wind tunnel model of the GAM-87 Skybolt missile – seen above and at the top of this article – came from a retired Douglas employee in Wichita, KS, but unfortunately no data or history came with it.
After studies in 1958 had shown that it was feasible to air-launch ballistic missiles from high-flying strategic bombers, the USAF issued a requirement in 1959 for a long-range ALBM (Air-Launched Ballistic Missile) to be carried four at a time on pylons under the wings of a new H variant of the Boeing B-52 Stratofortress. In May 1959, Douglas was awarded a development contract for the WS (Weapons System) 138A missile, designated GAM-87 Skybolt.
Skybolt was powered by a two-stage solid-fuel rocket motor and guided by a stellar-inertial navigation system. While on the pylon, the Skybolt was fitted with a tail cone to reduce aerodynamic drag but this was ejected after the missile had been released from the B-52H and the first motor stage ignited. After first stage burnout, the Skybolt coasted for a while before the second stage ignited. First stage control was by movable tail fins, while the second stage was equipped with a gimballed nozzle. Skybolt was designed to deliver a single thermonuclear warhead over a range of 1 150 miles at a maximum speed of Mach 9.
Douglas subsequently awarded development subcontracts to Nortronics (guidance system), Aerojet General (propulsion), and General Electric (reentry vehicle). Full-scale development was approved in February 1960, and in January 1961, the first drop tests of unpowered Skybolts occurred. Powered and guided flight tests of XGAM-87A prototypes began in April 1962, but the first five tests were all failures.
The first fully successful Skybolt flight occurred on 19 December 1962, but on that same day the whole program was cancelled by the United States Congress and the production of the operational GAM-87A stopped. Although Skybolt certainly had its technical difficulties and was well behind schedule, the cancellation was also very much influenced by economic and political factors.
In May 1960, Great Britain had negotiated the purchase of 100 Skybolts for use on the RAF’s Avro Vulcan bombers, which would have carried one under each wing. Indeed, Avro had proposed a “Phase Six” development of the Vulcan large enough to carry six GAM-87s, and with an additional fleet of 48 of these giant delta winged bombers, the RAF would have had the option of keeping 84 Skybolts in the air at any one time.
Following the cancellation of Skybolt however, the RAF’s V-bombers were equipped with British made Blue Steel stand-off missiles although during the 1970s Britain’s nuclear deterrent was taken over by American-supplied Polaris missiles carried in purpose built Royal Navy submarines.
However, a mock up of a Douglas Skybolt – notably without the front canards and with different rear fins to the wind tunnel model – survived to be preserved at RAF Cosford.
Staying with Douglas, one of Paul’s more recent acquisitions has been this 10.5″ long by 7.5″ wide model of a Proposed Jet Engine Powered Cruise Ship Catamaran presented by the company to Robert J. Pfeiffer, who in the mid 1960s was CEO of Matson Shipping and later became the Line’s Chairman, having steered Matson through the introduction of containerised freight through which the venerable organisation survives today.
The model – beautifully realised and in its own wooden carrying case – was purchased from the estate of the late Robert J. Pfeiffer while the watercolour painting of a possible US Navy variant of the same concept was obtained from an airliner show at Los Angeles International Airport.
If you are interested enough in transport to be reading this you have probably received a related promotional gift at some time – my RAF Falcons pen still writes even if the clip has snapped off – but image how pleased Robert J. Pfeiffer must have been when presented with this sturdy brass-fitted box and its contents!
Of interest even before lifting the lid is this colour rendition of the Douglas logo, featuring both a trio of stylised swept wing aircraft and a space rocket superimposed on a globe with the Americas facing the viewer. This reflected the involvement of Douglas in both jet airliners – such as the DC-8 which rivalled the pioneering Boeing 707 – and in rocketry with the Nike and Thor projects.
This logo was kept on in a modified form when Douglas merged with McDonnell aircraft in 1967 and continued until the McDonnell Douglas Corporation (MDC) merged with Boeing in 1997. Although McDonnell Aircraft never built passenger aeroplanes it, like Douglas, made carrier borne Naval aircraft and was heavily involved with NASA’s Mercury and Geminispace program. Both McDonnell and Douglas companies were also founded by Americans of Scottish ancestry who had graduated from the Massachusetts Institute of Technology and had previously worked for Glen L. Martin.
The Douglas logo was also replicated in monochrome at the front of the transparent plinth on to which the model is attached: the model itself being painted in the famous white and gold livery of Matson Lines with their traditional blue graphics.
To Gloucestrians, Matson is the name of a suburb not famous for its connection with luxury liners as it is built on the slopes of Robinswood Hill away from the Severn but the Navigation Company that bears the name was founded by Swedish emigre orphan William Matson who arrived in San Francisco in 1867 as an 18 year old after a voyage round Cape Horn.
After working on the private yacht of tycoon Claus Spreckels and making friends with him, Matson acquired the three masted schooner “Emma Claudina” in 1882 and began taking plantation stores to Hawaii before bringing sugar back to San Francisco. As this trade grew, Hawaii became recognised as a tourist destination and Matson opened his first hotel there in 1901.
By the time of Captain Matson’s death in 1917 his fleet contained the largest, fastest and most modern freight carriers in the Pacific and between the World Wars the passenger, hotel and dock infrastructure of the company reached its zenith. The White Ships were even joined by a Matson airline operating Douglas DC-4s from the US Pacific coast to Hawaii during the late 1940s although this was soon stopped by pressure from Pan American World Airways.
Indeed, as would be the case in the North Atlantic, jet airliner travel was to supplant shipping for passenger transport to such an extent that all the luxury Matson vessels had ceased cruising by the end of the 1970s – making the appearance of the Douglas jet-powered catamaran model most interesting.
British Hovercraft Corporation SRN4 Mountbatten Class air cushioned vehicles began carrying motor traffic and passengers across the English Channel in 1968 – Hoverlloyd services from Ramsgate International Hoverport at Pegwell Bay taking 40 minutes to reach a similar installation at Calais from 1969 onwards.
As well as bringing aerospace technology to sea travel, each Mountbatten Class hovercraft was powered by four Bristol Proteus gas turbines buried in the hull, each of which both turned a lift fan to inflate the skirt and – through a gearbox – turned a propulsion fan. As can be seen in this contemporary postcard, each propulsion fan was mounted on a pylon which could be turned to supplement the steering functions of the two rear rudder fins.
In comparison, it would seem that the Douglas Catamaran would have been steered either by air blown over its fins by the propellers and diverted port or starboard by rudders inset in them or by the propellers themselves, which could presumably alter in pitch perhaps even to the extent that one or other could have been put in reverse for sharp turns or emergency braking. Like the SRN4, the Catamaran seems to have no under water control surfaces and even more intriguing is the horizontal aerofoil linking the two fins. This is more reminiscent of the 1979 vintage Soviet Sea Eagle ( pictured left), an ekranoplan designed to fly at low altitude over the sea using the wing in ground effect principle and since this article first appeared, reader Lincoln Ross has kindly alerted me to the US Patent application for this Douglas vehicle which does in fact state that it is designed to use ground effect.
For both technical and commercial reasons, the SRN4 hovercraft were withdrawn in 2000 and their high speed replacements were wave-piercing catamarans powered by diesel engines energising water jets, the largest and fastest of which, LD Line’s “Norman Arrow” can make the longer journey to Le Havre from Portsmouth in 3 hours 15 minutes. The 40 knot capable machine – introduced in 2009 – was built in Tasmania by Incat, whose 1997 vintage catamaran “HSC Express” crossed the Atlantic from Manhattan to Tarifa, Spain in 3 days 7 hours 54 minutes in June 1998, beating the previous record set by the more conventional ocean liner SS United States in 1952.
The Douglas catamaran model would have appealed to Robert J. Pfeiffer not only in the possibilities of its radical design and the adaptation of Matson markings but also in the way that each hull was named after a famous White Ship. How practical that would have been in identifying the new vessel at sea would have been another matter, but “Lurline” was applied to Captain Matson’s second ever ship – a brigantine of 1887 – as well as steamships in 1908 and in the 1930s.
The original “Matsonia” meanwhile had been completed in 1913 and served as the USS Matsonia during the First World War before being sold out of service in 1937 as the “Etolin” after which the former SS “Malolo” – completed in 1937 – took over the “Matsonia” name until being sold and renamed SS “Atlantic” in 1948.
Finally in this section, the painting of the US Navy version of the Douglas catamaran depicts four jet engines as well as a bridge radome and other military appendages as well as a level attitude as it skims across the sea leaving twin rooster tails of foam in its wake. Such a naval vessel would have the advantage of leaving a less permanent wake than a conventional ship – making it less visible to aircraft and satellites – and also less vulnerable to mines and torpedoes, especially if made out of non ferrous metals or composite materials. Since the 1960s the US Navy has made great use of air cushioned vehicles as landing craft while the 1967 vintage USS Tucumcari became the basis for the later Pegasus class of hydrofoil patrol boat. However, after experience with the Research Vessel Triton the Royal Navy has rejected a trimaran format in favour of a single hulled Type 26 Global Combat Ship for the 2020s.
“This is my first water tunnel model, a Northrop N350 – VTXTS. The model came with its original sting, unfinished nose fairing, drawings and slides showing the evolution of the design. Drawings include the inboard profile, section cuts, fold-out 3-views and view graphs. Rarely does any documentation stay with the model, this time I got lucky. I would love to find photos of this model, in the water tank, being tested.”
Northrop designed the N350 at the end of the 1970s to fulfil the requirements of the U.S. Navy VTXTS program, combining a replacement for the existing North American T-2 Buckeye with a new training system for naval aviators. However, Northrop’s proposed new twin jet straight winged trainer was cancelled before submission, possibly because the company could not support this effort along with three other major programs – ATA, ATB, and ATF – going on at the same time and also possibly because the US Navy decided to opt for a cheaper derivative of an existing aircraft in preference to an all-new design.
In fact the admiral’s choice was for the McDonnell-Douglas T-45 Goshawk, a derivative of the British Aerospace Hawk and before entering his current real estate career Paul worked in Logistics Support for the T-45 at McDonnell Douglas in Long Beach, CA, and witnessed the first example take off from there to Yuma, AZ, for flight testing in 1989/90.
Northrop spent a tremendous amount of money on the N350 program, with analytical work, water tunnel and wind tunnel tests. The 12″ long resin / aluminium model came with the “sting” that the aircraft was mounted on while in the water tunnel but there are no fairings that would normally fit over the intakes to smooth out the flow. The sting attached at the top of the fuselage, so that the model was inverted in the water tunnel.
Paul is currently designing a stand for his 29 inch long, 13.5″ wide McDonnell Douglas National Aero Space Plane (NASP) wind tunnel model but is finding this tricky due to its 48 pound weight and razor sharp edges.
In his 1986 State of the Union address President Ronald Reagan called for “a new Orient Express that could, by the end of the next decade, take off from Dulles Airport, accelerate up to 25 times the speed of sound, attaining low earth orbit or flying to Tokyo within two hours.”
Although this project was finally cancelled amid budget cuts and technical concerns in 1993, McDonnell Douglas, Rockwell International and General Dynamics all invested heavily in the idea of a single stage to orbit (SSTO) aerospace craft for both freight and passengers and more specifically worked towards building the two-man Rockwell X-30 advanced technology demonstrator.
This would have been powered by air breathing Rocketdyne or Pratt & Whitney supersonic ramjets with the liquid hydrogen fuel travelling to the combustion chamber via the wings to cool them as they experienced atmospheric friction at speeds of Mach 8.
Although the X-30 shape would have handled poorly at low speeds, it was optimised as a wave-rider, harnessing the shock wave of its own passing to generate lift. As such, construction would have involved advanced aluminium and titanium alloys and silicon and carbon composite materials.
Despite cancellation of a man-rated X-30, hypersonic scramjet experiments have continued with unmanned X-43 and X-51 scramjet vehicles launched from B-52 bombers.