Category Archives: Rail

Bennie Railplane test

Bennie Railplane

By William Pearce

George Bennie was born near Glasgow, Scotland in 1892 (some say 1891). From a young age, he became interested in rail travel. By the age of 34, he had patented his idea for a new form of public rail transportation. He envisioned a combination airplane and locomotive—an aircraft that flew on rails. This vehicle would be capable of high speeds and would operate independently of standard rail transportation.

Bennie Railplane poster

A poster forecasting the George Bennie Railplane (G•B•R) line.

In his System of Aerial Transport patent from 1923, Bennie describes a vehicle suspended between two rails positioned above the ground. A single bogie attached the vehicle to the upper rail. This rail would support the vehicle while it was at rest and at slow speeds. The lower rail would stabilize the vehicle via a set of guide wheels at each end of the carriage and would also prevent the body from swinging out as it traveled around curves.

A propeller was situated at each end of the vehicle. In the patent, only one of the fixed pitch propellers would be used to pull the vehicle along the track. The propeller at the opposite end would be used for breaking or pulling the vehicle in the opposite direction. The propellers could be driven by internal combustion engines or by electric motors powered via an electrified rail. As the vehicle’s speed increased, lifting planes positioned on the roof would support some of the craft’s weight, increasing its efficiency by decreasing the friction from the rails.

Bennie Railplane test

The Railplane moves away for the platform along the short test line.

Working with consultant engineer Hugh Fraser, Bennie’s vision became a reality in 1929. A test track for the George Bennie Railplane System of Transport, also known as the Railplane Line, was built in Milngavie, near Glasgow. The test track was about 425 ft (130 m) long and was built over a section of the London and North Eastern Railway (LNER) line. The elevated track was built by Teesside Bridge and Engineering Company. It had a 16 ft (4.9 m) vertical clearance above the railway (standard bridge clearance at the time), and each of its five spans was 80 ft (24.4 m) long. The elevated track would allow the Railplane to traverse geography not traditionally covered by a standard railroad track. In addition, utilities such as telephone and electricity could be incorporated into the elevated track.

The Railplane test car differed from the original patent in a number of ways. No lifting planes were incorporated into the Railplane, and it was suspended from the upper rail by two bogies. The bogies had laminated springs to dampen the ride. The two-blade, 9 ft (2.7 m) propellers worked together to send the Railplane along the line. Electric motors were used and they received their power through the rail. The motors provided a continuous 60 hp (44.7 kW) at 1,200 rpm but could be operated at 240 hp (179 kW) for up to 30 seconds. For braking, the propellers’ rotation could be reversed and the bogies had provisions to grip the rails.

Bennie Railplane

The Bennie Railplane on its elevated track as seen from the ground. The two-blade propellers can be see on both ends of the Railplane.

The Railplane test car was built by William Beardmore & Company Ltd. It was skinned in aluminum over an aluminum frame with a steel keel. The Railplane was 52 ft (15.8 m) long, 8 ft (2.4 m) in diameter, and weighed 12,000 lb (5,443 kg) complete. Two sliding doors with stained glass windows allowed passengers to enter and exit the Railplane. The plush interior of its 24 seat passenger area was outfitted by Waring & Gillow.

On 8 July 1930, the Railplane Line was officially opened to the press and invited members of the public. Although the rail and subsequent ride were short, they did illustrate the service a full Railplane Line would provide. It was noted that the Railplane was very smooth in both acceleration and ride. Bennie estimated the top speed of the Railplane as 120 mph (193 km/h). However, higher speeds could be obtained with increased power to the propellers.

Bennie Railplane interior

The plush interior of the Railplane which accommodated at least 24 passengers.

Other power arrangements were proposed. The Railplane’s electric motors could be powered by an onboard internal combustion engine connected to a generator. Alternatively, internal combustion engines could be directly connected to the propellers. Bennie also designed a way to couple multiple Railplanes together via their propeller hubs. It appears this system incorporated a four-blade propeller with an extended hub. A single engineer in the lead Railplane would control all of the propellers.

A Railplane Line was seen as a way to ease congestion by operating above and much faster than freight trains. Although there was considerable interest and various Railplane Line proposals, no main financial backers were found, and none of the proposals moved forward. By 1937, Bennie was bankrupt and the Railplane was abandoned. The Bennie Railplane track and carriage remained in place until 1956, when it was disassembled and scrapped.

Bennie Railplane four blade

The Railplane outfitted with a four-blade propeller and a special hub to couple to another Railplane.

In the intervening years, Bennie continued with the Railplane concept. In 1946, the George Bennie Airspeed Railway Ltd was founded, followed by the George Bennie Airspeed Railway (Iraq) Ltd in 1951. As with the original Bennie Railplane Line, these endeavors failed to move forward. George Bennie passed away in 1957, never having achieved his goal of creating a high speed public rail system.

Below is a video of the Bennie Railplane in action uploaded to YouTube by British Pathé.


“System of Aerial Transport” US patent 1,459,495 by George Bennie (granted 19 June 1923)

Hispano-Suiza Type 86 engine

Hispano-Suiza Type 86 Railcar Engine

By William Pearce

In the mid-1930s, Hispano-Suiza developed the Type 86 engine specifically for use in railcars. A railcar is a self-propelled railroad coach meant to carry passengers or cargo on routes that are not profitable enough to operate a regular locomotive pulling non-powered railroad cars.

Hispano-Suiza Type 86 engine

The Hispano-Suiza Type 86 railcar engine. From left to right across the top of the engine are the fuel pump, air compressor, carburetor (another on the opposite side), two magnetos with a speed governor, and two starters above the housing on the right. The oil cooler is positioned under the cylinder head.

Hispano-Suiza became involved in powering railcars with the adaptation of its six-cylinder automotive Type 56 engine of 487 cu in (8.0 L) and 46 hp (34 kW). In 1931, the V-12 Type 68 auto engine was bored out and modified for use in French “Micheline” (rubber-tired) railcars. This engine displaced 690 cu in (11.3 L) and produced 250 hp (186 kW). Unlike the previous Hispano-Suiza engines, the Type 86 engine was specifically designed for use in railcars.

The Type 86 was a horizontal (flat) 12-cylinder engine. The engine was designed to keep its height to a minimum so that it could be mounted transversely in place of one of the railcar’s bogies. The railcar’s drive wheels were connected by hydraulic couplings to gearboxes on both ends of the engine. This installation maximized the usable space in the railcar while lowering its center of gravity. Engine accessories, such as the compressor, carburetors, magnetos, and starters, were placed on top of the engine for ease of access and maintenance.

Hispano-Suiza Type 86 crankcase.

The two-piece aluminum crankcase for the Type 86 engine. Note the 14 long studs used to secure each cylinder bank to the engine.

With a 5.91 in (150 mm) bore and a 6.69 in (170 mm) stroke, the Type 86 displaced 2,200 cu in (36.05 L). The forged and hardened aluminum alloy flat top pistons had three compression rings and one scraper ring. Floating piston pins attached the pistons to tubular fork-and-blade connecting rods. The blade rod and its big-end cap meshed together through a tongue and grove design. Two tapered pins secured the blade rod around the crankshaft. The fork rod had a conventional big-end cap securing it around the crankshaft. Reportedly, these connecting rods and their bearings were the same as those used on some versions of the Hispano-Suiza 12Y V-12 aircraft engine. Although the Type 86 had the same bore and stroke as the 12Y, no other components were interchangeable.

The forged, chrome-nickel steel crankshaft was supported in the crankcase with seven main bearings and weighed 243 lb (110 kg). The single camshaft was positioned on top of the aluminum crankcase and was also supported by seven bearings. The camshaft was driven by the crankshaft via a helical spur gear at one end of the engine. This gear also drove the fuel pump and an air compressor for powering brakes and other accessories. At the other end of the engine, the camshaft drove two 12-cylinder magnetos and an engine speed governor.

Hispano-Suiza Type 86 crank and rods

The crankshaft and fork-and-blade connecting rods for the Type 86 engine. Note the blade rod with a tongue and groove design on the big end.

Each cylinder bank was attached to the crankcase by 14 long studs. Six open cylinder liners made of nitrided steel were installed in each aluminum cylinder bank. A single-piece, aluminum head (flathead) was attached to each cylinder bank by 50 bolts, in addition to the 14 long studs. The engine’s compression ratio was 5.85 to 1.

The intake and exhaust side valves were positioned parallel to and directly above the cylinder barrel. The valves opened into a small combustion space adjacent to the cylinder. The intake port and combustion chamber made the incoming air/fuel charge turbulent to allow for better mixing of gases. The chrome silicon valves were sodium-cooled and used three valve springs each. The valve seats were faced with Stellite for wear resistance. The valves were actuated by roller lifters. Two spark plugs were positioned in the cylinder head and directly above the valves. This position allowed the spark plugs to be easily accessed for maintenance.

Hispano-Suiza Type 86 head and cyl bank

At top is a complete cylinder bank assembly for the Type 86 engine. The middle image shows the same assembly as it would bolt on to the crankcase. At bottom is the flathead. Note the recessed space that formed the combustion chamber and allowed clearance for the side valves .

The Type 86 engine had pressure lubrication to all turning parts. Oil was drawn from the crankcase and sent though the engine via a pump located in the center of the crankcase. Two additional sump pumps drew oil from both ends of the crankcase. These pumps fed oil through oil coolers on both sides of the engine. The cooled oil was returned near the main pump in the crankcase.

A centrifugal water pump on each side of the engine drew cooling water from the radiator and through the oil cooler. After the water passed though the pump, it then flowed through the cylinder head and into the cylinder block via drilled passageways. The heated water would exit the top of the cylinder head via ports on both sides of the head and flow back to the radiator, positioned on the railcar.

Each side of the engine had one downdraft carburetor attached to an intake manifold located above the cylinder bank. Horizontal carburetors were proposed to reduce the engine’s height, but it is not known if they were ever used. The engine’s speed governor limited the engine to 2,500 rpm by regulating the butterflies of the carburetors. The exhaust manifold was also positioned above the cylinder bank, and its configuration varied depending on the engine’s installation.

Hispano-Suiza Type 86 intake and water pump

The downdraft carburetor, manifold, and water pump (not to scale) used on the Type 86 engine.

For starting the engine, the Type 86 used two 24 volt electric starters with a maximum speed of 3,500 rpm. The starters were geared to the engine at a reduction of 37 to 1 so that they would turn the engine over at less than 95 rpm. Although one starter could start the engine when it was warm, the starters acted in unison, and both were needed to start the engine when cold, turning the engine at 80 rpm.

Internal splines in each end of the crankshaft received a coupler used to connect the engine to a gearbox. The couplers used hydraulic clutches, and one of the two couplers had a ring gear for starting the engine. The couplers were not mechanically locked at full load, which ensured smooth transmission of power to the gearboxes. Each gearbox used electromagnetic gear selection for its planetary gear reduction. At one engine revolution, the four gear reduction speeds were 0.237, 0.389, 0.610, and 1.0.

Hispano-Suiza Type 86 cam piston and lifter

While not to scale, the camshaft, piston, and roller lifter for the Type 86 engine can be seen in the above image. Note the adjustment rod on the roller lifter to provide proper valve clearance.

With interruptions only for routine maintenance, the Type 86 was designed to provide continuous service for about a year, traveling 310–375 mi (500–600 km) per day. That service life worked out to around 125,000 mi (200,000 km) before an overhaul was scheduled. The power section of the engine was 58.1 in (1.475 m) long but grew to 122.4 in (3.109 m) with the couplers and gearboxes. The engine was 40.3 in (1.024 m) wide and 39.1 in (.993 m) tall. The Type 86 produced a continuous 550 hp (410 kW) at its normal operating speed of 2,000 rpm. But the engine could produce 650 hp (485 kW) at 2,000 rpm and 750 hp (560 kW) at 2,200 rpm.

A smaller engine called the Type 87 was also planned. This engine’s bore was reduced by 1.18 in (30 mm) to 4.72 in (120 mm). As a result, its total displacement was reduced by 792 cu in (12.98 L) to 1,408 cu in (23.07 L). It was believed this engine would develop 330 hp (246 kW). However, in the late 1930s, French industries were focused on rearming the French military, and few resources were available for other projects. Hispano-Suiza directed its attention to manufacturing aircraft engines, and development of the railcar engines was stopped.

Hispano-Suiza Type 86 GA

Side and top view drawings of the Hispano-Suiza Type 86 engine.

Notice Descriptive du Moteur Hispano Suiza Type 86 by Hispano-Suiza (~1936)
Hispano Suiza in Aeronautics by Manuel Lage (2004)