Propeller-Driven Sleighs

THE SIKORSKY SLEDS

Igor Sikorsky is famous for his pivotal role in developing a practical helicopter, but years before this he built a rather more specialised form of transport. He produced not one but two propeller-driven sleighs when he was only twenty.
In late 1909 and early 1910, and after, Igor Ivanovitch Sikorsky and two or three passengers would drive at high speed around the snowy streets of Kiev in a sleigh driven by a rear-mounted engine and propeller. It all sounds highly dangerous to pedestrians, but perhaps you could get away with that sort of thing in pre-revolutionary Russia if you had the right rank. Sikorsky's motives were not mere joyriding; he was studying engine-propeller combinations in preparation for aircraft design.

Left: A Sikorsky Propeller-Driven Sleigh in 1912. Sikorsky is at the wheel. Note the large headlight for night running. The blurred propeller blade at upper left and the snow being thrown up by the front skis seem to indicate that the sleigh was in motion when the photograph was taken.

Few mechanical details of these machines are known. Steering was presumably through swivelling front skis, and the dark framework to the left of the picture appears to be a rudimentary propeller-guard. Its main function was probably to protect the propeller blades if the machine turned over.

At least three different engines were tried on the sleighs; the last two are known to have been 15 and 25 horsepower motorcycle engines.

Sikorsky attempted to make a helicopter in 1910, but like his contemporaries found the control and stability problems to be too great. By 1913 he had built the world's first four-engined aeroplane, the 9000-pound Bolshoi-Baltisky, but it was not until 1938 that he returned to the work on helicopters which is his greatest claim to fame.

THE MOTOR SLEIGH OF GRAND DUKE CYRIL

Left: The Motor Sleigh of Henri Coanda and Grand Duke Cyril: 1910 This propsleigh is possibly unique in having a ducted fan rather than an open propeller. Unquestionably much safer, but the installation here has the exiting air blowing right at the driver and passenger. There is also an exhaust pipe pointed right at the driver's face, which shows, I think, a certain lack of forethought. The engine appears to have two cylinders, and steering is by swivelling the front skis. In 1910 the famous Romanian designer Henri Coanda, at the age of only 24, built and attempted to fly a ducted-fan aeroplane. The fan was driven by a petrol engine. He claimed to have made a single brief flight in December 1910, and apparently crashed just after takeoff. In later years he claimed that he had burnt fuel in the air leaving the fan, making it the first (sort-of) jet aeroplane. No-one outside Romania believes this. In Romania he is a national hero. The airport in Bucharest is named after him. I have to tell you that as soon as I saw this image, I was suspicious; the perspective against the fence in the background looks wrong.

Left: The Motor Sleigh of Henri Coanda and Grand Duke Cyril: 1910 Hearing of Coanda'a aeroplane, the Russian Grand Duke Cyril Vladimirovich approached him and asked him to build an aerosled. This was built in Coanda's Paris factory. The sledge was blessed by Russian Orthodox priests at the Despujols plant near Paris on 2 December 1910, because that's how the Russians did things then. Here is the aerosled in Coanda's Paris factory; the similarity with the picture above is obvious. Someone has substituted a snowy background.

Left: The Motor Sleigh of Henri Coanda and Grand Duke Cyril: 1910 This looks like another picture taken in the Paris factory. The caption is in Swedish. It claims a maximum speed of 100 kph. (=66 mph) But no record has been found of an actual run. The sled was exhibited at the Twelfth Automobile Salon of France, and also at the Grand Palais, from 3rd to 8th December 1910, and was described in leading car magazines. The Grand Duke Cyril Vladimirovich was one of the senior Russian nobles. His father was the third son of Emperor Alexander II of Russia, and he was a first cousin of Tsar Nicholas II. The Wikipedia page says "In 1911 he designed a propeller-driven sled that is considered to be one of the predecessors of the Aerosani." Aerosani is Russian for Aerosledge. Given Cyril's title, you might expect he intended the aerosled to be used for military reconnaissance. In fact, the only reference found so far to its intended use was for racing at the alpine resort of St Moritz.

Left: A Propeller-Driven Sleigh on the cover of Popular Science in 1912 The magazine contains an article on a German prop-sleigh. Steering is by the small front skis, and sprag-brakes can be seen at the rear, operated by the lever being held by the rear passenger. A speed of 60 mph is claimed.

Left: French Propeller-Driven Sleigh: 1914 All that is known about this machine is that it was alleged to have crossed the Alps, presumably via one of the mountain passes. This a rather small V-twin petrol engine driving a large propellor through belt reduction. From Popular Mechanics, April 1914

Left: Unknown Propeller-Driven Sleigh: 19?? This appears to be a conversion of a sail-powered ice-yacht. More info here. The photo may have been taken on Lake St Clair in Detroit.

CANADIAN PROP-SLEIGH
A Canadian prop-sleigh was built by 15-year-old Armand Bombardier in Valcourt, Quebec in 1922.

It was powered by the engine from a Model T Ford, and had a frame with four ski runners. The front runners were steered by a rope, and the engine was mounted at the rear, driving a hand-carved wooden propellor. There was a single seat at the front. It made its first (and possibly last) trial run in December 1922.

RUSSIAN PROP-SLEIGHS

Left: An aerosled in Russia: 1919 This appears to be a prototype of the Russian ANT aerosled series, the first of which were built in September 1919 by the Soviets and used in the civil war raging at the time. Note the curved prop-guard to the right.

Left: An ANT-IV aerosled: introduced 1924. The ANT-IV was fitted with a 100 HP air-cooled radial engine. In 1930 it was used in the first regular mail and passenger aerosled line between the cities of Cheboksary and Kanash in Chuvashia. In the first 35 days 244 passengers and 1132 kg of mail were transported, covering over 5000 km in total. The 85 km journey from Cheboksary to Kanash was completed by the aerosled in 2.5 hours, instead of 10-12 hours on horseback. The ANT-IV was used with success in Kazakhstan and other republics.

AMERICAN TWO-PROP SLEIGH

Left: Two-prop sleigh in America: 1922 This seems to be a well-engineered machine; the talk of guy wires and turnbuckles suggests that the designer had some experience in early aircraft construction. The use of two propellors running at different speeds is interesting. Normally when you have pull and push propellors in tandem, the rear one is less efficient as it works in air disturbed by the front propellor; this was found out in the design of airship nacelles. Whether running the rear prop faster reduces this effect is a good question; I suspect not. However, the use of two propellors, wholly without guards, suggests that this machine might well have been twice as dangerous as the average prop-sled.

THE RUSSIAN MILITARY AEROSLEDS
Prop-sleighs were actually used in by the Soviet Army; they were normally called "aerosleds". The Red Army had several aerosled detachments that were employed with some success in winter operations against the Finns during the Winter War. They were also used in fighting the Germans in the severe winter of 1941/42, giving the Russians a significant advantage in mobility on deep snow.

Left: A NKL-26 Russian military aerosled. This version had a five-cylinder air-cooled radial engine. The fuel tank was in the rear of the hull. The V-shaped frame to the right is a guard to prevent the propellor breaking if the vehicle turned over. The driver sat behind the vision slit at the front, steering by turning both the front and back skis with a small steering wheel; the gunner sat behind him. Note that some crude retouching appears have been applied.

Left: Diagram of the NKL-26 Russian military aerosled. I am afraid I am quite unable to translate the Russian, but most of it is self-explanatory.

The Russian aerosleds were used primarily for maintaining communications between units and formations, and moving ammunition, rations, and petroleum products to forces operating away from their supply bases. The aerosleds also evacuated the wounded from the battlefield. Sometimes aerosled detachments were used on combat missions, launching surprise attacks against the enemy.