Unique Soviet steam car

2024 Author: Seth Attwood | [email protected]. Last modified: 2023-12-16 15:55

The unique truck, which will be discussed, was born back in 1949. Then there were still sharp memories of the harsh wartime, when transport workers had to carry out their tasks in the rear and at the front with a shortage of liquid fuel - gasoline.

Gas-generating vehicles with heavy and capricious installations, which made it possible to obtain luminous gas for powering traditional engines and fired with wood, helped in part to solve the problem. Similar machines were produced then at the Gorky and Ural automobile plants, they gained some distribution in the logging of Siberia, but due to the low power of the motors, they were distinguished by low efficiency. It became clear to the designers: the gas generator fulfilled its historical task, a more advanced alternative engine was needed, and they remembered the steam plants that were used in limited quantities abroad on trucks in the 20s-40s, but consumed as fuel not firewood, but coal …

1949 year. There is a "cold war" between the Soviet Union and America, which risks escalating into a real one (just this year the USSR tested the first atomic bomb). And at the institute NAMI are building ferry cars running on wood! Now you can see the unique drawings of these machines and reports on their tests …

Can you build a wood-fired steam car? Nobody in the world has ever solved such a problem. And the specialists of the leading branch research automobile and automotive engine institute were offered by NAMI to take on a new, unexplored business. An energetic engineer Yuri Shebalin was appointed as the head of the project, and the design was based on the 7-ton truck YAZ-200, the production of which was mastered by the Yaroslavl Automobile Plant in 1947.

The carrying capacity of the steam car had to be at least 6.0 tons with a total mass of not more than 14.5 tons, which included 350-400 kg of firewood in bunkers and 380 kg of transported water in the boiler of the steam engine. The maximum speed was provided for 40-45 km / h, and the consumption of firewood, which had a moisture content of up to 47%, was supposed to be limited to 4-5 kg / km. One refueling was supposed to be enough for 80 km. In case of successful completion of work on a prototype with a 4 × 2 wheel arrangement, it was envisaged to develop an all-wheel drive modification, and then a whole series of steam trucks for various purposes and carrying capacities for work in areas where the delivery of diesel fuel and gasoline was difficult, and the local fuel was firewood. was available in abundance.

Before us are blueprints that have turned yellow from time and wiped at the folds. In the lower right corner it is displayed: "Steam car NAMI-012". Below is the abbreviation BPA - Bureau of Steam Vehicles. Three signatures: "designer", "checked", "approved". And the date is October 18, 1949.

Do you know what this day is significant? Then the pilot Tyuterev on a jet fighter MiG-15 for the first time overcame the sound barrier!

But back to earth. Even before the war, in the thirties, NAMI (which was then called NATI) was actively developing gas generating plants: they made it possible to obtain gas for carburetor engines from everything that could burn. Coal, peat, wood chips, even briquettes of pressed straw. True, the installations were heavy and capricious, and the power of the engines after switching to "pasture" fell by almost a third.

Sentinel S.4 from England served as the prototype of NAMI ferry cars (a Soviet number is visible on its board)

Considering the cumbersomeness of the steam power plant, Yu. Shebalin and his main colleague in this work Nikolai Korotonoshko (later the chief designer of NAMI for off-road trucks) adopted a layout for the truck with a three-seat cab located above the front axle. Behind it there was an engine room with a steam power plant, which included a boiler unit. A cargo platform was installed behind the engine room. A vertical three-cylinder steam engine that develops 100 liters. With. at 900 min^-1, was placed between the spars, and the water-tube boiler unit, manufactured in conjunction with the fuel bins, was installed on the rear wall of the engine room.

General view of the steam engine

On the right in the engine room, the designers allocated a place for a 200-liter water tank and a condenser, behind which there was an auxiliary steam turbine of the so-called "crumpled" steam, with an axial fan for blowing off the condenser and a combustion blower. There was also an electric motor for rotating the blower when the boiler was fired up. As can be seen from the names of units and mechanisms listed above, unusual for the ear of motorists, in the NAMI truck, the experience of creating steam power plants for compact steam locomotives of that time was widely used.

Three-plate clutch

All equipment requiring supervision and maintenance in operation was located on the left in the direction of the machine. Access to the service areas was provided by doors and shutters of the engine room. The transmission of the steam car included a three-plate clutch, two-stage reduction gear, propeller shafts and a rear axle. Compared with the YaAZ-200, the gear ratio of the bridge was reduced from 8, 22 to 5, 96. The designers immediately provided for the possibility of diverting power to the front axle.

The gearbox had a direct and a reduction gear with a gear ratio of 2, 22. The design of the clutch made it possible to engage a reduction gear without a complete stop of the car, which subsequently had a positive effect when testing the modification of NAMI-012 - an all-wheel drive car NAMI-018, on the off-road.

The clutch used driven and pressure discs YaAZ-200. At the same time, the pressure spring was very powerful, of a tractor type, which made it possible to transmit torque up to 240 kgf • m. A competent design of the clutch drive allowed to reduce the effort on the pedals to 10, 0 kgf.

Driving a steam car, despite the fact that it was identical in the number of levers and pedals to the YaAZ-200, required special training from the driver. At his disposal were: a steering wheel, a lever for switching the cutoffs of the steam distribution mechanism (three cutoffs for moving forward, providing 25, 40 and 75% of the power, and one reversible for moving in reverse), a lever for engaging a downshift, clutch pedal, brake and throttle control valve, levers of the central parking brake and manual throttle valve control.

While driving on a flat stretch of road, the driver mainly used the cut-off shift lever, occasionally the clutch pedal and the downshift lever. Starting off, accelerating and overcoming small climbs was carried out only by acting on the throttle valve and on the cut-off lever. It was not necessary to constantly operate the clutch pedal and the gear lever, which made the work of the driver easier.

Three valves were installed under the driver's left hand at the back of the seat. One of them was a bypass, and served to regulate the supply of water to the boiler by a drive feed pump, and the second and third provided the start-up of a direct-acting steam feed pump and an auxiliary turbine at parking lots. On the right, between the seats, there was a lever for adjusting the air supply to the firebox. The bypass valve and shifter were used only if the automatic regulation of the water level and pressure failed.

The double-acting steam engine had three cylinders measuring 125 × 125 mm. It included a block crankcase, a crankshaft, a connecting rod mechanism, a block cover with valves and a steam distribution mechanism attached to the block. In the crankcase there was a camshaft, which received rotation from the crankshaft using two pairs of helical gears and a vertical drive shaft. This shaft had three groups of cams serving individual cylinders. Cutoff change and reverse was achieved by axial movement of the cam mechanism.

However, there were areas where 40 to 60 percent of the trucks ran on gas generators. Do you know why? After all, then in the USSR there were only two main oil fields - in Baku and Grozny. And how fuel was delivered from there to somewhere in Siberia, it is difficult even to imagine.

But gas-generating cars, whatever one may say, were created on the basis of gasoline ones. Is it possible to build a machine that is designed like a steam locomotive: you throw fuel into the furnace, and the steam pressure in the boiler turns the wheels?

Immediately after the end of the Great Patriotic War, the Scientific Automotive Institute (NAMI) was given the task to create a steam car for the timber industry enterprises. In capitalist countries, such cars have existed for a long time. For NAMI (then called NATI), the design of steam cars was not a novelty. Back in 1939, on the basis of the YAG-6 chassis, a steam car was created, which was supposed to run on liquid fuel or anthracite. In 1938, NAMI acquired for research "a six-ton dump truck of the English company Sentinel with a low-pressure boiler" (as it was called in the reports). The car was heated with selected Donetsk coal (for which a fireman was required), and, despite the monstrous consumption of coal - 152 kg per 100 km of track, the operation turned out to be profitable. After all, a liter of gasoline then cost 95 kopecks, and a kilogram of coal - only four kopecks.

Therefore, as early as the next year, on the YAG-6 chassis, a steam car was created (or copied from English?), Which was supposed to run on liquid fuel or anthracite. But they did not have time to build it: in the last pre-war years, the country had no time for exotic ferry cars …

During the war, apparently, this was remembered with regret - there was not enough gasoline in the USSR. A fairly significant part of the car park was even transferred to gas generating plants (which, by the way, were also developed in NATI).

After the war, they remembered about steam cars. Only they decided to use not coal as fuel, but firewood - after all, the car was intended for timber industry enterprises (a kind of waste-free production).

However, after the Victory, the designers of the institute were given a task: to create a car for timber industry enterprises that works … That's right, on wood. Waste-free production! Especially considering that there were more than enough lumberjacks in the country: the camps were full of political prisoners and prisoners …

Unlike gas generating machines, the ferry was supposed to be fueled not with small chocks, but with so-called firewoods. Firewood is a half-meter log with a diameter of up to 20 centimeters. Approximately these were used in stationary steam engines (locomotives), but no one has ever drowned cars with them!

A boiler unit of an unusual design was used on the NAMI-012 car. The driver did not have to constantly observe the combustion process and supply firewood to the firebox as it burns out. Firewood (chunks measuring 50 × 10 × 10 cm) from the bunkers, as they burned out, under their own weight, dropped onto the grate themselves. The combustion process was regulated by changing the air supply under the grate by an air pressure machine or by a driver from the cab.

One filling of bunkers with wood with a moisture content of up to 35% was enough for a continuous run along the highway up to 80-100 km. Even with forced operating modes of the boiler, the chemical underburning was only 4-5%. Correctly selected boiler performance when working on wood with high humidity (up to 49%) guaranteed the normal operation of the car. The steam capacity of the boiler unit was 600 kg of steam per hour at 25 atm pressure and overheating at 425 ° C. The evaporating surface of the boiler was 8 m², superheater surface - 6 m².

The successful placement of the heating surfaces and the good organization of the combustion process made it possible to efficiently use the fuel. At medium and forced loads, the boiler unit worked with an efficiency of more than 70%. The temperature of the exhaust gases under the same conditions did not exceed 250 ° C. The weight of the boiler unit was 1 210 kg, including 102 kg of water. It was fixed to the frame at three points on elastic supports, which excluded the possibility of breaking its frame when the frame was skewed. The cold boiler had to be fired up to full pressure in 30-35 minutes, and the steam car had to start moving at a low speed when the steam pressure reached 12-16 atm. The design of the combustion device allowed, after a slight alteration, its transfer to such a low-calorie fuel as peat or brown coal.

NAMI-012 model 1949 in winter tests. I wonder if the loaded wood is used for fuel, how many kilometers will it go?

So, in 1948, an experienced NAMI-012 was built on the chassis of a seven-ton YaAZ-200 (later MAZ-200). The characteristics of a three-cylinder steam engine were quite familiar: power - 100 hp, revs - up to 1250 per minute. And the dimensions and weight turned out to be even less than that of a diesel engine with a gearbox. True, this economy was negated by a heavy (about a ton) "boiler unit".

Perhaps it makes no sense to talk in detail about the device of the steam engine itself with a mass of such exotic equipment as a "turbo blower" or "crumpled steam turbine". The time of such units has passed a long time ago …

The operation of the ferry car was simple - at first it was necessary to throw in a full bunker of firewood (a firewood - a half-meter log with a diameter of up to 20 centimeters), and then heat the car for about half an hour - and then if the firewood was not damp. Surely all this economy smoked and smoked mercilessly … But the fireman was not required on the way: the firewood, as it burned, fell on the grate of the furnace “automatically”, under its own weight.

Since the starting moment of the ferry car depends on the pressure in the system, when the accelerator is gently pressed, the ferry car started smoothly, as if with an "automatic" gearbox.

The water-tube boiler unit with fuel bins was "saddle-shaped" mounted on the frame

Tests of NAMI-012, carried out in 1950, showed good results. It turned out that the car is not inferior in dynamics, and even surpasses the diesel YaAZ-200 in acceleration to 35 km / h. No wonder the NAMI-012 engine developed a torque of 240 kgf • m at low revs at 80-100 min^-1, i.e. 5 times more than diesel YaAZ-200. When operating a car in logging, the reduction in the cost of transportation per unit of cargo was 10% compared to trucks with gasoline engines, and more than twice when compared to gas generators. The experienced truck drivers liked the simpler handling of the machine, which turned out to be surprisingly very reliable in operation.

The main attention that was required when caring for the machine was to monitor the water level in the boiler and regulate it during the time.

With a trailer, the carrying capacity of the road train with the NAMI-012 tractor was 12 tons. The vehicle's curb weight was 8.3 tons. The favorable distribution of the equipped weight over the bridges (32: 68%) contributed to the good passability of the vehicle on dry dirt roads. With a fully loaded trailer and its own side platform, the road train reached a speed of up to 40 km / h, which was quite satisfactory for transport workers in logging. The consumption of firewood in real conditions was from 3 to 4 kg / km, water consumption - from 1 to 1.5 l / km. Cruising in store with full load (without a trailer) on the highway: by firewood 75-100 km, by water - 150-180 km. The time required for the car to start moving after an overnight stay was from 23 to 40 minutes, depending on the moisture content of the wood.

Water tank with a capacity of 200 l - with turbo blower, oil separator and condenser

Driver's workplace

So the firewood was loaded into the bunker

The function of the gearshift lever (the box itself, of course, did not exist here) was performed by the switch lever for the cutoffs of the steam distribution mechanism: three cutoffs "forward" (25, 40 and 75% of the cylinder filling) and one "backward" were provided. There were three pedals in the cab, as usual, but the clutch had to be squeezed out only to engage a downshift.

The truck (the first model was onboard) transported six tons, but the maximum speed was not impressive: the report states that it was … only 42.3 km / h. At the same time, it took from 350 to 450 kg (this is not a typo) firewood for a hundred kilometers of the way - a full bunker. All this firewood had to be cut, chopped, loaded, fired up the boiler … In cold weather, water (200 liters!) Had to be drained overnight so that it would not turn into ice, and in the morning it had to be poured again.

Hard work! However, if such machines really went to the timber industry, then convicts would work for them …

Following the prototype, two more were built (at the end of 1949 and mid-1950): outwardly they differed in more rounded cabins, a massive chrome molding with a "beak" disappeared from the front end. It is curious that both specimens were tested both as trucks and as timber haulers: that is why in the historical literature you can find photographs of them both with a flatbed body and with a timber trailer.

The tests took place in conditions close to combat. Frosts reached 40 degrees, water was poured from the nearest lake … Finally, the cars even made a run along the route Moscow-Yaroslavl and back: all in all, one of them covered 16 thousand kilometers, the other - 26 thousand.

However, as noted in the articles of that time, "in an empty state due to the large weight on the front axle, the steam car has a deteriorated passability." Apparently, cars were simply stuck on forest roads!

Therefore, in 1953, the fourth copy was built - the all-wheel drive timber carrier NAMI-018 (developed by N. Korotonoshko). Its drive was plug-in thanks to the original "razdatka": when the rear wheels skidded, the front ones began to "row". According to the sources of those years, in terms of cross-country ability, NAMI-018 was not inferior to the most powerful diesel timber carrier of that time MAZ-501.

Timber truck NAMI-012

The car had a very interesting transfer case design, which is definitely worth getting to know. We give its longitudinal section. The torque was transmitted to the rear drive axle through shaft 1, and to the front - through shaft 2, on which the rear axle shut-off mechanism was installed when the car was operating without rear wheels slipping. This mechanism consisted of two roller freewheel clutches, one of which worked when moving forward, and the other - backward. In the first case, gear 3 was connected to the outer ring 4 of the freewheel clutch, and in the second - to the outer ring 5. The change in the direction of movement of the tractor was achieved by reversing the steam engine, as a result of which the switching fork of the outer ring of the freewheel clutches was kinematically connected to the reverse control lever.

Transfer case of the NAMI-018 tractor

State tests NAMI-012 in 1951

To ensure that the front wheels are always off in the absence of slipping, the total gear ratio of the main gear of the front axle is made 4% more than the gear ratio of the main gear of the rear axle. As a result, shaft 2, in the absence of slipping of the rear wheels, rotated faster than gear 3, and the freewheel was turned off. When the rear wheels slipped due to a decrease in the forward speed of the tractor, gear 3 rotated faster than shaft 2, which led to the inclusion of the front wheels. With the cessation of slipping, the front wheels automatically became non-leading.

NAMI-018 in the final version - 1953

There was also an option for liquid fuel (albeit only on paper): it is depicted in one of the drawings that fell into our hands. Since he no longer needed wood bunkers, the cab was designed with a more spacious, two-row design.

Articles about amazing machines and detailed calculations of their supposedly fantastic performance were published in automotive magazines and reports by NAMI until the end of the fifties - mainly under the names of the developers, Shebalin and Korotonoshko. And then there was silence.

By that time, Stalin had died long ago, the camps were empty, the party changed course … And the ferry cars simply turned out to be of no use to anyone.

In the early 50s, all work on steam trucks was curtailed. The fate of the prototypes NAMI-012 and NAMI-018, as well as a huge number of other interesting domestic developments, met a sad fate: they died without becoming museum exhibits. The world's first wood-fired steam car was the last car of its kind, as no one has ever made a similar machine.

Now it is no longer possible to establish the true reasons for their birth, but there is one assumption. It is possible that ferry cars were supposed to play the same role in the country's defense as the countless steam locomotives that stood on the siding. If the atomic war really began, the only fuel on the territory of the country would be firewood. This is where the ferry cars had to come in handy! Not useful.

And the last thing. In England, about a dozen Sentinel ferry cars are still preserved - the same S.4 model that NAMI condemned as a prototype for cars. Well-groomed and polished steam locomotives participate in the rallies of veterans, they are cared for and cherished.

And where and when the unique Soviet ferry cars were cut for scrap metal - history is silent …

The first instance was distinguished by a chrome "beak" and a large emblem

By the way…

It is curious to see how the attitude towards steam cars in the Soviet scientific and technical literature has changed over the years. We open the Brief Technical Dictionary of 1934 (when there was no question of any ferry cars in the USSR!): “Steam cars are very rare. The main disadvantages are the need for a large supply of heavy fuel, slow start-up due to prolonged heating …"

In 1959, the compilers of the Small Soviet Encyclopedia publish a photograph of NAMI-012 and sing praises to him: "The most favorable indicators … The steam power plant compares favorably with others …"

But the 1976 Polytechnic Dictionary puts everything in its place: "The steam car did not become widespread due to its constructive complexity." And the point!