Coal-gas Powered Vehicles

Gallery opened 8 Apr 2020

Updated 25 Apr 2020

Coal-gas boat added
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Cars running on LPG (Liquefied petroleum gas) are not especially unusual. This page deals with vehicles specifically running on coal gas. (also called town gas)

During war-time it can be useful to be able to run vehicles on coal gas (also known as town gas, which contained hydrogen, carbon monoxide, methane, and ethylene) because it's made from, well, coal rather than oil, which tends to be in short supply. Typically it was carried around in a gas-bag mounted on top of the vehicle. The gas-bag was made of fabric, made gas-tight by some sort of coating, such as rubber solution.

I have seen it written in more than one place that said that carbon monoxide, in particular, cannot be compressed into steel cylinders, which would be much more handy than big gas-bags, because it would explode. This is completely untrue, and is probably a confusion with acetylene, which most certainly will explode when compressed. This site has some info on compressed carbon monoxide. The people here appear to have subjected carbon monoxide to shock compression to 90 GPa (900 kbar) with no mention of explosions. I strongly suspect the real reason is that gas cylinders were rarely used is that their manufacture requires quite a lot of high-grade steel, which in war-time will probably be required for rather more important applications. That also makes them relatively expensive compared with a gas-bag. Gas cylinders are of course also rather heavy compared with a gas-bag, and that alone might have doomed the idea. It did see some use in France.

The gas-bags were made of fabric coated with rubber to make it (more or less) gas-tight. The pressures were inevitably low, partly because of the limited mechanical strength of the gasbag material, but also because hydrogen, which is an important constituent of coal-gas, (typically 50%) will diffuse through pretty much anything, including solid steel.

The extremely specialised subject of gasbag motorcycles is already exhibited in The Museum.

Left: Two cars with gas storage bags on the roof: WW2

This gives a good idea of how cumbersome the system was, with enormous gas-bags as big as the car required to give any sort of useful range.

I deduced that the image was from WW2 (not WW1) from the car styling, and definitely in England because of the Austin cars and the format of the number-plates.

However, Steve Holland, one of my correspondents, did rather better. The place is Suffolk St in Birmingham. The tram is one of the Birmingham 3ft 6in gauge fleet. Going by the number plates, the two cars are registered in Birmingham. You can see Suffolk St before and after modern development here.

Left: Car with gas storage bag on the roof: WW2

This site has more information on gasbag vehicles here.

Image from unknown source, but from the number plate and the position of the steering wheel, it's in Britain.

Left: Car with gas storage cylinders on the roof: WW2

Three gas cylinders are mounted on the roof-rack of a rather battered Citroen.

Image from unknown source.

Left: Gas-powered tram in Morecambe: 1918

This is a single-decker tram with a very large gasbag enclosure on the roof. Note the pipe on the right running down to the engine.

The Morecambe Tramways Co Ltd was a private concern that operated from 1887 to 1924.

What the chap with the hose and the cart is doing is obscure, and probably nothing to do with the gas-tram. The cart could not hold enough gas for any useful replenishment, and the hose (if that's what it is) is too small for a reasonable rate of gas transfer.

Image from unknown source

This description of the Morecombe tram conversion comes from The Commercial Motor for 29th August 1918:

"Several departures from standard motorcar practice were adopted in designing the cars, but the power unit is practically identical with the 55 h.p. four-cylinder engine fitted to the Leyland fire-engine. The cooling system works from both ends of the car, a radiator being placed to face the front, which ever way the car is travelling. The transmission has naturally undergone revision, hut there are some points of resemblance with that of the five ton lorry. The gearbox is modified from standard to permit of the use of all four speeds in either direction, power being transmitted to one axle by-a double reduction spur gear enclosed in an oil-tight casing with a central, enclosed propeller shaft. There is also a heavy roller chain provided from axle to axle to distribute the drive, the chain performing the functions of the side connecting rods of the ordinary railway locomotive. As there is a straight run and return on the track, and the cars are reversed at the end of the journey, double controls are provided, but the control not required is thrown out of action by simply extracting a locking pin when the driver leaves one end."

"With the beginning of this year, on the approach of the holiday season, and faced with the difficulty of not being able to keep the cars on the road when the rush of passengers presented itself, the directors of the company resolved to supplement their allowance of petrol by converting three of the four cars to coal-gas. One car is of the open "toast-rack" pattern, and to fit a gas container to this would be a difficult matter. But, with. the three covered cars, a boxwork fitting has been erected on the roof, as will be seen from the illustrations on previous page. This extends practically the full length of the car and is of considerable depth. Inside, and with its flaps strapped to the woodwork, is the gas container of a capacity of nearly 900 cu ft. The containers were manufactured by Messrs. John }Ina-pc and Sons Ltd; Burnley, and are among the largest gas containers in existence. When full they extend somewhat above the wooden framework, but when the charge of gas is partially exhausted the generous size of the solid framework prevents flapping. Filling is done at the sheds, a specially made pipe of fabric being run out of the depot and the car filled in the yard as a safeguard against fire. The filling pipe from the meter connects with a wrought-iron pipe with a screw connection, which comes out of the box portion of the container and finishes level with the canopy. Through this pipe gas is supplied to the container, and, when filling is completed, a valve is closed at the base."

"Gas is drawn to the engine through a length of flexible metallic tubing which is connected to the filling pipe immediately above the valve, find carried down to the carburetter. On the new fuel, with the engines being well up to their work, ample power is provided. There are no overhanging obstructions on the route, and, consequently, the additional height is no disadvantage. By an occasional use of petrol when the charge of gas is exhausted and a refill at convenient times—generally when the drivers are having meals during a quiet part of the day—an efficient service can now be maintained. Eight double journeys, 11 miles each way can be performed on one charge of gas, and thus a service probably as cheap as any in the country is maintained."

So it appears the gas-tram could do 8 x 22 = 176 miles on one bag of gas, which is I think very respectable.

Left: Boat with gas-bag storage: WW1

The boat is called Wendy, but that's about all that is known. The soldiers are wearing British army uniforms from the First World War. There appears to be a duct at the rear of the boat leading from the gas-bag to the engine.

Note that the gas bag weighs very little, judging by the flimsy supports holding it up. This is probably because two of the constituents of coal-gas are lighter than air; hydrogen much lighter, and carbon monoxide slightly lighter. In fact, in the nineteenth century it was common to fill balloons with coal-gas; it had only half the lifting power of pure hydrogen but was cheaper and readily available. This suggests that the problem with the gas-bag might not be holding it UP, but holding it DOWN. No confirmation of this has been found so far.

Image from unknown source, even if these guys are pretending to have the copyright. I'd like to know who signed it over to them

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