Stove-Engine by Michael Bradley
The very first Third World aid project undertaken by my old 1980-83 Halifax-based group was to design a simple steam engine that could be made with existing native skills and materials by a break-away region in West Africa. The idea was to provide power for lashed-together “double canoes” to transport modest quantities of local goods between river villages, and between the interior and the coast using giant tributaries of the Niger River. We were commissioned by an impatient, intelligent and rather ruthless tyrant, and so the project was implemented rapidly and successfully.
Local wood-carving, village metal working (mostly necklaces, agricultural tools and spear shafts) and ceramics had been refined to a high level for centuries in this West African region. We designed a “back-and-forth” action steam engine that was inspired by the local design of traditional cooking stoves aboard the trading dugouts of the area.
This steam engine had no boiler. It used the thick-walled ceramic cylinder itself as a flash boiler with the assistance of several railroad spikes per cylinder head as “heat transfer components” kept red hot by the “cooking fire” in the stove “module”. These spikes came from a scrap heap in the “capital” – detritus of a failed colonial railway intended to haul hardwood out of the interior. The fire was fed as necessary to maintain or increase power.
There was no flywheel, connecting rod or machining of any kind. The power-developing rod was just a straight spear-shaft forged by village smiths out of dubious iron. Fixed to this shaft were two 10-inch diameter ceramic pistons with spiral metal necklace-like soft iron sealing rings wound around the piston edges to augment a leather sealing disc between the piston halves – like Newcomen used in the 1690s. The stove-engines were intended to move a large-bladed (8 sq. ft.) Chinese yuloh “back-and-forth” (with rope-action feathering of the blade).
A spray of water was injected into the cylinder ends, and directly onto red-hot spike heads, via sewn goat-skin tubes from goat-skin bags of water on each side of the double-canoe. Pressure was supplied and properly timed when the end of the yuloh handle poked one of the goat-skin bags of water. Boat children dipped water from the river to keep the goat-skin bags full.
We worked with about 5-7 psi pressure operating on an area of almost 80 sq. inches at only 30 strokes per minute. A famous Nova Scotia potter threw the first 5 prototypes.
The calculated horsepower was laughable, about the power of two very strong men working the yuloh – about .3 hp delivered to the yuloh handle. On the other hand, we quickly discovered that Western calculated horsepower figures are misleading when it comes to actually doing work. By comparative tests, the stove-engine-and-yuloh combination was easily the equivalent of a conventional 10-horse outboard with its small prop turning at high rpm.
The “back-and-forth” action of the power rod – or “God-breath powerfully thrusting double penis” as it was called in Anyang – moved the large Chinese yulohs to scull the trading “double-canoes” from the stern. Steering was by separate traditional paddles or oars over the quarters.
The stove-engine powered yulohs and drive trains were tested in the Acadia University (Kentville, Nova Scotia) Olympic swimming pool during Christmas holidays 1979-80. Our test yulohs were made of plywood, but the actual yulohs were to be beautifully carved in local hardwood by master craftsmen. These yulohs would last an estimated half-century performing useful people-feeding work. The yulohs were driven by either a rope-and-pulley system or a wooden rocker system.
The stove-engines burned mostly dried cattle dung from the northern part of the break-away region (sold to passing vessels as strings of cow pies by 1981), and trash or quick-growing brush in the more thickly inhabited southern coastal region where the only two actual “cities” were located.
Thrown by local potters, the basic stove-and horizontal ceramic cylinders, pistons and wired-on and leather-gasketed ceramic cylinder heads had a 20% wastage rate at the potter’s wheel – in which case they were sold only as cooking stoves.
A successfully thrown stove-engine would last an average of 21 months before it broke and cracked. The power rod was recycled, and new ceramic parts were made by village potters.
Altogether, 621 units were manufactured and moved an estimated 3,000,000 ton-miles of locally-produced goods and agricultural produce per annum over three years. The equivalent of a 10 hp outboard was produced by the big-bladed (8 sq. ft.) yulohs moving 4 feet every two seconds. The loaded double-canoes could make about three knots. The double-canoes could operate upstream against the current by using counter-currents along the shore. The stove-engines were 100% locally produced, and so was their fuel (simultaneously used for cooking aboard, at times).
Since women were the traditional cooks and stove-masters, these engines brought women aboard the trading double-canoes for the first time. The women greatly increased the ton-mile efficiency of river trading, and this was not wholly appreciated by boatmen. River-trading voyages had formerly been undertaken for adventure at least as much as for trade income.
When this break-away region was forcibly re-united with the UN-approved ex-colonial “official government”, our tyrant disappeared while under house arrest. Under a policy of “progressive” Westernization loudly supported by all right-thinking Western Liberals (who had never visited the place), the stove-engines were replaced by outboards from Western manufacturers.
The cost of a high-revving, small-propped 10-hp outboard to do the same job as a slow, large yuloh indebted a boat family for life. Fuel for these outboards had to be imported since the local low-quality (high sulfur content) oil was refined abroad and imported as gasoline. The imported outboards didn’t employ the local people. All the profits from the outboards and fuel went back to the Western World at the expense of the Third World local population (naturally).
The “progressive” Western and Liberal-approved government actually made stove-engines illegal. The reason was supposedly that they “used valuable hardwood resources for fuel”. They did not, but the propaganda appealed to Liberal “rainforest savers” who were just then getting started. Actually, the hardwood was coveted by Western upscale furniture and piano manufacturers who became responsible for greater rain forest harvesting than ever before 1983. And, of course, locally-made stove-engines challenged the market for outboard sales – and continual sales since no outboard repair facilities were set up. Aid business as usual, courtesy of the World Bank and USAID.
I find that all the photos I have left from this project also show identifiable people making and using the stove-engines in West Africa. Some of these people may still be alive and I do not wish to jeopardize their wellbeing with the liberal and democratic government. I have a sexy photo of one of “Col. M’butu’s” mistresses promoting a stove-engine-equipped double-dugout – but you can’t see much of the stove-engine. Not enough of it to tell how it works.
I will eventually provide a drawing of the stove-engine-and-yuloh combination, and will run this photo with it – this charming and well-endowed lady was raped and murdered by the “liberating” UN-sponsored troops.
The steam-powered stove-engine-and-yuloh drive for boats up to about 35 feet long is definitely a survivalist item. It would last a lot longer if the cylinder barrel, pistons, etc. were metal. Plywood-bladed yulohs with spruce shafts would work, but would not be nearly as beautiful as one-piece carved iroko yulohs. And, of course, plywood barges could substitute for dugout double-canoes and could be augmented by sails. I didn’t offer this for West Africa, knowing that Africans are basically landlubbers and do not take to sailing.
In conclusion, and as an aside, I can’t see any reason why stove-engines could not have been made and used 5000 years ago…or more. They would have left only ceramic shards as evidence. I have covered this in my in-progress book “Hot Air and Ancient Wonders” because I think it more than likely that stove-engine contraptions were put to a variety of tasks in the Ancient World. I can think of: Sumerian “extrusion molding” of clay bricks by the thousands, Egyptian (and other) stone-sawing, canal channel-clearing…and many more uses that could help to explain ancient wonders that were constructed by limited populations of supposedly technologically primitive peoples.
David Beede speaking now.
I'm often contacted by people wanting more information on this stove engine. It seems the original article is no longer on the web. I corresponded with the author a few times before his email address went bad. From our exchanges I have some doubt about the veracity of his report. Several folks beside myself have searched for more on this curiosity, with no luck. It makes this the only reference to the steam yuloh that anyone has ever found. I've considered removing the article, but have been encouraged to keep in up.
I did do a crude sketch to ask Mr. Bradley if I was on the right track. He gave it a cursory nod without any helpful feedback. So all I know about the stove engine is now on this page. For what it's worth here's my crude sketch..
Feel free to email me, David Beede simplicityboats
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