Two-stroke semi diesel

Interesting question.

Most of the hot-bulb engines that we recorded on the website list were Scandinavian/Western European rather than Baltic, but I think a case of mechanical simplicity and lack of susceptibility to water on the ignition system were probably major selling points.

They certainly blossomed for 20 or more years in the late 1800's to early 1900's and then almost as quickly they vanished from the scene as diesels became more reliable and affordable.

It is strange that Hot-Bulb engines had such a 'half-life' out of the glare of the big engine developments, and yet they carved a sizeable niche for themselves in the maritime industry.

The fuel question is also an interesting one, and a study of the oil-wells of the period does indeed show that Rumania for one had significant production, which would have been distributed overland to those places needing it. The USA was also starting its own oil fields and the far east had some as well, but Rumania would have been the most significant in terms of European product.

There were some big engines as well, not just single-cylinder 'tonky-tonky' types :-))

Peter

-- Peter & Rita Forbes Email Address: snipped-for-privacy@easynet.co.uk Web Pages for Engine Preservation:

& I think Huntesteds made their last in about 1989!! (For fitting to an ex- Baltic trading ketch)

Cheers Tim

I hate to be picky :-) but I think you will find that Sweden, Norway, Denmark, Russia Latvia, Lithuania (and many others) all have a Baltic coast. Russian fields began before Rumania I think but in any event Russian oils were more likely to be exported from Russia owing to the well developed trade-links. Interestingly The Low Countries and Britain had longstanding trade links with that area because they relied on their Navies and essential timber, pitch and tars also came from "Baltic" countries. That might perhaps go some way to explaining a similar popularity for such engines here and in Holland. ttfn Roland

'tonky-tonky'

Not really an answer but from the era, on the subject of marine hot-bulb engines...

"...By reason of the moderately heavy oils that can be used, such as gas oil, gasoleum, low grade paraffin and even solar oil, it is a most economical engine to run, hence it's popularity among the owners of commercial craft, where the running has to show a profit.. Also the slow revolutions allow a good propeller efficiency to be obtained with a heavy boat, or where the deadwood aft would obstruct the proper flow of water to a small and fast running propeller."

It also gives the results of fuel consumption tests conducted at the Copenhagen Exhibition of 1912 on various marine hot bulb engines and the fuels used. They included: Russian Solar, Alfa Solar, E.O.G. Solar and, Kraftogen Solar.

Consumption varied between, 0.547 lb/hp/hour (Bolinders) to 0.924 lb/hp/hour for a Dan, which was a 4 stroke. "The Marine Oil Engine Handbook" of 1916

Tom

Not being picky, just my early-morning geographical error ! I've been doing some work on a Turkish quote and that of course is the Black Sea area which is what popped into my pointy head this morning.

The one country that doesn't seem to have developed much in the way of engine related industries is Finland, although they did have one manufacturer who is still around.

Peter

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Interesting theory, really have no comment to offer beyond that I guessed that the fishing boat and trading vessel people in the area had found a formula which worked, and stuck to it. The simplicity must have been attractive to people brought up on sailing vessels. Another associated phenomenon is that a great proportion of these Baltic and Scandinavian engines were fitted with feathering/reversing propellors, rather than reversing gearboxes. That would also have been attractive for fitting to vessels which still used sails (eg the Baltic trading ketch/Galleas) since the propellor can be feathered out of the way whilst sailing.

The Bolinders semi-diesels as fitted to Narrow Boats were labelled as, IIRC, "Bolinders Patent Crude Oil Engine". That would tie in with your idea about using Light Russian Crude as fuel. I believe slightly different sprayer nozzles & spindles were offered for use with different fuels.

It would be interesting to see price comparisons over the years for new semi-diesel marine units relative to good quality 4-stroke units of equivalent horsepower.

Cheers Tim

.. Also the

I wish the builders of modern canal pleasure boats, and the suppliers of engines for them, would take more note of that. It seems most of them will never think beyond the standard 2:1 gearbox, which with a modern high-speed engine generally means a much smaller, less efficient, propellor than can be accommodated. I'm convinced that this is one of the main reasons why accepted engine powers for narrow boats have escalated in recent years - 15 or 20bhp through a little egg whisk is going to be pretty poor at starting & stopping even a moderately heavy boat, whereas driving a decent sized propellor at about 500rpm max, it was sufficient for a pair of loaded 70' boats carrying about 50 tons of cargo.

Cheers Tim

What is Solar oil?

Compare to a 1930's Gardner (very efficient for its day), ISTR about

0.35 lb/bhp/hour on gas oil.

Cheers Tim

Sisu are a large Finnish engine maker and are likely to grow in size now they have been bought by AGCO, their engines go into most of the larger MF tractors.

Regards

Dan

It's listed as a Lignite-based oil with a S.G. of 0.820 to 0.850, in between light Benzine and light Tar-Oil.

Peter

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