Landships II

James H · Legend

"Water Caterpillars"

Roger Todd · Legend

It depends on what you mean by 'caterpillar track'. I don't think these so-called 'water caterpillars' imply any need to re-think what we know about caterpillar tracks in general. To me it seems like these are interesting variations on the paddle-wheel theme, built solely for propulsion in water, but with no real relation to what I would regard as a caterpillar track, which is a land-based system, the most important aspect of which is its ability to cover soft or broken ground.

And even if you think there is a case for Desblanc's 1782 invention to be accorded a prior place, there's the matter of Richard Edgeworth's design for what we would wothout any doubt recognise as a land caterillar in 1770, over a decade earlier. The fact that Edgeworth may not have built it is neither here nor there, the fact is that an unambiguous land caterpillar was devised well before the water caterpillars.

And there's also the more contentious d'Herman endless roller patented in 1713, which if you accept the water caterpillar's claim to priority should be accepted as having an even greater claim, despite being rather unconventional (to modern eyes):

http://www.unusuallocomotion.com/pages/locomotion/changes-around-the-track-i-off-road-locomotion.html

http://www.unusuallocomotion.com/pages/locomotion/airoll-marginal-terrain-vehicle.html

Meanwhile, at a tangent, look how similar these German tractor wheel treads from the 1950s (or 1960s, I can't quite tell)...

http://www.baggerundbahnen.de/Walzen/weiherhammer-guertelrad.htm

...are to the German heavy gun tracks of the Great War (in this case, Dicke Berta):

http://www.landships.freeservers.com/bbertha_2.jpg

I've attached a photo of another such tractor taken in 1957, it's a PDF from this German archive:

https://www2.landesarchiv-bw.de/ofs21/bild_zoom/zoom.php?bestand=21715&id=2837771&gewaehlteSeite=02_0001129372_0001_2-1129372-1.png

-- Edited by Roger Todd on Friday 7th of October 2011 01:52:35 AM

James H · Legend

Ah. Mr. T. I thought this might be in your territory. The reason I mention it is that it certainly looks like what we call nowadays a caterpillar track. I once saw a doco (presented by Adam Hart-Davis, possibly) that featured a paddle-steamer wheel fitted with an arrangement of springs and suchlike that ensured that the blades were permanently perpendicular to the water surface. This apparently increased its efficiency by an appreciable amount. Echoes of that can, I think, be seen in the Diplock Wheel and other "footed wheels" in which it was ensured that the soles of the "feet" were always horizontal when coming into contact with the ground. But anyway, from Boydell onwards footed wheels are ten-a-penny.

The terrestrial caterpillar track produces more of what I now know to be adhesive friction than does an ordinary wheel. (You can tell I've been reading up on this, can't you?) My physics has not improved since I came to loathe it at school, but I would guess that the "water caterpillar" produces an aquatic equivalent of some kind. It certainly looks more like a Holt or Bullock track than do many attempts at load-spreading, including the recently-discussed Joseph Hawker device.

We've had a look at the most interesting Unusual Locomotion site before, and I've tried to find more details of the people and machines mentioned, though with very little success. I'm always a bit wary of passing references (especially surnames with no initials or forenames), and I can't find much about some the people mentioned there. It would be nice to put some flesh on the bones.

On the subject of Richard Edgeworth, I refer the honorable gentleman to this discussion: http://63528.activeboard.com/t32932992/memoirs-of-richard-lovell-edgeworth/

Although mention of him seems to be obligatory in any work about Tanks and Tracks, it seems to me that somewhere along the way someone has taken Edgeworth's description of a "machine, that should carry and lay down its own road," put 2 & 2 together and made an answer greatly in excess of 4. His own account talks of what amounts to a wooden horse on eight retractable legs and capable of striding over high walls, rather like two leapfrogging coffee tables and with a hint of "Elephant's Feet." I'm sure I saw something along the same lines in a Blue Peter item on robots, many years ago. It's also rather suspicious that some sources embellish the account by saying that the machine was steam-powered. The earliest date I can find for a portable steam engine is 1800. Writing in 1808, Edgeworth makes no mention of a steam engine in this connection.

In fact, his other design, a barrel within a much larger cylinder (p144 onwards), comes closer to the principle than the wooden horse, being some sort of gearing. But that's not what is generally referred to when attempting to give Edgeworth credit. I think Mr. E's device is as much of a red herring as Leonardo's "tank."

Anyway, the point is that I would respectfully suggest that the Water Caterpillar is another signpost along the road. As we have found on occasions in the past, sometimes the accepted wisdom can be successfully challenged, and sometimes people can be looking in the wrong place.

If anyone can come up with more on Messrs. Desblancs et al it would be brilliant.

Ironsides · Legend

Hi James in a previous thread�I posted a patent by G.H.Pond for a water locomotive this runs on an endless rail supported by pontoons, it wouldnt take a leap of the imagination that this machine could also be used on land....

Cheers wink

-- Edited by Ironsides on Monday 10th of October 2011 01:39:36 AM

Roger Todd · Legend

James H wrote:
It seems we might have to rethink the matter of caterpillar tracks.
From Popular Science, December 1918:
"Their invention predates that of the land caterpillar by many years. The first water caterpillar on record was invented by Desblancs in 1782 and was propelled by a steam engine. In the United States the first marine caterpillar was patented in 1839 by William Leavenworth of New York. Since then more than 200 patents have been granted to various inventors of marine caterpillars by the U.S. Patents Office."

Another reason I feel 'water caterpillars' do not require us to re-think caterpillars in general is that I am very sceptical about the account given in Popular Science. I've scoured the internet and the only references to this 'Desblancs' are merely repetitions of the Popular Science comments. Now, of course, this is not conclusive proof of anything, but it's odd that with such a vast amount of information on the web there isn't a different source for the Desblancs story.

Another reason I'm suspicious of it is that it claims Desblancs powered it by steam. Now, I'm quite interested in ships (though mainly warships) and have read a fair bit over the years about the early history of powered shipping and cannot recall a 'Desblancs' or his water caterpillar. A powered vessel as early 1782 would be a really significant milestone in the development of powered shipping - the earliest accepted steam boat was the Marquis de Jouffroy's boat of 1776, the next was John Fitch's in 1785 - so it is surprising that Desblancs' so-called steam boat has never been mentioned outside an obscure Popular Science article of 1918.

Until I see an account of Desblancs and his caterpillar that clearly originated from a source other than the Popular Science article, to be brutally frank I don't believe Desblancs and his boat even existed.

James H · Legend

I share your scepticism entirely, Mr. T. As I say, bald surnames are generally suspicious (unless it's Shakespeare or someone of that calibre). Anything else rather smacks of cloning.

However, Mr. Leavenworth's claim does seem to stand up, although in a rather surprising way. It's not an elongated paddle-wheel, but a track that grips the bed of the canal. I reckon that is pretty close to the mark.

�http://www.google.com/patents/about?id=Oqw_AAAAEBAJ

-- Edited by James H on Thursday 13th of October 2011 02:13:12 PM

Roger Todd · Legend

Now, that is more interesting, but not much more because it also solves nothing - the date of that patent is 1839, so as far as we know, there's nothing water-caterpillar-wise preceding this date apart from the dubious 'Desblancs' of 1782. Yet even if we discount Edgeworth's 1770 device (which we probably should, because I've looked into it a bit more and it doesn't sound much like a caterpillar track after all) we have Sir George Cayley, better known as an aeronautical pioneer, publishing a detailed design for an unambiguous land-borne proto-caterpillar in Mechanics' Magazine in 1826! Further, according to this source, Cayley had started thinking about the track as early as 1809.

All in all, unless someone can demonstrate there were water-caterpillars before Cayley's 1826 design - and we've already seen that the only such reference, that of Desblancs of 1782, is dubious, to say the least - then I regard the 'water caterpillar preceding land caterpillar' thesis as unproven.