Ok, this is to stop me going way OT on my own Bristol 22 thread:http://www.practicalmachinist.com/vb/showthread.php/ot-bristol-22-crawler-196103.html
at one time crawlers were really popular in the UK, Im not sure if there were tax or austerity advantages (during and after the war, wheeled tractors were more available on lugged steel wheels, so they could not be used (abused and wasted)for personal transport!).
All of the tractor makers seemed to have their own crawler models, or third party conversions.
The single cylinder 2 stroke track marshall was a particularly individualistic one (I think Lanz also had a crawler on their Bulldog). David Brown used to produce very nice crawlers, and both County and Roadless produced crawler and four wheel drive conversions of Fordsons. There were also half track conversions (with mid mounted axle) for fordsons and fergusons.
Probably the cutist crawler was the little Ransomes, which was little bigger than a motorised wheelchair. http://www.google.ie/search?q=ranso...s=org.mozilla:en-GB:official&client=firefox-a
Another make which springs to mind was the Howard Platypus.
Peter points out that a later Bristol went on to become the "Track Marshall" newer Track marshall models continued up into about the 1980s under the nationalised "British Leyland", with ever increasing HP put through a transmission designed for 65HP. I'm told that the 65HP ones are still the most desirable. I think there are still some working in Cambridgeshire and Bedfordshire, on clay soil that is full of sharp flints!
Internationally, I think Komatsu is bigger than Caterpiller. I heard a rumor, perhaps someone here can confirm or deny, that Komatsu machines continued to be made in the USA during WWII?
I believe that Caterpiller bought their track design from Hornsby, who produced IC (top) and steam "chain tractor" prototypes.
I need to look up the name of the guy in England who modelled the steam version. I'm told the original was used for a short while to haul coal to the Yukon.