- Maple_Leaf_Eh
The office guys I spoke to said the 'old military crawlers' were imported on ships from overseas. without their turrets or top sides. Too heavy and not required for the conversions. Many of the 'Oh-seventy-one' conversions were done in the 1970's in the hundreds in Nanaimo. They were perfectly serviceable logging machines, that improved on the earliest designs. Prior to the arrival of tracked crawlers, towers were dragged around on trucks, sleds and wagons. The tracked undercarriages were well suited for the steep sloped forests of BC, Alaska, Washington, Oregon, Northern California, New Zealand and Australia. Apparently there are still hundreds in use in the forests too. The modern crawlers are now hydraulic drive with fully automated controls.
Tracked vehicles for relocation, anchoring and retrieval (of anything) is a widely practiced, and potentially dangerous, skill. The same method of yarding fallen logs is also used for grooming black diamond slopes at many ski resorts. Many "Pisten Bully" snowcats have tracks and a winch boom in addtion to their blade. They sometimes used a fixed anchor at the top of a steep slope (say, in the 35-40+ degree range) or will work with another Snow Cat as an anchor at the top so they can make controlled ascents and decents on the slope by cable winching.
One of my favorite runs in the world, the "No. 9 Express" at Alta, got it's name when the cable broke on the #9 Snow Cat during a grooming session, making for an an exciting decent for the driver. Incredibly, it turned around on the decent and the only damage was a broken running light.
Tank chassis, of course, are way too heavy with too much ground pressure for this kind of work.