Quote Originally Posted by desbromilow View Post
friction disc about 18" diameter mounted on a trolley and powered by a petrol (or diesel) IC engine. These saws (cutoff machines) are operated by people on the ground and manually fed into the steel rail. The disc is 3-4mm thick (around the 1/8" mark) and treated as a consumable. No lubrication is used, and locally the gang will have one person dedicated to "fire watch" due to the sparks the saw throws out.
example