1939 – Walking Draglines – (English)
The earliest known actual walking dragline was from Ransomes & Rapier 1939 using the patented Cameron and Heath walking method. Model W170, it had a 4-yard bucket. TRACTION OR PROPULSION MECHANISM OF THE WALKING TYPE – Cameron et al. Colin McLeod Cameron and Alfred Thomas Heath British Patent 320,223 Granted Feb 21, 1940. Filed Mar …