Developed in 1964 and 1965, these earlier Skagits were called the GT-5 (for 'Guylineless Tower, Model #5'). Early models were Tank-mounted
with hydraulic stabilizers and used a hydraulic 'stiff-leg' jillpoke-style contraption between the boom and the ground. They used a line-shortener
device to run the grapples, and notice the twin mainline fairleads are directly beside one another- a feature that changed quickly after field tests.