The initial Track Loader models were developed from the early hydraulic Traxcavator models built by the Trackson Company to fit on to Caterpillar tractors. The “Traxcavator” name was used by Caterpillar on the early machines they designed and built after acquiring the Trackson company.
The Caterpillar 977 (Series D) Track Loader was introduced in 1955 to replace the Caterpillar No.6 Shovel. Starting a series which lead from 977E, 977H, 977K until 1982 the 977L as the last model in the 977 series.
Of the 977 series Track Loaders are 1:50th scale models of the 977(D) released by Norscot in conjunction with the Antique Caterpillar Machinery owners Club (ACMOC) and within the Evolution Series Diecast Masters released the 977 – 963K Tack Loader Set. In 2023 appeared a custom resin built scale model of the 977L.