(rail transport) A wheel arrangement for diesel-electric locomotives signifying that a locomotive has eight axles on two bogies, six axles are powered by electric motors, with one outer axle on each bogie unpowered.
1963 January, G. Freeman Allen, “Why B.R. are dropping high-power diesel-hydraulics”, in Modern Railways, page 25:
Thus, in the diesel-electric Type 4 range, B.R. have progressed from the early 2,000-2,300 h.p. 1Co-Co1s of 130-140 tons to the latest Brush/Sulzer 2,750 h.p. Co-Co of about 114 tons weight; [...].