@RickO posted:Well it was also true of the prototypes. The Bigboy has nearly double the horsepower.
Bigboy :
Maximum speed 80 mph (130 km/h) Power output 5,500–6,290 hp (4,100–4,690 kW) @ 41 mph (Drawbar) Tractive effort 135,375 lbf (602.18 kN)
Centipede:
Maximum speed 93 mph (150 km/h) Power output 3,000 hp (2.24 MW) Tractive effort 102,500 lbf (455.94 kN)
For what it's worth, there is no way in he%% that a UP 4000 class 4-8-8-4 could even go 80 MPH!!!! They had 68" diameter drive wheels and were limited to under 65 MPH (and that's why you never see the restored #4014 EVER over 60 MPH).