Updated: 29 Oct 2004

The Pennsylvania Railroad Turbine loco: 1944. Note the huge connecting rods, and the 6-wheel bogies front and back.

This loco has the turbine geared down and mechanically connected to the driving wheels, which were linked by connecting rods as in normal steam locos. As usual with mechanical drive, a separate turbine had to be provided solely for reversing.
Built by Baldwin in 1944, with turbines by Westinghouse, class S2 number 6200 was a 6-8-6. It was intended to be a 4-8-4, but WW2 restrictions on lightweight metals meant that 6-wheel bogies were needed to handle the weight.
The power output was 6900hp, making it the fastest and most powerful mechanical-drive steam turbine locomotive ever built.

The loco from the other side. The reverse turbine is installed between the second and third driving wheels, with the big (exhaust?) pipe coming from it. Apparently the reverse turbine was as big as the forward turbine, avoiding the problems of the LMS Turbomotive.

Engineering like you mean it. This is one of the two middle driving axles. The huge central gear transmitted power from the turbine gearbox to the driving wheels and coupling-rods.

The S2 regularly pulled 1000 ton trains at over 100 mph. E W Cox, a British locomotive engineer, once travelled on the footplate and reported that "100mph was maintained and exceeded for 12 consecutive minutes".
The S2 was withdrawn in 1949.

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