It would take some doing but it is theoretically possible to run a diesel on half cylinders much
like the multiple displacement systems GM uses on their vehicles. This would fuel only a selected
group at a time cutting the fuel use by some percentage. If I'm doing a large hydraulic drive the
bigger electric motor and the large high efficiency pump will have a higher overall efficiency
than multiple pumps and multiple motors and that's exactly Dick's point. I also agree with him
that the number of moving parts adds to the final maintenance costs. The advantages are that they
are easier to emissions control and you achieve fuel economy by shutting down "piston" groups.
The 4000 hp hydraulic we proposed to MK had about the same overall efficiency as a DC locomotive,
low speed tractive effort and the overall control of an AC unit. The thing that killed the
proposal was the lack of enthusiasm from both the SP and UP even though we could demonstrate all
that we claimed.