I was discussing this locomotive with a colleague in Progress Rail who was responsible for this repower project. According to this person they conducted a study & found that the typical routine for these specific locomotives (before repower) included a significant portion of time spent idling or on a lower throttle setting where it was inefficient to keep the large engine running. I am not sure if I understood it correctly but it was somehow impractical to shut-down & restart the engine as needed, as in an automobile.
So PR43C has 2 Caterpillar high-speed (1800 rpm) Tier II / Tier III compliant 4-stroke engines – a 16-cylinder Vee, C-175 as the primary engine (3600 hp) & an inline 6-cylinder C-18 engine (700 hp). At idle or at lower throttle settings only the C-18 would be running & the C-175 would be shutdown. The control system would automatically decide to use the C-18 for traction & all other power needs. At higher throttle settings, the control system would use C-175 &/or the C-18.
Also if I remember it correctly, these projects were initiated before Caterpillar acquired EMD.
These are just my opinion.
Thanks,
Naveen Rajan
Originally Posted by willygee:
How do the 3600 and 700 hp engines couple when needed?
