Apparatus and method for controlling a locomotive consist

A method of controlling a locomotive comprising:

• relaying a control signal from a legacy locomotive controller to an intercept locomotive controller, the control signal comprising an encoded request for a locomotive power setting;
• determining a desired power output corresponding to the locomotive power setting;
• allocating a first portion of the desired power output to an auxiliary power source;
• and
• transmitting an auxiliary command signal from the intercept locomotive controller to the auxiliary power source to cause the auxiliary power source to supply the first portion of the desired power output to a locomotive bus on the locomotive.

A retrofit kit for a locomotive comprising:

• a first control interface electrically coupleable to a legacy locomotive controller on the locomotive;
• an auxiliary power unit assembly comprising:
• an auxiliary power source;
• an auxiliary controller programmed to control the auxiliary power source;
• a power cable coupleable to a power bus of the locomotive;
• and
• a second control interface electrically coupled to the auxiliary controller;
• and
• an intercept locomotive controller electrically coupled to the first and second control interfaces, wherein the intercept locomotive controller is programmed to:
• interpret a signal received on the first control interface as a request for locomotive power;
• define an auxiliary power command based on the request for locomotive power;
• and
• transmit the auxiliary power command to the auxiliary power unit assembly via the second control interface.