While doing some research into an Amtrak F40 diesel for weathering purposes, the road number I have was listed as a "Cabbage". I've been trying to figure out exactly what this means. From what I've found so far - assuming this is correct - a Cabbage (diesel in this case) does not have an operating motor but some controls to brake the train while another diesel pushes from the rear? Is this right? I noticed a pretty big roll-up type door on the side of the F40 that I assume was made during some modifications to the powerplant? One newspaper story I read about upcoming Amtrak service with this type of diesel mentioned extra baggage would be carried inside the diesel unit. Anyone know anything about this topic?