thanks for all the info guys!
I did a little investigation of my own.
The TSM notes that "If the BAT 1 and 2 pushbutton switches are selected OFF, the start contactors are disconnected from the power supply"
After digging out the ASM 49-42, it does look as if the Main start contactor 5KA is connected to BCL 1 & 2. Can anyone confirm this?