"A" Car / "B" Car

How can you tell the difference between the "A" car and "B" car? If the pair both have an "F" end, is it simply the direction the train is going? This way "A" is the front car in each set?

F is front of unit. On an MU set, A is first side, and B is second side. On the C3, A is front, and B is back except for the Cab where the head end would be designated with an F.

RC '75,

All present LIRR Electric cars (M1/M3/M7):

Odd numbered cars are "B" cars.
Even numbered cars are "A" cars.

"B" cars all have bathrooms on LIRR EMUs. Think "B" is for bathroom, if that works for you.

The electric cars are not plainly labeled A car or B car.

"F" (front) end labeling is required by FRA on locomotives. All EMU cars are considered locomotives.

Tom