After the BAR merger, an inventory of BAR rolling stock found the hulks of F3A’s 40 & 45 sitting in the Derby deadline, and rather than scrap them they were handed off to the Portland shops to be reused.

At Portland they were gutted, fitted with class I electrical gear, the placed back to back on a set of class I trucks, repainted in the centennial paint scheme BAR F3 #42 had, and put out on the line as a 10000HP motor (like the actual class I’s, but about 9000 pounds more tractive effort thanks to the larger & heavier F3 carbodies.)

This is a fairly tall unit; it stands 15'7" (pantograph locked down) above the rails, so it stays on lines that are at least plate F; this includes the BAR from Bangor to Brownsville Junction, so it does actually see some service on the BAR.

In a more sensible world, this unit would have been classified as class I3, but the Portland Shops did all the paperwork and the builder’s plate as class FF3 (due to it having two F3 carbodies, of course.)