The 2BB2 400 class were two electric locomotives built in 1926 for the Paris Orléans (PO) railway of France.

[1] After wartime coal shortages during World War I, post-war reconstruction from 1919 focussed on electrification, powered by hydro electricity.

In 1923 the PO began electrification of the 200 km section of the Toulouse main line from Paris to Vierzon using a supply of 1,500 V DC.

As express passenger locomotives, this also permitted large diameter driving wheels, rather than small-wheeled bogies beneath the frames.

Suspension travel between the driven wheels and the fixed motors was achieved through Kandó's triangular linkage design.