2-6-6-6

The 2-6-6-6 (in Whyte notation) is an articulated locomotive type with 2 leading wheels, two sets of six driving wheels and six trailing wheels. Only two classes of the 2-6-6-6 type were built. One was the "Allegheny" class, built by the Lima Locomotive Works. The name comes from the locomotive's first service with the Chesapeake and Ohio Railway beginning in 1941. The other was the "Blue Ridge" class for the Virginian Railway. These were the heaviest reciprocating steam locomotives ever built.