The Canadian Pacific Railway had preliminary drawings for a 4-4-4-4 duplex drive as did the New York Central Railroad - Class C1a. The Pennsylvania Railroad also had preliminary drawings for two additional duplex drives. One was a 4-4-6-6 but the other wheel arrangement escapes me at the moment although I have drawings for both.
My question is, does any out there know anything about the proposed Texas and Pacific duplex drive?