There is disclosed herein an electrical rail coupler assembly (1) to maintain in use electrical contact between adjacent railway carriages. The assembly (1) includes a pair of complementary coupler sub-assemblies (5) securable together in use to maintain electrical contact therebetween. Each coupler sub-assembly (5) includes a base (10) to be fixed to a respective one of the carriages. A body (15) is attached to the base (10) and at least one electrical plug portion (25) engages an electrical receptacle portion (26) of the other sub-assembly (5) so that the sub-assemblies (5) when secured together are electrically connected. The electrical portions (25, 26) are moved, into electrical contact engagement by relative movement, in a predetermined direction by at least one of the bodies (5) being movable in the direction relative to its associated base (10) to provide for engagement and disengagement of the plug and receptacle portions (25, 26). Securing means (30) extends between the bodies (15) to releasably secure the bodies (15) together with the plug and receptacle portions (25, 26) in electrical contact.