Heljan 3931 LNER Gresley O2/1 Tango 3481 BlackHeljan 3931 LNER Gresley O2 1 Tango 3481 Black Introduced by the Great Northern Railway in 1921 to a design by Nigel Gresley, these powerful 2 8 0s were built to haul heavy mineral trains. Several batches were built over a 22 year period by the GNR and LNER, with numerous improvements such as better cabs and bigger tenders. Tech Specs: NEM Couplings Sprung Buffers 21 Pin DCC Interface Locomotive And Tender Pickups