Baldwin delivered 24 Atlantic locomotives to the Nippon Tetsudo in 1897, which were to remain the only Japanese engines with this wheel arrangement. In terms of design, it was a typical American Atlantic, but it had been reduced in size for the Cape gauge of 3 ft 6 in and the significantly smaller loading gauge. Thanks to the trailing axle and the space-saving bar frame, it was possible to arrange the firebox completely behind the coupled axles and to make it very wide, which was otherwise difficult with steam locomotives with a smaller gauge. Also typically American were the large driver's cab and the high-mounted running boards. Due to the inside Stephenson valve gear of American design, the locomotives looked very tidy, since only the connecting and coupling rods could be seen from the outside.

In the initially private railway they were designated as Bbt2/5 with the operating numbers 506 to 529 and were used on today's Joban line on the east coast. The available coal was not of high quality, but thanks to the large grate area, the boiler could still produce a lot of steam. After nationalization in 1906, the locomotives were given the numbers 6600 to 6623 by the JNR. Since only two of the five axles on Atlantic locomotives were powered, they were soon replaced by newer superheated steam locomotives with greater adhesive weight. All 24 machines were quickly scrapped in April and May 1925.