Like other LCDR locomotives delivered prior to 1874, the locomotives originally had no numbers, being distinguished by name. In November 1875, William Kirtley (who had replaced Martley following the latter's death in 1874) allotted the class letter O. The locomotives were then given the numbers 1 and 2. In 1884, no. 2 was rebuilt with a new boiler; no. 1 was similarly treated in 1890. They passed to the South Eastern and Chatham Railway (SECR) at the start of 1899, and their numbers were increased by 459 to avoid duplication with former South Eastern Railway locomotives. Both were withdrawn from service in May 1903.
