shorter journey times remained the same. As a result, the engines gradually became largely unsuited for their original purpose, and they were replaced by the larger D1 class tank engines. However the 'Terriers' were so reliable that they were put on other work, often finding use on branch line passenger and freight workings and as shunting engines. Twenty-three members of the class were withdrawn between 1898 and 1905, but the majority of these were sold in working order rather than scrapped. Purchasers of these locomotives included the Newhaven Harbour Company, the Isle of Wight Central Railway (four locomotives), Pauling & Co. (five locomotives), the Kent and East Sussex Railway (two locomotives), the London and South Western Railway (two locomotives), and the South Eastern and Chatham Railway (one locomotive). Others were transferred from capital to departmental (non-revenue earning) stock as pilots at Brighton locomotive works and Lancing carriage works. It is likely that the remainder of the class would have been withdrawn over the subsequent few years if the railway had not adopted push-pull or 'motor-train' working on many lightly used branch line services. The 'A1' class (as the locomotives were designated after 1905) were found ideally suited for conversion to this form of working. Between 1911 and 1913, twelve survivors were re-boilered under the instruction of Douglas Earle Marsh, Stroudley's successor as CME of the LB&SCR, with another four so treated after the Great War; these engines formed the A1X class with an increased weight of . Other changes made during the rebuilding were the extension of the smokebox (removing the smokebox 'wings', and moving the sandboxes from this same area (where they formed a forward extension of the leading driving wheel splasher) to below the running plate (although some locos rebuilt later retained the original sandboxes). The tube which had been used as part of the original condensing arrangement between the smokebox and side-tank was also removed. The engines were repainted during this time in 'Marsh Umber' livery. Five locomotives were bought by the British Government in 1918 and sent to Scotland to work at the U.S. Navy's North Sea Mine Barrage minelaying project at Inverness and Dalmore, near Invergordon. The facilities were built by the Admiralty, using distillery sites, but administered by the U.S. Navy. The locos were Nos 37 Southdown, 79 Minories, 81 Beulah and 83 Earlswood at Dalmore, and 38 Millwall which was used at Glen