5F "Crab"

Mixed -Traffic engine : a locomotive that is intended to haul both passenger and freight trains.

Class 5F No 42765 at Kidderminster station, Severn Valley Railway, September 2001 Introduced : 1926 Number built : 245 Wheel arrangement : 2-6-0 "Mogul" Prior to the Grouping, the Caledonian Railway had designed a 2-6-0 mixed traffic engine, which George Hughes decided had potential for use by the LMS. However, the restrictive loading gauge of the former Midland lines meant that inclining the cylinders was a necessity and the final design had extremely inclined cylinders which coupled with a raised running plate at the front end, made the locomotive somewhat distinctive. Hughes decided on a parallel Belpaire boiler for the locomotive pressurised to no more than 180 lb per sq inch, which meant that the cylinders had dimensions of 21 inches diameter by 26 inches of stroke, using long lap Walschaerts valve gear. This arrangement would result in the nickname "Land Crabs" or just "Crabs". Hughes retired before the locomotives were finished, and the designs ended up with Fowler, who promptly proceeded to apply Derby engineering principles to the design, somewhat to the detriment of the original Horwich design. The boiler design was retained, only because it was too late to get a standard Derby boiler onto the engine, but the steam brake, injectors and clacks became pure Derby. Worst of all, the locomotives were given standard Derby tenders which were narrower than the locomotive, spoiling the lines of the original design. These tenders were to remain with the locomotives throughout their working lives. Although intended as a freight engine, the "Crabs" unofficially became a mixed traffic engine, so could occasionally be found on passenger services. By the end of their career, British Railway officially recognised them as such, giving them the power classification of 5P5F. They were considered to be a successful design and were the only non-Derby inspired design of the Fowler era. Original Number Location of building Year of Building 13000-13006 Horwich 1926 13007-13029 Horwich 1927 13030-13035 Crewe 1926 13036-13099 Crewe 1927 13100-13107 Crewe 1928 13108-13109 Crewe 1929 13110-13129 Horwich 1929 13130-13149 Horwich 1930 13150-13224 Crewe 1930 13225-13234 Crewe 1931 13235-13244 Crewe 1932 The class was renumbered in 1934 to become numbers 2700-2944, with 40000 being added to these numbers upon nationalisation. Three examples are preserved; numbers 2700, 2765 & 2859. Backup Links Entry Page 'Gateway' Home Locomotive Introduction Locomotive Roster 1944