Urie/Maunsell N15 "King Arthur" class 4-6-0

In the autumn of 1918 the LSWR's works at Eastleigh turned out the first three of a new express passenger 4-6-0 class designed by Robert Urie. A further seven appeared between February and November 1919. With 6 ft 7 in drivers, carrying the characteristic Urie stove pipe chimney and retaining a Drummond style cab the N15 class was otherwise styled along H15 lines. The new locomotives were initially welcomed by the operating department, however at that time the schedules of the principal expresses they were working were undemanding with a maximum speed of 60mph. When timings were accelerated, though, they proved to be poor performers since they were not free steamers and were unable to sustain high power outputs.

North British built Nº767 Sir Valance heads a passenger train during Southern Railway days prior to the fitting of smoke deflectors.

photograph: Mike Morant collection

Upon assuming the job of C.M.E. of the Southern Railway Richard Maunsell undertook a review of the existing locomotive stock. Although he had his own new designs planned the need to maintain services before they became available led to an improvement programme on existing designs. A revised front end design applied to the N15s including increasing the area of the steam and exhaust ports, fitting a modified chimney and blastpipe significantly improved the class' performance.

As Maunsell's new express passenger design was not going to be ready in time for the summer 1925 timetable and this was going to leave the railway short of suitable locomotives the Southern placed an order for 20 engines to the N15 design with the North British Locomotive Company. These were built and supplied in record time. This batch became nicknamed by crews as "Scotchmen". Simultaneously Eastleigh built a batch of ten N15s to replace the Drummond G14 class and they adopted their numbers and tenders. These and later batches differed to the original Urie design in that they had smaller cylinders, a higher boiler pressure (200 psi instead of 180 psi), front end features from the N Class and an Ashford style cab to the composite SR loading gauge.

Nº750 Morgan Le Fay and train at speed in Southern Railway days. The location of this photograph is not known.

photograph: Mike Morant collection