Bulletin: SR Merchant Navy Class Address 3 Manufacturer Wickness Project number WMN Project version V1.1 The SR Merchant Navy class (originally known as the 21C1 class, and later informally known as Bulleid Pacifics, Spam Cans or Packets) is a class of air- smoothed 4-6-2 Pacific steam locomotives designed for the Southern Railway of the United Kingdom by Oliver Bulleid. The Pacific design was chosen in preference to several others proposed by Bulleid. The first members of the class were constructed during the Second World War, and the last of the 30 locomotives in 1949. Incorporating a number of new developments in British steam locomotive technology, the design of the Merchant Navy class was among the first to use welding in the construction process; this enabled easier fabrication of components during the austerity of the war and post-war economies. The locomotives featured thermic syphons and Bulleid's innovative, but controversial, chain-driven valve gear. The class members were named after the Merchant Navy shipping lines involved in the Battle of the Atlantic, and latterly those which used Southampton Docks, a publicity masterstroke by the Southern Railway, which operated Southampton Docks during the period. Due to problems with some of the more novel features of Bulleid's design, all members of the class were modified by British Railways during the late 1950s, losing their air-smoothed casing in the process. The Merchant Navy class operated until the end of Southern steam in July 1967. A third of the class has survived and can be seen on heritage railways throughout Great Britain. Key Function Sound slots Volume CVs Volume values F0 front light on/off 22 427 15 F1 sound on/off 1, 2, 24 259, 267, 443 128, 128, 128 F2 long whistle #1 3 275 128 F3 long whistle #2 4 283 128 F4 coal shoveling 5 291 70 F5 air pump (slow) 6 299 55 F6 shunting mode F7 curve squeal sound on/off 15 371 95 F8 AUX1 F9 cylinder blow out 9 323 128 F10 conductor's signal 10 331 60 F11 coupler clank 8 315 100 F12 sanding valve 11 339 30 F13 set/release brake 13 355 90 F14 station announcement #1 7 307 100 F15 short whistle signal 16 379 128 F16 safety valve 12 347 128 F17 rail clank on/off 17 387 85 F18 station announcement #2 14 363 100 F19 injector 20 411 45 F20 ir pump (fast) 21 419 55 F21 vacuum air brake 18 395 100 F22 Main Soundscape 19 403 128 F23 automatic warning system AWS - 23 435 128 horn F24 sound fader F25 disable brake squeal sound F26 Not in use F27 Not in use F28 Not in use.