To modernize the shunting operation, the Rhaetian Railway RhB ordered ten diesel-hydraulic shunting tractors from the German manufacturer Schöma. The vehicles are very similar to the 420 CT 4H type purchased from RACO from 1991. The second series, comprising six vehicles, was put into operation by the RhB with track numbers 115-120. The two-axle vehicles are powered by a six-cylinder Cummins QSX diesel engine with an impressive 336 kW, which transfers its power to a three-speed converter transmission. The locomotives are stationed at larger stations such as Thusis, Ilanz or Davos. Due to a modified cooling system, the vehicles have a greater overall length than the first series locomotives, which also came from Schöma. With a maximum speed of 60 km/h, the tractors can also prove themselves in front of light local freight trains. An eddy current brake that acts almost to a standstill enables wear-free deceleration.
| Key | Functions | Sound slots | Volume CVs | Volume values |
|---|
| F0 | front light | | | |
| F1 | sound on/off | 1, 2 | 259, 267 | 240, 150 |
| F2 | air horn | 3 | 275 | 160 |
| F3 | apply/release spring brake | 28 | 475 | 128 |
| F4 | radio conversation #1 (shunting distance) | 7 | 307 | 128 |
| F5 | heavy load | | | |
| F6 | acceleration/brake time, shunting mode/shunting speed | | | |
| F7 | curve squeal | 15 | 371 | 100 |
| F8 | AUX#1 | | | |
| F9 | compressed air let off | 31 | 499 | 90 |
| F10 | radio conversation #2 | 4 | 283 | 128 |
| F11 | coupler clank | 8 | 315 | 80 |
| F12 | coasting | | | |
| F13 | apply/release brake (automatically) | 30 | 491 | 85 |
| F14 | vacuum pump (3 steps / push the function button twice to step into the next step) | 29 | 483 | 65 |
| F15 | esu smoke generator | | | |
| F16 | open / close cab door | 12 | 347 | 90 |
| F17 | brake function 1 (with brake valve sound) | 24 | 443 | 80 |
| F18 | radio conversation #3 | 10 | 331 | 128 |
| F19 | radio conversation #4 | 13 | 355 | 128 |
| F20 | radio conversation #5 | 14 | 363 | 128 |
| F21 | radio conversation #6 | 16 | 379 | 128 |
| F22 | radio conversation #7 | 18 | 395 | 128 |
| F23 | radio conversation #8 | 19 | 403 | 128 |
| F24 | 9radio conversation #9 | 20 | 411 | 128 |
| F25 | radio conversation #10 | 21 | 419 | 128 |
| F26 | sound fader | | | |
| F27 | disable brake squeal sound | | | |
| F28 | radio conversation #11 | 22 | 427 | 128 |
| F29 | radio conversation #12 | 23 | 435 | 128 |
| F30 | sanding valve | 25 | 451 | 40 |
| F31 | automatic vigilance device | 27 | 467 | 128 |
Make sure that index CV31 is set to 16 and index CV32 is set to 1 before changing a volume CV.