The HG 2/4 was a combined rack and adhesion locomotive of the meter-gauge Appenzell Tramway introduced in 1904. Since the HG 2/3 introduced in 1889 had a too complex Klose steering mechanism, the new locomotives were to be simpler in construction. The requirement was that they still could run the flatter sections in pure adhesion mode and engage the combined mode on the rack sections.

They were designed after the Winterthur system that combines the adhesion and rack drive with compound working. This meant that the high pressure cylinders were at the bottom and drove the wheels, while the low pressure cylinders at the top drove the crank axle for the rack drive. The crank axle worked onto the rack wheels via a 1 to 2,21 reduction gear, what meant that the low pressure cylinders moved at more than twice the speed of the high pressure cylinders, enabling all to be of the same size.

Numbers 5 and 6 were completed in 1904, followed by 7 and 8 in 1909 which were heavier. In adhesion mode they reached a top speed of 30 km/h. On the rack section, the maximum was 24 km/h when running uphill and 18 km/h when running downhill. In 1918, No. 6 was the only one to receive a superheater. Despite this it was one of the two which were retired first in 1931, while the others followed in 1932 and 1934-

During the construction of the Bernese Oberland Railway (BOB), it was planned to purchase one type of adhesion locomotive for the less steep section and one type of purely rack locomotive for the steeper section. By the time the line opened in 1890, the decision was made to purchase only one type with a combined adhesion and reck drive. The first three HG 3 were delivered in 1890 and three more in 1893. They later became HG 3/3 according to the Swiss system.

These were 0-6-0RT tank locomotives and had outside frames. The rack drive was mounted on the driving axles to avoid problems with the suspension. Of the two rack gears under the locomotive, one was used for driving and one for braking. The boiler was inclined by five percent compared to the frame.

After the BOB was electrified in 1914, these locomotives were no longer needed in daily operations and five of them were sold. Three were converted from the gauge of 1,000 mm to 950 mm and sold to the Italian Mediterranea-Calabro-Lucane. Two went to the Arosa Railway, but were sold to industry after a short time. The sixth locomotive remained with the BOB as a reserve.

The Brig-Furka-Disentis railway ordered ten rack locomotives from SLM while under construction, the first three of which were delivered directly to the construction sites. They were based on the HG 2/3 of the Visp-Zermatt Bahn, but had a significantly higher power thanks to superheated steam. The four cylinders worked in compound operation, with the gearwheels driven by the low-pressure cylinders and always operated together with the adhesion drive. With the electrification of the railway, the locomotives were retired there in 1940. One was sold to France and four to French Indochina (Vietnam). The latter four came back to Switzerland in 1990 and two of them are now running on the Furka mountain line after being refurbished.

Under the designation G 2/2+2/3, the Rhaetian Railway operated two Mallets delivered by the SLM in 1896 for 65,500 Swiss Francs each. The G in the designation stood for a narrow gauge locomotive, while 2/2+2/3 stood for a leading bogie with two driving axles and a second group in the main frame that had also two driving axles and an additional trailing axle. All axles were mounted in outside frames. These locomotives can be seen as the follower of the two G 2x2/2 of the preceding Landquart-Davos Railway.

The requirements were that they could haul 70 tonnes on a 4.5 percent incline with 15 km/h. While the trailing axle was not present on the predecessors, it was added here to increase the supplies. In service it was found out that the trailing axle led to increased wear on both the tracks and wheel flanges. This is why the following G 2/3+2/2 had the carrying axle at the front. The two G 2/2+2/3, named “Maloja” and “Chiavenna”, were used by the RhB until 1926. Then they were sold to Oberhasli Power Plants company, who scrapped them in 1940.

To open the new line from Filisur to Davos, the RhB needed new locomotives that had to have sufficient tractive effort on the line, which had a gradient of up to 3.5 percent. Above all, it should not only be possible to transport passenger trains, but also the mixed trains that were common on the RhB. As with the G 2/2+2/3, a Mallet was procured with four coupled axles, but the carrying axle was now at the front. A total of eight locomotives were built in 1902 and 1903 at a price of 76,800 Swiss francs each.

Like its predecessor, the G 2/3+2/2 had an outer frame. This ended at the front at the pivot point of the bogie, so that the boiler overhanged the front without a frame. The starting valve of the four-cylinder compound engine was activated automatically when the reverser was put to the extreme ends. Thus, live steam with reduced pressure was then admitted into the high-pressure cylinders in order to obtain a higher tractive force for starting. The locomotives could transport 300 tonnes at 38 km/h on the level or 90 tonnes on the 3.5 percent of the new line at 20 km/h. However, there was a limit of 18 km/h on the line.

Since the entire RhB network had been electrified by 1920, the locomotives became superfluous. Three units were sold to the Chemin de fer Yverdon-Ste-Croix (YStC) and had just been fitted with a superheater in the RhB workshops. They were used there until 1946, when this railway also electrified its network. This meant that two of these locos were sold to Spain and after several changes of operator were scrapped in 1961 and 1969. The other five were sold to Madagascar and converted to 950 mm gauge. One of them was scrapped in 1930, but the others only in 1958.

At the beginning of the century, the Brünig line, the only narrow gauge line of the Swiss Federal Railways, needed new, more powerful locomotives for the adhesion section in the lower sections. While the previous locomotives only had three coupled axles, the new G 3/4 got an additional leading axle. Only numbers 201 and 202 were built in 1905. Six followed in 1912 and 1913, of which only the last one, No. 208, had a superheater from the start.

In the middle of the twenties, all others were superheated, too. After the top speed had been 45 km/h from the beginning, they were approved for 55 km/h in 1930 and for 60 km/h in 1936. After the Brünig line had been electrified in 1941 and 1942, they came to the Réduit, what was the Swiss system of fortifications and hidden gun positions.

After the war, three locomotives could be sold to the Thessalian railways in Greece. Two were scrapped already in 1947 and the rest got other tasks in Switzerland. 207 and 208 were the last ones to be retired in 1965. 208 was preserved as one of two SBB narrow gauge steam locomotives and was operational until it got damaged by a fire in 2013. In 2016 it came to the RhB shop at Landquart to be restored again.

When it opened in 1884, the meter-gauge Tramelan-Tavannes Railway procured two small tank locomotives from the SLM, which were intended to be able to cope with the line, which was then up to four percent steep. They had a 0-4-0WT wheel arrangement and used their frames as a water tank. For safety reasons, the chassis was protected on all sides with a wooden plank.

In 1891 a third, almost identical locomotive was purchased. These locomotives were actually a bit too small for the line, but they remained in use until electrification in 1913. Since other meter-gauge lines in Switzerland were subsequently electrified, the locomotives were rented out for the construction work. After some time in reserve they were scrapped in 1940 and 1943.