For its electrification of its line in the lower Engadine, the RhB ordered seven Ge 2/4 in 1910. These locomotives, which were delivered in 1913, were intended for passenger service and had half the traction equipment of the Ge 4/6. They had two driving axles powered by a common repulsion motor via a crank axle and coupling rods. One Bissel axle at each end ensured guidance in curves and proper weight distribution.
As it turned out that their power of 210 kW was not enough for passenger service even on flatter lines, they were increasingly used in shunting service. For this use, their repulsion motor was not suited at all due to its suboptimal starting characteristics and its very high consumption of coal brushes when changing direction very often. Additionally, the two cabs meant that the driver had to change the cab frequently when shunting.
To extend their service life, five were rebuilt in the forties where they got a completely new electric equipment including a single-phase motor. The reduced size of the new motor allowed to increase the top speed from 45 to 55 km/h. Two of these had been converted to switchers in the same process by changing the boxcab design for a central cab and lower hoods. This allowed the driver to switch the direction without moving from one to the other cab.
Since Chur station also had some tracks which led to the Arosa line which were electrified with DC, one of the shunters was equipped with batteries which were charged then running on the AC tracks. This changed its designation to Gea 2/4. In 1967, this one got a diesel engine instead of the batteries and was designated Gem 2/4.
The rebuilt boxcab locomotives were retired in the seventies and No. 222 was preserved and is operational. The two electric-only switchers were used into the eighties and one of these is on static display today. The Gem 2/4 was used until 2001 and then scrapped. The two non-rebuilt locomotives with the numbers 205 and 207 are preserved, but on static display.