The first four Consolidations No. 21 to 24 delivered to Ethiopia had been ordered by the Swiss Alfred Ilg from the SLM in 1902 and 1903. They were metre-gauge, two-cylinder cross-compound locomotives with a driver diameter of 1,000 mm. After one of these was tested on the RhB network in Switzerland, this railway also ordered a similar type that was to become the G 4/5.
After construction of the line was continued with French support, eight more were ordered from SACM. These were built in 1910 after the same basic design and received the numbers 25 to 32. SACM designated them type UG 181 and from 1913, they introduced the superheated two-cylinder simple of the type UG 190 that was numbered 121 to 129 on the CFE. In 1914, a single additional locomotive of the original design was delivered by the SLM and numbered 33.