SACM delivered a test locomotive with the number 242 AE 1, which was similar in design to the 242 BE 1. It also stood on two chassis that were closely coupled to each other, each consisting of two powered axles and a two-axle lead bogie. Like the BE 1, the AE 1 also got single-axle drive with fully sprung engines. The special feature here was that the bogies had a different version of the quill drive. While one had a Westinghouse quill drive, the other got a special drive developed by SACM with a joint mechanism and the so-called “dancing ring”. This drive was later further developed by SACM and Alsthom and used in the record locomotive CC 7100 and several Italian locomotives. However, the 242 AE 1 had no direct successor and was used on the Mont Cenis railway as SNCF 2BB2 3201 until 1967.

The first electric locomotive for trial operation on the Maurienne was the 242 BE 1, which was delivered in April 1925 before the electrification of this route was completed. It was therefore initially operated on the Paris-Orléans network until it was transferred to the correct route in July. The locomotive had two two-axle powered bogies that were closely coupled to each other to transmit the tractive forces. Each axle was driven by a double motor and an Oerlikon quill drive. To improve the running characteristics and to absorb the mass, a bogie with two carrying axles was added at each end. The locomotive body was in one piece, but at each end of the locomotive, like the crocodile locomotives, there was a small front hood that was mounted on the bogies. 

After testing, it was used on passenger trains until 1934 and then on freight trains. In the meantime, the larger 262 AE had emerged as a direct derivative, since the 242 BE had proven itself in service. The latter was given the number 2BB2 3301 when it was taken over by the SNCF. It was damaged by a voltage flashover in 1961 and was initially parked. Since no repairs were made, it was scrapped some time later.

The next electric locomotive for the Maurienne line came in 1925 from Fives-Lille, the 242 CE 1, which consisted of two halves and was the only one with power transmission by rods. Although the designation “242” is more indicative of a 2-B+B-2 loco, it still had a running axle at the end of each half. There was a large electric motor in each half, while competing locomotives featured a single or double electric motor per driven axle. The power was not transmitted to a rotating jackshaft, but to a reciprocating lever, which in turn drove the driver and coupled axles. A special approach was also taken with the electrics by dispensing with starting resistors and using a special, self-regulating starting system. Whether the special technical solutions of the 242 CE would have proven themselves in operation could not be determined conclusively, since it fell victim to an electrical fire in 1926 after a mileage of 6,889 km and could no longer be repaired. At 164 tonnes, it is still considered the heaviest electric locomotive ever built in France.

One of the four trial locomotives on the Mont Cenis line was the 161 AE 1, supplied by Schneider and Alsthom. It shared the total number of eight axles with the 242 BE 1 and 242 AE 1, but the body was divided into two parts, as with the 242 CE 1. In contrast to all the others, however, six axles were powered and only two axles were used as carrying axles. This was realized by mount each half of the locomotive on two bogies, of which the outer one consisted of a carrying and a driving axle. The power came from axle-mounted motors with spring-loaded gears that allowed 110 km/h. It was later reclassified as 1ABBA1 3500 and remained in service until 1967.

The 161 AE 1 was the only one of the four locomotives from trial operation that was reordered in a total of ten units as a direct development. The production locomotives were designated differently as 161 BE, since they were intended for use in front of freight trains. In return, they got simple axle-mounted motors without spring-loaded gears and a different gear ratio, which only allowed a maximum speed of 80 km/h. The hourly and continuous output was increased by 90 and 110 kW, respectively, and the weight also increased. The SNCF used the locomotives until 1973 and named them 1ABBA1 3601 to 3610.

After the 161 AE proved to be the best of the four test locomotives on the Maurienne route, each ten locomotives with a total of six powered axles and only two carrying axles were ordered from SACM and Fives-Lille, the electrical parts of which were designed by CEF (Constructions électriques de France). SACM's contribution was the 161 CE, which had a one-piece body. In contrast to the 161 AE and BE, three powered axles were stored in a bogie. The carrying axle at each end of the locomotive was designed to be radially adjustable.

The locomotive body did not have small hoods at the ends, but platforms with doors on the front. The continuous output was only 1,170 kW, but was sufficient for freight trains. The locomotives remained in use on the original route for most of their lives, only four were temporarily relocated during the Second World War. Their SNCF numbers were 1CC1 3701 to 3710. They were retired between 1967 and 1972 and then all were scrapped.

Fives-Lille supplied the ten freight locomotives 161 DE 1 to 10, which again consisted of two halves. In each half of the locomotive, three powered axles were mounted in the frame, which, like the 161 CE, were supplemented by a movably mounted leading axle. The weight distribution was designed in such a way that the leading axles each had to carry less than ten tonnes and therefore more adhesion mass was available. Instead of platforms at the ends of the locomotives, there were smaller hoods, while the doors were attached to the sides. When the locos were taken over by the SNCF, they became the 1CC1 3801 to 3810. The last examples remained in service until 1973.

A special feature of the series came about during the war, when 1CC1 3805 fell victim to a bomb attack in Modane. Only one half of the locomotive was badly damaged, while the other remained largely intact. It was not until 1949 that the intact half was refurbished and used as an independent locomotive with the number 1C 1001 in shunting operations in Saint-Jean-de-Maurienne. The contact shoes for the third rail were removed so that the locomotive could only work under the catenary. The continuous output was increased to 1,070 kW and use ended in 1966.

After the electric locomotives originally tested on the Maurienne route had been developed for express service and the production machines were all designed for freight transport at a maximum speed of 80 km/h, there was a new need for express train locomotives. Finally, four more locomotives were ordered from Batignolles-Châtillon to cover this need. They were based on the 242 BE 1 and also got the electrical equipment from Oerlikon, but were larger and significantly more powerful. By adding an extra driving axle to each bogie, a 2-C+C-2 wheel arrangement was obtained. This made them not only the longest electric locomotive of the later SNCF, but also the most powerful one-section locomotives in the world at the time.

The order originally dictated that passenger trains of up to 600 tonnes could also be transported on the Marseille-Nice route. Ultimately, the locomotives were only used on the Maurienne route, where rather lighter trains were pulled on gradients of up to three percent. At the SNCF they were classified as 2CC2 Nos. 3401 to 3404. They, too, were later caught up by newer locomotives, which gradually pushed them into freight service. They later became dispensable in this role as well, so that they were retired by 1974. The only one that survived was 2CC2 3402, which has been prepared since 2002 and moved under its own power for the first time in 2008.