The SS1 was the first mainline electric locomotive to be manufactured in China. The “SS” stood for “Shaoshan”, Mao’s birthplace. The first seven prototypes with the designation 6Y1 were built between 1958 and 1966 with Soviet help and were based on the ВЛ60. In the area of electronics, experience from the 6Y2 supplied by Alsthom was also incorporated.

In the years that followed, the prototypes were continuously improved. The actual production locomotives were ultimately only built between 1980 and 1988. Including all prototypes, 826 SS1s were built, which were used for various types of trains and the first of which had reached the end of their service life after almost 30 years. The last one ran for the last time on September 19, 2014.

Another type of electric locomotives imported from abroad in the 1980s was the 8K, supplied by Alstom. The reason for ordering a heavy goods train locomotive was the lack of capacity to haul large quantities of coal, which was urgently needed in Shanxi Province in particular. In order to be able to achieve sufficient traction with two-axle bogies, the 8K was designed as a double locomotive with two four-axle sections. The basis used was the BB 15000, which had been used by the SNCF since 1971. 148 units were delivered from France and two more were built in the Zhuzhou locomotive works in order to gain knowledge of modern technology.

Visually, the locomotives built for China differed from their originals in that they lacked the “Nez Cassé”, i.e. the bent fronts. In terms of power train technology, the biggest difference was that each axle had its own motor and not the typical French monomotor bogies were used. As with the 6K, traction motors with 800 kW each were used, resulting in a total output of 6,400 kW. The top speed was also set at 100 km/h.

As planned, the locomotives were mainly used to pull coal trains, which usually weighed around 4,000 tonnes. Later, train weights of 6,000 tonnes with one locomotive or 10,000 tonnes with two locomotives were tested. Although the power of the locomotives was sufficient, only the tests with 6,000 tonne trains were successful. With the heavier trains, it had been shown that the couplings were not up to the loads. Outside of their normal area of operation, the 8Ks were also used to haul passenger trains during the Chinese New Year celebrations, when passenger traffic was extremely high. The retirement took place between 2010 and 2015 due to the increasingly serious lack of spare parts. Four examples have been preserved for posterity, but not in working condition.

The E 50 was developed from 1950 as a heavy freight locomotive to have a modern successor to the E 94. A lot of experience from the development and operation of the E 94 was brought in, but it was created as a standard electric locomotive together with the E 10 and used the same modern components and production methods.

To ensure sufficient traction and tractive power, the locomotive was designed with six axles. This means that the power per traction motor could also be slightly lower compared to the E 10 in order to achieve cheaper production and a longer service life. Since there was not much confidence in the new power transmission via rubber ring springs for heavy freight train use at the beginning of production, the motors in the first 25 engines built were designed with nose-suspended motors and only then was the new technology used. It's not surprising that the early examples didn't fare any worse when you consider that most locomotives up to 160 km/h are now being built with nose-suspended motors. In order to prevent the front bogie from lifting when starting off with a heavy train, the bogies were connected with a cross coupler. In order to reduce wear on the rails, however, this coupling was no longer used in the last series and instead replaced by adjustments to the bogies themselves.

Production ended in 1973 after 194 units, after the locomotive now known as class 150 had a successor in the form of the 151. It proved to be a reliable workhorse, even if reduced performance in the upper speed range became apparent over time due to the simplified traction motors compared to the E 10. The more powerful and faster 151 was initially only able to compete for part of its missions, until it was increasingly pushed out of route service by the modern 152. In the end it was only used for pushing on ramps and for maneuvering and was retired in 2003. Lacking the prestige of an express train loco, all but two were scrapped within a short period of time.

When the demand for high-speed freight locomotives increased in the 1960s, a further development of the E 50 was examined. The requirements stipulated on gradients of 0.5 percent to run express freight trains with 120 km/h and 1.000 tonnes or regular freight trains with 80 km/h and 2.000 tonnes. A change in the gear ratio of the E 50 failed because its traction motors, which were weaker than those of other standard electric locomotives, would not have been sufficient at higher speeds. However, a completely new development was ruled out due to time constraints. The solution now consisted of finding a compromise between the proven technology of standard locomotives and more modern assemblies.

Since the traction motors of the E 50 were not suitable for a larger increase in output, the traction motors from the E 10 and E 40 were further developed. With a total of six of these traction motors, an hourly output of 6,288 kW and a braking power of 6,600 kW over a short period could be achieved. Since the bogies and the electrical equipment of the E 50 were not suitable for this power, the technology of the class 103 was used. To facilitate maintenance, new design principles were used, which had also been used with the 103. The entire paneling of the engine room consisted of three large hoods, which, like the driver's cabs, could be removed as a whole. Compared to the previous class, the interior of the driver's cabs has been modernized in terms of comfort and ergonomics.

According to their design, the locomotives were used almost exclusively in front of fast or heavy freight trains. Nevertheless, they had the necessary equipment to be able to pull passenger trains when there was a shortage of locomotives. Only on the Franconian Forest ramp they were used in front of scheduled passenger trains, which has not been permitted since 2003 due to the lack of door blocking.

The heaviest freight trains used in Germany were ore trains, initially weighing 4,000 and later 6,000 tonnes, which ran from the North Sea ports to the steelworks inland and were each pulled by two class 151 locomotives. Since these loads were too great for the screw couplings common in Central Europe, 20 locomotives and a sufficient number of freight cars were equipped with central buffer couplings. When these services were discontinued in the 1990s, the locomotives were fitted with screw couplings again and assigned to other areas of application.

In contrast to the other standard locomotives, most of the locomotives remained painted in their original chrome oxide green color scheme into the 1990s. Their importance decreased with the increasing number of four-axle three-phase current locomotives for freight train use, since the DB wanted to quickly part with locomotives with three-axle bogies due to the increased wear on wheels and rails.

Since 2003, they have mostly only been used to push vehicles up ramps. At the same time, sales began to private companies, who will continue to use the locomotives for longer due to their performance and reliability. The largest customer was a consortium of Railpool and Toshiba, which signed the contract for the purchase of 100 of the 170 machines manufactured in 2017. At Deutsche Bahn, the locomotives are now being phased out when the maintenance deadlines expire.

The E 92⁷ was an electric locomotive for the Silesian mountain routes, which the Prussian State Railways ordered before the First World War. Due to the war, they were not put into operation until 1923, when the Deutsche Reichsbahn already existed. Their original designation was EG 571 ab to EG 579 ab, with the “ab” indicating that they were double locomotives.

The specifications stipulated that the locomotive should be able to pull 1,200 tonnes at a gradient of one percent and 500 tonnes at two percent, and at the same speeds that the steam locomotives of the time could reach. In order to meet these requirements, the then still new technology of the axle bearing single axle drive was used.

Both halves of the locomotive had a driver's cab in the middle, in front of which was a narrower hood with a transformer and other equipment. This arrangement restricted visibility considerably, since the driver could only look past the hood through narrow windows. Behind the driver's cabs were luggage compartments, which also contained some electrical equipment. The transition between the locomotive halves was closed with bellows.

In use on the Silesian Mountain Railway, the machines proved themselves despite the many gradients of up to two percent and tight curve radii of up to 184 meters. In February 1945 they were moved to Central Germany because of the approaching Soviet troops. After the war, eight of the nine examples came to the Reichsbahn, where they initially had to be handed over to the Soviet Union. After six returned, they were used until 1962.

The E 93 was developed to be able to increase the train weights on the Geislinger Steige to 1,200 tonnes. Like the E 44 it had nose-suspended motors but was designed as a crocodile with the main machinery room and driver's cabs on a bridge frame and large hoods mounted on the bogies. It formed the basis for the more well-known E 94. The use in regular service on the Bundesbahn ended in 1976 and the last locomotives were used as helper locomotives until 1984, still on the Geislinger Steige.

The E 94 was developed directly from the E 93 and was to be used on difficult mountain ramps not only in Germany but also in Austria, which had just been annexed. Externally, it differed from the E 93 mainly in the perforated longitudinal beams of the bridge frame. As a war electric locomotive, domestic materials were increasingly used in production. The Bundesbahn took over most of them and used them in southern Germany until 1988. In the 1950s, even 43 new locomotives were built with a significantly increased hourly output. While the Reichsbahn had only received a few locomotives, the ÖBB still had 44 units. These were later modernized and some were used until 1995.

The Reichsbahn had the class 250 manufactured for universal use in front of heavy passenger and freight trains. It was designed with a LEW conical spring drive for a speed of 160 km/h, but was only approved for 125 km/h due to the infrastructure in the GDR. The locomotives, which were also otherwise developed according to then modern points of view, were taken over by the DB AG in 1994 as the class 155 and initially continued to be used to pull heavy passenger trains, too. They came to DB Cargo during the railway reform and were only used there in front of freight trains until the last locomotives were phased out in 2019.