In the mid-1920s, the Austrian Federal Railways had powerful electric locomotives with the “Arlberg Crocodile” class 1100 for mountain use and with the class 1029 passenger electric locomotives for the lowlands, but there was no suitable locomotive for heavier trains on the valley routes in Tyrol and Vorarlberg available. The new locomotive should be in the same power class as the 1100, but be faster.

Since both the traditional rod drive and the nose-suspended motor were not suitable for higher speeds, another form of transmission had to be found. Siemens-Schuckert in Vienna therefore developed a new type of vertical drive, which became the first single-axle drive for electric locomotives in Austria. The drive consisted of vertical shafts, each of which drove an axle directly via a conical gear wheel. This made it possible to accommodate powered and carrying axles in a common bogie at the same time.

The locomotives had a bogie at each end, which had a carrying axle on the outside and a powered axle on the inside. Two more powered axles were mounted in the middle under the locomotive body. With this chassis, the locomotives had sufficient adhesive weight and good ability to negotiate curves, but the transmissions required constant monitoring of the lubrication and thus made a second crew member necessary.

Thus, the locomotives proved themselves in service, but the power was not sufficient. Therefore, production was stopped after only four examples and the class 1670 was developed as a replacement. The class 1570 locomotives came to the Reichsbahn after the annexation of Austria by Germany and were listed as E 22. They got their original number again in 1953 and were used by ÖBB until 1978. Today only the 1570.01 is preserved in a museum and is located at Strasshof.

The four examples built in 1925 from the class 1570 were considered relatively successful from a design point of view, but the power was not sufficient for the assigned applications. In order to increase power, it was decided to replace the four individual traction motors with four double motors, thus creating the power 1670. The additional weight in the electrical system was compensated for by the mechanical equipment being designed to achieve the maximum possible lightweight construction. A series of 29 locomotives was ordered, which were initially manufactured by Krauss in Linz. When Krauss closed the factory in Linz after 24 units, the rest were built in Floridsdorf. The locomotives were stationed in Innsbruck and used from there along the valleys.

Due to the exaggerated lightweight construction, damage frequently occurred, which led to the shutdown of all locomotives. Now all the necessary points on the design have been reinforced, which increased the weight by around ten tonnes and reduced failures. In 1932, five more locomotives were ordered, which were built more sturdily from the factory and were designated as class 1670.1. In the period that followed, there was still damage to the drives, which mainly occurred when the locomotives were being towed. However, it was possible to rework the drives in such a way that the second man to monitor the lubrication could be omitted and less damage occurred in the future. The two series became E 22¹ and E 22² during the German occupation and they got their old numbers back in 1953. They were used until 1983 and today two examples of the 1670 and one example of the 1670.1 have been preserved. These are the locomotives numbered 09, 25 and 140 and all of them are still running.

For the increasingly heavier trains on the Lötschberg line, the BLS needed a new locomotive in the mid-1920s that was supposed to be more powerful than the Be 5/7. On the route with a gradient of 2.7 percent, it had primarily to transport freight trains of 510 tonnes and, if necessary, also be used in front of the heaviest express trains. Since the route was single-track and therefore rapid operation had to be guaranteed, the speed to be reached was set at 75 km/h.

Since a rod drive fell out at the required speed, it was not possible to fall back on a type that had already been developed, such as the SBB Ce 6/8 II. The choice fell on the Secheron spring drive with double motors, a form of the quill drive. The locomotive stood on two bogies, each with one leading and three driving axles, which were coupled to each other. For the first time in Swiss history, there was a seat in the cabs so that the driver no longer had to stand.

With a maximum speed of 75 km/h, the locomotive was assigned to train series B, which led to the designation Be 6/8. In the years 1926 to 1931 only four pieces were made at Breda, another four were made between 1939 and 1943 at SLM. The second series was approved for 90 km/h with a different gear ratio and the locomotives of the first series were soon rebuilt in the same way. This was accompanied by a classification in the train speed row A, which led to the designation Ae 6/8, which is better known today.

The train weight of the freight trains over the Lötschberg was increased in the first few years with the Be 6/8 from 510 to 550 and finally 600 tonnes. As planned, they also took over express trains that were too heavy for the Be 5/7. They were the most powerful locomotives in the world until the SBB introduced the Ae 8/14 two-section locomotive in 1931. From 1960, thanks to engine to the chassis, the speed could be increased to 100 km/h. The last machine was only retired in 1995 and today there are still three preserved.

In the 4.75 mile long Hoosac Tunnel in Massachusetts, growing traffic volumes at the beginning of the century caused major problems for the operation with steam locomotives due to smoke and steam. So the Boston & Maine planned to use electric locomotives to pull trains with their steam locomotive through the tunnel. With the steam locomotive idling, it created much less smoke and steam. So they electrified the tunnel with 11.000 V AC at 25 Hz in 1910.

Five electric locomotives were ordered from Baldwin and Westinghouse and numbered 2501 to 2505. They were of conventional boxcab design and rode on two bogies consisting of two powered axles and a leading axle. Three got a gear ratio for freight service, while the two others got a faster ratio for passenger service. Just one year later they were renumbered 5000 to 5004. In 1917, two more were built which were the first to be retired in 1942 and 1945. After diesel locomotives took over, all were retired until 1947.

Between 1914 and 1916, the Milwaukee Road undertook the largest mainline electrification to date by equipping their 438-mile Rocky Mountain line with 3,000 V DC. This included longer grades with two percent and so, powerful electric locomotives had to be built for both freight and passenger traffic. ALCO and General Electric designed these boxcab locomotives, which were made up of two sections, each one having two trucks with two powered axles each and a two-axle leading truck.

A promotional film made by GE called these locomotives “Kings of the Rails”. 30 EF-1 were built for freight traffic which were geared for 35 mph, had an hourly output of 4,100 hp and a continuous output of 3,340 hp. Additionally, twelve EP-1 were built for passenger traffic which were geared for a higher top speed and had a steam heating boiler. Only a few years later, all EP-1 were rebuilt to EF-1 by re-gearing them to 35 mph and removing the boiler.

Later, new classes were created by combining more sections. This process started in the thirties when 18 EF-1 were combined to twelve three-section EF-2. Even though more EF-2 followed later, the EF-3 was also created from three sections. Here the unused cab of the central section was removed, alongside with the leading bogie. They still had roughly the same adhesive weight as the EF-2, but weighed 51,000 pounds less in total. Between 1951 and 1961, a total of ten locomotives was even created with four sections and called EF-5. A single section that had been left over was used as switcher and designated ES-3.

In 1950, two were rebuilt for passenger service. One of those received streamlined fronts and now had an output of 4,500 hp. Another rebuild was the installation of multiple controls used to control a trailing diesel-electric locomotive. The introduction of the EF-4/EP-4 “Little Joe” meant that this feature was only rarely used and the boxcabs were increasingly used as helpers. Nevertheless, the older locomotives were approved for 45 mph in the fifties. Their service ended in the mid-sixties and today, one two-section unit and a single section are on static display.

The series 1000 was an electric locomotive that the NS ordered based on the Swiss Ae 4/6. This has been adapted to operate under 1,500 volts DC in the flat terrain of the Netherlands. The carrying axles were also combined here with the adjacent driving axle to form a Java bogie. The first three locomotives were manufactured by SLM with electrics from Oerlikon and the other seven only had the electrics from Switzerland. Despite their failure proneness, they were used until 1982, but almost exclusively in front of freight trains.

The total of six E 95 were designed to haul coal trains weighing 2,200 tonnes from Silesia to Dresden or Berlin. The development of the nose-suspended motors now allowed to build a locomotive of this power class with this type of drive. Thanks to the carrying axles, they were able run at speeds sufficient for passenger trains. On the other hand, the locomotives accelerated coal trains weighing up to 2,568 tonnes to 60 km/h during test runs. After the Second World War, they came to the Soviet Union as reparations and were later refurbished again in the GDR after their return. However, increasing problems led to their being phased out by 1969.

In the twenties, the Great northern built the new Cascade Tunnel and electrified the complete 73 mile (117 km) section over Stevens Pass with 11,000 V one-phase AC. Previously, only the old tunnel itself was electrified at 6,600 V three-phase AC and they now needed a replacement for the old GE boxcab electrics. So they ordered six 1-C+C-1 boxcabs from ALCO, which got their electric part from General Electric. They were numbered 5010 to 5017 and became class Y-1.

The alternate current from the overhead line was changed to direct current by a motor-generator. Over one hour, the locomotives delivered 3,300 hp, with a continuous output of 3,000 hp. In World War II, 5011 was badly damaged in an accident and its remains were used for a total rebuild where it got the streamlined cabs from the EMD FT.

In 1956, the Cascade Tunnel was dieselized and equipped with large fans to carry away the exhaust fumes. Since the frame of 5011 had been bent in the accident, it had several problems in service and was scrapped. All catenary was removed and the remaining locomotives were sold to the PRR, which called them FF1. The PRR scrapped three of them in the following years, but the last four were used until 1966.