New locomotives for Tanzania

The Tanzania Railways Corporation (TRC) is undertaking a major project to build an entirely new rail network, for the first time with a 1,435 mm gauge; the existing lines were of a 1,000 mm gauge. A 25 kV 50 Hz electrified railway is being built in several phases from the most populous (formerly capital) city of Dar es Salaam, which should eventually reach neighbouring Rwanda, Burundi and eventually the Democratic Republic of Congo. The first phase is a 300-km stretch to Morogoro, which should be operational by early 2024. 

Both second-hand vehicles (ex-ÖBB Class 1014 locomotives and ex-DB Regio double-deck cars) and new-built vehicles (locomotives, cars and EMUs from South Korea) will be purchased to ensure operation. The new passenger locomotives are four-axle ones, with a maximum speed of 160 km/h and designed for the 25 kV 50 Hz voltage.

The manufacturer of the 17-strong batch is Hyundai Rotem. The company ordered a complete set of electrical equipment from Škoda Transportation in October 2021 in a contract worth approximately 23 million EUR. With this order, Škoda has continued its previous cooperation with Hyundai Rotem in the form of traction equipment supplies for 80 Class E 68000 locomotives for TCDD, delivered since 2013.

The final assembly of the locomotives for Tanzania is taking place at Hyundai Rotem's Changwon plant in South Korea, where the first locomotive for TCR was presented on 26 July 2023. It has already been transported from South Korea to Tanzania and, after the necessary preparations, started test runs at the end of November 2023 between Pugu (on the western outskirts of the capital Dar es Salaam) and Soga (approximately 30 km to the west).

During the tests, the locomotive's behaviour on the 25 kV 50 Hz voltage is monitored, because in South Korea it was tested on the 25 kV 60 Hz overhead line voltage, so for the correct operation of the vehicle it is necessary to change the software of the input four-quadrant pulse rectifier. The synergy of mechanical and electrodynamic brake is also being fine-tuned and testing at higher speeds is underway, as the factory test track in Changwon can only enable a maximum of 40 km/h. As the TRC's E6800 locomotives differ from the TCDD's Class E68000s by having the top speed increased from 140 km/h to 160 km/h, testing at 176 km/h is also being carried out in Tanzania.

In other main parameters, the two classes are basically the same, i. e. rated power 5,000 kW, maximum tractive effort 285 kN, maximum braking force (of recuperative) EDB 150 kN, length over buffers 20,000 mm, bodyshell width 2,950 mm, distance between bogie pivots 9,900 mm, bogie wheelbase 3,000 mm, wheel diameter 1,250 mm when new and maximum axle weight 21.5 t. The traction equipment is based on high-voltage IGBT modules with parameters of 3.3 kV and 1,500 A.

Škoda Electric supplies the complete electrical equipment, which for each locomotive includes the main switch, traction transformer, two traction converter boxes, a fully redundant auxiliary drive converter, cooling towers and complete traction drive blocks (traction motors, axle gearboxes and wheelsets). The entire batch of 17 sets is already in South Korea and two more locomotives have already been transported to Tanzania.

In Tanzania, the Korean-Czech locomotives will be deployed on the roughly 550 km long new line between the port of Dar es Salaam in the east of the country and the city of Makutupora in the central part, where they will have to cope with challenging climatic conditions and large differences in altitude.