SME Models South African Railway 7E Electric Locomotive, Blue

The South African Railways Class 7E is an electric locomotive, South African Railways placed 100 Class 7E electric locomotives with a Co-Co wheel arrangement in service in 1978/79. They were the first 25kV AC locomotives to enter service in South Africa. One hundred Class 7E locomotives were delivered in 1978 and 1979, numbered in the range from E7001 to E7100. Beginning with the Class 7E, the SAR numbering practice for electric locomotives was changed to make the class number a part of the locomotive’s number.

These dual cab locomotives have a roof access ladder on one side only, just to the right of the cab access door. The roof access ladder end is marked as the no. 2 end. Control of traction and rheostatic braking on the Class 7E is by stepless solid-state electronics. The electrical equipment was designed for high power factor operation, obtained by a sector control method.

These were the first South African AC electric locomotives with thyristor technology from the 50 ^c/s Group.The Class 7E was built with sophisticated traction linkages on the bogies. Together with the locomotive's electronic wheel slip detection system, these traction struts, mounted between the linkages on the bogies and the locomotive body and colloquially referred to as grasshopper legs, ensure the maximum transfer of power to the rails without causing wheel slip by reducing the traction force of the leading bogie and increasing that of the trailing bogie by as much as 15% upon starting off.

The Class 7E was the first SAR electric locomotive on which the pantograph contact shoe centres were located directly above the bogie pivot centres. This reduces the risk of pantograph hookups on catenary in sharp curves such as in turnouts as a result of sideways movement of the pantograph in relation to the overhead wire.

Fitted with Lenz DCC Decoder

HO scale