Abridgment of Great Northern railway electrification in the cascades

The paper gives first a brief history of the series of improvements to better operating conditions over the Cascade Range which have been undertaken by the Great Northern Railway since the line was put in operation in 1893. The paper next gives (Part II) a description and the principal operating characteristics of the motor-generator type of locomotives now in service on the electrified section from Skykomish (Washington) to Cascade Tunnel Station, and to be used through the new tunnel and extension of electrification to Wenatchee when work now in progress is completed. Part III gives a description of the electric transmission and distribution system along the railroad line with particular emphasis on the relay protection designed to guard the system so far as practicable against interruption of power supply at the locomotives. Part IV describes the three-point power supply and includes a description of the frequency converter stations at Skykomish and Wenatchee for converting the 110,000-volt, 60-cycle, three-phase power purchased at these points to 25-cycle, single-phase power required for the traction service.