The New Zealand Railways Magazine, Volume 3, Issue 7 (November 1, 1928)
Railway electrification is making vast progress these days on the continent of Europe. In France, the Orleans line has now completed the electrification of three main-line sections:-Paris (Quai d'Orsay Station) to Bretigny, a distance of 22 miles; Bretigny to Les Aubrais (Orleans), a distance of 55 miles; and Les Aubrais to Vierzon, a distance of 50 miles. The branch line Bretigny-Dourdain (15 miles) has also been converted to electricity. Section one (Paris to Bretigny) carries a very dense main-line and suburban passenger business. Section two bears a heavy main-line business. Section three carries a moderately heavy trunk traffic.
After considerable experiment the Orleans Railway decided to utilise direct current at 1,500 volts, with overhead transmission. The overhead lines are supplied from rotary sub-stations, placed at varying distances according to the density of traffic, gradients, and so on, and these in turn receive current from the Eguzon power station on the River Creuse, at 90 kilo volts A. C. Suburban passenger services are worked by multiple unit trains, in which old four-wheeled passenger stock has been incorporated. On the main-line, however, electric locomotives are employed for train haulage. The standard type is an eight-wheeled double bogie machine specially designed for medium speeds. Fast types of electric locomotive are being tried out, among which is one of the American 2-C-C-2 type; a Swiss 2-D-2 type; and two locomotives of the Hungarian 2-B-B-2 arrangement. One of the latter machines has the hyperstatic system of transmission and the other is equipped with isostatic rods.
From Paris to Bretigny light signals are employed throughout, alternating current being utilised for this service. An interesting feature of the Orleans electrification plan is the fact that during the summer months, when the natural water power at the Eguzon station is liable to fail, an ingenious arrangement has been devised for obtaining power from the thermal station at Genne-villiers (Paris). Subsequently all units thus obtained during the summer for the operation of the railway are returned to Gennevilliers during the winter at a pressure of 150 kilovolts, which will eventually be raised to 220 kilovolts.