Adhesion surveys over Shap & Beatock summits Autumn & Winter 1973-1974 (TM-ADH-13)

The introduction of electric haulage on the Northern part of the West Coast Main Line is making greater demands on the adhesion levels available for traction purposes. This is due to the use of higher power 4-axle locomotives in place of the 6-axle diesel-electric locomotives, in the main, previously used.