Casgliadau Arlein

Plan on greenish-white paper of the National Coal Board S.W. Division Area 3, plan of power supply interconnectors between collieries in Area 3. Blue ink drawing with some details drawn in green or red pencil. Place names handwritten in blue ink. In the bottom left hand corner there is a table containing a colour-coded key. Scale = 1" to a mile, Drawing No. E.MISC. 40A. Dated 2nd June 1950. Loose within peach card file with other documents relating to Powell Duffryn Electrical System.