The side elevation drawing of the proposed coal tips numbers 4, 11 and 12 prepared by the East Ferry Road Engineering Company Ltd., of Milwall, London. The title is "Proposed 25 Ton Hydraulic Fixed Coal Hoist for the Taff Vale Railway - Penarth Dock" and is drawn at a scale of ⅜ inch = 1 foot. The drawing number is D. 2783. It was drawing office custom and practice back in 1912 to add a colour wash to emphasise the steelwork and machinery against the void white background. The centre three hydraulic cylinders identified on the drawing as "Hoisting Tipping Cylinders" have the dual role of adjusting the working height of the cradle; the cradle being the platform onto which the coal wagon was placed. The upper cylinders were then brought into operation in order to tilt the wagon and tip the coal down the shute. Additional power is introduced to raise the 23 ton wagons by utilising the centre of the three lower cylinders. The cylinders on the left side are the "Crane Hoisting Cylinders". Each has sheaves (wheels) over which the wire ropes are placed and mechanical advantage of 2:1 is obtained by the arrangement i.e. the power of each hydraulic cylinder is enhanced by a factor of two to one. [142]