A blueprint from the Newcastle Archives showing cross-sectional views of the shore booms in their upper and sunken positions. This arrangement ensured that the pontoon was securely attached to the quay wall during lifting operations. The height of the quay wall is dimensioned as about 42' - 8" (13 m) and in the upper view, the instruction is that the overall width from the quaywall to the extents of the pontoon must not exceed 99' - 0" ( 30.2 m). The scale of the masonry work required to retrofit these slots is clearly visible and extends to about half way down the quay; that being well below the normal water level of the dock. [062]