Page:Walker (1888) The Severn Tunnel.djvu/71

24 The Company agreed to furnish all the land required permanently for the works; the contractor undertook to provide all that was required for temporary purposes.

The contractor was made responsible for the setting out of the works, for the lines and levels; and the Company, on their part, agreed to the usual terms for payment monthly as the works proceeded.

The open cuttings at both ends of the tunnel were to be surrounded by embankments several feet above the level of the highest recorded tide, so that the most extreme high tide should not, when it flooded the meadows, run down the open cuttings and drown the tunnel.

The tunnel was specified to be lined with brickwork, three bricks or 2 feet 3 inches thick, but only half the tunnel was to have an invert. The brickwork was to be of Cattybrook vitrified or Staffordshire brindle bricks, approved by the engineer.

The mortar was to be made of one part of Portland cement and two parts of perfectly clean, sharp sand.

The concrete, if used, was to be one part of Portland cement and five parts of sand and gravel.

There were to be a number of bridges over the open cuttings, which were all specified in detail.

The ballast for the permanent way was to be broken stone in the bottom, with gravel or hard slag for upper ballast. The rails and sleepers for the permanent way were to be furnished by the