General description of the Britannia and Conway tubular bridges on the Chester & Holyhead Railway / Published, with the permission of Robert Stephenson ... by a resident assistant [E. Clark?].

  • Edwin Clark
Date:
1849
Catalogue details

Licence: Public Domain Mark

Credit: General description of the Britannia and Conway tubular bridges on the Chester & Holyhead Railway / Published, with the permission of Robert Stephenson ... by a resident assistant [E. Clark?]. Source: Wellcome Collection.

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    fourths of an inch: some of them weigh nearly seven hundred weight, and are among the largest that it is possible to roll with any existing machinery. In the sides, the plates are alternately six feet six inches and eight feet eight inches in length, two feet in breadth, and half an inch thick, except at the ends, where they become somewhat thicker. They are joined together, and greatly strengthened and stiffened at the joints by T shaped iron both inside and out, reaching from the top to the bottom, and forming a complete pillar at every two feet, in the same manner as the frames in a window sash form a pillar between each two panes. It is the projection of this T iron inside the tubes that reduces the clear space to thirteen feet eight inches. The longest plates are in the bottom. They are twelve feet long, by two feet four inches in width, arranged in double layers, each layer being nine- sixteenths of an inch thick at the centre of the large tube, and seven sixteenths at the ends. Those forming the top are each six feet in length, and one foot nine inches in breadth. In the middle of the tubes they are three-quarters of an inch thick, diminishing to five-eighths at the ends. These thick¬ nesses are all dependent on the amount of the strains in the tube, as the direction of the plates was before noticed to be. In the top and bottom will be seen the cells or flues of which slight mention has been before made. Of these there are eight at the top, each one foot nine inches square; and six at the bottom, of the same depth, but wider—viz., two feet four
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