Paralysis caused by working under compressed air in sinking the foundations of Londonderry New Bridge / by T.H. Babington and A. Cuthbert.

  • Babington, Thomas H.
Date:
[1863]
Catalogue details

Licence: Public Domain Mark

Credit: Paralysis caused by working under compressed air in sinking the foundations of Londonderry New Bridge / by T.H. Babington and A. Cuthbert. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    [Reprinted from the Dublin Quarterly Journal of Medical Sciencej November, 1863.] t Paralysis Caused hy Working Under Compressed Air in Sinking the Foundations of Londonderry Neiu Bridge. By T. H. Babington, M.D, Surgeon Londonderry County Infirmary; and A. Cuthbert, M.D., Medical Officer Glendermott Dis- pensary, Londonderry. The new bridge recently erected over the river Foyle, at London- derry, is an iron structure, nearly 1,300 feet long, consisting of two platforms or roadways—the lower for railway traffic; the upper, a carriage Avay, with footpaths for passengers and ordinary traffic. The whole structure is supported on 16 cast iron cylinder piles, placed in pairs, 35 feet apart, at intervals of 119 feet. Resting on the centre cylinder there is a swing-bridge, which is opened and closed for navigation. Each cylinder is 11 feet in diameter; li inch thick; and, when sunk to the proper foundation, was filled with concrete, composed of sand, gravel, and cement. The centre cylinder supporting the saving bridge is 30 feet in diameter; and rests on seven smaller ones, 8 feet in diameter. These cylinders were all sunk to solid foundations before being filled with the concrete; and these foundations were obtained at various depths—the greatest depth 75 feet from the sm’face of the water,® and 40 feet below the bed of the river. * In tbe London Times for July 7, 1859, we find tbe following notice of a bridge built on tbe Nile :— “Tbe Kaffre Azzyat Bridge.—This important, malleable, iron girder beam-bridge across tbe Nile, is nearly 1,400 feet long ; bas 11 openings—2 of wbicb are 104 feet each ; and spanned by a swing beam. The centre of tbe swing rests upon a founda- tion pier, composed of 6 pillars of 10 feet diameter each ; and tbe remaining 11 foundation piers are of 2 pillars each, 10 feet diameter. These 28 foundation pillars were sunk by compressed air, on Mr. John Hughes’ principle, to an average depth of nearly 60 feet below the bed of the river, and to 85 feet below high water. The internal pressure on the caissons, while sinking, ranging from 20 lb. up to 34 lb. on the square inch, in accordance with the depth of the ground and the height of the Nile.”