etch
Mechanical
- May 8, 2002
- 169
Despite Railtrack's best efforts in recent years, the Tay Bridge disaster remains one of Britains worst ever railway accident. A terrific storm, which had spread mayhem and destruction throughout central Scotland, was howling down the Tay just as the Edinburgh train was crossing the bridge. As the train reached the "high girders" at the centre of the bridge, they suddenly collapsed - plunging the train and its sevnty-five passengers and crew into the icy waters. There were no survivors, and only forty-six bodies were ever recovered.
The bridge, which had been hailed as an engineering masterpiece on its opening the previous year, was found to have been severely flawed. The official enquiry discovered that the iron superstructure was of inferior quality and had been badly maintained. Most damning of all, little or no account was made of wind pressure in the design of the bridge. The enquiry laid the blame at the door of the designer, Sir Thomas Bouch. Bouch vehemently denied the charge, but his career was in ruins. He died just ten months after the fall of the great bridge.
Though none of the passengers were saved, there was a survivor of a sort. The engine that had hauled the train to its doom was recovered from the river bed and put back into service. Sardonically nicknamed "The Diver" by railway staff, it carried on working for the North British Railway until 1908. (typical of a scot eh?)
The first Tay rail bridge was completed in February 1878 to the design of Thomas Bouch. Bouch was responsible for the design, construction and maintenance of the bridge. Most of his bridges were lattice girders supported on slender cast iron columns braced with wrought iron struts and ties. The building of the Tay bridge culminated in him being knighted. The Tay bridge was nearly two miles long, consisting of 85 spans and at the time was the longest bridge in the world. The spans carried a single rail track; 72 of these spans were supported on deck spans, the remaining 13 navigation spans were through girders. These "high girders", as they were known, were 27 ft high with an 88 ft clearance above the high water mark. It was these spans which fell. Most of the deck spans, all of which remained standing, were transferred to the present Tay rail bridge. At the time of the collapse Bouch was working on the design of the proposed Forth Bridge. In consequence, the design of the bridge was transferred to Benjamin Baker and Sir John Fowler.
A Court of Inquiry was set up to try and ascertain the reason for the collapse of the bridge. The Court of Inquiry report (8) concluded that, "The fall of the bridge was occasioned by the insufficiency of the cross bracing and its fastenings to sustain the force of the gale." The Court of Inquiry indicated that if the piers, and in particular the wind bracing, had been properly constructed and maintained, the bridge could have withstood the storm that night, albeit with a low factor of safety - 4 to 5 was the norm at the time. Sir Thomas Bouch was held chiefly to blame for the collapse in not making adequate allowance for wind loading. He used a wind pressure of 10 lbsf/sq ft for the design of the Tay bridge. It is interesting to note that when working on the design of a proposed Forth bridge (1866) he used 30lbsf/sq ft(6). To this day, however, there is still speculation as to the fundamental cause and as to whether or not the designer, Thomas Bouch, was to blame.
OKay sorry for the very long post but, i once heard a theory that a contributing factor in the failure was that the iron was so defective, the suppliers had mixed iron filings and album (egg white) and pasted them into the cracks. Has anyone ever heard this theory or got other explanations?
The bridge, which had been hailed as an engineering masterpiece on its opening the previous year, was found to have been severely flawed. The official enquiry discovered that the iron superstructure was of inferior quality and had been badly maintained. Most damning of all, little or no account was made of wind pressure in the design of the bridge. The enquiry laid the blame at the door of the designer, Sir Thomas Bouch. Bouch vehemently denied the charge, but his career was in ruins. He died just ten months after the fall of the great bridge.
Though none of the passengers were saved, there was a survivor of a sort. The engine that had hauled the train to its doom was recovered from the river bed and put back into service. Sardonically nicknamed "The Diver" by railway staff, it carried on working for the North British Railway until 1908. (typical of a scot eh?)
The first Tay rail bridge was completed in February 1878 to the design of Thomas Bouch. Bouch was responsible for the design, construction and maintenance of the bridge. Most of his bridges were lattice girders supported on slender cast iron columns braced with wrought iron struts and ties. The building of the Tay bridge culminated in him being knighted. The Tay bridge was nearly two miles long, consisting of 85 spans and at the time was the longest bridge in the world. The spans carried a single rail track; 72 of these spans were supported on deck spans, the remaining 13 navigation spans were through girders. These "high girders", as they were known, were 27 ft high with an 88 ft clearance above the high water mark. It was these spans which fell. Most of the deck spans, all of which remained standing, were transferred to the present Tay rail bridge. At the time of the collapse Bouch was working on the design of the proposed Forth Bridge. In consequence, the design of the bridge was transferred to Benjamin Baker and Sir John Fowler.
A Court of Inquiry was set up to try and ascertain the reason for the collapse of the bridge. The Court of Inquiry report (8) concluded that, "The fall of the bridge was occasioned by the insufficiency of the cross bracing and its fastenings to sustain the force of the gale." The Court of Inquiry indicated that if the piers, and in particular the wind bracing, had been properly constructed and maintained, the bridge could have withstood the storm that night, albeit with a low factor of safety - 4 to 5 was the norm at the time. Sir Thomas Bouch was held chiefly to blame for the collapse in not making adequate allowance for wind loading. He used a wind pressure of 10 lbsf/sq ft for the design of the Tay bridge. It is interesting to note that when working on the design of a proposed Forth bridge (1866) he used 30lbsf/sq ft(6). To this day, however, there is still speculation as to the fundamental cause and as to whether or not the designer, Thomas Bouch, was to blame.
OKay sorry for the very long post but, i once heard a theory that a contributing factor in the failure was that the iron was so defective, the suppliers had mixed iron filings and album (egg white) and pasted them into the cracks. Has anyone ever heard this theory or got other explanations?
