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On May 23, 1970, the Britannia Bridge, over the Menai Strait in Wales, caught on fire.
Hat tip, the BBC. There's a video.
Bridge inferno: 'Like looking into hell'
Fifty years after the fire on the Britannia Bridge, firefighters recall being surrounded by flames.
22 May 2020
Fifty years after the fire on the Britannia Bridge, firefighters recall being surrounded by flames.
22 May 2020
Britannia Bridge
The modern Britannia Bridge.
Coordinates: 53°12?58.5?N 4°11?9?W
Carries: From 1850: North Wales Coast Line
From 1980: A55
Crosses: Menai Strait
Locale: Anglesey, North Wales
Characteristics
Design
1850: Tubular bridge
1972: Two-tier truss arch bridge
Material
1850: Wrought Iron, Stone
1972: Steel, Concrete
Total length: 461 m (1,512 ft)
History
Designer: Robert Stephenson
Construction: Start, 1846; Opened, 5 March 1850
Britannia Bridge (Welsh: Pont Britannia) is a bridge across the Menai Strait between the island of Anglesey and the mainland of Wales. It was originally designed and built by the noted railway engineer Robert Stephenson as a tubular bridge of wrought iron rectangular box-section spans for carrying rail traffic. Its importance was to form a critical link of the Chester and Holyhead Railway's route, enabling trains to directly travel between London and the port of Holyhead, thus facilitating a sea link to Dublin, Ireland.
{snip}
Design
Britannia Bridge entrance
The original box section Britannia Bridge, circa 1852.
Postcard picture of the bridge from circa 1902
The opening of the Menai Bridge in 1826, one mile (1.6 km) to the east of where Britannia Bridge was later built, provided the first fixed road link between Anglesey and the mainland. The increasing popularity of rail travel shortly necessitated a second bridge to provide a direct rail link between London and the port of Holyhead, the Chester and Holyhead Railway.
{snip}
Fire and reconstruction
During the evening of 23 May 1970, the bridge was heavily damaged when boys playing inside the structure dropped a burning torch, setting alight the tar-coated wooden roof of the tubes. Despite the best efforts of the Caernarfonshire and Anglesey fire brigades, the bridge's height, construction, and the lack of an adequate water supply meant they were unable to control the fire, which spread all the way across from the mainland to the Anglesey side. After the fire had burned itself out, the bridge was still standing. However, the structural integrity of the iron tubes had been critically compromised by the intense heat; they had visibly split open at the three towers and had begun to sag. It was recognised that there was still danger of the structure collapsing. As a consequence, the bridge was rendered unusable without the enactment of major restorative work.
In light of events, the chief civil engineer of British Railways' London Midland region, W.F. Beatty, sought structural advice from consulting engineering company Husband & Co. Following an in-depth investigation of the site performed by the company, it was determined that the cast iron beams inside the towers had suffered substantial cracking and tilting, meaning that the tubes required immediate support at all three towers. The Royal Engineers were quickly brought in to save the bridge, rapidly deploying vertical Bailey bridge units to fill the original jacking slots in the masonry towers. By the end of July 1970, a total of eight Bailey bridge steel towers had been erected, each being capable of bearing a vertical load of around 200 tonnes.
Further analysis showed that the wrought iron tubes had been too badly damaged to be retained. In light of this discovery, it was decided to dismantle the tubes in favour of replacing them with a new deck at the same level as the original tracks. With the exception of the original stone substructure, the structure was completely rebuilt by Cleveland Bridge & Engineering Company. The superstructure of the new bridge was to include two decks: a lower rail deck supported by steel arches and an upper deck constructed out of reinforced concrete, to carry a new road crossing over the strait. Concrete supports were built under the approach spans and steel archways constructed under the long spans on either side of the central Britannia Tower. The two long spans are supported by arches, which had not been an option for the original structure as a result of the clearance needed for tall-masted vessels; modern navigational requirements require much less headroom.
The bridge was rebuilt in stages. The first stage was to erect the new steel arches under the two original wrought-iron tubes. The arches were completed, and single-line working was restored to the railway on 30 January 1972 by reusing one of the tubes. The next stage was to dismantle and remove the other tube and replace it with a concrete deck for the other rail track. Then the single-line working was transferred to the new track (on the west side); this allowed the other tube to be removed and replaced with a concrete deck (which is used only for service access) by 1974.. Finally the upper road deck was installed and by July 1980, over 10 years after the fire, the new road crossing was completed, and formally opened by the Prince of Wales, carrying a single-carriageway section of the A55 road.
During 2011, a £4 million joint programme by national railway infrastructure owner Network Rail, Welsh Assembly Government and the UK Highway Agency, was performed upon the Britannia Bridge, aiming to strengthen the 160 year old structure and improve its reliability. The work involved the replacement of eroded steelwork, repairs to the drainage system, restoration of the parapets and stonework, and the painting of the steel approach portals of the bridge. A detailed inspection of the internal chambers of the three towers was performed, while a special walkway was also built to enable easier and safer access to the structure for future inspections of the masonry piers; special protective efforts adopted for the work included the use of special pollution-minimising paint and the decontamination of all equipment prior to being brought onsite.
{snip}
The modern Britannia Bridge.
Coordinates: 53°12?58.5?N 4°11?9?W
Carries: From 1850: North Wales Coast Line
From 1980: A55
Crosses: Menai Strait
Locale: Anglesey, North Wales
Characteristics
Design
1850: Tubular bridge
1972: Two-tier truss arch bridge
Material
1850: Wrought Iron, Stone
1972: Steel, Concrete
Total length: 461 m (1,512 ft)
History
Designer: Robert Stephenson
Construction: Start, 1846; Opened, 5 March 1850
Britannia Bridge (Welsh: Pont Britannia) is a bridge across the Menai Strait between the island of Anglesey and the mainland of Wales. It was originally designed and built by the noted railway engineer Robert Stephenson as a tubular bridge of wrought iron rectangular box-section spans for carrying rail traffic. Its importance was to form a critical link of the Chester and Holyhead Railway's route, enabling trains to directly travel between London and the port of Holyhead, thus facilitating a sea link to Dublin, Ireland.
{snip}
Design
Britannia Bridge entrance
The original box section Britannia Bridge, circa 1852.
Postcard picture of the bridge from circa 1902
The opening of the Menai Bridge in 1826, one mile (1.6 km) to the east of where Britannia Bridge was later built, provided the first fixed road link between Anglesey and the mainland. The increasing popularity of rail travel shortly necessitated a second bridge to provide a direct rail link between London and the port of Holyhead, the Chester and Holyhead Railway.
{snip}
Fire and reconstruction
During the evening of 23 May 1970, the bridge was heavily damaged when boys playing inside the structure dropped a burning torch, setting alight the tar-coated wooden roof of the tubes. Despite the best efforts of the Caernarfonshire and Anglesey fire brigades, the bridge's height, construction, and the lack of an adequate water supply meant they were unable to control the fire, which spread all the way across from the mainland to the Anglesey side. After the fire had burned itself out, the bridge was still standing. However, the structural integrity of the iron tubes had been critically compromised by the intense heat; they had visibly split open at the three towers and had begun to sag. It was recognised that there was still danger of the structure collapsing. As a consequence, the bridge was rendered unusable without the enactment of major restorative work.
In light of events, the chief civil engineer of British Railways' London Midland region, W.F. Beatty, sought structural advice from consulting engineering company Husband & Co. Following an in-depth investigation of the site performed by the company, it was determined that the cast iron beams inside the towers had suffered substantial cracking and tilting, meaning that the tubes required immediate support at all three towers. The Royal Engineers were quickly brought in to save the bridge, rapidly deploying vertical Bailey bridge units to fill the original jacking slots in the masonry towers. By the end of July 1970, a total of eight Bailey bridge steel towers had been erected, each being capable of bearing a vertical load of around 200 tonnes.
Further analysis showed that the wrought iron tubes had been too badly damaged to be retained. In light of this discovery, it was decided to dismantle the tubes in favour of replacing them with a new deck at the same level as the original tracks. With the exception of the original stone substructure, the structure was completely rebuilt by Cleveland Bridge & Engineering Company. The superstructure of the new bridge was to include two decks: a lower rail deck supported by steel arches and an upper deck constructed out of reinforced concrete, to carry a new road crossing over the strait. Concrete supports were built under the approach spans and steel archways constructed under the long spans on either side of the central Britannia Tower. The two long spans are supported by arches, which had not been an option for the original structure as a result of the clearance needed for tall-masted vessels; modern navigational requirements require much less headroom.
The bridge was rebuilt in stages. The first stage was to erect the new steel arches under the two original wrought-iron tubes. The arches were completed, and single-line working was restored to the railway on 30 January 1972 by reusing one of the tubes. The next stage was to dismantle and remove the other tube and replace it with a concrete deck for the other rail track. Then the single-line working was transferred to the new track (on the west side); this allowed the other tube to be removed and replaced with a concrete deck (which is used only for service access) by 1974.. Finally the upper road deck was installed and by July 1980, over 10 years after the fire, the new road crossing was completed, and formally opened by the Prince of Wales, carrying a single-carriageway section of the A55 road.
During 2011, a £4 million joint programme by national railway infrastructure owner Network Rail, Welsh Assembly Government and the UK Highway Agency, was performed upon the Britannia Bridge, aiming to strengthen the 160 year old structure and improve its reliability. The work involved the replacement of eroded steelwork, repairs to the drainage system, restoration of the parapets and stonework, and the painting of the steel approach portals of the bridge. A detailed inspection of the internal chambers of the three towers was performed, while a special walkway was also built to enable easier and safer access to the structure for future inspections of the masonry piers; special protective efforts adopted for the work included the use of special pollution-minimising paint and the decontamination of all equipment prior to being brought onsite.
{snip}
