Transportable bridges: how the Bailey Bridge idea has spanned the decades
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Publicado por : dnfsdd812
Publicado en : 25-10-21
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Transportable bridges: how the Bailey Bridge idea has spanned the decades
The revolutionary Bailey Bridge
has played an important role over the years – initially providing critical
connections in the Second World War, but more recently in getting vital supplies to people
across the globe, both in civilian and military applications.
The modular, rapidly deployable Bailey Bridge has its origins in the years before the
Second World War, when civil servant Donald Bailey came up with the concept, producing his
original sketch on the back of an envelope in 1936.
His idea was largely ignored at the time, but then war broke out. An upgraded version
of the First World War Inglis Bridge failed, as the new and improved military vehicles were
too heavy. So on 14 February 1941, Bailey received a letter from the War Department telling
him to prepare for a full-scale trial of his bridge design in May that year at the
Experimental Bridging Establishment at Christchurch, Dorset.
Successful trials meant the Bailey Bridge went into production in July 1941 and was
issued to the army that December. British, Canadian, Australian and US engineers used the
system – its rapid rollout showed just how progressive and easy to implement it was.
The Axis Powers didn’t have this kind of trick up their collective sleeve, so the
bridge’s contribution to the war effort was vital. As Field Marshal Bernard Montgomery put
it: “Bailey bridging made an immense contribution towards ending World War Two ... I could
never have maintained the speed and tempo of forwarding movement without large supplies of
Bailey bridging.
“Without the Bailey Bridge, we should not have won the war. It was the best thing in
that line that we ever had.”
Ease of transporting hefty military hardware using the
Modular Steel Bridge
essentially won the war. For example, the Battle of Remagen, where Allied forces captured
the Ludendorff Bridge over the Rhine and pretty much shortened the war in Europe, is where
the Bailey Bridge fully flexed its muscles.
Pontoon Bridges were set up
across the Rhine in Germany to aid the advance. The longest was called ‘Blackfriars Bridge
’. It was 558m long and was built close to the Dutch border by the Royal Canadian
Engineers of the 2nd Canadian Corps. After two days of construction – delays were due to
heavy fog and hampered delivery of components – the floating section of the bridge was
rated as Military Load Class 40; enough for 40-ton tanks to cross over safely.
The bridge used modular panel construction, so elements could be transported and
assembled on site, according to the length needed. “At its peak, around 20,000 panels were
produced each month during World War Two,” says Callum Skeat, military sales manager at
Mabey Bridge, the company that took on and developed the Bailey Bridge. “Over the entire
war, over 700,000 panels were produced; enough to stretch from London to Leningrad.”
It was light and quick to assemble – it usually took 24 hours – and was strong enough
to carry the heaviest tanks over a 60m span.
“The simple deployment of the Steel Foot Bridge has not really changed since its first use in 1942,” says
Skeat. “Original Bailey Bridges were built by hand and cantilevered [cantilevers, which
are projecting beams or members supported at only one end, can hold a bridge up to 550m]
over a gap using a light nose section dismantled on the far bank, and pushed out by
rollers.”
The first span can be easily joined to other panels to form multiple spans. You just
feed them across the gap on rollers until you have the bridge length you want.
So what made it so snazzy? Well, the First World War Inglis Bridge required building a
bridge twice as long as you wanted, swinging it out over a gap on a pivot, and then you’d
dismantle the bits of bridge you didn’t need. “This was a timely process, but the Bailey
’s simple, robust and modular design meant it was infinitely more versatile and quicker to
build. Plus, all parts could be assembled by hand, which was a revelation during the 1940s,
” Skeat adds.
Over the last 75 years, its original design and improved descendants, such as the Super
Bailey, Mabey Universal, Mabey Compact 200 (C200) and the Logistical Support Bridge (LSB)
have provided access for communities and maintained and enhanced supply lines for the
military.
Nowadays, steel panels are used instead of wooden timber, making the
Suspension Bridge more
durable. Panels are galvanised, meaning they can last for over 50 years.
Only one site supervisor is needed to oversee installation, and a locally sourced and
trained workforce can build the
Steel Truss Bridge. Pretty simple.
The Bailey concept played an important role over the years in development of civil
engineering, providing critical connections and vital supplies to people around the world.
Most Mabey Steel Box Beams
are now used as civilian aids, helping children get to school, and assisting communities
after natural disasters such as floods and earthquakes – when an earthquake occurred in
Kashmir in Pakistan, as part of aid efforts the British government supplied around 30 C200s
for emergency bridging.
Skeat says: “In 2016, more than £2.5m was invested to develop robots to support more
efficient manufacturing of the Mabey Compact 200 (C200) Bridge, the most widely used Bailey
successor. This reduced manufacturing time for the C200’s panels and chords by almost
half, doubling production capacity as well as reducing manual handling elements in
products, leading to enhanced safety.”
Bailey Bridges are not manufactured anymore, but some militaries still use them and
their improved descendants. Skeat says: “The phrase ‘if it is not broke, do not fix it
comes to mind here. The original concept of the Bailey Bridge is still very much alive, and
I doubt we’ll find a more flexible, quick and effective solution.”
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