   #copyright

Forth Road Bridge

2007 Schools Wikipedia Selection. Related subjects: Engineering; Road
transport

   CAPTION: Forth Road Bridge

   Forth Road Bridge
   The Forth Road Bridge, viewed from the Fife side, straddling the Firth
   of Forth.
   Official name Forth Road Bridge
   Carries Motor vehicles
   ( A90 road)
   Cyclists
   ( National Cycle Route 1)
   Pedestrians
   Crosses Firth of Forth
   Locale Edinburgh, Scotland
   Maintained by Forth Estuary Transport Authority
   Design Suspension bridge
   Longest span 1006 m (3298 ft)
   Total length 2512 m (8242 ft)
   Width Dual two-lane carriageway, two cycle/footpaths (total width 33 m)
   Clearance below 44.3 m
   AADT ~32,000 vehicles (2004 estimate)
   Opening date 4 September 1964
   Toll Motorcycles - free
   Cars - £1
   Goods vehicles - £2

   The Forth Road Bridge is a suspension bridge in east central Scotland.
   The bridge, built in 1964, spans the Firth of Forth, connecting the
   capital city Edinburgh at South Queensferry to Fife at North
   Queensferry. The toll bridge replaced a centuries-old ferry service to
   carry vehicular traffic, cyclists, and pedestrians across the Forth;
   rail crossings are made by the adjacent and historic Forth Bridge.

   Issues regarding the continued tolling of the bridge, and those over
   its deteriorating condition and proposals to have it replaced or
   supplemented by an additional crossing, have caused it to become
   something of a political football for the Scottish Parliament.

History

   The first crossing at what is now the site of the bridge was
   established in the 11th century by Margaret, queen consort of King
   Malcolm III, who founded a ferry service to transport religious
   pilgrims from Edinburgh to Dunfermline Abbey and St Andrews. Its
   creation gave rise to the port towns which remain to this day, and the
   service remained in uninterrupted use as a passenger ferry for over
   eight hundred years. As early as the 1740s there were proposals for a
   road crossing at the site, although their viability was only considered
   following the construction of the first Forth bridge in 1890.

   The importance of the crossing to vehicular traffic was underpinned
   when the Great Britain road numbering scheme was drawn up in the 1920s.
   The planners wished the arterial A9 road to be routed across the Forth
   here, although the unwillingness to have a ferry crossing as part of
   this route led to the A90 number being assigned instead.

   There was a period of renewed lobbying for a road crossing in the 1920s
   and 1930s, at which time the only vehicle crossing was a single
   passenger and vehicle ferry. Sir William Denny championed the expansion
   of that service in the 1930s, providing and operating two additional
   ferries on behalf of the London and North Eastern Railway that aimed to
   supplement the services of the adjacent railway bridge. Their success
   allowed for the addition of two more craft in the 1940s and 1950s, by
   which time the ferries were making 40,000 crossings, carrying 1.5
   million passengers and 800,000 vehicles annually.

   With the then-newest and nearest bridge spanning the Forth (the
   Kincardine Bridge, built in 1936) still around fifteen miles upstream,
   the upsurge in demand for a road crossing between Edinburgh and Fife
   prompted the UK government establish the Forth Road Bridge Joint Board
   by Act of Parliament in 1947 to oversee the implementation of a new
   bridge to replace the ferry service. The final construction plan was
   accepted in February 1958 and work began later that year.

   Mott, Hay and Anderson and Freeman Fox & Partners designed and
   constructed the bridge at a cost of £11.5 million, while the total cost
   of the project including road connections and realignments was £19.5
   million. Seven lives were lost during construction before the bridge
   was opened by Queen Elizabeth II and the Duke of Edinburgh on 4
   September 1964. The ferry service was discontinued as of that date. The
   bridge's management was delegated to the FRBJB, and remained so until
   2002 when its operation was transferred to a new body with a wider
   remit, the Forth Estuary Transport Authority.

Statistics

   High-tensile wires suspending the deck of the northbound carriageway.
   Enlarge
   High-tensile wires suspending the deck of the northbound carriageway.

   The bridge's central main span is 1006 m (3298 ft) long, its two side
   spans are each 408 m (1338 ft) long, and the approach viaducts are
   252 m (827 ft) on the north side and 438 m (1437 ft) on the south side;
   at a total length of 2512 m (8242 ft), it was the longest suspension
   bridge outside the United States and the fourth-largest in the world at
   the time of its construction. The bridge comprises 39,000 tons of steel
   and 115,000 cubic metres of concrete. Its width comprises a dual
   carriageway road with two lanes in each direction bounded by
   cycle/footpaths on each side. The main strung cables are 590 mm in
   diameter and each carries 13,800 tonnes of the bridge's load by
   suspending 11,618 5 mm diameter high tensile wires.

   The bridge forms a crucial part of the corridor between south-east and
   north-east Scotland, linking Edinburgh to Perth, Dundee and Aberdeen by
   the A90 road and its sister M90 motorway which begins at the bridge's
   northern terminus. The bridge carried around 2.5 million vehicles in
   its first year but this figure has risen steadily over time to around
   11.8 million vehicles in 2004. The bridge carried its 250 millionth
   vehicle in 2002.

   It was awared Historic Scotland's Category A listed structure status in
   2001.

Tolling issues

   The bridge has been tolled since opening to pay for the cost of
   construction and maintenance. The current toll is £1 for most vehicular
   traffic, increased from 80p in October 2005. The toll for buses with
   over sixteen seats is £1.40, and most goods vehicles pay £2.

   Initially, it was suggested that tolling would cease once the original
   cost of construction plus interest accrued had been repaid - this was
   done in 1993 and tolls were slated for removal by May 1995. However,
   the legislation enabling the levying of tolls has instead been renewed
   by Parliament (originally that of the UK but now the responsibility of
   the Scottish Parliament) on three separate occasions in 1998, 2003 and
   2006.

   Originally, a toll was paid for each direction of travel with sets of
   toll booths on both carriageways. In 1997, a decision was made to
   double the northbound toll (then 40p, to 80p) and remove the southbound
   toll. The belief was that almost all traffic makes a return journey
   across the bridge, resulting in a reduction of congestion for
   southbound traffic without reducing overall toll revenues.

   The Forth Estuary Transport Authority (FETA) has justified the
   continued use of tolls by suggesting they are necessary for a raft of
   maintenance and improvement works. These include the construction of
   defences around the submerged piers forming the bases of the main
   towers in the event of collision in the Firth. The main towers have
   also been strengthened with internal steel columns (the original tower
   structure having been hollow) and had hydraulic rams jack up these
   sections to transfer a portion of the load to the new steelwork. Also,
   the vertical cables suspending the deck have had their bolts replaced
   after a single detected failure. A new paint system required
   development for the bridge (the original having been phased out due to
   environmental concerns) and the toll plaza and booths have been
   replaced allowing more comfort for toll-collection staff and the
   introduction of electronic tolling.

Variable tolling proposals

                                                CAPTION: Forth Road Bridge
                                                     variable tolling plan

                                                   Start   End       Toll
                                                   00:00 07:30         £1
                                                   07:30 08:30         £2
                                                   08:30 14:00         £1
                                                   14:00 15:00         £2
                                                   15:00 16:00         £3
                                                   16:00 18:00         £4
                                                   18:00 18:30         £3
                                                   18:30 19:00         £2
                                                   19:00 24:00         £1
                                                   source: Edinburgh Today

   In late 2005, FETA's committee approved a proposal for a complete
   revamp of the system of toll levies. The minimum toll would be set to
   the existing £1 figure, but would increase dependent on the time of
   day, rising to a maximum of £4 for evening rush hour travel. All tolls
   would be halved for cars with more than one occupant, as an incentive
   to drivers to share cars and make fewer journeys. According to FETA's
   chairman Lawrence Marshall, the system would provide the most
   efficiency, claiming that 80% of peak-time journeys are made by
   single-occupant vehicles. The proposal, passed with the chairman's
   casting vote after the committee was deadlocked, was referred to the
   Scottish Executive in December 2005, and implementation planned for
   October 2007 subject to approval by transport minister Tavish Scott.
   Environmental groups welcomed the proposal, although local politicians
   condemned it as simply a means of raising capital. At the same time, a
   counter-argument was tabled by Fife councillors proposing the complete
   removal of tolls..

   The Scottish Parliament debated the proposals in January 2006, and the
   affair became a major political issue after Westminster-based MPs
   Gordon Brown and Alistair Darling ( Chancellor of the Exchequer and
   Secretary of State for Scotland respectively) were seen to describe the
   variable tolling plan as "dead in the water". Scottish First Minister
   Jack McConnell insisted his Labour Party colleagues were misquoted and
   himself refused to rule out the plan, receiving considerable
   condemnation from the opposition Scottish National Party.

   The political situation was particularly important given that by late
   January 2006, campaigning was well underway for a by-election scheduled
   to take place for the Westminster constituency of Dunfermline and West
   Fife in which the north end of the bridge is situated. The by-election,
   scheduled for February 9, was contested by - in addition to the major
   political parties in Scotland - an Abolish Forth Bridge Tolls Party. It
   was eventually won by Liberal Democrat candidate Willie Rennie,
   overturning a large Labour majority on a 16% swing.

   In the aftermath of the by-election defeat, media speculation suggested
   the Executive had turned against the proposals, and Tavish Scott
   eventually confirmed their rejection and the retention of the existing
   toll structure on 1 March. FETA condemned the decision, while local
   opposition MSPs charged the minister that his tolling review
   short-changed Fifers as tolls were axed on the Erskine Bridge leaving
   tolls on only the Forth and Tay Road Bridge, both in Fife.

Structural issues

   An inspection of the integrity of the cables underway on the bridge.
   Enlarge
   An inspection of the integrity of the cables underway on the bridge.

   There has been concern at FETA over the structural wear-and-tear of the
   bridge. The planned theoretical capacity for the bridge (30,000
   vehicles per day) is routinely exceeded as traffic levels have
   outstripped predictions. FETA predicts the demand will rise to an
   average of 40,000 vehicles per day by 2010 and the Scottish Executive
   admit that 60,000 vehicles is not uncommon for weekday travel. This has
   raised concerns about the lifespan of the bridge, originally planned at
   120 years.

   2003 saw an inspection programme launched (at a cost of £1.2 million)
   to assess the condition of the bridge cables after excessive corrosion
   was discovered in a number of bridges in the United States of a similar
   design, size, and era. The study, which was completed in 2004, found
   that 22 (out of over 11,000) high-tensile steel wires are known to have
   snapped. There have been allegations of poor workmanship on the bridge
   which, combined with the adverse weather while it was being
   constructed, has led to speculation that these steel wires have become
   crossed instead of being parallel as intended.

   Further investigation of the implications of this is underway, with a
   study using listening devices to monitor any further strands snapping
   and pinpoint their location within the main cables. The traffic loads
   and worries over corrosion have halved the bridge's predicted lifespan
   to just 50-60 years; there are fears a ban on heavy goods traffic will
   be necessary by 2013, due to the severe stress the traffic loading has
   on the bridge and internal corrosion of the steel cables. A full
   closure is feared to be necessary by 2020.

   A number of options are being considered to increase the bridge's
   lifespan. These include an extensive dehumidification programme to slow
   the corrosion rate of the cables. Engineering consultants Faber
   Maunsell expect to begin work on the project in 2006. The works, if
   approved, are planned to take two years at a cost of £12 million. As
   part of the works, some of the corroded cable strands are to be
   spliced.

Proposals for a new Forth Road Bridge

   The Forth Bridges, with the road bridge crossing to the left of the
   rail bridge.
   Enlarge
   The Forth Bridges, with the road bridge crossing to the left of the
   rail bridge.

   With a complete closure of the existing Forth Road Bridge predicted by
   approximately 2020 without drastic action, there is a threat of serious
   economic consequences, due to the strategic importance of the bridge in
   the Scottish transport network and the estimated 10+ year timescale for
   construction of a replacement.

   Proposals for an additional road crossing had initially been drawn up
   in the early 1990s, but met stiff opposition from environmentalists and
   from Edinburgh City Council on the grounds of the increased traffic it
   would generate. Following the Labour victory in the 1997 General
   Election, the proposals were shelved; however, they have resurfaced as
   of 2005, given the concerns over the existing bridge's lifespan. A new
   bridge, either as a complement to the existing bridge or as a complete
   replacement, is now under consideration by FETA, with its cost
   estimated at £700 million. There remains considerable opposition to the
   project on the same grounds as before, particularly from the Scottish
   Green Party.

   A decision on the proposal is expected by Easter 2006.
   Retrieved from " http://en.wikipedia.org/wiki/Forth_Road_Bridge"
   This reference article is mainly selected from the English Wikipedia
   with only minor checks and changes (see www.wikipedia.org for details
   of authors and sources) and is available under the GNU Free
   Documentation License. See also our Disclaimer.
