Construction


The south bank of the River Clyde provides a magnificent view of the Erskine Bridge. This bridge spans the river to create a link between West Dunbartonshire and Renfrewshire. More specifically, to the south of the bridge lies Erskine village in Renfrewshire, which provides the M898 Motorway; starting point for this end of the bridge. On the other hand the northern side of the bridge ends in Old Kilpatrick, West Dunbartonshire, where it connects with the A82 road. In fact the bridge itself is otherwise known as the A898 road as it is an extension of A898 road from the M8 motorway.

The Erskine Bridge carries a dual carriageway. On the road bound Northward towards the A82 i.e. towards West Dunbartonshire, the left lane that comes off the bridge leads toward Helensburgh and Crianlarich while the right lane heads for the A82 eastbound towards Glasgow. On the other hand if you are travelling southwards bound on the bridge i.e. towards Renfrewshire, when you come off the bridge you could either take a slip road that leads into A726 bringing you to the Erskine Hospital and Erskine or you could travel straight onward from the bridge which will bring you to a junction formed with the M8 (Junction 30). From here, take the M8 westbound road if you want to go to Greenock, Gourock and Wemyss Bay or take the M8 eastbound leading toward Paisley, Glasgow Airport, Glasgow, Edinburgh, Carlisle, M80 and M74. Currently, the bridge is estimated to carry 35,000 vehicles per day and is the most downstream bridge on the River Clyde.

A considerable proportion of this traffic consists of travellers arriving from Glasgow International Airport heading towards holiday destinations near Glasgow such as Loch Lomond and The Trossachs. Therefore an important purpose of the bridge is to mitigate the possibility of excess traffic in Glasgow itself, as it provides an easy alternate route to and from Glasgow and places around it. Travellers on the bridge must keep in mind that stopping is prohibited on the bridge but exceptions can be made in the event of an emergency. Furthermore, aside from regular SOS phones being available on the bridge, there are also phones that advertise the ‘Samaritans’, a community that offers confidential emotional support to those in distress, due to the relatively high occurrences of suicides on this bridge.

The bridge has a ‘box girder’ bridge design. In a ‘box girder’ bridge, the beams (which are the horizontal structural elements of support) consist of ‘girders’ shaped like hollow boxes. A ‘girder’ is just another type of supporting beam used in construction and may take on several forms including those of box or ‘Z’ shapes. The box girder design usually involves the use of a composite of steel, pre stressed concrete or structural steel. Furthermore the Erskine Bridge is ‘cable stayed’. A ‘cable stayed’ bridge is one that has one or several pylons (vertical structural elements of support that transmit the weight of the upper part of the bridge to lower structural elements), with cables that support the bridge deck. ‘Bridge Deck’ simply refers to the actual road surface of the bridge.

The designer of the Erskine Bridge was William Brown (16th September 1928- 16th March 2005), a renowned structural engineer and bridge designer. From 1956 to 1985, he was an essential part of Freeman Fox & Partners, now known as Hyder Consulting and in 1987 he started a company called Brown Beech & Associates. He was particularly talented in the field of suspension bridges and is accredited with inventing the valuable aero-foil shaped cross section for bridge decks, an invention created to combat an array of wind conditions. Not only was Erskine Bridge designed by a famous personality it was also inaugurated by one; Princess Anne, daughter of the Duke of Edinburgh and Elizabeth II opened the bridge for use on 2nd July 1971.

At the time of construction of Erskine Bridge, the existing West Gate Bridge in Australia which has been constructed in a similar fashion to by the same structural engineers (Freeman Fox & Partners) as Erskine, collapsed. The collapse was a significant one and not without casualties. The verdict for the cause of the collapse was made official on 14th July 1971, and was partially attributed to the structural design provided by Freeman Fox & Partners. The reason appeared to be that there was a 4.5 inch difference in camber between 2 half girders on the west end of the span. By this time Erskine had already been opened for use but now failed to meet the new standards established due to the collapse of West Gate Bridge. Therefore Erskine saw further stiffening after it had been opened.

There were several firms involved in the initial construction of the Erskine Bridge. The structural engineering was done by Freeman Fox & Partners. The contractors were Christiani & Nelsen, Fairfield-Mabey, Lehane Mackenzie & Shand Ltd out of which Lehane Mackenzie and Shand Ltd were responsible for the foundation of the bridge. The stay cable steel supplier was Bridon International. Further down the line, FORCE Technology was responsible for new wind tunnel testing. The construction material used to construct the deck and pylons was steel. The main span of the bridge is 305 m with the total length being 1321.87 m. On the other hand the clearance of the bridge is 45 m with the span lengths of the main bridge being 110 m – 305 m- 110 m. Deck width is 31.25 and pylon height is a high 38 m.

However, further stiffening of the bridge was not the only change Erskine saw after opening. On 4th August 1996, a 70 m oil rig which had been constructed upstream at Clydebank was being towed downstream and collided with the underside of Erskine Bridge as it attempted to pass under it. This is unsurprising as the clearance of the bridge is 45 m and the height of the oil rig was 50 m. Although the rig managed to pass through the clearance, an engineering inspection was carried out and bridge was closed. It was then reopened to pedestrians and cyclists on 22nd August 1996, to cars and motorcycles on 30th August 1996 and to vehicles carrying heavy goods on the 22nd December 1996. The repair costs resulting from this debacle amounted to GBP 3.6 million not including the addition GBP 700,000 lost due to lack of toll revenue.

In fact, the toll history of Erskine Bridge is an interesting one. From its commencement in 1971 it had always been a toll bridge, however an oversight made by Scottish Executive workers in July 2001 caused much political turmoil and raised fingers amongst the concerned parties. The officials in charge of renewing the order that permitted the charging of tolls on the bridge failed to do so by the due date of 2nd July 2001, resulting in illegal tolls being collected for 2 months which amounted to GBP 800,000. When this folly was discovered, the tolls were suspended immediately however were reinstated courtesy fast-track procedures of the Scottish parliament. The Scottish Executive’s official position was apologetic and the Scottish Transport minister stated that “This error is deeply unfortunate. It should not have happened”. On the other hand the opposing political party used this opportunity to brand this error a “stunning act of incompetence”. Furthermore the West Dunbartonshire council used the opportunity to campaign for permanent abolishment of tolls on the Erskine Bridge, in a bid to promote development on their side of river Clyde. Although reinstated, the tolls were abolished permanently on 31st March 2006, by which time Erskine Bridge was 1 of the only 3 tolled bridges remaining in Scotland, the others being Forth Road Bridge and Tay Road Bridge who faced similar toll abolishment on the 11th of February 2008.

Share and Enjoy:
  • Print
  • Digg
  • StumbleUpon
  • del.icio.us
  • Facebook
  • Yahoo! Buzz
  • Twitter
  • Google Bookmarks
  • Google Buzz

Comments are closed.