Despite a catalogue of threats to its survival, a scheme to solve one of Essex’s most notorious congestion problems is still on course.
Plenty of projects fell victim to the cuts in last autumn’s Comprehensive Spending Review. Others are counting the cost of being buried by thick winter snowfall.
Some have had to rework their plans around local landowners, or the behemoth that is the Olympics. But one project has come face to face with all of these obstacles since 2003, and has proceeded with greater momentum than ever.
Sadlers Farm junction is famous in Essex. Located near Basildon, the gyratory is an interchange between the A13 from London, and the A130, a major route into north Essex. However, the junction’s effectiveness is undermined by the sheer amount of traffic that ploughs determinedly toward it.
During the three-hour morning and evening traffic peaks, the junction serves 8,000 vehicles per hour.
Push for regeneration
The resulting congestion makes the immediate towns of Pitsea and Benfleet − and the wider region − unattractive to developers. “It’s hindering the regeneration of the area because people just avoid it,” says Essex County Council project manager Ian Allen. The government’s London to Ipswich multi-modal study first flagged up this problem in 2003.
Following its own subsequent study, Essex County Council devised a new 1km long strategic link to act as a dedicated turning for those travelling from the A13 to the A130, bypassing the busy roundabout. The scheme also includes upgrades to 5km of existing roads which would see the A13 widened from a dual two lane to a dual four lane carriageway, and the A130 widened from a dual two-lane carriageway to three dual lanes.
In addition, four new composite bridges are being built, two subways extended, an existing bridge demolished and a contiguous pile wall constructed.
Projections showed that the strategic link would remove 30% of the roundabout’s traffic. A planning application was submitted in February 2008, and approved in November that year.
By this point, however, the London Organising Committee of the Olympic Games and Paralympic Games had made a decision that would put a tight squeeze on the Sadlers Farm project. The mountain biking venue for 2012 had been moved from Weald Country Park near Brentwood to Hadleigh Farm about 5km east of the roundabout − putting Sadlers Farm firmly on the Olympic Route Network (ORN).
That meant the Olympic Delivery Authority (ODA) would have the power to impose a non-negotiable deadline of June 2012 for road works. That decision put real time pressure on the project, and added another task to the project managers’ list: devising a mitigation plan for a late finish, and getting it approved by the ODA. In a nutshell, says Allen: “We’d have to stop what we’re doing, tidy up, do abortive work, then pick it up again afterwards.”
The next year, the project met its second major obstacle in the shape of a public inquiry, which took place in July 2009. A landowner affected by the widening plans had objected to the scheme. “If one statutory stakeholder objects, that’s enough to take it to inquiry,” says Allen.
It was a worrying prospect − but in the end, no other landowners objected. The inquiry lasted just two and a half days, and found in favour of continuing the project. “I think in general the public are in favour of this scheme,” says Birse Civils project manager Stephen Gray.
The Sadlers Farm congestion is so notorious that improvements are welcomed by most, he says. With a final business case submitted in December 2009, the project received full approval for Department for Transport (DfT) funding in March 2010.
“I think in general the public are in favour of this scheme”
Birse Civils project manager Stephen Gray
Just two months later, the General Election changed everything. With the new coalition government in place, Essex County Council had to wait for the Comprehensive Spending Review to find out the fate of its project, pushing back the May start date by many months.
Once again, the project emerged unscathed, one of only two transport projects in the east of England under review to be maintained. Gray says this was probably thanks to its strategic importance for the regeneration of the wider area, and for ORN travel times from the Olympic Park.
Also in the project’s favour was the fact that the £63.5M budget had barely changed since 2005. In fact, it had decreased from £63.6M.
With government funding secured at last, work could get underway on site. The project is being delivered in two phases. Phase one involved an early contractor involvement team comprising Essex County Council, Birse, Birse’s sub-consultant Mouchel and Atkins, which is the council’s consultant.
The team produced preliminary design, worked on stakeholder engagement, and sought funding approvals. Phase two involves detailed design and construction.
At the end of 2010, the big obstacles seemed to be in the past. That is, until the snow began to fall − and it didn’t stop. All earthworks were originally supposed to be completed before winter, but the delayed start date meant that excavations were buried by the snow.
“We worked three days out of the month of December,” says Gray. The thaw, when it came, was not much kinder, he says, as the water table rose to a level that made earthworks impractical. “We couldn’t do anything on the A130 for about six weeks.”
An exceptionally dry spring is now going some way to amend that, allowing work to continue for 12 to 13 hours a day. The team is confident of making up the time lost to snow.
Accordingly, the project is expected to come in on schedule and on budget − a major feat, considering the number of obstacles traversed. “We’ve had a few challenges, but at the end of the day it’s going to finish when we said, and it’s not going to cost any more than planned,” says Gray.
Design as you go
One of the reasons for this is the fact that thorough work in phase one has allowed for flexibility now. “Because we started late, we’re designing as we are building it,” says Allen.
“We can adapt quite quickly to any changes,” agrees Gray. Indeed, a number of clever adaptations have been made over the project’s life, with four major revisions occurring since March 2010. “We have had to really look at switching things around to maintain the project,” says Gray.
One example of this that had a large impact was the decision to raise the level of the strategic link. The original design had two bridges that cross the strategic link sitting at ground level, with the road running underneath. This required a considerable amount of excavation producing 190,000m³ of surplus spoil.
“We can adapt quite quickly to any changes. We have had to really look at switching things around to maintain the project”
Birse Civils project manager Stephen Gray
By changing the design so the bridges and the road were almost 2m higher, engineers ensured that the excavation process could be completed more quickly, significantly reducing the amount of spoil.
Now, just 130,000m³ is being excavated, and the surplus spoil from the project is just 50,000m³. Thanks to deals with neighbouring landowners to take large amounts of that for agricultural use, no spoil will leave the site. These changes produced significant cost savings.
Another saving was made from the contiguous pile retaining wall that will support the excavated section. It was calculated that if Essex County Council bought a little more land, it would be possible to construct an earth embankment on one side of the strategic link, thereby negating the need for part of the retaining wall.
Some 150 piles were removed from the original design, leaving around 600.
The four new bridges − all of a similar construction with steel beams and concrete decks − range from a 60m single span design to a 140m double span.
Church Road Bridge on the A13 will replace an existing bridge 10m to the west, which has too short a span to accommodate the new lanes. The new central pier is now in place there, but this bridge will be the last to be completed.
The bridge at London Road will be finished first, in September, and its concrete pour began last week.
The two remaining bridges at Sadlers Farm and Sadlers Hall will be completed by December. Piling for these bridges is already finished, and engineers are now working on the piers. Steelwork for all four bridges is supplied by Mabey.
The scheme is a relatively simple solution to a major traffic problem, says Gray. The complexity has come from the difficult interfacing with all the different stakeholders, and the external challenges that have impacted on the scheme.
With work now chugging along nicely, the team is looking forward to the milestone of the strategic link’s completion in December.
Looking at the impressive list of challenges that have failed to derail this project so far, it’s easy to imagine that that deadline will be passed with flying colours.