Brunel viaduct receives makeover in readiness for new use as part of tram network

An historic Dudley landmark has been undergoing a major restoration, ahead of its new use as part of the West Midlands Metro network. Peter Plisner finds out what’s been done to the structure

In this article:

• Parkhead Viaduct, built in 1849 by Isambard Kingdom Brunel, was originally a timber structure encased in brick later.
• Restoration work includes strengthening ties, brick repairs, and preparing for tram operations along a new extension.
• The viaduct's future involves trams and potential freight rail use, ensuring its preservation and regional connectivity.

It might seem like just another Victorian viaduct, but this one is special because the chief engineer was the famous Isambard Kingdom Brunel.

Not only that, but the structure was originally timber-built and later encased with masonry to become the way it looks today.

Parkhead Viaduct, which is 164 yards long, was built in 1849 as a multi-span wooden structure comprising eight timber trusses supported on trestles with driven timber piles. It curves to the east on a radius of about 40 chains.

It’s said that the original wooden structure was needed because of soft ground in the area. However, even with its lightweight construction, historical notes suggest that the viaduct’s wooden piles still showed signs of sinking.

Its strengthening and encasement in bricks, which took place in 1877, cost £9,400 (around £1.4 million in today’s money). The bricks came from a local company, and the work also required the acquisition of mine workings beneath the structure.

Parkhead was designed to carry the Oxford, Worcester and Wolverhampton Railway (OW&WR) over the Pensnett and Dudley canals and associated basins.

Parliamentary authority to build the line and the viaduct was granted in August 1845, and the line opened in stages between 1852 and 1853.

By 1863, having previously been amalgamated with both the Newport, Abergavenny and Hereford and the Worcester and Hereford railways, which became the West Midlands Railway, it was eventually absorbed into the Great Western Railway.

Notes from the time suggest that progress on building Parkhead Viaduct was slow. By June 1849, all the money raised had been spent, with only the middle section close to completion.

Great Western then embarked on a legal fight with the Railway Commissioners, prompting the OW&WR to switch its allegiances to the London and North Western and Midland railways in February 1851, signing agreements that allowed those companies to finish and then run the line themselves.

However, the GWR was successful in challenging that arrangement, thereafter offering the company a similar deal on its own terms.

Today’s work to prepare the bridge for its new use - carrying trams - is being carried out by the Midland Metro Alliance, a collection of designers and contractors employed to expand the West Midlands Metro.

“It’s not a listed structure, so there was an option to demolish and build a new viaduct,” says Tim Betts, Senior Delivery Manager for Colas Rail, which is part of the alliance.

Three options were considered: repairing it; demolishing it; or reconstructing it with steel or concrete.

“The view was taken to try and repair the existing viaduct and future-proof it,” explains Betts.

Repairing the existing bridge was the cheapest and best option logistically. But access to the viaduct wasn’t easy, because it’s a constrained site.

Betts adds: “It’s either through the existing rail corridor from each end, which is not particularly good, or it’s through a residential area. So, just getting access to build a new viaduct in that location would be very costly.”

Having been disused for 30 years, one of the main issues was that the viaduct needed strengthening. One of the main problems was that the height of the rails had progressively been raised when it was in use. British Rail engineers had propped up the rail and then packed it with ballast. This meant that over a number of years, it began to push the parapets out.

Betts says: “The original track was obviously lower than the parapet. Over the years, they’ve actually had to put a handrail parapet on the brick parapet because they packed it up so much. That put undue pressure on the existing parapets.”

This meant that during the latter part of its operation, the viaduct had to have strengthening ties installed.

“These ties were introduced to pull it back together. So, our job has been a combination of increasing these, replacing the existing plates, and also increasing the number of ties.”

The latest work has also brought the base level of the track back down to its original height. Contractors have also carried out repairs to the brickwork.

Betts notes: “We expected to do around 110 different brickwork repairs, but we’ve ended up doing nearer 200. Some of those are relatively minor. Some are what we call ‘stitch’ repairs, just trying to stitch the brickwork back together.”

These brickwork repairs took over a year to complete, with repairs to the tie rods carried out at the same time.

A third set of repairs involved dealing with its original wooden structure, which had been encased within the brickwork.

Betts explains: “When we cored into the structure of the Victorian piers, we found some of the old timber in there.

“They put an endoscope camera through a core hole, and basically you could see the fibrous nature of the wooden supports. There was actually a void around the timbers. So, the other part of what we’ve been doing is grouting up those piers as well.”

There are seven intermediate piers and eight arches, so quite a lot of grouting required.

Now the bridge needs to be prepared for its next use, carrying trams.

Betts says: “Between the brickwork parapets, we’re going to introduce a concrete trough inside that and that’s where the tram will go across. And it’s going to be ballasted track within the trough, but it’s retained. The ballast that we put in won’t apply any pressure to the parapets because it will be retained within an extended U-shaped trough.”

The work also involved working closely with the Canal and Riverside Trust. The viaduct crosses the Dudley Canal near the southern portal of the Dudley Tunnel, which is almost two miles long.

The future-proofing of Parkhead Viaduct is all part of a plan to connect the Dudley area to Birmingham and Wolverhampton. It has involved the installation of a new delta junction at Wednesbury, where the existing Metro line between the two cities passes through the area.

The new extension will reuse two disused railway lines. It starts off on the old South Staffordshire Railway and then diverges off the old alignment to allow trams to travel through Dudley town centre.

In doing so, the route bypasses the Dudley Tunnel, which is now in use by the Black Country Innovative Manufacturing Organisation and houses the Very Light Rail National Innovation Centre. It has a 2km test track on its site, which includes the tunnel.

Once through the town centre, trams drop down onto the alignment of the OW&WR and soon after cross Parkhead Viaduct.

Once across the viaduct, the line passes close to the old Round Oak Steelworks (now Tata Steel). The steelworks has its own sidings and a headshunt, both accessed via Stourbridge Junction.

The same advanced works that has renovated Parkhead has also involved moving the headshunt to create enough space for two tram tracks.

Betts explains: “They still run a train up from Port Talbot to Round Oak. We had to get space to put another two tracks in alongside that headshunt, and we’ve had to slew that across. It’s effectively a live railway line.”

Betts admits that working on the viaduct has been a steep learning curve.

“We’ve been applying Network Rail standards when doing the brickwork repairs because there aren’t any relevant tram standards to work to. It was a British Rail structure back in the day, wasn’t it?”

And applying Network Rail standards to the work is pretty crucial.

As part of the handover of the disused line to Transport for West Midlands for development as a tram track, it was agreed that Network Rail could develop a shared scheme to reintroduce freight rail services on the route.

However, this would be on a number of conditions - including that a business case is agreed and approved by the Transport Secretary, and costs met by Network Rail.

A TfWM spokesperson says: “Trains stopped running on this route many decades ago and their reinstatement has not been a priority for the rail industry.

“However, as a result of the investment in Metro, we are seeing a number of bridges and structures along the route repaired or removed and rebuilt.

“This could potentially open up options, longer term, for the development of freight and passenger rail services - in parallel with Metro - along the wider Walsall to Stourbridge route in future.”

For its part, Network Rail says: “As part of the regulated land-disposal process, Network Rail is required to consider any future potential rail use, and we foresaw there may be a future need for freight or other traffic along this route.

“To assist in the efficient construction and operation of the Metro, we agreed to sell this land to the West Midlands Combined Authority [and TfWM] with the condition that should there be a requirement for freight or other traffic, it could be restored alongside Metro services with at least ten years’ notice.”

It seems highly unlikely ever to happen, so the operation of the trams into the Black Country looks set to continue.

As does the survival of Parkhead Viaduct, which following the recent work now has a new lease of life.