Campaigners hoping to convert an abandoned rail tunnel in the Welsh Valleys were given a boost over the Christmas period after transport secretary Grant Shapps agreed to remove one of the key blockers to the project.

Shapps has agreed to transfer the ownership of a 132-year-old abandoned rail tunnel from National Highways control to Welsh ownership to allow the project to continue.

If successfully converted the 3.1km tunnel would become Europe’s longest tunnelled cycle route.

However, the Rhondda Tunnel Society, which is working to re-open the tunnel, has warned that funding is still needed to progress the project.

A tweet from the group added: "We still can't move forward and apply for the funding we need to bring this project to fruition until the Welsh Gov [sic] or Local Authorities are in a position to take ownership from Central Gov [sic]. We'll see what 2022 brings. Happy New Year."

Project secretary Tony Moon added: "That [the tweet] is true as far as the main links of the tunnel goes. 90-odd percent of the tunnel is managed by National Highways but the end that's owned by Neath Port Talbot Council is different and we're still looking at the possibility of going ahead with that end by getting planning permission from Neath Port Talbot Council.

"Getting a Heritage Lottery grant would depend on a change of ownership."

The masonry arch structure runs between Rhondda and Afan valleys and was completed in 1890 and closed in 1968.

In 2018, Balfour Beatty engineers set the transformation on its way by carrying out the initial examination to the structure.

The work carried out by the contractor was a precursor to the tunnel – together with the Abernant tunnel - receiving a £250,000 grant to carry out additional detailed inspections and analysis of the work needed to make the reopening a reality.

Speaking to NCE in 2018, Balfour Beatty examining engineer Richard Storey said that 90% of the structure  was in “incredibly good condition” but that the remaining 10% was the “interesting bit”.

Of this 10%, Storey said there were three to four specific areas which required special attention.

One such stretch is a 200m long section where the structure has been reinforced as mine workings above have caused parts of the masonry arch to fall in.

“They put in ribs in a classic ‘lash up’”, he said. “They were trying to keep the trains running quickly, so you get whatever you can there to keep it stable.

“As such they’ve used bull-head rails and curved them to form ribs to support the masonry arch. They’ve then filled in between with timber laggings to stop the masonry falling locally between the ribs.”

Storey said this area would be challenging and would require strengthening before opening as the timbers had rotted.

He said the challenge with the area would come from how it is to be strengthened. He said keeping the rails would add to the historic story, and act as a temporary support for a strengthening measure, but would create a “shadow” in a sprayed concrete lining.

He said the ribs could be removed but then the team could face a potential collapse as the face would then be unsupported.

Another area he said would need careful attention was a hinge fracture which caused “substantial” movement to the masonry and finally resulted in the closure of the tunnel in 1968. Although he says there are two 5m long timber structures and one 7m long timber structures which were built to support the tunnel lining to prevent further collapse, he does not believe these have actually taken any load in the 50 years since they were installed.

The team which takes on the restoration work will also have to contend with a 2.1m thick concrete wall around 200m from the entrance of the country end portal. Around a 400mm diameter hole made up of several cores was cut out during the examination, but its full removal will present a significant challenge said Storey.

A full drainage survey will also have to be carried out as water was found to have backed up behind the wall to around 1.2m deep. It was also found to be pouring through the brickwork at the London end portal, however Storey said this was not actually causing any damage to the brickwork.

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