The Curse of Clydach strikes again

Works to upgrade the A465 Heads of the Valleys Road between Gilwern and Brynmawr in South Wales are running over budget and behind time. It may well be a case of history repeating.

News reports this week suggest that Section 2 of the work to upgrade the A465 to dual carriageway, which runs through the ecologically sensitive and topographically difficult Clydach Gorge, is now expected to finish six months late, in autumn 2019, and is running 23% over budget. The Welsh Assembly Government dispute whether they are liable to pay the increased costs.

Costain, the company who are upgrading the road, say that the overrun and overspend are because the project is turning out to be "far more difficult to deliver than they originally envisaged".

Perhaps the engineers on the project were unaware of the history of the road when they signed the contract. 54 years ago, a company called John Morgan (Builders) Ltd. won a contract to upgrade the A465 between Abergavenny and Brynmawr, and built the road through the Clydach Gorge that Costain are now upgrading to dual carriageway. The scheme was beset with problems, from a shortage of skilled labour to skyrocketing prices for raw materials, and it ran over budget and finished spectacularly late. Building the road very nearly put John Morgan out of business altogether.

Costain say that the "topography" and "complex ground conditions" are to blame. No surprise. When they weren't short of men or running wildly over budget, John Morgan suffered exceptionally poor weather conditions, unexpected geological faults, collapsing embankments and rock falls onto the road bed. The two-year construction scheme eventually took five years to complete, and disputes over the cost continued for years afterwards.

So far the budget overrun of £51m is eyewatering, but the delayed finish date is not catastrophic. It remains to be seen whether costs will go up again or the end date will slip any further. But one thing is for sure - if you're taking on a major road project, you need to fully understand not just the engineering but also the history of the site to avoid falling prey to the Curse of Clydach.

• CBRD has an extensive history of the construction of the Heads of the Valleys Road in the 1960s, including the tribulations of John Morgan's company in the Clydach Gorge, which are well worth a read.
• More details on the current upgrade works are in CBRD's Road Schemes section.