Shaping up to the challenge: the surprise that greeted our engineers fixing a gas main in Manchester

Back in the 1930s, no doubt the mantra of gas engineers as they installed this big metallic gas main under Oldham Road, Manchester, was “where there’s a will there’s a way.”

Faced with having to navigate a route obstructed by a high-pressure water main, they designed and custom-made a section in an oval shape, rather than the conventional round pipes.
 
This allowed the new gas main, which helps distribute gas to thousands of local homes, to pass above the water pipe and carry on its journey down Hulme Hall Lane.
 
Fast-forward more than 80 years and the same pipe recently developed a small leak.
 
Modern-day engineers from gas network Cadent, which manages the hundreds of miles of gas mains beneath Manchester, were surprised by their find and are now busy carrying out a repair to fix the leak.
 
Adam Hassall, Cadent network engineer for this area of Manchester, said: “Our pipes come in a range of sizes, some smaller than the diameter of a 10p coin, others – like this one – are bigger than a car tyre. But the one constant is that they’re all generally round. We do find the odd one now and again – usually from pre-War or even the 19^th century – that are a different shape. We’ve worked on rectangular and square ones on bridges, for example. But oval is a new one on me.
 
“We found a small leak on this one right under one of the busy lanes of Oldham Road and it’s been a challenging job to fix. But we’ve worked on it ‘live’ – so no gas supplies have been interrupted – and we’ve worked with the city council to arrange some temporary measures to safely keep traffic moving around our work area. We know that’s caused tailbacks at times. We know that’s frustrating and far from ideal. It’s unavoidable and essential work to maintain safe gas supplies.”
 
Given its unconventional shape, a bespoke part is now being made. The Cadent team will then install it, check it’s working safely, reinstate the road surface and have all lanes of Oldham Road back open as normal. At this stage, it is envisaged this considerable work will run into next week.
 
Cadent is the UK’s biggest gas network. In North West England, it manages and maintains more than 21,000 miles of underground gas mains and hundreds of above ground stations which carry gas used to heat 2.7m buildings, cook meals, fuel vehicles and power industrial processes.
 

What goes a-round…five things you maybe didn’t know about gas pipes
 

1. Some of the gas mains running under your feet were installed in the 1800s. Cadent is undertaking a huge, multi-million-pound upgrade programme to replace these ageing mains, to keep gas flowing safely and reliably well into the future. Gas heats 83% of UK homes.
2. Some of the first ‘service pipes’ – the small-diameter pipes running from the big main in the road direct to your home – were made from the barrels of rifles deemed redundant after the Napoleonic Wars. Upgraded in the years since, they’re now mostly made of tough plastic.
3. While most gas mains are round, every now and then Cadent engineers will encounter pipes of unexpected, unconventional shapes. Two years ago, a team found a big, rectangular main in Burnley, Lancashire, and similar-shaped pipes are occasionally found on bridges.
4. A few years ago, Cadent engineers working in Holborn, London, found a gas main made from wood (elm, to be precise). Long redundant and left in situ after being replaced with a metallic main, a section of it is now on display in a Cadent training base in Hitchin, Hertfordshire.
5. Cadent looks after a network of more than 80,000 miles of gas mains in four areas of the UK; placed end to end, that amount would circumnavigate the globe more than three times. Of those, around 21,000 miles run underneath North West England.