Maysand’s latest project was more like a surgical operation than a masonry restoration, because the tool kit included hypodermic syringes. The 'patient' in this case was a grade 1 listed bridge in Manchester city centre dating back to medieval times. The earliest reference to it occurs in 1343, but the present structure may be a later rebuilding or remodelling circa 1421 – 1500.

Lying directly beneath Hanging Bridge Chambers near the Cathedral, Hanging Bridge was hidden from view for centuries but revealed when the chambers were redeveloped as the Cathedral’s Visitor Centre. It’s a two-arch stone bridge, part of which can be seen outside the Centre, and part from the basement café.

Fortunately the reference to hanging is less gruesome than it sounds, referring to textile manufacture rather than capital punishment. In the early days of textile production in Manchester, a fulling mill alongside the Cathedral used the alleyway for hanging textiles out to drip dry after the fulling process – hence the alleyway ‘Hanging’ Ditch and ‘Hanging’ Bridge which crossed it.

When cracks were discovered in the bridge, Manchester City Council called in the experts. Following a series of surveys by Buro Happold engineer Barry Cockerham, Maysand was chosen to bring its special brand of restoration to the task, and come up with an emergency repair plan, working closely with the engineers and English Heritage.

Mick Fowles, Maysand’s masonry surveyor, explains what was involved: “First we sealed the joints and voids around the damaged stones by squeezing in clay. Then, using a hypodermic syringe, injected a special mix of lime grout through the clay into the voids behind. Holes were opened up to check the grout flow and allow air to escape before being replugged with clay to stop the grout running out. After 48 hours we removed the clay leaving the grout firmly in place and the stonework securely repaired.”

A partly fractured voussoir was pinned or ‘skew-stitched’ first using stainless steel dowels, before the fracture was filled using the same grout injection process.

“Obviously it’s time consuming work,” says Mick. “There are extra factors such as having to work upside down from a Michelangelo-like position! And of course everything is done by hand so that the masonry isn’t scratched or damaged – even acrow props had to be used with protective hessian to safeguard the stone surface and could only add support to the stone, not put the structure under any pressure.”

Mick and his team are also carrying out a full survey and study of Hanging Bridge Chambers and investigating the natural deterioration of damp stones in these particular atmospheric conditions.

With Maysand’s help, it looks as though Hanging Bridge should be well on the way to making a full recovery.