Manchester’s towering glory: Tonkin Liu’s heat and energy centre

I have a picture on my phone, my first view of Manchester’s Tower of Light from the centre in St Peter’s Square. In the distance, as tram tracks and wires appear to converge, is the delicate looking 40m tower, dwarfed by its backdrop of the raking cladding of the Axis tower. Flick through the other photos and I see that many of Manchester’s chimneys, typically solid Victorian brick remnants of industry, have plenty of competition for attention and scale in this energetic city.  

The Tower of Light Manchester Civic Quarter Heat Network & Energy Centre is the work of Tonkin Liu. For years it has  been designing an eclectic portfolio of projects using a shell lace structure that draws on the principles of shell geometry (curvature, corrugation, stiffening and more) to design strong, spare structures with aesthetic ebullience.

 

One of those designs won the practice the competition for a combined heat and power centre for Manchester City Council’s civic quarter under the old railway arches – over which trams now trundle. But it wasn’t all hidden away; the five flues needed a chimney to live up to the grand buildings it served, including Manchester Convention Centre next door, the Central Library, Town Hall and Manchester Art Gallery.  

I talked to Mike Tonkin and Anna Liu fresh from watching David Attenborough’s Life on Earth; they are animated by nature and what we can learn from it. The most fitting of their many natural inspirations here is of a skeleton of a cholla cactus, standing erect, its diagonal grid forming the starting point for the tower. This is a form Tonkin Liu believe could be scaled up to that of a residential apartment tower – that would be exciting to see.

The diagonal grid of the design allows the steel envelope of the chimney to be skin and structure in one, saving 12 tonnes of carbon on an oblong, double layered tower. The perforations and the oval plan reduce the wind load. Working with engineer Ed Clark of Arup they played around with the thickness of the steel, getting it down to just 4mm in one design iteration, but settling on increasing the thickness by 20 per cent on that, to 6 or 8mm – and enjoying increasing the openness of the structure by a corresponding 20 per cent. 

 

Flat panels of steel were laser cut before being rolled into eight 4m-tall drums which were craned in, two per night. Inside, mirror-finished gold reflectors give a sense of movement though the day and work with the lighting design so that the tower can be used for messaging and celebration throughout the year. 

Around the base, a long window allows the inquisitive to peer at the workings of the energy centre, superimposed with Tokin Liu diagrams. The walls are in wave form, white ceramics pieces, each the same weight and finish as the classic Belfast sinks traditionally made by the supplier Darwen Terracotta. 

It is a very clear step away from the much graffitied and apparently unpopular concrete of Tadao Ando’s curving wall in the city’s Piccadilly Gardens, which was demolished in 2020. This should fare better. Its luscious curves are already coated in heavy dust, but at least all it needs for a clean is a high pressure hose. And stepping back it still appears white as white and of a piece with the tower. 

This is just one incident among many in the city, but it is one that brings promise of a lower carbon future and the possibility of natural ideas brought into our buildings.