Manchester has long liked garnishing industry with ornament. For all the four-square practicality of its Victorian streets, its buildings are eclectic in their detail – Byzantine, Flemish, gothic and baroque, encrusted and polychrome, with turrets, domes, gables, swags and cartouches formed from stone, brick and soot-resistant ceramics. Mancunian architecture grew fantasy from the filth of coal-fired wealth.
The Tower of Light, white and sparkling, updates this tradition for a low-carbon age. It is essentially a big chimney, but not as LS Lowry would have known it. It’s a dispersion flue, to use the technical term, a 40 metre-high device for extracting fumes from a gas-fired combined heat and power unit beneath it. Its swirling forms resemble those that Antoni Gaudí put on top of Barcelona apartment blocks. They are inspired, say its architects Mike Tonkin and Anna Liu, both by the ornate chimneys on Tudor palaces and by the glass sponge, a submarine organism that is one of David Attenborough’s favourite creatures.
The tower is the most visible manifestation of the Manchester Civic Quarter Heat Network, a £24m project to provide a more sustainable heat and power system to the landmarks such as the city’s town hall, central library and convention centre, and the Bridgewater Hall music venue. Conceived in 2019, the network is not so far advanced as to dispense with fossil fuels altogether, but the city council and its partner Vital Energi say it’s a considerable upgrade on previous arrangements. Renewable power sources, they add, can be plugged into the system at a later date.
The tower serves a symbolic as well as a practical function, as a statement of the council’s desire for cleaner energy. As this is, in effect, a small power station near the heart of the city, it was felt that something other than a standard flue tower was desirable. A design competition was held, with the hope of creating some sort of marker to what is considered an important gateway to the city’s centre.
Tonkin Liu won the competition with a design that aims to be more than an artistic statement. The outer form of the tower – a vertical steel tube that supports the extract flues inside – puts into practice a concept called the “shell lace structure”, which they have developed with the engineers Arup over the past 12 years. It uses principles derived from nature to make a building as strong as possible with the minimum amount of materials. It’s a rigid object shaped by the flow of forces, by dynamics of rotation that, says Tonkin, are fundamental to natural energy.
So the steel skin of the tower is stiffened with corrugations and undulations like those of a sea shell. Its structure, like a glass sponge, is a lattice, which efficiently resists both horizontal and vertical loads. It becomes more open and perforated towards the top, where less strength is needed, which also allows the wind to blow through it more easily. Its shape is an ellipse in plan, with the narrower ends aligned with the prevailing wind, so as to reduce resistance. Its spiralling form helps to break up wind pressures, as similar patterns do on ornate Tudor chimneys. All these features allow the steel sheet from which the tower is made to be an exceptionally thin 6mm.
The mathematics of this biologically-inspired engineering also create the filigree form that passersby will notice more than anything else, and which amply fulfils the council’s desire for a landmark. It rises from the Wall of Energy, a curving horizontal base clad in robust ceramic tiles – each one made with the techniques and to the approximate size of a Belfast sink – whose three-dimensional undulations echo those of the tower. A long window allows you to see the workings of the heat and power plant inside. Almost everything on both base and tower is white and curvy, but the lower part is more weighty and earthy, the upper more ethereal.
By day, light bounces off it and penetrates through it, and reflects off the stainless steel flues that you can glimpse through the openings. By night it’s illuminated with shifting colours that can be changed to suit an occasion – Pride, for example, or a triumph by the city’s blue or red football teams. Car headlights put the rippling tiles into continuous visual motion.
This glistening thing is borderline kitsch – it could be one of those futile objects which, in the name of public art, public authorities sometimes commission – but it is saved from such a fate by the determined thought that went into its engineering. Those shapes are not pure whimsy. It’s a work of skill, both by its architects and engineers and by the Lancastrian businesses, Shawton Engineering and Darwen Terracotta, that made the steelwork and the tiles.
The next question is how the principles behind the tower might be applied at a larger scale and in a more everyday way. It stands in an area of Manchester that has been extensively redeveloped, with big blocky developers’ towers standing nearby. These are more conventionally constructed, with rectangular frames and concrete cores. In theory, shell-lace construction, applied to buildings like this, could save many tonnes of steel and concrete.
In practice, the approach has a way to go. The companies that build such towers usually like both straight lines and techniques they already know. Rooms, windows and doors tend also to come in right-angled shapes that would have to be reconciled with the curves of a shell-lace structure. One can but dream. Meanwhile, you’d have to have a heart of stone not to enjoy the simple pleasures the Tower of Light offers, and the inspired commitment with which it was designed and built.