A few years ago, rain penetrating the colossal steel shed housing Templebrough foundry in Rotherham evaporated before it hit the floor. Operating at 1,200degreesC, the works' four arc furnaces scorched the air.
Built in 1917 to supply steel for munitions, Templebrough was enlarged and modified during the 1960s and 70s, becoming the largest foundry in Europe. It was in almost constant operation for 74 years, closing in 1993.
Throughout its working life there was little concern for the physical condition of the foundry's cavernous shed - it was massively structured and corrosion never seemed an issue in such a torrid environment.
After the works shut the building and its contents were left to rot.
Nobody looked at Templebrough again until 1998, when Rotherham City Council launched a £37.2M, Lotterybacked bid to resurrect the hulking building as a science adventure centre. Known as Magna, the project capitalises on Templebrough's spectacular post-industrial decay. Four gemlike pavilions are now being placed within the existing and little altered structure.
Magna addresses Templebrough's steel making past, but is more than a steel heritage centre. Each of the pavilions is themed to a different natural element - earth, water, fire and air.
Magna will explain how humans have harnessed and exploited them over time.
The steel framed Templebrough shed stands 20m tall to the eaves, is just over 44m wide and over 160m long. Two bays wide, its massive columns and 2.5m deep beams were designed to carry enormous loads imparted by 250t capacity overhead cranes.
'People locked into the idea that we had inherited a structure with huge strength and that we could do anything we wanted with it, ' recalls Mott Macdonald project manager Andy Poyser, responsible for structural engineering. Seizing the opportunity for architectural acrobatics, designer Wilkinson Eyre proposed hanging two of the four pavilions from the existing structure, in mid-air. Another was buried in the foundry's 10m deep basement.
But the Templebrough shed was not all it appeared to be, says Alan Bristier, operations director with construction manager Schal. 'You had a structure that, on the face, of it could handle any loads you wanted to place on it. When it came to it, though, there were perforated columns and degraded concrete slabs. Some columns were shot and had to be plated.' And drawings were in short supply. The building had to be surveyed from scratch and the competence of all structural members tested.
Poyser explains that, though there is a high degree of redundancy in the shed structure by today's standards, the quality of materials varied far more widely when the foundry was built.
Three quarters of a century of neglect - none of the steelwork was ever painted - had resulted in severe localised corrosion.
Structural members had been knocked and deformed. And slag and molten steel had been dropped onto reinforced concrete floors causing them to break up as rebar expanded.
Decrepitude in the existing structure has been most critical in designing the support systems for Magna's two aerial pavilions, fire and air. It has also affected erection methods - contractors have not been able to position cranes on the suspended floor above the basement. All lifting has had to be carried out either from the edge of the shed where the floor is on solid ground, or using a beam crane installed by specialist steelwork contractor Billington Modern Structures.