Industrial evolution

Less than a decade ago the Magna building in Rotherham was an active steelworks. In its prime, around the middle of the last century, the Templeborough works site contained as many as 14 open-hearth furnaces churning out much of the country's steel. Back then nobody would have imagined that just a few generations later production would come to an end and the site would be redeveloped into a visitor attraction.

The original design brief set by the Magna Trust was not just for a steel heritage museum but for an interactive learning centre based around the four elements of steel making – earth, air, fire and water.

Redeveloping the enormous 37 160 m2 building was not an easy task. Yet some imaginative designing and a lot of hard work has seen the site transformed into what is described as the UK's first science adventure centre. The project was funded with a combination of Lottery, public and private money.

The design and build team consisted of Schal as the project and construction manager; consulting engineer Buro Happold; architect Wilkinson Eyre; Bingham Cotterell as structural and civil engineer; and Crown House Engineering as m&e contractor.

Before building work began in December 1999, Buro Happold conducted an environmental prediction to clarify if a visit to Magna would be a 'coats on' or a 'coats off' experience. Following this it was decided that, due to its size, Magna should be a 'coats on' experience.

Heating such a huge area was never really an option, as repair and improvements to the building's shell to provide adequate insulation, not to mention plant and running costs, would have been excessively expensive. Therefore the shell is effectively used as a cover with each individual pavilion providing an appropriate environment. The only areas that receive heating are the pavilions, which are set at a comfortable 16°C.

Aiming for sustainability
Making the building as sustainable as possible was essential, therefore natural ventilation was used whenever possible. The only areas at Magna requiring mechanical cooling are the control rooms. Comfort levels are maintained using a combination of opening panels forming air inlets and high level mechanical extracts only where needed.

On entering the shed and viewing the interior from the elevated walkway that connects the pavilions, it is impossible not to be impressed by the size of the structure. The shell is a massive 350 m long, seven storeys high and still retains much of the original machinery, including crane hooks and gantries. The tour starts with a display showing the life and history of the works. Visitors then move on to an awesome pyrotechnics display. Shooting flames 8 m high, the show re-enacts the steel making process using the original arc furnace equipment, and reminds everyone of the original purpose of this massive structure.

Below the walkway, under ground level, sits the Earth pavilion. This area is extremely popular with the younger visitors as they can operate diggers and excavation machinery. Ensuring adequate ventilation in this confined space was essential due to the high dust levels created by this equipment. Dave Hull, partner at Buro Happold explains: "We knew it would be tricky making sure the area was ventilated properly so we set about examining occupancy levels and employed fan convectors concealed within the perimeter walls that respond directly according to the number of people in the pavilion."

Water safety first
Taking a trip up to the Water pavilion, back on ground level, provides a totally different experience. The area is formed from a curving stainless steel structure and offers a number of imaginative displays, including a tropical storm complete with rainfall, sound and spectacular visual effects. The zone is interactive with water jet shooting games on offer.

The pavilion uses recirculated water, which posed potential health risks. Hull explains how this was overcome: "The water is constantly recycled. The jets and sprays form mists, therefore it was essential that a strict filtration and sterilisation programme be in place. Buro Happold conducted a study and found that the combination of ultraviolet treatment and biocide reduced the quantities of chemicals used, without compromising public safety."

Fresh air is bought into the Water pavilion via a concrete-enclosed void situated beneath, providing passive cooling of the incoming air without resorting to mechanical cooling.

Light and air
The Air pavilion is designed to resemble an airship. The structure is made of layers of translucent inflated bags of ethyltetrafluoroethylene (etfe). It is suspended 12·5 m above the ground by steel girders but, depending on viewpoint, looks as though it floats in mid-air. Back-projected films of moving clouds and rippling coloured lights enhance the floating effect. The entrance to this pavilion is through a wind tunnel and inside attractions, designed by Event Communications, include a walk across a bridge as it collapses in a storm.

Fresh air is pumped beneath the steel walkways and is allowed to diffuse naturally upwards towards the occupants. Air is removed at the ends of the airship by a huge exposed extract fan.

Fire finale
The journey ends with a trip into the Fire pavilion, which is best described as an enormous black box spanning the width of the site. It incorporates imaginative lighting and visual images to complement the exhibits. At the centre of the pavilion is a 4·5 m high fire tornado that works by igniting kerosene, which is then whipped up into a swirling column of flames.

Ensuring the safety of the visitors at this attraction was essential. Dave Hull says: "We knew the best way for visitors to really appreciate the effect would be up close, which meant we had to be extremely careful to ensure we had complete control over the tornado. The way we achieved this was by linking the effect to the bems, so when the tornado is in full flow the air conditioning is switched off – stopping any drafts affecting the tornado's direction."

As part of the effect the Fire pavilion is set at a warmer temperature than other areas. This is achieved by using fan convectors located in the walls that also provide fresh air inlets.

High-level variable-speed extract fans maintain air quality and room temperature. In the winter waste heat from this area is redirected to warm air coming in to the exhibit area.

The lighting, designed by Speirs & Major, has been geared towards enhancing the experience of Magna. The walkways are minimally lit, while the exhibit lighting is designed to reflect the atmosphere of the individual pavilions. Dimmed tungsten luminaires are used inside the exhibits, which are interfaced with the audio and visual systems to dramatic effect.

All lighting is controlled via an intelligent dimming and switching system and is connected and controlled by a central processor. As part of the intelligent lighting system each emergency luminaire has its own address on the lighting network, allowing any problems to be easily identified.

Incorporating existing systems
During the build process one of the most difficult challenges facing the engineers came from the existing electrical services. The site had a large number of hv/lv transformers, some of which are still live and form part of the network owned by Corus. They supply neighbouring industrial plants and existing offices.

The engineers worked closely with Yorkshire Electricity and Corus to reorganise the mains supply. This was achieved by effectively splitting up the electrical service into three phases, 'enabling', 'base build' and 'fit out' to allow the design team to continue developing the idea while services installation was progressing.

Electrical services infrastructure designed for the base build scheme included networks for lighting and emergency lighting, security, intruder detection, cctv, IT cabling and mechanical services supplies.

There were two new sub-stations installed to serve the four pavilions' services requirements, together with the main entrance and restaurant area. It was decided that the design of the electronic systems would be divided into three separate zones, allowing field wiring to be localised. Control panels are linked to host computers in the central area.

Individual but together
As all the pavilions are separate it was important to treat them individually. In particular the Air pavilion, which has all services incorporated inside the structure. Mechanical and electrical services are integrated with structural beams, including heating convectors within the walkway structure. Cables and lighting track were integrated into the curved extended frame of the pavilion envelope for maximum effect.

Experience not to forget
The sense of history is not lost in this hugely impressive structure despite the vast changes and this is in large part due to the work of the project team. There can be little doubt Magna is fast becoming one of the major visitor attractions in the north of England. Visitor estimates in the first year were originally set at 300 000. And only six months after its official opening, this unique interactive learning centre is well on the way to achieving this goal.