One of the most remarkable and unusual structures to be built in the UK for many years is now taking shape on the Olympic Park in London, and is gaining from the use of Layher stairtowers to provide multi-personnel access during its construction. The ArcelorMittal Orbit Tower, designed by Anish Kapoor and Cecil Balmond, is being constructed by Team Orbit who, in turn, have appointed GBG Construction to provide the access scaffold – at the heart of which more than 40 x 2m high aluminium stair flights from Layher form a staircase that rises to almost 85 metres of the structure’s overall 115 metre height.
Andy Collins is Director of GBG Construction (founded by the late Gerry Gleeson) and explains the thinking behind the use of the Layher system and highlights the innovative method of construction used –
“We are assembling the stairtower sections inside one half of the steel-work which will ultimately house the lifts for The Orbit structure,” he says. “A series of eight steel frames, the majority built to 12 metres in height, are assembled at ground level and contain up to six staircase lifts within one of the voids that will ultimately house one of the lift carriages. Each structure – steel frame and staircases combined – is then craned into position to be progressively fixed to the section below. This method has helped us raise workforce access as the build proceeds and, importantly, the 700 mm staircase width has permitted time-saving multiple personnel usage throughout.”
The initial 10 metres of the framework and staircase combination was built from ground level with the first craned section – which, at just over four metres in height provided two lifts – then attached. Sections are then being added progressively to keep pace with the construction of The Orbit itself – much of the construction work being undertaken via workforce access from an adjacent cherry-picker.
“The cherry-picker is able to operate from ground level for the first 40 metres of construction, but thereafter is itself being craned onto a temporary platform built on top of the two lift shaft structures,” adds Andy Collins. “This is where the installation of the Layher stair system becomes key as it elevates the assembly teams to the same level with personnel access through the platform from the top of the stair system. This clearly helps to ensure that the project can proceed smoothly and efficiently throughout the build programme.” Some 72 weeks have been scheduled for construction of The Orbit with completion targeted for March 2012.
Before craning, the stairtower lifts are fixed to each frame using Layher ladder beams, which are then removed as each section is bolted into position and replaced by ties to the lift shaft structure itself. GBG Construction highlights a comparison between using the Layher system, which is centred on a modular design, and the alternative option of using tube and fittings throughout. The latter, Andy Collins says, would have used significantly more material, greater man-power and, perhaps crucially, markedly more construction time.
“There is no doubt that The ArcelorMittal Orbit Tower by Anish Kapoor and Cecil Balmond will become one of the most recognisable and iconic structures of its type ever seen and is set to attract visitors well beyond the major sporting events of summer 2012,” comments Layher’s UK Managing Director Sean Pike. “We believe that the ease of construction, lightweight design and inherent safety of our stairtower systems – which have been supplied for this project by hire and sales company Rotamead – have made a major contribution to meeting the very specific requirements of this important project.
“We are delighted to have worked closely with GBG Construction and main contractor Team Orbit to help meet very clear cut operational objectives and deadlines to provide the required access throughout the build period – simply, effectively and safely,” he concludes.
