Harsco Infrastructure have used a special ‘double-decker’ MASTCLIMBERS™ access system to enable specialist contractors to install large-format blast-proof cladding to the outside of Heron Tower – currently the UK’s tallest building.

The record-breaking contract for cladding company Scheldebouw required a mast climbing access system capable of handling the large cladding panels that make up the blast wall on the building’s south-east core.

To fit the 4 m high metal and glass panels, Scheldebouw needed access to the top and bottom of the panels at the same time. “It just isn’t possible to do this with standard access equipment” comments John Richardson, senior site manager for Scheldebouw.

Harsco Infrastructure’s solution was to propose two masts each carrying a pair of climbing platforms, one above the other. Working in parallel, each pair of platforms would thus provide simultaneous access to the fixing points at the top and bottom of each panel.

“This was itself difficult to achieve” comments Nick Davies, branch manager for Harsco Infrastructure. “We had to get design and engineering approval from manufacturer Alimak Hek before we could extend the parameters relating to how close together two platforms on the same mast could operate.”

Another problem, which sprung directly from the height of the cladding panels, was that anchor points tying the masts into the building had to be placed a minimum of 12 m apart.

“With relatively few anchor points we had to design the ties to suit high loads” says Mr Davies.

Harsco started work on site in August 2009 and was scheduled to remain on site for only 20 weeks. “We were originally required to install the MASTCLIMBERS™ up to Level 21 [91 m]” explains Mr Davies.

“But in January 2010, Scheldebouw asked us to extend the masts to 180 m – the full height of the elevation – to speed up the cladding operation and safeguard site operatives” he adds. At 180 m, the Heron Tower is the highest MASTCLIMBERS™ installation ever recorded in the UK.

With the double-deck platforms erected, installation of the cladding to the blast proof core could be carried out entirely from outside the building and with the maximum level of safety.

Harsco’s ability to provide an engineered solution outside of the normal hire industry parameters was a major factor in Scheldebouw’s decision to award the contract. “We have worked with Harsco a great deal during the past 12 months and that gave us confidence in their abilities” comments Mr Richardson.