New Build Construction

Swale River Crossing, Kent, England

Alimak Hek provides customised 
column access on Swale River crossing.

Two 7.5m long mast climbing work platforms were used on each reinforced column for safe and efficient access during the construction process. The crossing superstructure is supported by a series of 18 pier bases, each pier base comprising of two tapering reinforced concrete columns to a maximum height of 30 metres. Five pier bases were within
the tidal river estuary with the remaining thirteen pier bases on land.

The challenge was for the provision of a safe and efficient access to the concrete columns during construction. Each pair of columns were different in height and tapered from a maximum diameter of 3.85 metres at the base to a uniform 3 metres at the top. A unique solution was engineered using mast-climbing work platforms supplied by Alimak Hek Ltd, the country’s leading authority on vertical access methods.

Due to the tapering of the columns, Alimak Hek technical engineers utilised two inclined and independently operated mast climbing work platforms on each column. Each platform had a specially profiled 7.5 metre long deck which was fully adjustable to meet the tapering column dimensions and to ensure total encapsulation at all times. The two platforms then provided a flexible and unobstructed access solution to all areas of the pier columns.

The first work platforms were installed in August 2004 with the final pier completed in May 2005. The use of eight Alimak Hek customized work platforms working in pairs allowed for optimum speed throught out the construction programme including the positioning of the prefabricated steel reinforcing cages, the erection of the steel shuttering, the pouring of the concrete and the striking of the steel formwork shuttering. A travel speed of 10 metres per minute and a distributed payload capacity of 1,200 kg allowed the easy transportation of personnel and materials to the required working height. Onboard power outlets on the platforms made it possible to use power tools as conveniently as if in the workshop.

The platforms provided a rigid working area from which to construct all the column piers and worked with few problems during the contract period. The main contractors major problem was the high wind speeds, which restricted working at certain times.

The work platforms for the river pier sections were installed within temporary cofferdams, several metres below water level. The two pier bases either side of the navigable channel were excavated to a depth of 10 metres below the river bed. These massive bases are designed to withstand impact by ships using the Swale River.

The access problem was unusual in that it required a flexible solution that enabled working around the columns but was adjustable to suit the changing column dimensions. Scaffolding was an option but it would have been extremely time consuming as the framework would have been extended after each lift. The mast-climbing work platforms provided the solution. With scaffolding, the workers would have found it more difficult to access the formwork and to carry tools and materials to the top of each column, which would have required either a crane or a hoist.
The crossing superstructure was commenced early in 2005 and the scheme is scheduled for completion by summer of 2006.

Downloads

Image From The Swale River Crossing (1)

Image From The Swale River Crossing (2)

Image From The Swale River Crossing (3)

Image From The Swale River Crossing (4)

Swale River Crossing reference sheet

New Build Construction


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SE-T lift range provides a safe, reliable and flexible temporary lift solution allowing independent access for all when a buildings existing lift is being replaced or refurbished.