SAFESCREEN®, the combined edge-protection and screen system from formwork specialist SGB, is helping to ensure safe working and rapid progress on the construction of a major mixed-use development in central London. Concrete frame contractor Byrne Brothers is using the system during construction of the concrete frame and floor slabs on the £100 million, 33-storey Nido Spitalfields development near Liverpool Street.
Main contractor ISG Group is managing the project for client Nido Student Living, a specialist developer providing modern student accommodation. The building, on Middlesex Street, will house more than 1,200 students and will also feature 50,000 sq ft of commercial office accommodation on the first five stories, plus six ground floor retail units and a gym. SGB worked closely with Byrne Brothers from an early stage to develop a suitable self-climbing perimeter screen that would provide protection without disrupting the construction programme. To allow maximum program flexibility, Byrne Brothers required a system that could be moved independently of the falsework and follow the changes to the slab edge profile as the construction progressed.
There was also a requirement for a system that would protect four storeys at once, allowing the contractor to start work on the upper slab level prior to the screen being moved, and effectively maximising the degree of protection provided.
SGB’s solution was to provide four levels of protection consisting of a 12m high screen in 4.6m wide sections. In order to resist the calculated wind loadings while providing the optimum protection, each section was clad with 10m of solid panels with 2m of steel mesh at the top.
SGB provided Byrne Brothers with detailed layouts from the second to the seventh floor, where a total of 39 SAFESCREEN® units were employed. This layout was then used as a template for subsequent floors. A challenge for the designers was how to accommodate the recessed first floor slab, which was overhung by the upper floors by some 650 mm.
SGB overcame this by attaching the system’s support shoes to a series of MKII Soldier beams, cantilevered out to artificially ‘extend’ the first floor slab and align the support with the floors above. To ensure maximum safety, SGB designed and supplied vertical and platform infill pieces to close off gaps between the screen and floor slab, and around the main vertical channels. These were designed so they could be quickly removed or folded back prior to the climbing operation and then replaced after the screen had been repositioned.
SAFESCREEN® is the first system of its kind to be designed and produced specifically as a perimeter climbing screen for use on high-rise construction projects. A very flexible system, with a choice of screen materials and configurations, it can be introduced at level two whereas rival systems cannot be introduced until level four, leaving the first and second storeys requiring alternative and additional edge protection systems.
The system’s lightweight and compact dimensions allow it to be climbed quickly and with minimal disruption as the building progresses. Simple low-pressure hydraulics ensure that the climbing operation is safe and easy.