The supremely elegant buildings that comprise the National Maritime Museum in Greenwich have a distinguished pedigree; designed by architects including Inigo Jones and Sir Christopher Wren, the site is one of the architectural treasures of London. So, when it came to adding a new wing for the 21st century, enabling visitors to enter the museum via Greenwich Park, it was vitally important that every aspect of the design work was in visual harmony with the existing site. To provide a high performance, shallow water drainage system, the architects turned to ACO Building Drainage and capitalised on the company’s proven ability to provide robust yet aesthetic drainage solutions.
The key challenge for ACO was that only three downpipe outlets were available for use as discharge points for the channel design. With a rainfall intensity of 200mm/hr set out by the consulting engineer and a large surface area to drain, ACO needed to design a system with high capacity for drainage but with minimal surface visibility, to ensure that the architect’s designs were also met.
To provide a system with a limited number of outlets that could nevertheless drain a high intensity of rainfall, ACO based its design on the use of a large channel. The architect did not want a visibly large channel at surface level, so ACO designed a solution that could be buried below the paving slabs. This was fed by a smaller, 58mm wide discreet channel visible at the surface via 50mm pipes at 1000mm centres. The buried channels were manufactured from galvanised mild steel to save on cost, but the grated finish was in grade 304 stainless steel, with a flexible coupling separating the two dissimilar metals. Access points were also required to the channel and these were designed as recessed covers finished with masonry, which kept the design in line with the architect’s desire to achieve discreet drainage.
ACO Building Drainage’s completely bespoke surface water removal system with a grated stainless steel finish works in sympathy with the surrounding stone, while maintaining a full hydraulic design capacity to ensure that the drainage areas are kept clear from water, even at times of extremely high rainfall.
“ACO Building Drainage worked closely with us to achieve a custom-built solution,” said Nick Adkins of Szerelmey, the installer responsible for the stonework and paving at the new wing. “This was a challenging project but the design and execution offered up by ACO enabled us to satisfy the architect’s brief while completing the work on time and on budget.”
The Sammy Oferwing of the National Maritime Museum opened in 2011. ACO Building Drainage played a significant role in enabling Churchman Landscape Architects to successfully carry out the sensitive task of creating a new build within a World Heritage site, adding an attractive, tasteful addition to a beloved public space and a site of great historical importance.