Sheffield is world famous for its steel production and boasts a history in the industry that dates back as far as the seventeenth century. Much of the present infrastructure and foundries in the city were built in the nineteenth and early twentieth centuries, meaning that bringing these buildings up to current flood protection standards is a sizeable task that requires a blend of several technologies.
The Forged Solutions Group invested £500,000 into flood protection for critical assets at its sites at Meadowhall and the River Don, both in Sheffield, which have suffered the impact of severe floods in recent years. The Meadowhall site is the group’s largest in the city, spanning 11,000m² and housing three large hydraulic presses alongside heat treatment and machine shops. These premises are used to manufacture complex metal extrusions and forgings used by industries across the globe.
Based near the Don and with Blackburn Brook running through the site, there is an ever-present risk of flooding and the site succumbed to serious floods in November 2019, prompting Forged Solutions to take the decision to protect the site’s critical assets from future risks.
The contract to carry out the works went to tender in September 2020 and M3 Global Flood Technologies were awarded the deal, with work commencing at the Meadowhall site in March 2021. The accepted proposal included a mixture of flood technologies for both above and below ground to protect the site.
M3 Global Flood Technologies CEO, Peter Marchant, commented: “Unfortunately, flooding is making the headlines a lot right now for all the wrong reasons, and it is causing untold damage. Being specialists in methods and technologies for protecting property from flood damage, we were more than happy to take on this project.”
Following the guidance of the flood risk assessment conducted prior to the works, the recommended protection level including an allowance for some freeboard was set at 34.8m AOD. This equated to a maximum depth of 1.05m at the lowest point on the plan.
A mixture of various sized non-return valves and surface-mounted flap valves were installed in the surface and foul water drains at the site to stop backflow waters entering the drainage systems. In other locations, existing manhole covers were replaced with sealed bolt down covers, all of which are passive and come into operation as soon as water starts to rise above the pipe invert levels.
With the site dependent on forklift trucks to move the forgings from building to building, level thresholds across the main roller shutter doors were a fundamental requirement in the scope. To facilitate this, M3 proposed a combination of Defender barrier walls. These consist of single-piece flood boards and intermediate posts which are deployed prior to a flood event into ground sockets and side channels that are permanently installed across the door entrance.
Pedestrian access into the buildings and offices was serviced with the installation of Defender hardwood flood doors and steel emergency escape flood doors as single and double units to match the existing openings.
Forged Solutions’ electrical transformer and substation buildings came with five openings that required flood protection but also had to maintain sufficient air flow to aid cooling. M3 designed and installed five steel flood gates, four singles and one twin leaf units with open mesh tops at widths of 1.8m, 3.0m and 5.4m to achieve the required flood protection in the area without compromising key operational features.
Several of the buildings on site also came with steel cladding down to ground level that offered zero flood protection. To resolve this, reinforced concrete block walls were designed and constructed by M3 staff inside the existing cladding. The existing single skin brick walls were strengthened with an outer skin of high-density concrete blocks, all of which were subsequently sprayed with polymer tanking. Antiflood airbricks were also installed to replace the existing terracotta units.
The most critical location at the site was where the two hydraulic presses; the 3,500-tonne Bliss and 5,500-tonne Davy units, were housed with all the supporting infrastructure.
Marchant explained: “To safeguard these units for the Forged Solutions Group, we installed a double flood protection designed to protect inundation from any direction. Externally, we installed Defender wall barriers, steel flood doors and duct sealing. Internally, two welded steel panel walls supported by reinforced concrete and block walls were constructed, with additional access provision being provided by two deployable defender wall systems and two pedestrian steel swing gates.”
To facilitate early warning of any impending floods in future, two wireless remote GSM flood alarms were installed at either end of the site which were set at the critical trigger levels determined by Forged Solutions. These remotes are situated in the Blackburn Brook open channel and in one of the existing drainage manholes. When activated, these will send GSM messages on up to eight different devices.
Further information about M3’s array of flood protection products can be found here.
Photo by Benjamin Elliott on Unsplash