Ballast tanks keep gates open

The new stainless steel ballast tanks,

ECS Engineering Services has completed an overhaul of the radial gate at Pillings on the River Soar in Leicestershire, a vital asset for controlling water levels upstream. The group has replaced the ballast tanks and carried out preventative maintenance on the gate for the EA.

With its shallow gradient, the River Soar has been prone to flooding during heavy rainfall in the past. To combat this, the Soar Valley Improvement Scheme was implemented to install a water control infrastructure along the river’s course.

One key asset is the radial gate at Pillings. Usually, the gate is closed, sending water over the adjacent weir. However, when water levels rise, counter-weight ballast tanks automatically open the gate, providing another outlet for water to flow through and reducing the risk of flooding upstream.

The EA requested an overhaul of the site when it identified corrosion on the corner joints of the existing mild steel ballast tanks. The best value solution was decided upon as being the fabrication of new replacements in stainless steel, while carrying out preventative maintenance on the structure.

ECS is certified to fabricate in stainless steel up to EXC4, against the BS EN 1090 CE standard. The fabrications team designed and fabricated two 3 m x 1.5 m x 1 m stainless-steel ballast tanks, each weighing in at 1.3 tons. Stainless steel is highly durable and offers inherent resistance to corrosion – ideal for a long service life in submerged applications.
Before the new tanks could be installed, the area around the gates needed to be isolated with stop logs. ECS installed seven stop logs upstream and downstream of the gate, using a dive team to ensure that no sand or silt would compromise the seal. This was especially important, as a scaffold would be erected in the dry channel for maintenance work. Once sealed, water in the channel was pumped out. Subsequently, the gate could be raised and pinned into its maintenance position to allow ECS to remove the old, corroded tanks.