Galvanised steel tanks in Northamptonshire

Who uses them in the county

Arable farms in the Nene valley and towards Oundle and Thrapston store water for irrigating crops through dry spells. Haulage depots and logistics yards along the A14 and the M1 hold wash-down water for lorries and trailers. Industrial units on the estates around Northampton, Wellingborough and Corby keep process or recycled water close to the line.

Large warehouse roofs also make good catchments, and a steel tank can store harvested rainwater for flushing or wash bays without a deep excavation.

The base comes first

A full tank is very heavy, so the foundation matters more than the steel. On Northamptonshire clay, which shrinks in dry summers and swells in wet winters, the slab or pad has to be designed by others with that movement in mind and built to carry the tank at its full weight. When it is finished we survey it for level and mark out the ring before the first panel goes up.

Assembly, lining and commissioning

Ring after ring of galvanised panels is bolted up, and the shell stops growing once the stored volume on the drawing is reached. All the water is held by a liner cut to fit this particular tank, so no bolted seam in the steel is ever wetted. Inlet, outlet and overflow connections are sealed through the liner, and level indication is added where you need it.

The tank is then filled in stages, and each stage is checked before the next. That staged fill is the commissioning test, and the tank enters service once it has held at full volume.

• Panel supply and bolted assembly
• Liner made to the tank's diameter and height
• Pipe connections, overflow and a level gauge
• Fill in stages, checked at each one, before handover

Planning the visit

Panels arrive flat-packed on a lorry, so we need a route on to the farm or yard that a delivery vehicle can use and a hardstanding to unload on. Agree that with us at the start and the crew can go from first ring to full tank without waiting around.