The ensuing lava-cooling operations were the most ambitious that had ever been undertaken. "Sandey" was able to spray up to 400 litres per second (105 US gallons per second) onto the advancing flow, and a network of pipes was laid on top of the lava to distribute the seawater over as wide an area as possible. Wooden supports for the pipes caught fire where the lava was hottest, and even aluminium supports melted, but the pipes themselves were prevented from melting by the cold seawater flowing through them. Up to 12,000 square metres (3 acres) of lava flow could be cooled at one time, with internal barriers then being created within the flow, which thickened and piled up upon itself.