At eight in the evening, Inspector Korr Var and Ada Morland recalculated the peak volume figures sent from the highland watchtowers. The numbers were inexorable. A single twenty-four-inch sleeve, even with its offering tear-seam, could carry only nine thousand five hundred gallons per minute without exceeding the safe speed threshold.
‘If the mountain crest hits forty thousand cubic feet per second,’ Korr Var explained. He drew two parallel lines on the master slate, ‘a single sleeve will run at full burst capacity continuously. If the offering seam vents, we lose our only bypass while the crew is patching the fabric.’
‘Then we build twin sleeves,’ Pella stated without pause. ‘Two twenty-four-inch sleeves running side by side through the Station Two bypass, connected to a Y-shaped bronze splitter pipe hub. Each sleeve carries eight thousand gallons. If Sleeve One experiences a tear, we swing the diverter valve, isolate Sleeve One for repairs, and run the entire flow through Sleeve Two at reduced head.’
Master Dima rubbed his stiff fingers, looking at his tired seamstresses sitting on the reed bolts. ‘Building a second sleeve means another hundred and sixty yards of cloth, another sixty yards of Bulldog stitching, and another four hours of work before dawn.’
