The triumph lasted less than five minutes. The heat of the water circulating through the sleeve rose past forty degrees. Then, the vegetable reed fibers began to soften under the combined attack of heat and water-pressure load.
With a sickening, slow warping, the central belly of the sleeve began to sag downward. He dropped four and two-tenths inches below the centerline of the iron flanges. The sag created a huge asymmetric bending moment at the eastern clamping collar. The upper canvas was stretched taut as an iron wire. Meanwhile, the lower seam buckled into deep, puckered folds.
Jo Saye scrambled onto the test cradle, shining her rubber flashlight onto the eastern collar. ‘STOP PUMPING! DUMP THE VALVE!’ Jo shouted, her voice cutting through the thumping of the pistons.
Eren threw the relief valve open, discharging twenty gallons of warm brown water into the drainage ditch. The sleeve collapsed onto the timber baulks with a wet, squelching sigh.
‘Look at the eastern collar,’ Jo said, pointing her flashlight at the canvas. Under the modern white beam, the outer layer of reed cloth was visibly distressed. Three warp threads had snapped. The linen Bulldog Seam was pulling away from the clamp by an eighth of an inch. ‘The heat softens the resin. When the belly sags, the entire weight of forty gallons of water hangs on two inches of fabric right at the iron lip. If that was the Third Gate bypass, that collar would have torn clean off in twenty minutes.’
