An unpublished hypothesis about Warspite's steam surges

Warspite combines Yarrow boilers with Parsons turbines, unlike the slower Barham. A Royal Navy engineer's unpublished hypothesis links her occasional extra speed to boilers capable of a higher operating level, with uneven settings causing steam surges. Those surges would explain intermittent bursts of power above her sisters. The engineer died before publishing the book, and Alex Clarke read manuscript sections shared by the engineer's family through their connection with his father. The mechanism remains an unpublished hypothesis. Later Brown-Curtis turbine designs became more efficient, including the generation fitted to Hood.