Shaft horsepower depends on steam volume, steam pressure and turbine efficiency. More boilers or higher-pressure boilers do not guarantee the same proportional increase in power at the shafts. Less efficient turbines can waste the advantage of a stronger steam supply. The interaction also works in the other direction, because turbine efficiency depends partly on the steam conditions available. Dividing Tiger's stated 85,000 shaft horsepower by thirty-nine boilers produces about 2,200 horsepower per boiler. That figure is a rough comparison tool rather than an independent rating for each boiler.
Notable Point · 31:07-33:00
Why boiler count does not directly determine horsepower
Steam quantity, pressure and turbine efficiency interact, limiting simple comparisons between boiler numbers.