How a steamship could exceed its rated speed in an emergency

Could a post-1910 steamship exceed its rated top speed by ten or twenty percent without regard for damage or safety?

It could sometimes exceed normal speed temporarily, but only by consuming engineering margin and accepting close monitoring, damage, and later repair.

A ten- or twenty-percent speed increase could not be treated as available without regard for safety or damage. Steam machinery could sometimes be driven beyond normal settings if the alternative was losing the ship, but it needed close monitoring. Boiler strength included a substantial margin above working pressure, although the suggested ratio was expressly described as a generalisation. Using that reserve risked machinery damage and made more sense when engine replacement was already expected. The comparison with submarine test and crush depths illustrates the difference between a normal operating limit and an ultimate structural limit.