How could the Swiftsure class reach 14,000 miles?

How did the Swiftsure-class pre-dreadnoughts achieve a quoted 14,000-mile range?

It combined exceptionally reliable engines with a very large fuel capacity.

The answer reduces the Swiftsure class's impressive range figure to two practical design qualities. Exceptionally reliable engines could sustain economical operation over a long passage. A very large fuel capacity gave that machinery enough stored energy to exploit its reliability. Fuel alone would not create useful endurance if the engines could not operate dependably, while reliable engines could not compensate for inadequate bunkerage. The short exchange is a compact reminder that quoted cruising range emerges from machinery and storage working together.