The White-Forster boiler is largely adopted in the British Navy for destroyers, torpedo boats, and smaller vessels. It consists of a large centre drum and two small ones at the wings, the generating tubes are entirely drowned and are curved sufficiently to determine the direction in which they will move when subjected to heat. They are all curved to the same radius and take up in each row positions due to the converging of the tube holes as if they had been rotated on their ends through a small arc. A divided uptake is adopted, causing the gases on their way to the funnel to dip down and embrace the lower half of the tube surface. The tubes can be readily removed and replaced through the manhole as shown.
Source: Jane's Fighting Ships, 1906-07 ed. (London: Sampson, Low & Marston, 1906), 454.
