HMS Lagan provides the concrete design comparison: an effective River-class ASW frigate of about 1,370 tons and 20 knots whose characteristics sat within the earlier treaty limits. Britain could have matched its annual destroyer orders with roughly sixteen escorts a year. Construction in Canada, Australia, India, South Africa, and perhaps New Zealand could raise the prewar total to about 340 first-rate ocean escorts. Reserve crews could maintain the force while dispersed yards and suppliers remained ready for wartime expansion.
Chapter · 38:24-41:38
River-class performance was treaty-compatible
A River-class-style 1,370-ton, 20-knot frigate shows that a first-rate ocean escort could fit the treaty exemption and be built throughout the interwar period.