Dutch crews found the British 120 mm guns familiar, but the transferred destroyers lacked the Hazemeyer air-defence equipment fitted to their own design. The suggested preference is for radar-directed 40 mm guns, a system the Royal Navy had not brought into service before the war. The British-built ships instead carried four-inch guns, 20 mm Oerlikons, and half-inch machine guns, with uncertainty over whether either even received a pom-pom. Equipping roughly a dozen Dutch ships was a different undertaking from supplying several hundred British destroyers. The prewar cost and availability problem helps explain why an advanced mounting suited the Dutch emphasis on stronger individual ships. Wartime British demand was broader: the Royal Navy then wanted such equipment wherever it could fit it, although these transferred vessels continued without it.
Notable Point · 29:04-30:49
The missing Hazemeyer advantage
The transferred destroyers lacked the radar-directed 40 mm protection their crews might have preferred, while fleet size changed the cost of supplying advanced mountings.