Royal Navy escort trawlers

During WWI a great number of trawlers were requisitioned by Admiralty for escort and auxiliary duties. In order not to infringe on the supplies of fresh fish, Admiralty in 1916 decided to commence on a building program for escort trawlers, resulting in 120 Mersey-class, 300 Castle- and 160 Strath-class units being ordered.

Shakespearian-class escort trawler HMS Macbeth. IWM

By the end of 1918, no less than 365 had been delivered to Royal Navy, while 82 were cancelled and a further 133 completed for commercial owners. During the interwar years most of the naval trawlers were sold for fishing.

During the mid-1930s Royal Navy again began to plan a new generation of escort trawlers, with HMS Basset being completed as the prototype in 1935. She differed from ordinary trawlers in having less sheer, longer foc’sle and engine/boilers amidships. A further five followed of the class, of 163.5 ft length.

Based on HMS Basset, a further 197 vessels were ordered from a modified design of 164 ft, to be of the following classes:

Tree 164 ft 20 ea

Dance 164 ft 20 ea

Shakespearian 164 ft 12 ea

Isles 164 ft 145 ea

In addition, another 70 escort trawlers were built in smaller numbers to other design in Britain, New Zealand, Portugal and Brazil:

Admiralty 156 ft 3 ea

Portuguese 139 ft 6 ea (wood)

148 ft 6 ea

Brazilian 176 ft 6 ea

Castle 134 ft 17 ea

Hills 181 ft 8 ea

Fish 162 ft 10 ea

Round Table 137 ft 8 ea

Military 193 ft 9 ea

The vessels were fitted out for escort duties with anti-submarine weapons as well as for mine-sweeping, net-layers, harbour duties, etc.

Further files:

The Isle class and sisters

Acquisition and transfer

Conversions for commial use

Portuguese class