assessment of diving depths and the designed diving depth of the R Class was given as 250 feet, but the operational diving depth would have been fixed at 150 feet.
The R Class were the first Royal Navy submarines to be fitted with six 18-inch bow torpedo tubes, which was a powerful torpedo armament for the size of boat. One spare torpedo was allowed for in the design, but during the war, six spares were stowed at the expense of the Senior Ratings' accommodation. Originally it was intended to fit a 4-inch gun forward of the bridge, but this was never adopted, as it would have had an adverse effect on submerged speed, which was the main. characteristic of the design.
Having a greater submerged radius than most submarines of the
