Patreon 41: RN Strategic & Tactical thinking on submarines & anti-submarine forces between the Wars

The Royal Navy treated submarine and anti-submarine capability as mutually dependent, using each to make the other more realistic.

Mediterranean, Atlantic, and Far Eastern patrols demanded very different ranges, bases, and submarine designs.

A quiet diesel submarine can wait like a mobile minefield, while a nuclear boat can sprint ahead, attack, and escape.

The operational gain was less compelling in Britain's expected theatres, while hull space and design changes competed with equipment such as radar.

No: conventional submarines lack the visible presence role of surface capital ships, though hidden SSBNs serve a different deterrent purpose.

The T-class hull carried features from earlier British boats into a period when underwater performance was becoming more important than surface speed.

British submarine radar installations emphasized warning of aircraft while also offering limited surface-search capability.

The O, P, and R boats emerged through successive experiments to give Britain long-range submarines for the Far East.

The S class replaced ageing H boats with a medium design that could serve in the Atlantic while still fitting Mediterranean requirements.

No: it used Royal Fleet Auxiliary ships as simulated merchant convoys and trained escort and hunting groups, though the armed stand-ins created unrealistic assumptions.

Not deliberately: fixed schedules, prestige targets, safety limits, and peacetime incentives made exercise behaviour differ from wartime choices.

River-class fleet boats and purpose-built minelayers explored how submarines might accompany a fleet or attack through mines.

Only to a limited extent: most US submarines stayed in the Pacific, where British and American boats were separated into assigned operating areas.

During the 1920s, especially as reliable fittings and trained crews became sufficiently widespread by the middle of the decade.

The U class was designed for short-range underwater ambush work from Mediterranean and North Sea bases.

No: it was a long-range Far Eastern successor to the O, P, and R boats, while the loss of HMS Thetis was an accident rather than a class-wide diving tendency.

A convoy escort needed endurance and reliable ASW gear, while a fleet escort also needed speed, guns, and air defence.

No: escorted surface ships carried much more, while submarines were used for exceptional high-value, low-volume supply runs such as those to Malta.

Not significantly; operating range and the resulting size of the boat mattered more than a separate insulation scheme.

Only if the boats arrived early: a large force available in 1939, especially U-class boats in the Mediterranean, would matter far more than the same total completed by 1945.

No, but effective convoying needs many escorts, and modern navies usually lack enough spare ships to do it on a large scale.

ASDIC gave escorts a directional echo and range, but speed, weather, thermal layers, and false contacts limited its use.

The drive toward Hedgehog-like weapons came from the problem of losing ASDIC contact during a stern depth-charge attack.

Treaty limits below 2,000 tons and 20 knots still allowed Britain to build long-range escorts optimized for ASDIC and convoy defence.

It was a long-range Indian Ocean and Far Eastern ASW sloop designed for heavy depth-charge work and construction in Australian, and potentially Indian, yards.

It could be physical damage: a close explosion could harm the thin sonar dome, allowing rushing water to create disabling noise.

Diesel engines transmitted more troublesome vibration and harmonic noise through the hull before effective machinery rafting was available.

Corvettes generally followed commercial construction and triple-expansion machinery, while sloops used naval standards and turbines, with differences also in steel, subdivision, and equipment isolation.

They needed skilled labour, heavy capital, sustained orders, and local political and commercial support that the Royal Navy could not provide by itself.

Commercial-style trawlers were less capable than purpose-built escorts but could be produced rapidly in great numbers for coastal duties.

It never shifted completely: helicopters and submarines expanded the system, but ships still provide important sensors, processing, coordination, and weapons.

Overseas industrial development is linked to Britain's longer transition from empire to Commonwealth, with an explicit rejection of a benevolent-empire reading.

It had fixed seabed hydrophones in some locations, but nothing approaching the capability of the later SOSUS system.

The Hunt class added speed to the escort role, allowing it to pursue contacts away from a convoy and regain station.

Numerous small escorts acted like a skirmish line, finding or triggering submarine attacks before they reached the main force.

The Admiralty would have had to pay the industry-wide extra cost from its own limited budget, so it built some naval trawlers and relied on rapid wartime conversion instead.

The limit was a real constraint, and an unconstrained design might have approached Daring-class size, but the second torpedo bank receives no definite verdict.

Using a rough thirds model, about seven could be forward, seven in transit or preparation, and seven in refit, with roughly one additional boat.

Interwar exercises generated real ASW knowledge, but conditions and assumptions could produce misleading confidence.

Rear Admirals Submarines and Destroyers gave both sides of the undersea contest senior advocates, including Andrew Cunningham and Hugh Sinclair.

Yes: destroyers trained constantly, with regular ASW exercises against nearby submarine flotillas and wider forces joining larger practices.

They included Commonwealth navies, but not the French Navy or other foreign powers in the same way.

It considered the idea, but carriers and cruisers already carried aircraft, and monitor experiments had shown the tradeoffs of operating them from smaller ships.

Designing submarines and ASW systems means anticipating an opponent's future technology and tactics before either is tested in war.

The distance from the Falklands War leaves much contemporary ASW practice grounded in exercises and theory rather than peer combat.

There was no reliable single average: ninety might be an official sloop load, while captains often carried more and some wartime escorts embarked loads in the hundreds.

There was a submarine threat, but one boat was caught on the surface at South Georgia and stopped by gunfire before it could press the attack.

They may, but simulations and exercises cannot establish the wartime result with certainty because their inputs can preserve untested assumptions.

No: they were not fast battleships as built, though additional boilers might hypothetically have raised them to about 28-29 knots.

Yes: several Black Swan-class sloops and hunter-killer groups achieved repeated submarine kills, with some Flower-class corvettes also recording high totals.