The quiet death of the Royal Canadian Navy

It apparently originated in the late 1950s and early 1960s as a Canada-US-UK development partnership, with a primary goal of finding ways of countering the nuclear submarine. The problem was that under typical Atlantic operating conditions the new nuclear submarines were faster than the frigates which were meant to counter them. The submarines could run rings around the frigates.

One solution was to use rocket launched torpedoes such as ASROC, but these had limited utility.

Another was to find ways to make the ASW escports faster. There were three projects. The US were to work on non-surface piercing hydrofoils, Canada was to work on surface piercing hydrofoils (this relates to how the hydrofoil surface is arranged), while the UK was to work on hovercraft.

Bras D'Or was Canada's test platform. The video mentions that the US built an number of hydrofoils which they tried to use as gunboats (I suspect as attempts to justify spending money on experimental ships), but these had limited success. The video doesn't mention what the UK did with their hovercraft.
The problem with using high-speed dynamically supported craft in the deep ocean is that by definition, they need to be lightweight. Which tends to be incompatible with operating in the North Atlantic - and certainly not for extended periods unless you like living next to a tanker.

I think the three navies sorted this out fairly quickly. The USN hydrofoil (USS Plainview AGEH-1) was an experimental craft built to trial the hydrofoil concept. She didn't last long.

The patrol craft hydrofoils were a different concept - the idea being that they could provide a high-speed anti-shipping capability in enclosed waters (Baltic / Med). Half a dozen of them ended up in 6th Fleet for a short while and then ended up being transferred to the Caribbean to counter narco "go-fasts". ISTR they dropped off the plot in the mid 90s.

The Brit hovercraft (BH7) still exists at the Hovercraft Museum in Hampshire, which is a fascinating place.

The Collection – The Hovercraft Museum

Having realised that really high-speed surface ships were not a sensible answer to the nuclear submarine ASW problem, attention switched to long-range sensors and ASW helicopters ideally with dipping sonars.

Which led to the need to have a platform capable of maintaining low ship motions (to enable helicopter ops) in high sea states. Which led inexorably to SWATH. Trouble with SWATH is that they tend to require higher powering than a monohull of a comparable size to maintain decent cruising speeds (high teens, low twenties). Which is why they didn't catch on either for that role - although they did for the Towed Array station ships (T-AGOS).

As it happened, other drivers appeared, which tended to make ships bigger, which improved the motions, which improved the operability - particularly with things like Haul-down systems. Brief segue's into trimarans were also part of that piece.
 
The problem with using high-speed dynamically supported craft in the deep ocean is that by definition, they need to be lightweight. Which tends to be incompatible with operating in the North Atlantic - and certainly not for extended periods unless you like living next to a tanker.

I think the three navies sorted this out fairly quickly. The USN hydrofoil (USS Plainview AGEH-1) was an experimental craft built to trial the hydrofoil concept. She didn't last long.

The patrol craft hydrofoils were a different concept - the idea being that they could provide a high-speed anti-shipping capability in enclosed waters (Baltic / Med). Half a dozen of them ended up in 6th Fleet for a short while and then ended up being transferred to the Caribbean to counter narco "go-fasts". ISTR they dropped off the plot in the mid 90s.

The Brit hovercraft (BH7) still exists at the Hovercraft Museum in Hampshire, which is a fascinating place.

The Collection – The Hovercraft Museum

Having realised that really high-speed surface ships were not a sensible answer to the nuclear submarine ASW problem, attention switched to long-range sensors and ASW helicopters ideally with dipping sonars.

Which led to the need to have a platform capable of maintaining low ship motions (to enable helicopter ops) in high sea states. Which led inexorably to SWATH. Trouble with SWATH is that they tend to require higher powering than a monohull of a comparable size to maintain decent cruising speeds (high teens, low twenties). Which is why they didn't catch on either for that role - although they did for the Towed Array station ships (T-AGOS).

As it happened, other drivers appeared, which tended to make ships bigger, which improved the motions, which improved the operability - particularly with things like Haul-down systems. Brief segue's into trimarans were also part of that piece.

I did some more searching, and there's more to the story. I put my references at the bottom of the post.

It turns out that the Canada - UK - US three pronged development programs of the 1960s were preceded by a Canada - UK program beginning in the late 1940s. There were a series of small ships, culminating in the R103, being built in the UK. This latter was a 17 ton prototype which was hoisted aboard HMCS Bonaventure and taken to sea trials where Canada was to conduct the sea trials. This ship is currently in a museum in Ottawa.

The UK was interested in developing a 50 tonne patrol boat for use in coastal waters. This lines up well with what you had said about use in the Mediterranean and Baltic.

Canadian research into hydrofoils dates back to the famous Bell/Baldwin experiments on lake Bras D'or in 1919 and continued by various people up into the late 1940s.

RCN involvement started in WWII with trials on using hydrofoils to lay smoke for amphibious landings. In the late 1940s they purchased a hydrofoil being built by someone in Montreal who had plans on setting speed records. This was then used as a test bed for further hydrofoil research in parallel with UK developments.

The Canada/UK R103 proved to be a dead end due to engineering design problems. The foil design was fine in sheltered waters but had inherent stability problems on the open ocean, being prone to porpoising and the like. I think it was after this that the UK lost interest in hydrofoils and focused on hovercraft.

However, Canada's interest in hydrofoils was different from the UK's. Canada wanted to use them for ASW on the open ocean from the North Atlantic to the tropics.

After the UK dropped out Canada went back to their previous lines of research and continued work on different foil designs, with a focus on stability and how to address foil cavitation problems. This led to several new hydrofoil boats with entirely different foil layouts and principles which served as a prototyles of HMCS Bras D'or. These are also now in museums in Canada.

Finally the Bras D'or was built. This was to go through three stages of trials. The first two stages were to address sea going capabilities and were completed.

The final stage was to involve mounting of armament, which included towed sonar and anti-submarine torpedoes. The ship was intended to spend most of its time hull borne using its sonar. It could dash between patrol areas using its foils. When a submarine was detected it could pursue the attack on foils using torpedoes. I don't know if the towed sonar was supposed to be stowed during the attack phase or dropped and recovered later.

Just prior to the weaponry being mounted the hydrofoil program was cancelled and Bras D'or mothballed, later ending up in a museum. A variety of different reasons have been given for the cancellation, but as I said in my previous post I suspect the main one was that developments in helicopter technology over the 1960s rendered the concept obsolete.

The major point to note from the above however is that while Canada was working jointly with the UK in hydrofoils from the late 1940s up to the R103, Canada's interests diverged from the UK's in terms of the ultimate objective. I suspect that this divergence didn't happen all at once, but rather developed over time due to different geographic and strategic situations.

Here's another video on the history of HMCS Brad D'or.


Here's an RCN web site on ships' histories.
HMCS Bras D’Or
In 1919 a hydrofoil craft developed by Alexander Graham Bell and F.W. Baldwin attained the unheard of speed of 60 knots in trials on Cape Breton’s Bras D’Or Lake. It was powered by two aircraft engines and air propellers. The potential of such a craft as an anti-submarine vessel was finally considered in the early 1950s, when a small test vessel was built in Britain to Naval Research Establishment specifications. It arrived at Halifax aboard HMCS Bonaventure in 1957, and its performance led to the awarding of a contract to De Havilland Aircraft of Canada in 1963.


HMCS Bras D’Or, named for the scene of the first tests and designated a fast hydrofoil escort (FHE), was commissioned in 1968. When “hull-borne” at low speeds, the craft is driven by a 2,400-BHP diesel engine, but at about 23 knots the foils lift the hull clear of the water, and propulsion is taken over by a 30,000-SHP gas turbine engine powering twin screws. Trial speeds as great as 63 knots were attained.


Despite the evident success of the prototype FHE, she was laid up in 1971 and, in 1982, presented to a marine museum at L’Islet-sur-Mer, on the St. Lawrence River below Quebec.


Here's an Internet Archive copy of an older Canada Science and Technology Museum web page about it.
Skimming the Waves
The Royal Canadian Navy (RCN) began exploring hydrofoil technology for naval applications in the 1940s. The RCN’s early hydrofoil research was conducted with the British Admiralty, which sponsored tank tests in which the craft was towed through water under controlled conditions. Canada was responsible for carrying out the actual sea trials on these experimental vessels. Canada’s goal was to develop a hydrofoil capable of deep-sea, anti-submarine warfare; British interests were focused on developing a smaller hydrofoil for coastal patrol.

Initial results were discouraging—in part, because the lack of suitable lightweight engines limited the vessels’ size to 50 tonnes. This range was acceptable to the British, and they convinced the Canadian team to undertake sea trials on a 17-tonne prototype of a proposed 50-tonne patrol boat. The prototype, known as the R-103, was built in Britain in 1957, and is now preserved in the Museum’s collection (900323*). Learning from the R-103 sea trials, a new foil configuration (main lift foils aft, steering foil forward) was developed by the Canadian team.

Research after 1960 led to the creation of the 200-tonne FHE-400 “Bras d'Or,” which was 46.5 metres long and had a foil span of 20 metres. Construction of the prototype started in 1964, and sea trails began in 1968. These confirmed the technical design and feasibility of this highly innovative design. It was by far the most advanced and sophisticated hydrofoil of its time. However, cost overruns and new RCN priorities led to the project being shelved and ultimately abandoned. The Museum’s presentation model of the “Bras d'Or” (900032) was given to Richard Becker, of de Havilland Canada, for his contribution to the hydrofoil project.
 
Here's a very good historical video on the development of the helicopter haul down system, often known as "beartrap".

It's of relevance to this thread as it mentions that the development of bear trap and hydrofoils for anti submarine warfare were parallel projects in Canada in response to nuclear submarines. This has been a subject of recent posts above.

To those not familiar with what a haul down system is, it is a means of allowing large helicopters to land and take off from the pitching and rolling deck of a ship such as a frigate or destroyer. It uses a winch to pull the helicopter down into a "trap" which secures it to the deck and moves it into and out of the hanger. It was developed by Canada beginning in the 1950s and similar systems are currently used by most other countries who operate large helicopters from small ships.

The video is very good and uses a lot of historical footage and diagrams. Some of the footage of helicopters operating in heavy seas are quite startling and is very worth watching in order to understand the difficulties that had to be overcome.

 
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For general info, the RN (unusually) does not use a "beartrap" system, instead Fleet Air Arm helicopters have a "harpoon" firing downwards to engage with a grid on the deck. This requires a comparatively heavy landing to ensure the harpoon operates and is why Lynx, Wildcat and Merlin have gigantic oleos and landing gear in general compared to Apache.

I don't know enough to comment on relative merits

Those who've flown FAA will possibly have noticed a tendency to set the aircraft down quite hard: sensibly, it's what they're taught.
 
For general info, the RN (unusually) does not use a "beartrap" system, instead Fleet Air Arm helicopters have a "harpoon" firing downwards to engage with a grid on the deck. This requires a comparatively heavy landing to ensure the harpoon operates and is why Lynx, Wildcat and Merlin have gigantic oleos and landing gear in general compared to Apache.

I don't know enough to comment on relative merits

Those who've flown FAA will possibly have noticed a tendency to set the aircraft down quite hard: sensibly, it's what they're taught.
The "harpoon and grid" system is mentioned and shown in the video, although they don't go into detail about who uses it. According to the video however, the beartrap system (or copies of it) is more widely used.

I think a helicopter using a beartrap system still needs strong landing gear as any landing in heavy seas inherently stands a good chance of being a hard one, as some of the videos clips show.
 
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