Canada's naval strategy?

[Scott Kenny]

However, I don't like the lack of helo capability (both flight deck and hangar), as there's no telling how big future VTUAVs will become and no ability to act as a lilypad for land-based or ship-based helicopters. More generally, Vigilance is a little too barebones and defensive-minded for my liking. With that kind of sensor and weapons suite I would prefer a stealthier, more combat minded hull that could also have a clear forward deployed role (e.g. Red Sea escort, South China sea patrol) and that could also escort slower task force assets in wartime (e.g. amphibs, supply ships etc).

Agreed, I'd want a helo deck on an OPV, at least a place to land and refuel. Hangar strongly preferred but not required.

The entirety of noncombat missions of an OPV are greatly enhanced by having either a VTUAV or a manned helo/tiltrotor available, with the advantage going to the manned VTOL for search-and-rescue and medevac. Plus, fisheries patrol etc is easier with a helo that most fishing boats don't have a way to track!

 

[TomS]

These ships are supposed to be operating in the high Arctic.

Where are the other BMD radars up there?

There are BMD radars facing the Artic in Thule, Greenland and Clear, Alaska. And in a scenario where they were sending BMD armed patrol ships up there, I'd also expect the Sea-Based X-band Radar and maybe a THAAD TPY-2 radar to be oriented that direction.

 

[Rainbow1910]

Vigilance looks interesting... probably 1,500 tons or a little more (see Vard's 85m OPVs for New Zealand, which displace 1,900 tons).

The barebones modular approach is very reminiscent of the RN Black Swan sloop concept of a decade ago:

https://www.secretprojects.co.uk/threads/%E2%80%98black-swan%E2%80%99-class-sloop-of-war.15944/

However, I don't like the lack of helo capability (both flight deck and hangar), as there's no telling how big future VTUAVs will become and no ability to act as a lilypad for land-based or ship-based helicopters. More generally, Vigilance is a little too barebones and defensive-minded for my liking. With that kind of sensor and weapons suite I would prefer a stealthier, more combat minded hull that could also have a clear forward deployed role (e.g. Red Sea escort, South China sea patrol) and that could also escort slower task force assets in wartime (e.g. amphibs, supply ships etc).

Here's an alternative 1,900 ton / 90m patrol corvette concept I drew up by mashing up the 1,500 ton Gowind Adroit OPV design (with an additional 6m midships hull plug) with the new 2,400 ton Italian PPX OPV. The long & thin hull allows for a proper midships mission bay, with a second mission bay at the stern under the flight deck. This would be more capable than Vigilance while still allowing for 16 strike length VLS (located midships, as on Russian missile corvettes), towed sonar, RHIBs etc.

The lack of helicopter capability is an intentional design decision given the issues facing the RCAF fleet and the design constraints required to fit a hanger/flight deck aboard such a small vessel. The only maritime helicopter operated by Canada (CH-148) is quite large (nearly Merlin sized) and is only procured in few numbers (27 aircraft split between two coasts, three squadrons, 12 frigates and land use as well). In order to even land such a helicopter, you would need a substantial flight deck aft and an even more substantial hanger/shipborne infrastructure if you would want to organically carry one. These assets are very valuable and in short supply, they would not be deployed to this sort of vessel.

The RCAF will not be likely procuring another type of helicopter as well considering the logistics and costs required. The inclusion of a small UAV capable hanger and flight deck is a far more realistic option considering that the Navy can procure and operate these systems themselves, and they can provide some capability of a manned helicopter with far, far less of a footprint.

Vigilance is the way it is for a reason, primarily to cut down on costs and manpower requirements as much as humanly possible. Both of these aspects are key for the RCN going forward, who is facing a widespread manpower crisis and potentially a budget crunch in the future. The more that these vessels resemble a proper frigate, the more likely that this program could put the River class destroyer program at risk in the eyes of politicians. I am fairly sure the cost per unit and manpower requirements are fairly minimal for Vigilance, partially due to the use of civilian construction standards where possible and the lack of many of the described "combat focused" elements such as you describe.

The primary selling point of a design like Vigilance is the substantial mission deck on the aft of the vessel to take on modular cargos, a boat launching system within the stern and a modular mission bay amidships does not offer the same amount of flexibility and carrying capacity as Vigilance's system. These vessels will also be taking over mine countermeasures duties from the currently serving Kingston class, alongside drug interdiction, sovereignty patrols, fisheries patrols, humanitarian aid missions, etc. Such a VLS arrangement amidships would fundamentally limit the usefulness of the mission bay while also likely requiring the vessel to keep its VLS aboard at all times, something that isn't especially required for many of the missions Canada is looking for.

There is also a hard tonnage ceiling on this general type of warship for the RCN, as any vessels above 1,000t would require renegotiation of the National Shipbuilding Strategy or some funky bit of rejigging between the shipyards.

 

[Scott Kenny]

The lack of helicopter capability is an intentional design decision given the issues facing the RCAF fleet and the design constraints required to fit a hanger/flight deck aboard such a small vessel. The only maritime helicopter operated by Canada (CH-148) is quite large (nearly Merlin sized) and is only procured in few numbers (27 aircraft split between two coasts, three squadrons, 12 frigates and land use as well). In order to even land such a helicopter, you would need a substantial flight deck aft and an even more substantial hanger/shipborne infrastructure if you would want to organically carry one. These assets are very valuable and in short supply, they would not be deployed to this sort of vessel.

The RCAF will not be likely procuring another type of helicopter as well considering the logistics and costs required. The inclusion of a small UAV capable hanger and flight deck is a far more realistic option considering that the Navy can procure and operate these systems themselves, and they can provide some capability of a manned helicopter with far, far less of a footprint.

Understand reasoning, but it's really bad reasoning to not at least give a helo deck to lily pad those CH-148s from. You realize that they're all of 1m longer than an H60, right? And that's all in the rotors.

Again, probably 90% of the missions a Patrol Vessel do are greatly enhanced by the presence of a helicopter.

TL;DR: RCAF needs to suck it up and buy another ~10 helos to support the RCN missions.

 

[Rainbow1910]

Understand reasoning, but it's really bad reasoning to not at least give a helo deck to lily pad those CH-148s from. You realize that they're all of 1m longer than an H60, right? And that's all in the rotors.

Again, probably 90% of the missions a Patrol Vessel do are greatly enhanced by the presence of a helicopter.

TL;DR: RCAF needs to suck it up and buy another ~10 helos to support the RCN missions.

It makes no sense to lily pad CH-148's off these vessels given what I've explained above, it especially doesn't make sense given the design tradeoffs that having a flight deck and refueling gear to properly do this would require. The RCN is very interested in a variety of drone platforms that can fulfill the missions likely required for aviation on this type of vessels on a drastically lower footprint.

The RCAF won't be buying any more helicopters in all likelihood, so it's best to design and procure vessels that will operate within our reality.

 

[Scott Kenny]

It makes no sense to lily pad CH-148's off these vessels given what I've explained above, it especially doesn't make sense given the design tradeoffs that having a flight deck and refueling gear to properly do this would require. The RCN is very interested in a variety of drone platforms that can fulfill the missions likely required for aviation on this type of vessels on a drastically lower footprint.

The RCAF won't be buying any more helicopters in all likelihood, so it's best to design and procure vessels that will operate within our reality.

Then you are crippling a Patrol Vessel.

The 1100 ton US Coast Guard Reliance-class cutters have a helipad, FFS.

RCN Commodore needs to twist the arm of the RCAF Air Marshall until he supports buying another squadron of helos. It really is that important.

 

[Owens Z]

The Kingstons are being paid off by 2029.
There is a new replacement project for a multi-mission corvette (still early stage) dubbed "CMC", to enter service in the "mid 2030s".
Seems quite ambitious... they're talking SM-3 capability (!).

• "A capable warship, part of the order of battle, which bridges the gap between our constabulary Arctic Offshore Patrol Ships and high-end warfighters like the Halifax and River class"
• "Around 1,000 tonnes, but probably a little heavier"
• "105 meters long or less" (due to berthing constraints at Halifax)
• "Organic sensors : air search radar, sonar (hull mounted or towed array)"
• "Able to detect and defend itself against modern threats"
• "Able to contribute to North American continental defense - that likely means strike length VLS"
• "2 or 3 ships could go out, link with NORAD, provide radar coverage off the coast and also engage threats - ballistic missile threats, potentially hostile satellites"
• 40 sailors

Very comprehensive Canadian naval update here:
View: https://youtu.be/bPen3RhNHFw

Thanks very much for this, H_K; I have watched Captain Graham's recent unclassified PowerPoint presentation that you link to, which is interesting in itself and very relevant to this thread. Captain Graham is Director of the prospective Canadian Multi-Mission Corvette program, which as he says "needs to be much more" than the existing Kingston class. It's not mentioned in his presentation, so I have emailed Captain Graham asking whether the CMCs are planned to have ice-strengthened hulls, specially heated accommodation, and other needed adaptations for Arctic use.

 

[Owens Z]

Understand reasoning, but it's really bad reasoning to not at least give a helo deck to lily pad those CH-148s from. You realize that they're all of 1m longer than an H60, right? And that's all in the rotors.
Again, probably 90% of the missions a Patrol Vessel do are greatly enhanced by the presence of a helicopter.
TL;DR: RCAF needs to suck it up and buy another ~10 helos to support the RCN missions.

Then you are crippling a Patrol Vessel.
The 1100 ton US Coast Guard Reliance-class cutters have a helipad, FFS.
RCN Commodore needs to twist the arm of the RCAF Air Marshall until he supports buying another squadron of helos. It really is that important.

Shipborne helicopters are flown by the Royal Canadian Air Force rather than by Navy personnel (everybody is unified "Canadian Forces"). My prized old Arco/Salamander book An Illustrated Guide to Modern Warships stated that Canada "has always used larger helicopters in relation to ship size than other navies", and that trend continues today with the hefty Sikorsky H-92 (CH-148 Cyclone) and AW101 Merlin (CH-149 Cormorant). The unarmed Canadian Coast Guard deploys two dozen smaller Bell helicopters, with landing platforms on some of its larger ships.

Rainbow1910 and Apophenia said that Canada is no longer capable of designing a large warship like it had done with the St Laurent or Iroquois or Halifax classes, and indeed the planned 8kt River-class destroyers are a variation of the UK's Type 26, although DWG tells us the RCN ships will bear different sensors and weapon fits. But at a bit over 1000 tonnes displacement (not specified whether full load, or normal, or standard, or other) and an overall length between 75 and 100m, it seems the prospective Canadian Multi-Mission Corvette as described by Captain Graham could be an in-house design. A ship of such size with a pad usable by a CH-148 or CH-149, plus vertically-launched 1.5-ton SM-3 missiles, plus sonar and an ASW weapon, plus greater speed than the plodding 15-knot Kingstons, sounds like a design challenge. Even discarding anything above a navigation radar in favor of state-of-the-art lightweight datalinks to larger RCN warships, shore, and satellites, it's tough to get a quart into a pint pot.

 

[Owens Z]

Vigilance looks interesting... probably 1,500 tons or a little more (see Vard's 85m OPVs for New Zealand, which displace 1,900 tons).
The barebones modular approach is very reminiscent of the RN Black Swan sloop concept of a decade ago:

https://www.secretprojects.co.uk/threads/%E2%80%98black-swan%E2%80%99-class-sloop-of-war.15944/

However, I don't like the lack of helo capability (both flight deck and hangar), as there's no telling how big future VTUAVs will become and no ability to act as a lilypad for land-based or ship-based helicopters. More generally, Vigilance is a little too barebones and defensive-minded for my liking. With that kind of sensor and weapons suite I would prefer a stealthier, more combat minded hull that could also have a clear forward deployed role (e.g. Red Sea escort, South China sea patrol) and that could also escort slower task force assets in wartime (e.g. amphibs, supply ships etc).
Here's an alternative 1,900 ton / 90m patrol corvette concept I drew up by mashing up the 1,500 ton Gowind Adroit OPV design (with an additional 6m midships hull plug) with the new 2,400 ton Italian PPX OPV. The long & thin hull allows for a proper midships mission bay, with a second mission bay at the stern under the flight deck. This would be more capable than Vigilance while still allowing for 16 strike length VLS (located midships, as on Russian missile corvettes), towed sonar, RHIBs etc.

The heavier concept you have drawn up looks capable, H_K, with more room to hangar a CH-148 or CH-149 helicopter out of rough weather than the Canadian Multi-Mission Corvette could do, as you and Scott Kenny prefer. But Rainbow1910 points out that there would be political problems inside Canada for such a big jump in displacement. And phew, that is one ugly snout.

 

[H_K]

The heavier concept you have drawn up looks capable, H_K, with more room to hangar a CH-148 or CH-149 helicopter out of rough weather than the Canadian Multi-Mission Corvette could do, as you and Scott Kenny prefer. But Rainbow1910 points out that there would be political problems inside Canada for such a big jump in displacement. And phew, that is one ugly snout

With these requirements, I don’t see any design working under 80 meters length and 1,500 tons (full load), which would be 1,100 - 1,200 tons lightship.

I can already see the arguments that steel is cheap and air is free so why not make CMC a little longer and wider, say 95m / 2,500t. Which would bring a big jump in capability, sea keeping etc. That could well be true and I wouldn’t be surprised if the cost difference from adding 1,000 tons displacement was only 10% or 15%.

The design I picked is somewhere in the middle at 90m / 1,900t. Mainly I kept it fairly small because that made it more of a design challenge and interesting thought exercise. I also wanted something that is directly comparable to other small designs (K130, Sigma 9113, River Batch 2, Otago class OPV etc).

A small CH-149 compatible flight deck won’t necessarily take up much extra space - for example the River Batch 2’s have a 22m long, Merlin capable flight deck. Surprisingly it’s no bigger than standard NATO flight decks for NH90. I wonder if this small size comes with operational restrictions (eg. daytime only, sea state etc), but I definitely wouldn’t exclude the ability to land CH-148/CH-149. The hangar could be smaller though, mainly designed for large UAVs.

 

[Rainbow1910]

Rainbow1910 and Apophenia said that Canada is no longer capable of designing a large warship like it had done with the St Laurent or Iroquois or Halifax classes, and indeed the planned 8kt River-class destroyers are a variation of the UK's Type 26, although DWG tells us the RCN ships will bear different sensors and weapon fits. But at a bit over 1000 tonnes displacement (not specified whether full load, or normal, or standard, or other) and an overall length between 75 and 100m, it seems the prospective Canadian Multi-Mission Corvette as described by Captain Graham could be an in-house design. A ship of such size with a pad usable by a CH-148 or CH-149, plus vertically-launched 1.5-ton SM-3 missiles, plus sonar and an ASW weapon, plus greater speed than the plodding 15-knot Kingstons, sounds like a design challenge. Even discarding anything above a navigation radar in favor of state-of-the-art lightweight datalinks to larger RCN warships, shore, and satellites, it's tough to get a quart into a pint pot.

The CMMC is not an in-house design and there is nothing that points towards this in public media thus far. There is a substantial amount of foreign and domestic designs that could fit these requirements however, there is no way that the RCN is going to design this class in-house for the variety of reasons I touched on previously.

With these requirements, I don’t see any design working under 80 meters length and 1,500 tons (full load), which would be 1,100 - 1,200 tons lightship.

I can already see the arguments that steel is cheap and air is free so why not make CMC a little longer and wider, say 95m / 2,500t. Which would bring a big jump in capability, sea keeping etc. That could well be true and I wouldn’t be surprised if the cost difference from adding 1,000 tons displacement was only 10% or 15%.

The design I picked is somewhere in the middle at 90m / 1,900t. Mainly I kept it fairly small because that made it more of a design challenge and interesting thought exercise. I also wanted something that is directly comparable to other small designs (K130, Sigma 9113, River Batch 2, Otago class OPV etc).

A small CH-149 compatible flight deck won’t necessarily take up much extra space - for example the River Batch 2’s have a 22m long, Merlin capable flight deck. Surprisingly it’s no bigger than standard NATO flight decks for NH90. I wonder if this small size comes with operational restrictions (eg. daytime only, sea state etc), but I definitely wouldn’t exclude the ability to land CH-148/CH-149. The hangar could be smaller though, mainly designed for large UAVs.

As I described previously, there is legal challenges to building anything above 1,000t due to the National Shipbuilding Strategy and its terms. Under said terms, any vessel that is over 1,000t must be allocated to either Davie, Irving or Seaspan for construction. If the vessel is a combatant, it must additionally only be allocated to Irving and nobody else as they are the sole approved combatant constructor. Therefore, CMMC needs to be at most 1,000t or the NSS itself needs to be rewritten. Given the legal and logistical hurdles of the latter, it seems that the Navy is considering something more inline with the former. Cost is important but it ultimately is irrelevant if the program dies before getting off the ground as there is nowhere to physically build the vessels.

With the RCN seemingly very interested in containerized payloads and such small vessels being considered, these larger flight decks/hangers simply do not seem like a worthwhile use of design space to me. If we are following the Vard proposal with a large open mission deck aft to fit a variety of payloads, that is inherently going to be at odds with the inclusion of a flight deck as described. Especially when as I described previously, there is no doctrine for deploying or using rare and valuable Cyclones with these relatively small vessels. If the proposals eventually do get larger, then sure a deck that could potentially land and refuel a Cyclone could be useful if it doesn't come at the cost of more important design elements. There is also a strict 105m length requirement cutoff to fit within domestic Canadian berthing infrastructure.

 

[Owens Z]

The CMMC is not an in-house design and there is nothing that points towards this in public media thus far. There is a substantial amount of foreign and domestic designs that could fit these requirements however, there is no way that the RCN is going to design this class in-house for the variety of reasons I touched on previously.

Just to be clear, by in-house I meant "designed by Canadians" (not "designed by RCN personnel"). So house = Canada. As you told me, it's no longer possible for a larger warship like the River-class destroyers to be designed by Canadians, and indeed when I subsequently looked up details of the forthcoming class, I saw the choices had been a British design, a Dutch design, and a Spanish design. But you and Apophenia said that the design of a smaller corvette-sized warship by Canadians might still be practical.

As I described previously, there is legal challenges to building anything above 1,000t due to the National Shipbuilding Strategy and its terms. Under said terms, any vessel that is over 1,000t must be allocated to either Davie, Irving or Seaspan for construction. If the vessel is a combatant, it must additionally only be allocated to Irving and nobody else as they are the sole approved combatant constructor. Therefore, CMMC needs to be at most 1,000t or the NSS itself needs to be rewritten.

Yes, I mentioned your concern in post #49, Rainbow1910. If you know, please clarify for us what exactly Ottawa means by 1000 tons (Captain Graham mentions in his video presentation that the eventual Canadian Multi-Mission Corvette would probably be a bit heavier, which I took to be 1.1kt, but again, the measure used isn't specified). Is 1000 tons meant to be the ships' full load displacement? Or light displacement? Or standard displacement? Or other?

 

[H_K]

Is 1000 tons meant to be the ships' full load displacement? Or light displacement? Or standard displacement?

The cutoff is 1,000 tonnes lightship displacement.

This according to this official source which discusses the Coast Guard’s Mid-Shore Multi-Mission (MSMM) program which faces the same constraint:

Appearance before the standing Committee on Public Accounts by Simon Kennedy, Deputy Minister at Innovation, Science and Economic Development Canada – May 25, 2020 - Transparency

Appearance before the standing Committee on Public Accounts by Simon Kennedy, Deputy Minister at Innovation, Science and Economic Development Canada.

ised-isde.canada.ca

They acknowledge that this arbitrary displacement limit will require extra design work to optimize weight, not to mention force capability trade offs, which IMHO shows just how stupid this policy is.

 

[H_K]

To give an idea what 1,000 tonnes lightship displacement looks like (approx. 1,300 tonnes full load), here is the 85m long Gowind Control OPV.

This is about as long & thin as one could make it... more likely length will be constrained to 75m in order to provide more stability / beam / freeboard etc. Very unlikely that ice strengthening would be feasible within such a tight weight limit.

See more details here: https://www.secretprojects.co.uk/threads/dcns-gowind.10991/post-628197

 

[Scott Kenny]

As I described previously, there is legal challenges to building anything above 1,000t due to the National Shipbuilding Strategy and its terms.

When was this plan created, 1950? That's the size of the USCG's Reliance class! 1960s design, 1125 tonnes full displacement. Which, BTW, have a helipad for a Jayhawk or Dolphin.

Nevermind the Legend class that is replacing them, which is 4600 tonnes.

[2.3TB rant about stupid politicians deleted]

 

[H_K]

That's the size of the USCG's Reliance class! 1960s design, 1125 tonnes full displacement.

Yes I was thinking of the Reliance class (210ft WMECs) too. Turns out they have a lightship displacement of ~780 tonnes so you could extend the hull a little, by about ~10m, and stay under the 1,000 tonne limit. That would make a 74m hull with a full load displacement of ~1,400 tons.

 

[Rainbow1910]

The cutoff is 1,000 tonnes lightship displacement.

This according to this official source which discusses the Coast Guard’s Mid-Shore Multi-Mission (MSMM) program which faces the same constraint:

Appearance before the standing Committee on Public Accounts by Simon Kennedy, Deputy Minister at Innovation, Science and Economic Development Canada – May 25, 2020 - Transparency

Appearance before the standing Committee on Public Accounts by Simon Kennedy, Deputy Minister at Innovation, Science and Economic Development Canada.

ised-isde.canada.ca

They acknowledge that this arbitrary displacement limit will require extra design work to optimize weight, not to mention force capability trade offs, which IMHO shows just how stupid this policy is.

When was this plan created, 1950? That's the size of the USCG's Reliance class! 1960s design, 1125 tonnes full displacement. Which, BTW, have a helipad for a Jayhawk or Dolphin.

Nevermind the Legend class that is replacing them, which is 4600 tonnes.

[2.3TB rant about stupid politicians deleted]

This displacement cutoff had and still has a legitimate purpose, to concentrate the work available to Canadian shipyards into as few yards as possible so that investments show results and these shipyards remain viable. The National Shipbuilding Strategy was built to counter the typical "boom and bust" cycle found throughout Canadian shipbuilding history in recent years, given how it was specifically the splitting up of the Halifax class production between two separate shipyards that ultimately resulted in the loss of Saint John Shipbuilding in 2003, one of Canada's largest and most important yards due to a total lack of work. The NSS designated each yard as a "type" of builder, Irving is the combatant constructor while Seaspan is the non-combatant constructor. This allows both yards to have decade long order books to retain their staff, build expertise and utilize their investments without the fear of everything being wasted by doing all of your contracts too fast and being left with nothing.

The NSS was founded in 2010 and since then, Davie is being set up as an icebreaker constructor. This was largely done to take some of the burden off Seaspan when their order book proved to be behind schedule and overloaded, while also catering to the politics of Quebec. The idea of a displacement cutoff makes sense, given the fact that smaller Canadian shipyards previously didn't have the ability to build vessels above that set 1,000t figure and if they did, this would stop them from competing with the specialists in their respective field. It would allow them to spread out contracts for smaller vessels throughout the country to these smaller yards though. It shows how something like the CMMC was never actually planned for the RCN and how this is very much an adhoc decision later down the line.

 

[Owens Z]

The cutoff is 1,000 tonnes lightship displacement.
This according to this official source which discusses the Coast Guard’s Mid-Shore Multi-Mission (MSMM) program which faces the same constraint:
They acknowledge that this arbitrary displacement limit will require extra design work to optimize weight, not to mention force capability trade offs, which IMHO shows just how stupid this policy is.

Thanks H_K; this is helpfully clarifying. Your recent ugly-snout ship is more of a constabulary OPV-type design. Vessels more like fighting warships within Captain Graham's desired 75-100m length, like a Soviet Riga or Koni frigate, a Royal Navy Type 14, a Dealey-class destroyer escort, or a Descubierta-class corvette would still be too heavy. One would have to get down to something like, say, a D'Estienne d'Orves to not exceed Ottawa's 1000-tonne light displacement restriction. I agree with you and Scott Kenny about the value of an integral helicopter for a real warship (or even for constabulary patrol), and as mentioned earlier, Canada's current models of shipborne helicopter, as is traditional, are hefty. How a Canadian Multi-Mission Corvette could lily-pad (much less hangar) a CH-148/CH-149 is not obvious to my amateur eye, even given the RCN's longtime expertise in Beartrap-style hauldown gear, unless like retired IX-514 that hangs around New York Harbor (see attached photo), the ship is designed for nothing else. As you said, a heavier, more spacious vessel, like your snouter, or a MEKO A-100, or etc., would seem more appropriate for the blue-water multi-mission capability that the RCN wants for its new corvette.

"Requires extra design work and capability trade-offs": you don't say, Ottawa. Assuming 1000t light continues to be a hard limit into the 2030s, maybe Captain Graham and his colleagues will have to make do with a mini-hangar for a maritime VTOL UAV aboard, try to build on the great strides that armed drones have made in recent years, and hope for the best.

 

[Owens Z]

To give an idea what 1,000 tonnes lightship displacement looks like (approx. 1,300 tonnes full load), here is the 85m long Gowind Control OPV.
This is about as long & thin as one could make it... more likely length will be constrained to 75m in order to provide more stability / beam / freeboard etc. Very unlikely that ice strengthening would be feasible within such a tight weight limit.

Still looks tight, and (like you point out) rather slender for North Atlantic conditions. As Captain Graham said, maybe there's some give in the limit, to 1.1kt or so. Happily, this Gowind 1000 is much faster than the 15-knot Kingstons. I would delete the Gowind's stern launch hatches and boat garage, move the helicopter platform aft, and put the (presumably few) 1.5-ton SM-3 Standard missiles amidships. For weight reasons, this ship might have to forgo anything above civilian-level sensors in favor of state-of-the-art datalinks to larger warships, shore, aircraft, and satellites, for situational awareness and fire control. The forward four missile tubes (Exocets here) could instead carry the Naval Strike Missile. As per Captain Graham's presentation, weight and space would have to be found somehow for a capable sonar and its operators, but the ASW weapon could be put on the helicopter or UAV. The 76mm gun caliber shown here has not been in service with Canadian Forces since the Annapolis class was retired in the 1990s, and a jump to 127mm like the Iroquois class had, and the River class will have, looks impractical. Maybe a CIWS at that position instead?

 

[H_K]

Still looks tight, and (like you point out) rather slender for North Atlantic conditions. As Captain Graham said, maybe there's some give in the limit, to 1.1kt or so. Happily, this Gowind 1000 is much faster than the 15-knot Kingstons. I would delete the Gowind's stern launch hatches and boat garage, move the helicopter platform aft, and put the (presumably few) 1.5-ton SM-3 Standard missiles amidships. For weight reasons, this ship might have to forgo anything above civilian-level sensors in favor of state-of-the-art datalinks to larger warships, shore, aircraft, and satellites, for situational awareness and fire control. The forward four missile tubes (Exocets here) could instead carry the Naval Strike Missile. As per Captain Graham's presentation, weight and space would have to be found somehow for a capable sonar and its operators, but the ASW weapon could be put on the helicopter or UAV. The 76mm gun caliber shown here has not been in service with Canadian Forces since the Annapolis class was retired in the 1990s, and a jump to 127mm like the Iroquois class had, and the River class will have, looks impractical. Maybe a CIWS at that position instead?

FYI another example with a slightly shorter/fatter hull might be Fassmer's OPV 70 design. At 70x11m and 1,200 tons (full load?) it still has a little room to grow to around 75m / 1,300-1,400 tons full load while still staying under the 1,000t lightship limit.

https://www.fassmer.de/fileadmin/user_upload/6_Fassmer_Defence/21_06_FD_Sb_OPV_70_web.pdf

Here is my take on Fassmer's OPV 70 with a few small mods to bring it to 75m (added sensor mast from larger OPV 80L and lengthened bow by ~5m to improve sea keeping and reduce wetness forward):

There would be space for:

• 2x 40ft Mk 70 launchers amidships between the funnels (where the SSMs go in this drawing)
  • Or alternatively 4x 20ft containers to operate small UAVs.
  • Or alternatively 2x 20ft containers + Stanflex style missile modules for 8x NSM and 8-16x ESSM
• A 21.6m long flight deck (NATO standard) for NH90/Seahawk, or with some limitations CH-148/149 (this is the same length as the RN River Batch 2 flight deck)
• 2x stern ramps for RHIBs that could also be used for a containerized towed sonar array
• 3x 20ft containers under the flight deck, forward of the stern ramps
• I would eliminate the RHIB side bays due to low freeboard

Finally if they really want to to squeeze in an extra 20-30% displacement, there's always the option to build an aluminum hulled vessel. OCEA has a pretty large 85m long platform that shows what can be done with aluminum these days.

Philippine Coast Guard takes delivery of 84-m OPV built by Ocea | Mer et Marine

The Philippine Coast Guard formally took delivery of offshore patrol vessel BRP Gabriela Silang on 18 December 2019. The ship was built by French company Oc...

www.meretmarine.com

 

[H_K]

And here's the Fassmer OPV 70 (lengthened to 75m forward) with an AW101 / CH-149 on the flight deck.

Although it looks massive, the AW101 actually takes up about ~40cm less flight deck length than a US Navy Seahawk, as the Seahawk's tailwheel requires more clear deck space.

Flight deck length required (from rear landing gear to rotor tip):
9.6m NH90
11.0m S92 / CH-148
11.4m AW101 / CH-149
11.8m S-70 Seahawk

 

[Rainbow1910]

Still looks tight, and (like you point out) rather slender for North Atlantic conditions. As Captain Graham said, maybe there's some give in the limit, to 1.1kt or so. Happily, this Gowind 1000 is much faster than the 15-knot Kingstons. I would delete the Gowind's stern launch hatches and boat garage, move the helicopter platform aft, and put the (presumably few) 1.5-ton SM-3 Standard missiles amidships. For weight reasons, this ship might have to forgo anything above civilian-level sensors in favor of state-of-the-art datalinks to larger warships, shore, aircraft, and satellites, for situational awareness and fire control. The forward four missile tubes (Exocets here) could instead carry the Naval Strike Missile. As per Captain Graham's presentation, weight and space would have to be found somehow for a capable sonar and its operators, but the ASW weapon could be put on the helicopter or UAV. The 76mm gun caliber shown here has not been in service with Canadian Forces since the Annapolis class was retired in the 1990s, and a jump to 127mm like the Iroquois class had, and the River class will have, looks impractical. Maybe a CIWS at that position instead?

From what I gather, there is a lot of interest in containerized capabilities as far as the RCN goes with CMMC. Instead of requiring permanent fixings for VLS integration which take up weight and space at all times, you offload this into the containerized Mark 70 launchers and only fit them when required. Vard's Vigilance concept has shown off 3-4 of these launchers aft for a total of 12-16 strike length VLS cells. A sizable mission deck is going to be crucial as these vessels are going to have to take over the mine warfare, drug interdiction and sovereignty patrol work of the currently serving Kingston class. At the end of the day, being able to have a sufficient amount of space to take on these missions is more relevant than a helicopter pad to land a Cyclone.

Modern ship design can definitely let you fit a lot into a relatively small package, but there will be consequences obviously. Vigilance claims to be able to fit enough of a sensor suite to be able to conduct reasonable self defence actions, although the use of Mark 41 cells would largely be something off platformed through datalink. Cost is ultimately very important for the RCN as well and I would not be surprised if a partial civilian build standard is utilized where required to reflect that.

The best case scenario would be to amend the NSS to allow for larger ships as the CMMC is entirely unplanned however, CMMC itself is not funded nor within the actual defence policy right now. Makes little sense to move heaven and earth for a project that isn't even on its feet yet.

 

[Owens Z]

This displacement cutoff had and still has a legitimate purpose, to concentrate the work available to Canadian shipyards into as few yards as possible so that investments show results and these shipyards remain viable. The National Shipbuilding Strategy was built to counter the typical "boom and bust" cycle found throughout Canadian shipbuilding history in recent years...

I learned of Canada's sad loss of ability to design its own destroyers only on this thread. If the government policy you describe is the sole way to retain Canadian expertise in designing smaller corvettes, then I suppose this is indeed best. Until the whole world is at peace, Canada, with the world's longest coastline, needs that remaining design capability.

From what I gather, there is a lot of interest in containerized capabilities as far as the RCN goes with CMMC. Instead of requiring permanent fixings for VLS integration which take up weight and space at all times, you offload this into the containerized Mark 70 launchers and only fit them when required... A sizable mission deck is going to be crucial as these vessels are going to have to take over the mine warfare, drug interdiction and sovereignty patrol work of the currently serving Kingston class...

You mentioned this earlier, Rainbow1910, and it worried me because it made me think of the US Navy's littoral combat ships. An LCS has a clear aft deck meant sometimes for a helo and sometimes for containerized modules for different missions. As you've probably heard, these ships, despite being much larger than what is planned for the Canadian Multi-Mission Corvette, have been disappointing in practice. Their budget overrun and continued structural failures and propulsion breakdowns would not carry over to the CMC, but the US Navy is also unhappy with their overall concept and theme, which (you seem to be saying) the CMC plans to copy.

At the end of the day, being able to have a sufficient amount of space to take on these missions is more relevant than a helicopter pad to land a Cyclone.

I still second Scott Kenny's recommendation for the RCAF to acquire another squadron or two of useful CH-148s or CH-149 helicopters, but unfortunately Ottawa's halting and piecemeal procurement since 1987 has not allowed a rational bigger-order discount.

Modern ship design can definitely let you fit a lot into a relatively small package, but there will be consequences obviously. Vigilance claims to be able to fit enough of a sensor suite to be able to conduct reasonable self defence actions, although the use of Mark 41 cells would largely be something off platformed through datalink. Cost is ultimately very important for the RCN as well and I would not be surprised if a partial civilian build standard is utilized where required to reflect that.

I am skeptical about trying to fit too much into too small a displacement, which has a long and discouraging history worldwide (e.g. Tomozuru Incident). But we'll see what Captain Graham and his team come up with for the Canadian Multi-Mission Corvette program.

The best case scenario would be to amend the NSS to allow for larger ships as the CMMC is entirely unplanned however, CMMC itself is not funded nor within the actual defence policy right now. Makes little sense to move heaven and earth for a project that isn't even on its feet yet.

I think H_K and others would agree with you, Rainbow1910. But yes, let's see what the coming years bring for the program.

 

[H_K]

Here is my take on Fassmer's OPV 70 with a few small mods to bring it to 75m (added sensor mast from larger OPV 80L and lengthened bow by ~5m to improve sea keeping and reduce wetness forward):

There would be space for:

• 2x 40ft Mk 70 launchers amidships between the funnels (where the SSMs go in this drawing)
  • Or alternatively 4x 20ft containers to operate small UAVs.
  • Or alternatively 2x 20ft containers + Stanflex style missile modules for 8x NSM and 8-16x ESSM
• A 21.6m long flight deck (NATO standard) for NH90/Seahawk, or with some limitations CH-148/149 (this is the same length as the RN River Batch 2 flight deck)
• 2x stern ramps for RHIBs that could also be used for a containerized towed sonar array
• 3x 20ft containers under the flight deck, forward of the stern ramps
• I would eliminate the RHIB side bays due to low freeboard

Here's a top view to show the Fassmer OPV 70's modular capabilities and where containers can be carried.
As my own personal preference, I've added the reverse angle bow from their larger OPV 80S design, as I like the longer waterline which improves powering and reduces pitching. The long, raised foredeck also probably reduces deck wetness.

I have to admit I kind of like it and it makes me think that maybe a ~75m / 1,000 tonnes light / ~1,400 tonnes full load patrol corvette could work!

 

[siegecrossbow]

Minelayers along the northern shores of the Great Lakes might be a good start depending on how dumbass things get in the next couple of years.

 

[Scott Kenny]

Minelayers along the northern shores of the Great Lakes might be a good start depending on how dumbass things get in the next couple of years.

You do know that the proposed tariffs and sanctions have already been dropped, right?

 

[Scott Kenny]

This displacement cutoff had and still has a legitimate purpose, to concentrate the work available to Canadian shipyards into as few yards as possible so that investments show results and these shipyards remain viable. The National Shipbuilding Strategy was built to counter the typical "boom and bust" cycle found throughout Canadian shipbuilding history in recent years, given how it was specifically the splitting up of the Halifax class production between two separate shipyards that ultimately resulted in the loss of Saint John Shipbuilding in 2003, one of Canada's largest and most important yards due to a total lack of work. The NSS designated each yard as a "type" of builder, Irving is the combatant constructor while Seaspan is the non-combatant constructor. This allows both yards to have decade long order books to retain their staff, build expertise and utilize their investments without the fear of everything being wasted by doing all of your contracts too fast and being left with nothing.

The NSS was founded in 2010 and since then, Davie is being set up as an icebreaker constructor. This was largely done to take some of the burden off Seaspan when their order book proved to be behind schedule and overloaded, while also catering to the politics of Quebec. The idea of a displacement cutoff makes sense, given the fact that smaller Canadian shipyards previously didn't have the ability to build vessels above that set 1,000t figure and if they did, this would stop them from competing with the specialists in their respective field. It would allow them to spread out contracts for smaller vessels throughout the country to these smaller yards though. It shows how something like the CMMC was never actually planned for the RCN and how this is very much an adhoc decision later down the line.

The better answer is to have worked to enlarge the shipyards, so they could actually build a competent/capable ship...

 

[ArtosStark]

You do know that the proposed tariffs and sanctions have already been dropped, right?

No, they were paused for a month. Set to start beginning of March. Then 25% tariffs on aluminum and steel were announced (80% of US aluminum consumption is imported and 65% of that comes from Canada, and a large part of the steel imports that make up a quarter of US consumption). Those are slated to go into effect 12 March, and apparently will stack on top of the flat 25% tariff. Then there is the threat to put “50 or 100%” tariffs on autos made in Canada on top of that.

I’m afraid tariffs threats are still very much a thing.

 

[Rainbow1910]

The better answer is to have worked to enlarge the shipyards, so they could actually build a competent/capable ship...

There is only so much that the three major shipyards can enlarge themselves physically, given the era of environmental and zoning restrictions that we live in. Irving Shipyard is smack dab in downtown Halifax, Seaspan is in the Vancouver area and Davie is in Levis Quebec. Irving is being forced to actively infill the Halifax harbour to get the additional yard space required to adequately take on the River class construction, there realistically isn't much more that many of these yards can enlarge themselves. There is also the incentive to remain at a reasonable size as the larger the yard, the more difficult it is to keep work active there in the long term. The National Shipbuilding Strategy was specifically designed to keep each of the yards actively working away for over a decade, too much investment and that order book ends up being blown through and the yard goes back to closing.

 

[Owens Z]

Albertan Pierre Poilievre is in the running to replace Justin Trudeau as Canada's Prime Minister later this year. It's of course not my business to advise Canadians on whom they choose to govern them, but I notice that Poilievre's recent video "Take back control of our True North" on YouTube, politics aside, covers matters relevant to this thread about Canada's naval strategy, especially the defense of Arctic Canada that is of special interest to me. The new ships mentioned therein are two heavy icebreakers for the RCN (presumably armed, as the Canadian Coast Guard's icebreakers are not), and an unspecified replacement for the Victoria-class submarines. You might also find the video's comments (by Canadians and interested outsiders) to be stimulating.

See:

View: https://www.youtube.com/watch?v=vPoCjTUiGB8

 

[Apophenia]

... it makes me think that maybe a ~75m / 1,000 tonnes light / ~1,400 tonnes full load patrol corvette could work!

If this CMC is to operate on both East and West coasts, you also need to account for the North Pacific's longer swell lengths. Conventional wisdom suggests 100 metres loa as ideal rather than 75 m.

 

[Jemiba]

Just a clue to the participants in this thread:
This theme of course is prone to political comments, that are NOT part of an article/link/source, whatever, but just the posters opinion.

So, please think twice before posting !

 

[H_K]

Just a clue to the participants in this thread:
This theme of course is prone to political comments, that are NOT part of an article/link/source, whatever, but just the posters opinion.

I didn’t think that my comment about an SSBN nuclear deterrent was political. It clearly is relevant in a thread about “naval strategy”, even if far out there.

And because I am aware that SSBNs are extremely expensive, sensitive, and raise a ton of non-proliferation issues, for any chance of success such an option would require allies and joining an existing nuclear power’s protective umbrella, the only 2 options being the UK and France.

France has offered its SSBN deterrant to its EU partners in the past, so why not Canada?

 

[riggerrob]

Still looks tight, and (like you point out) rather slender for North Atlantic conditions. As Captain Graham said, maybe there's some give in the limit, to 1.1kt or so. Happily, this Gowind 1000 is much faster than the 15-knot Kingstons. I would delete the Gowind's stern launch hatches and boat garage, move the helicopter platform aft, and put the (presumably few) 1.5-ton SM-3 Standard missiles amidships. For weight reasons, this ship might have to forgo anything above civilian-level sensors in favor of state-of-the-art datalinks to larger warships, shore, aircraft, and satellites, for situational awareness and fire control. The forward four missile tubes (Exocets here) could instead carry the Naval Strike Missile. As per Captain Graham's presentation, weight and space would have to be found somehow for a capable sonar and its operators, but the ASW weapon could be put on the helicopter or UAV. The 76mm gun caliber shown here has not been in service with Canadian Forces since the Annapolis class was retired in the 1990s, and a jump to 127mm like the Iroquois class had, and the River class will have, looks impractical. Maybe a CIWS at that position instead?

You really need two or three sonar systems.
Even helicopter-mounted sonar comes in two or three different varieties. Onboard HMCS Athabaskan and HMCS Iroquois our Sea King helicopters carried both disposable sonabuoys and dipping sonar. The used to drop a grid of sonabouys - over a large area - then later dip the large sonar to narrow down the search. While helicopters can "dash" far faster than a submarine, they also have short endurance ... at best 4 hours.
That is when the ship's hull-mounted or towed sonar array comes in handy for keeping a watch all day and all night. The ship's sonar can only tell azimuth and a rough depth. Then you launch the helo to narrow the search.
Perhaps the sonabouy launching mission could be done by rockets or an un-manned drone. Even getting a torpedo within range of a submarine can be done by a simple 2 ton drone. The US Navy tried anti-submarine drones back during the 1960s but the Gyrodyne QH-50 lacked the data-link to use them to hunt submarines.
Linking a drone helicopter into the search phase is probably practical with modern data links. Mind you, data-links are vulnerable because next week the "Phantasians" will develop a nasty new weapon to kill data links.

Note: back during the Cold War, NATO army exercises often included a fictious enemy referred to as "Phantasians." Political-correctness prevented us from using a real name for a potential enemy because after "1984" who knew who we would be fighting.

 

[riggerrob]

From what I gather, there is a lot of interest in containerized capabilities as far as the RCN goes with CMMC. Instead of requiring permanent fixings for VLS integration which take up weight and space at all times, you offload this into the containerized Mark 70 launchers and only fit them when required. Vard's Vigilance concept has shown off 3-4 of these launchers aft for a total of 12-16 strike length VLS cells. A sizable mission deck is going to be crucial as these vessels are going to have to take over the mine warfare, drug interdiction and sovereignty patrol work of the currently serving Kingston class. At the end of the day, being able to have a sufficient amount of space to take on these missions is more relevant than a helicopter pad to land a Cyclone.

Modern ship design can definitely let you fit a lot into a relatively small package, but there will be consequences obviously. Vigilance claims to be able to fit enough of a sensor suite to be able to conduct reasonable self defence actions, although the use of Mark 41 cells would largely be something off platformed through datalink. Cost is ultimately very important for the RCN as well and I would not be surprised if a partial civilian build standard is utilized where required to reflect that.

The best case scenario would be to amend the NSS to allow for larger ships as the CMMC is entirely unplanned however, CMMC itself is not funded nor within the actual defence policy right now. Makes little sense to move heaven and earth for a project that isn't even on its feet yet.

Perhaps stow some of those containers under the flight deck. If they contain weapons (e.g. torpedoes), then make them side-firing.

Even if a ship does not have a dedicated helicopter, it still needs a flight deck for cross-decking the padre Sunday mornings, admiral's barge, .... er ... cough ... cough ... mid-ocean search and rescue, etc. missions. Back when HMCS Iroquois was attached to the Standing NATO Force Atlantic, we had a pair of dedicated Sea Kings and our flight deck often hosted Lynxes, etc. from other NATO navies when admirals wanted to visit, etc. Yes, it is possible to use winches to lower passengers onto the deck, but is an order-of-magnitude safer to land on the deck and let them walk onboard.

Perhaps this proposed RCN ship needs a flight deck similar to the Canadian Coast Guard with a dedicated flight deck and a telescoping hangar to protect the helo from rain and spray.

Master Corporal (reti'd) Rob Warner airframe technician - Grumpy, old, grey-bearded former flight deck crew onboard HMCS Athabaskan and HMCS Iroquois.

 

[Rainbow1910]

Albertan Pierre Poilievre is in the running to replace Justin Trudeau as Canada's Prime Minister later this year. It's of course not my business to advise Canadians on whom they choose to govern them, but I notice that Poilievre's recent video "Take back control of our True North" on YouTube, politics aside, covers matters relevant to this thread about Canada's naval strategy, especially the defense of Arctic Canada that is of special interest to me. The new ships mentioned therein are two heavy icebreakers for the RCN (presumably armed, as the Canadian Coast Guard's icebreakers are not), and an unspecified replacement for the Victoria-class submarines. You might also find the video's comments (by Canadians and interested outsiders) to be stimulating.

The most important proposal is the transformation of Forward Operating Location Iqaluit into a full, permanent Canadian Forces Base. The proposal includes the infrastructure to base and operate F-35A's, P-8 MPA and presumably Sky Guardian drones while the port itself will serve as a point of resupply for RCN and CCG vessels. While such a base will dramatically increase our presence throughout the Arctic, the construction of such a facility will be excessively difficult and expensive due to the remote location and regulations required due to the sensitive environment of the Arctic. Deployments to such a base also will face an uphill battle to attract personnel, as many people do not want to move alongside their families to a frozen, sub-zero hellscape which is perpetually light or dark depending on the time of year. There was also the announcement of an additional 2,000 Canadian Rangers being hired, which is very valuable.

Heavy armed icebreakers for the RCN is an excessively poor use of effort, personnel and funds for a force that lacks all three. This type of vessel is very specialized, cannot be utilized effectively elsewhere and is eye wateringly expensive. Canada's pair of Polar Icebreakers for the CCG are coming at a ridiculous $8.5 billion CAD, anything approaching that for two additional vessels for the RCN is not fiscally responsible. These ships would also require either a new design or be a modified Polar class for the CCG, both of those options are very poor. Davie and Seaspan are entirely unable to accept another pair of these vessels to their busy order books. The AOPS project originally was a very large, Polar Class 3 vessel with a 57mm gun that could operate in second year ice throughout the entire Canadian Arctic, year round. This was dropped due to the significant cost and general lack of purpose, only other very heavy icebreakers can operate in the Arctic throughout these thick ice periods, so there is little need to patrolling. Planned 6 month patrols for these vessels was quickly found to likely descend into doing literally nothing as there was nothing to physically do. AOPS was pared down to more numerous, cheaper and useful vessels that could also function outside the Arctic during the seasons where nothing occurs there. This concept was abandoned for good reason, I have little clue why it is being brought up again.

 

[Rainbow1910]

Perhaps stow some of those containers under the flight deck. If they contain weapons, then make them side-firing.
Even if a ship does not have a dedicated helicopter, it still needs a flight deck for cross-decking the padre Sunday mornings, admiral's barge, .... er ... cough ... cough ... mid-ocean search and rescue, etc. missions. Back when HMCS Iroquois was attached to the Standing NATO Force Atlantic, we had a pair of dedicated Sea Kings and our flight deck often hosted Lynxes, etc. from other NATO navies when admirals wanted to visit, etc. Yes, it is possible to use winches to lower passengers onto the deck, but is an order-of-magnitude safer to land on the deck and let them walk onboard.

Perhaps this proposed RCN ship needs a flight deck similar to the Canadian Coast Guard with a dedicated flight deck and a telescoping hangar to protect the helo from rain and spray.

Master Corporal (reti'd) Rob Warner airframe technician - Grumpy, old, grey-bearded former flight deck crew onboard HMCS Athabaskan and HMCS Iroquois.

Thank you for the comments, it's great to hear from somebody with legitimate real world experience on this topic.

Containers under the flight deck could contain deployable towed array sonars, torpedo launchers, medical/accommodation facilities and general supplies, but certain items cannot effectively be deployed from that location. Larger drones which are becoming commonplace require large launching and recovery cranes, I am unsure of the logistics required to do this from the enclosed space below the flight deck. As far as vertical launch weapons, they obviously cannot be utilized from under the flight deck as they cannot be side launched.

Helicopters certainly are important parts of all ships toolbox however, the restrictions placed upon this proposed corvette design are not conducive to helicopter operations. You have the clashing requirements to keep tonnage/length down but they also would like seemingly serious combat capability. In order to fit all of this into the design and taking into consideration the current issues with the RCAF maritime helicopter fleet, it seems unlikely that any serious flight deck will be included. You would need a substantial telescoping hanger to sufficiently cover a Cyclone, and I have heard many of those telescoping systems are rather troublesome in actual service conditions.

 

[Scott Kenny]

If this CMC is to operate on both East and West coasts, you also need to account for the North Pacific's longer swell lengths. Conventional wisdom suggests 100 metres loa as ideal rather than 75 m.

Gotta agree with this.

I learned how to drive subs in the Pacific.

Got transferred to a sub that had come over from the East Coast.

They didn't understand how big the swells could get.

Watched me slam full dive on the planes (edit) and hold it once, "helm, WTF?!?"
We didn't lose any depth.
"BIG swell, Dive."

 

[H_K]

If this CMC is to operate on both East and West coasts, you also need to account for the North Pacific's longer swell lengths. Conventional wisdom suggests 100 metres loa as ideal rather than 75 m.

You may well be right but then something's got to give... otherwise the 1,000 tonne (lightship) displacement limit will drive towards a 75-85m long hull.

For what it's worth, I took an existing design, the 87m Gowind OPV ("L'Adroit", now ARA Piedrabuena) below and tried to sketch out what it would take to squeeze under the 1,000 tonne limit. This design is a good starting point because it's only barely over the limit at ~1,100t light / 1,500t full load (though more like 1,800t with optional ice strengthening), and also fairly long and lightweight for its size compared to other OPVs. We also know it can be militarized into a corvette variant with added weapons, towed sonar etc.

With this parent hull, weight savings of ~100t would be needed, which could be achieved by cutting down the superstructure (eliminating the helicopter hangar), building the superstructure in aluminium (instead of steel), installing compact high speed diesels (instead of heavier medium speed diesels), and shortening the mid-section / engine room accordingly. Even with the benefit of an Axe style bow, waterline length would "only" be ~85m... which is actually unusually long for this tonnage.

85m / 1,000t lightship corvette (top) vs. 87m Gowind OPV parent design (bottom):



The main mission payload would be containers (in red) - 2x 40ft between the funnels and 5x 20ft under the flight deck. This corvette would also be able to deploy overseas to perform VBSS, escort merchant shipping etc, and could perform ASW patrols. There would be a 57mm gun forward and optionally 4x NSM could be added behind the gun (if ever needed), with also Stanflex style modules for VL ESSM being an option. Top speed would be 21-23 knots depending on propulsion (2x 2.7MW or 2x 4MW), range 8,000nm @ 12kts / 6,000nm @ 15kts, endurance 21 days with 45-60 crew.

 

[Apophenia]

You may well be right but then something's got to give...

Too true. And the RCN (Maritime Command, as once was) have/will always make Halifax the priority ...