Royal Canadian Navy Discussions and updates

[Novascotiaboy]

With todays technology would a fleet of remotely operated MCM vessels be a better choice? Control stations could be agnostic to platform to allow AOPS, or your suggested higher speed OPV to be the control point. This should be a simple process with a VARD design supporting a recycled BAE 57 mm cannon and facilities to support Skeldar but equipped with a helipad to land upwards of a Cyclone if needed. Something along the lines of the UK River as to capability. IMHO these would be excellent vessels for the constabulary tasks of fisheries protection, SAR, border protection more in line with RCMP, CBSA, Fisheries and other government departments. Instead of Coast Guard red and white these vessels would be grey hulled for use in the Carribean and off Africa but would be used in home waters as noted above.

 

[shadow99]

I can find photos of models and other images showing four, five and six bladed props. I can think of a number of possibilities but having been involved in developing models of as yet unbuilt ship classes, I would think the most likely one is that it wasn’t specified to the model maker who had to use his or her best judgement. The models tend to get modified as we go along and the design evolves and becomes more definite.

Hi spoz. Thats awesome I havn't seen any type 26 models with 6 bladed props, do you have a link per chance?

The type 26 design certainly has grown and evolved, especially from the early concept studies and I have to say she's evolved into a beautiful and impressive looking ship.

 

[Calculus]

Maybe my old eyes are deceiving me, but has the prop on the model changed from 5 blades to 6 from the latest image that Calculus posted?
And if so is that a deviation from the UK and Australian versions and what implications would this mean?

Not sure if ships are the same, but on my fresh-water boat switching to a four-bladed prop from the three-blade that came with my Honda outboard got me on plane noticeably faster, and also ran more smoothly (less vibration). I lost a bit on the top end, however, but it was a price I was willing to live with, as I never bothered switching back to the original prop. (It's been relegated to spare status - there are a lot of submerged logs around my area and it is not uncommon to hit one and lose the entire prop.) If this is the same with ships, more blades would result in less vibration/noise, which you would expect would be good for an ASW ship, and faster acceleration, but perhaps a reduced top speed. However, it would be good to hear from someone with more knowledge on how ship propeller design works to see if the same behaviours found on my 21 footer translate to a 494 foot ship. Obviously, the pitch of the blades is another factor, but all things being equal, it would be interesting to know the advantages and disadvantages of more/less blades on a ship propeller.

Nice catch @shadow99!

 

[John Fedup]

Having more blades reduces vibrations and allows for smaller diameter props which might be necessary for certain hull designs. The downstroke is 4,5,and 6 bladed props aren’t as efficient as a 3 blade. All sorts of other variables, e.g. skew, rake, etc. that influence the overall design. The other important consideration is the ship’s engine and what the number of revolutions the screw will be turning at.

 

[ASSAIL]

Not sure if ships are the same, but on my fresh-water boat switching to a four-bladed prop from the three-blade that came with my Honda outboard got me on plane noticeably faster, and also ran more smoothly (less vibration). I lost a bit on the top end, however, but it was a price I was willing to live with, as I never bothered switching back to the original prop. (It's been relegated to spare status - there are a lot of submerged logs around my area and it is not uncommon to hit one and lose the entire prop.) If this is the same with ships, more blades would result in less vibration/noise, which you would expect would be good for an ASW ship, and faster acceleration, but perhaps a reduced top speed. However, it would be good to hear from someone with more knowledge on how ship propeller design works to see if the same behaviours found on my 21 footer translate to a 494 foot ship. Obviously, the pitch of the blades is another factor, but all things being equal, it would be interesting to know the advantages and disadvantages of more/less blades on a ship propeller.

Nice catch @shadow99!

You are spot on.
In days of yore this 27yr old Lieutenant in command of an Attack Class PB was challenged by another young PB commanding Officer to a drag race between the half mile channel markers in the Port of Cairns fairway (as inter squadron rivalry demanded).
My fair ship had three bladed propellers his had five blades.
He was a boat length quicker off the mark but at the half mile mine had overhauled and was pulling away. Both boats had the entire crews standing on the foredeck to get the rear end out of the water, mind you, impossible to achieve in a semi planing hull.
Finally, I can’t recall any adverse vibration from the three blades.
This challenge was never recorded in the monthly Report of Proceedings so it remains an unofficial result, naturally

 

[seaspear]

So does it come down to speed or stealth with less vibration ?

 

[ngatimozart]

You are spot on.
In days of yore this 27yr old Lieutenant in command of an Attack Class PB was challenged by another young PB commanding Officer to a drag race between the half mile channel markers in the Port of Cairns fairway (as inter squadron rivalry demanded).
My fair ship had three bladed propellers his had five blades.
He was a boat length quicker off the mark but at the half mile mine had overhauled and was pulling away. Both boats had the entire crews standing on the foredeck to get the rear end out of the water, mind you, impossible to achieve in a semi planing hull.
Finally, I can’t recall any adverse vibration from the three blades.
This challenge was never recorded in the monthly Report of Proceedings so it remains an unofficial result, naturally

I take it that you put a fair sized dent in his bar bill then, as tradition would demand?

 

[shadow99]

- there are a lot of submerged logs around my area and it is not uncommon to hit one and lose the entire prop.) If this is the same with ships, more blades would result in less vibration/noise, which you would expect would be good for an ASW ship, and faster acceleration, but perhaps a reduced top speed.

Having more blades reduces vibrations and allows for smaller diameter props which might be necessary for certain hull designs. The downstroke is 4,5,and 6 bladed props aren’t as efficient as a 3 blade. All sorts of other variables, e.g. skew, rake, etc. that influence the overall design. The other important consideration is the ship’s engine and what the number of revolutions the screw will be turning at.

Been there with a submerged log, lucky I wasnt going too fast but bent the prop. Now theres vibration.

I can see vibration/noise being a large factor, as you guys point out, and overall, large naval prop design looks like an incredibly complex subject.
What I find interesting (if the model is indeed correct), the UK have already designed props specifically for the type 26 and could be purchased without additional design and test costs.

Since we can only speculate...
a- Canada wants/needs even quieter props than the UK design
b- Canada wants/needs faster props
c- Canada wants needs quiet yet fast props using a new technology like 3d printing
d- Model maker liked the look of the 6 bladed prop

 

[Black Jack Shellac]

Been there with a submerged log, lucky I wasnt going too fast but bent the prop. Now theres vibration.

I can see vibration/noise being a large factor, as you guys point out, and overall, large naval prop design looks like an incredibly complex subject.
What I find interesting (if the model is indeed correct), the UK have already designed props specifically for the type 26 and could be purchased without additional design and test costs.

Since we can only speculate...
a- Canada wants/needs even quieter props than the UK design
b- Canada wants/needs faster props
c- Canada wants needs quiet yet fast props using a new technology like 3d printing
d- Model maker liked the look of the 6 bladed prop

Possibly the model maker was not informed of the prop design. There is quite a bit of fluid dynamics and modelling involved in designing an efficient and quiet prop. Maybe Rolls Royce don't want the competition to see the prop design.

 

[oldsig127]

Possibly the model maker was not informed of the prop design. There is quite a bit of fluid dynamics and modelling involved in designing an efficient and quiet prop. Maybe Rolls Royce don't want the competition to see the prop design.

7. Model maker chose an off the shelf prop from the range available, on the TLAR principle. Having made architectural models for engineering firms I have some insight into this.

I think it's nuts speculating about this sort of detail on the basis of a manufacturers model when the real thing is not yet to be seen.

oldsig

(TLAR - that looks about right)

 

[Albedo]

b- Canada wants/needs faster props

Wasn't there a complaint from one of the losing CSC bidders that the Type 26 design didn't meet speed requirements? If they have to redesign the propellers to increase speed I wonder if the losing bidders can still appeal at this late stage, which will of course set everything back.

First CSC pics from SNA 2020 (showing 32 Mk41s forward, 6 x ExLS aft, and a bit more detail on the radar superstructure). Also looks like NSM has now replaced Harpoon definitively.

Pics from Type 26 Frigate (City Class) (RN) [News Only] - Page 158 - UK Defence Forum

View attachment 47061 View attachment 47062

On another CSC model note, it looks like it's using the 30 mm DS30M on each side of the hangar. I wonder if Canada will actually adopt the DS30M compared to going with the 25 mm Mk38? DS30M would have more hitting power and range and there's now the optional add-on of the Martlet missile. But the Mk38 with 25mm Bushmaster would allow commonality with the AOPS and LAV6. I have no idea if one or the other has advantages in accuracy, sensor quality or better ability to track fast targets.

 

[ngatimozart]

On another CSC model note, it looks like it's using the 30 mm DS30M on each side of the hangar. I wonder if Canada will actually adopt the DS30M compared to going with the 25 mm Mk38? DS30M would have more hitting power and range and there's now the optional add-on of the Martlet missile. But the Mk38 with 25mm Bushmaster would allow commonality with the AOPS and LAV6. I have no idea if one or the other has advantages in accuracy, sensor quality or better ability to track fast targets.

There is no reason why the RCN cannot change the Bushmaster 25mm gun on the Mk 38 Typhoon mount for the Bushmaster 30 mm gun. The Typhoon mount will quite easily accept the 30 mm gun. I would argue that the AOPS should also mount the 30 mm gun and that the LAV6 as well, bringing it in line with the current international practice.

 

[CJohn]

There is no reason why the RCN cannot change the Bushmaster 25mm gun on the Mk 38 Typhoon mount for the Bushmaster 30 mm gun. The Typhoon mount will quite easily accept the 30 mm gun. I would argue that the AOPS should also mount the 30 mm gun and that the LAV6 as well, bringing it in line with the current international practice.

This study is worth a read and shows the multiplying factor of the 30mm vs the 25mm in a naval setting.
Weapons Effectiveness Testing–25 vs 30mm

 

[Black Jack Shellac]

Article on the state of Canada's submarine fleet

I think that we should start looking to replace our submarines as soon as they have finalized the CSC design (this year?). Considering we starting looking to procure frigates in ~2008 and won't see the first until ~2025 - 17 years, we better get on with looking for submarines. Ours are already long in the tooth and will likely require replacement in the 2030's despite what the current government thinks. If we start this year, we might see the first by 2040 (considering that subs are likely more complicated than frigates).

I think a nice fleet of 10 Soryu class submarines would do us well. Nuclear would be better, but I don't think that could ever be sold politically in Canada.

 

[StobieWan]

7. Model maker chose an off the shelf prop from the range available, on the TLAR principle. Having made architectural models for engineering firms I have some insight into this.

I think it's nuts speculating about this sort of detail on the basis of a manufacturers model when the real thing is not yet to be seen.

oldsig

(TLAR - that looks about right)

Exactly - wouldn't (at all) be surprised if the design were driven by some experience with sub props and I fully expect the final article to be extremely quiet, not just on the hunt at a few knots but even up to low teens speeds, but looking at a model right now and speculating is likely to be way off unfortunately.

 

[Black Jack Shellac]

There is no reason why the RCN cannot change the Bushmaster 25mm gun on the Mk 38 Typhoon mount for the Bushmaster 30 mm gun. The Typhoon mount will quite easily accept the 30 mm gun. I would argue that the AOPS should also mount the 30 mm gun and that the LAV6 as well, bringing it in line with the current international practice.

Do you think it might be possible that the AOPS will get the 57mm Bofors from the Halifax frigates when they retire them?

 

[John Fedup]

Do you think it might be possible that the AOPS will get the 57mm Bofors from the Halifax frigates when they retire them?

The government would likely prefer to sell them but if there are no buyers then they should go to the AOPS or a future OPV.

 

[Redlands18]

The government would likely prefer to sell them but if there are no buyers then they should go to the AOPS or a future OPV.

They are going to be close to 35yo each by the time they are removed from the Halifax’s so in need of a major overhaul, may just be better off to buy new ones

 

[ngatimozart]

Article on the state of Canada's submarine fleet

I think that we should start looking to replace our submarines as soon as they have finalized the CSC design (this year?). Considering we starting looking to procure frigates in ~2008 and won't see the first until ~2025 - 17 years, we better get on with looking for submarines. Ours are already long in the tooth and will likely require replacement in the 2030's despite what the current government thinks. If we start this year, we might see the first by 2040 (considering that subs are likely more complicated than frigates).

I think a nice fleet of 10 Soryu class submarines would do us well. Nuclear would be better, but I don't think that could ever be sold politically in Canada.

I think it may be wise for the RCN to have a Plan B underway, i.e., a study project for replacement of the Victoria class SSK. Have all the data, possible candidates, costings, everything, and a proto business case giving strategic and economic benefits to Canada, as well as the costs to Canada if the Victoria class SSKs are not replaced. It must be thorough, focussed, and of a very high standard. Get acquisition people from the DND and Treasury experts involved. In the end when the time comes, the RCN and DND will have a very robust document ready to be submitted, as long as it's kept current.

10 Soryu?? You been on the waccky baccy?? None of your govts would fund that. Given your geostrategic situation, I would think that you should pay attentention to the RAN Attack class, just because of the range aspects and capabilities that it will offer compared to standard Euro SSKs.

 

[John Fedup]

Agree, the RAN Attack sub should be considered. As for quantity, 10 would be possible if the RCAF were to be downsized, something junior may have attempted had he won a majority as favouring the RCN over the RCAF may have been politically accepted by our defence challenged electorate.