Royal Australian Navy Discussions and Updates 2.0

[spoz]

I have heard that the issue was related to state of development and certification of the Leonardo weapon;,so far as I can see the version they wre offering us hasn't actually been installed anywhere in a production version as yet. That and a revised threat assessment. The BAE (Bofor Mk 4) 40, https://www.baesystems.com/en-media/uploadFile/20210404054312/1434555371622.pdf, has similar ammunition capabilities (3P) but of course doesn't have the range of the 57, https://www.baesystems.com/en-media/uploadFile/20210404051741/1434555371458.pdf, but has a much smaller footprint and weighs a lot less .

 

[Stampede]

The 57mm has other benefits, its in use with Indonesia, Malaysia, Singapore, Thailand and Brunei. There is commonality for training, spares and possibly ammunition sales from Australia (although Malaysia also makes plain ammunition). Dual feed, 1000 round mounting (if you want), 3P ammunition. For a gun, what else would anyone want? It throws more bang into the sky than the 76mm, flick between dumb and programmable rounds and is used throughout the region and is integrated. No one is going to accusing it of being a pea shooter.

the 40mm while a bit smaller and a bit light isn't likely to accommodate anything else around it, its still sizable. Maybe if we were talking 20-25mm, maybe some decoy launchers or something like this. Its likely to cost similar to the 57mm as well.

Which is I guess begs the question, why buy something else over the 57mm. In terms of fitting it to the ship, its probably the cheapest/fastest option in this case, and smaller rounds are going to be less capable (although plenty capable for a OPV). If the 30-40mm gun is the same or more expensive, what are we trying to procure and for what. Orphan in our region, with our friends and with our systems.

The 57mm is an impressive system.
If the Darussalam Class does in fact have the Mk 3 Mk 57mm, then it has an all up loaded weight of some 14t plus deck penetration for a magazine underneath.
Given the RAN had originally selected the lighter and non penetrating 40mm canon, do we still have the option to go heavier without major rework under the gun mount.
Whatever weapon is selected, it will be interesting if the weapon is a one off only for the Arafura Class, or part of a standardized role out across the fleet.
30mm, 40mm, 57mm, 16", something else!

Interesting

Cheers S

 

[swerve]

You can also add to that list USN's Independence, Freedom and (future) Constellation Class frigates too.

I agree that the Bofors 57mm appears to be the most ideal outcome for Arafura.

And the RN's Type 31, & perhaps the Arrowhead 140s ordered by Indonesia (though AFAIK the choice of gun for them haven't been announced).

 

[STURM]

throws more bang into the sky than the 76mm, flick between dumb and programmable rounds and is used throughout the region and is integrated. .

In your opinion what advantages would be had in going for a 76mm main gun over a 57mm one?

 

[spoz]

While I'm not the person you addressed that to, my answer would be - not really. The gun, is heavier and in sovraponte form (which you would probably need to use on the Arafuras to avoid deck penetration) it is considerably slower firing and it doesn't have as many on mount rounds. It has slightly longer range in some modes (and much longer if using volcano, yet to be proved) but for the function of the OPV it would seem to add little value; the 57 gets you out to about 17000 metres is surface DA (the Bofor 40 to about 12500). And, even the 57 might be stretching the friendship - while it is in the Bruneian vessels, which outwardly appear much the same, we don't know what the differences to the RAN ship are and how that might affect the ability to accept theweapon. For a example, it might well require a larger magazine than currently allowed for to enable the ship to embark a reasonable number of rounds, it's cooling and power requirements may well be greater than has been allowed for, that sort of thing. I've haven't seen the tender (and I doubt if anybody who has will post here or anywhere else on the net) but those will certainly be some of the issues which will be evaluated as well as weight and real estate requirements.

 

[StingrayOZ]

In your opinion what advantages would be had in going for a 76mm main gun over a 57mm one

Not much. The 76mm I believe we have some in storage of older models from the FFG's and some logistics for it. Its a bigger, heavier gun. Has some advantage for shore bombardment against hardened targets. We have seen many modern navies move away from the 76mm and fit 57mm guns, which typically shoot faster, carry more rounds, faster to target etc. As pointed out the Type 31, the constellations are going with the 57mm and they are pretty serious warships. The 57mm is pretty much in the sweet spot for range, altitude, accuracy, explosive power etc. I also don't believe our OPV are designed for the 76mm you need to move to the opV85 for that type of capability..

Which again raises the issue of 40mm on a ship, what does it get you, particularly if the ship is designed around a 57mm main mount? I can see value in the 40mm as a CIWS or secondary gun, where its lightness, and superiority over 20-30mm is going to be significant.

Is the smaller footprint and weight difference that important? Probably not. If cost, integration, proven, commonality, capability are all negative? Do we want to be the prototyping donkey for an orphan European weapon system? On our cheap and cheerful low cost, slow OPV? I get why we were interested, saving nearly 10 tons and having a neat little gun. But I don't see any must have capabilities, and costs are likely to be greater. IMO seems perhaps a better fit for a secondary guns on a bigger platform.

57mm is going to be quite good against things like high flying drones, low flying drones, loiter munitions and is able to strike out to basically horizon level etc. While warship on warship engagement for a OPV is unlikely, warship on drone is very likely. Given its OPV role, that is probably an area where it is valuable to have the extra punch of the 57mm. The drone threat is a real thing now, as seen in the Ukraine. Not just by large powers, but basically any power. In terms of kinetics and hitting, the 57mm a proven thing, and the 40mm came and went as an antiair caliber. It lack range, engagement envelopes are small and tight, it can't match the 57 for throw or punch or total explosive per second.

Why do we need to save weight on the OPV? The design can take the 57mm and still have weight for other weapon systems. If we fit the 40mm are we just fitting ballast instead? Then facing further integration costs. Who else is using it? With the 57mm we can embark some friendly's for training, and there are cheaper older 57mm mounts that may be of interest to PNG/Timor/Fiji etc.

Put it this way, if we ended up with the 57mm, I don't think anyone would be disappointed. We would be bringing a system that all our allies are operating or intending to operate. If we go with the 40mm Leonardo, we are all on our own in terms of integration, support, logistics, crewing, training, improvements, development etc.

 

[spoz]

I certainly wouldn't be disappointed! I think the Leonardo 40 is out of the picture, that is what was originally planned. If they were going to accept that, why introduce the delay of re-calling tendeers? If they go for the Bofor 40 then it is fairly widely fitted in Europe (including in the T31). It's a serious weapon; but would you prefer the 57 if you can? Probably, no almost certainly. I wonder what the cost differential would be? But if your money stretches no further than the 40 that is better than a 25 or 30 - and I suspect an RCI for the program is probably not going to be looked on favourably.

Seems the US paid about (USD) $ 7.2 m for one 57 for an LCS, not sure how long ago. Ammunition starts at a bit over $1000 per round. (Figures from the net, so how good? Who knows?). I haven't been able to find a price on either of the 40s.

 

[StingrayOZ]

Seems the US paid about (USD) $ 7.2 m for one 57 for an LCS, not sure how long ago. Ammunition starts at a bit over $1000 per round. (Figures from the net, so how good? Who knows?). I haven't been able to find a price on either of the 40s.

The ship we selected was designed and previously fitted with the 57mm gun. If we fit something else we are doing this RAN gold plating and customizing everything that goes against, particularly what we want to be doing for a OPV. Any weight and space advantage of the 40mm will be wasted on our current OPV design, we won't be reengineering the entire ship to try to use that space and volume, it will be concrete and steel ballast fitted instead.

57mm is a decent gun and one I can see being useful in the RAN. Its affordable and workable. While probably being a bit bigger than what the OPV needs, its commonality, usefulness, capability and cost probably overrun that.

It may be in 10-15 years time the 40mm becomes a very attractive configuration and maybe fits as a secondary gun. However, the 57mm imo will have resale value regionally either fitted to the OPV or by itself.

 

[hauritz]

In your opinion what advantages would be had in going for a 76mm main gun over a 57mm one?

I don't know exactly but I did some number crunching just to see which gun could potentially deliver the most damage per minute.

Kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. To get damage per minute multiply that by the rounds fired.

These are the relevant specs for an OTO Melara 76 mm shell.
Shell weight (without case or propellent) - 6.3 kg
Muzzle Velocity - 915 m/s
Rate of fire - 85 rpm
Damage Per Minute - 224,166,930 KE

Bofors 57 mm Naval Automatic Gun L/70
Shell weight (without case or propellent) -2.4 kg
Muzzle Velocity - 1,025 m/s
Rate of fire - 220 rpm
Damage Per Minute - 277,365,000 KE

The same calculation with a typical 127 mm shell
Shell weight (without case or propellent) - 8.3 kg
Muzzle Velocity - 790 m/s
Rate of fire - 20 rpm
Damage per Minute: 51,800,300 KE.

So my advice for the captain of a destroyer equipped with a 127mm main gun that got caught up in a pure gun battle with an Arafura equipped with a 57mm or 76mm main gun would be to turn tail and flee like the wind.

 

[Redlands18]

I don't know exactly but I did some number crunching just to see which gun could potentially deliver the most damage per minute.

Kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. To get damage per minute multiply that by the rounds fired.

These are the relevant specs for an OTO Melara 76 mm shell.
Shell weight (without case or propellent) - 6.3 kg
Muzzle Velocity - 915 m/s
Rate of fire - 85 rpm
Damage Per Minute - 224,166,930 KE

Bofors 57 mm Naval Automatic Gun L/70
Shell weight (without case or propellent) -2.4 kg
Muzzle Velocity - 1,025 m/s
Rate of fire - 220 rpm
Damage Per Minute - 277,365,000 KE

The same calculation with a typical 127 mm shell
Shell weight (without case or propellent) - 8.3 kg
Muzzle Velocity - 790 m/s
Rate of fire - 20 rpm
Damage per Minute: 51,800,300 KE.

So my advice for the captain of a destroyer equipped with a 127mm main gun that got caught up in a pure gun battle with an Arafura equipped with a 57mm or 76mm main gun would be to turn tail and flee like the wind.

Or just standoff outside the effective range of the 57/76mm and take him out with a handful of 127mm Rounds. And at 17,000m a 57mm Round is going to do little more then ruin the paint job.
Ranges
L 70 57mm 17,000m
OM 76/62mm 16-20,000m
Mk 45 127mm 12-37km
Otobreda 127/64mm 30-120km
That damage per minute is a bit of how long is a piece of string question, obviously a 57mm or 76mm Round is going to do a lot more damage at 100m then at 10,000m and how much damage are they referring to. What is a better result, 10 smallish holes in the Superstructure or 1 big one in the Hull.

 

[Todjaeger]

I don't know exactly but I did some number crunching just to see which gun could potentially deliver the most damage per minute.

Kinetic energy (KE) is equal to half of an object's mass (1/2*m) multiplied by the velocity squared. To get damage per minute multiply that by the rounds fired.

These are the relevant specs for an OTO Melara 76 mm shell.
Shell weight (without case or propellent) - 6.3 kg
Muzzle Velocity - 915 m/s
Rate of fire - 85 rpm
Damage Per Minute - 224,166,930 KE

Bofors 57 mm Naval Automatic Gun L/70
Shell weight (without case or propellent) -2.4 kg
Muzzle Velocity - 1,025 m/s
Rate of fire - 220 rpm
Damage Per Minute - 277,365,000 KE

The same calculation with a typical 127 mm shell
Shell weight (without case or propellent) - 8.3 kg
Muzzle Velocity - 790 m/s
Rate of fire - 20 rpm
Damage per Minute: 51,800,300 KE.

So my advice for the captain of a destroyer equipped with a 127mm main gun that got caught up in a pure gun battle with an Arafura equipped with a 57mm or 76mm main gun would be to turn tail and flee like the wind.

Umm, not really. First, the above is making estimates based upon the potential (heh) KE of a naval round, when much of the potential damage is going to be from the explosive charge within said round. It has been quite some time since naval guns were firing purely KE-only rounds, a la round shot...

Secondly, the shell weight of a 127 mm round is IMO wildly off. The weight of a 76 mm shell appears to be roughly correct, but a 127 mm round is about 67% greater in diameter than a 76 mm round and AFAIK is would also be noticeably longer to boot. Such a significantly larger round should weight proportionally significantly more, not only ~2kg more. From what I can find, most 127 mm rounds are more like 30 kg in weight. Nav Weapons has a page here which lists different shells and their weights. One has to remember though that the different shells explosive charges with the larger shells normally having a larger and more damaging charge.

FWIW I do not think it would be all that beneficial for the RAN to adopt a 57 mm naval gun. Such a gun IMO is either too much or too little for RAN purposes. It is too small and too limited for use in an anti-shipping or NGFS role, while being really too large (again, IMO) for use as a proper anti-FAC/CIWS. If the RAN were to adopt a minimally or non-deck penetrating 57 mm gun mounting, those only have about 120 'ready rounds' loaded + 40 in hoists, which would last a little over 30 seconds of full rate firing. A small calibre gun in the 30 mm to 40 mm range would typically have a larger number of available rounds even in a non-penetrating deck mounting. Using the OTO Breda 40mm/L70 Twin 'Fast Forty' in a Type B non-penetrating deck mounting, the mounting houses 444 HE rounds and 200 APFSDS rounds. That would also be exhausted in less than a minute of firing (about ~45 sec) but that would permit ~430 kg of ordnance being sent down range, whilst a 57 mm would top out around 390 kg or ordnance.

I recall having crunched numbers like these previously and posted the data with respect to weight of shot for CIWS, IIRC this was in the 1.0 RAN thread, I will check again later to see if I can find that post.

One final note has to do with ranges... it has been posted that the max range of a 57mm is up to 17 km, which sounds about right, but one needs to remember that there is a significant difference between max range, and effective range. IIRC that 17 km range is achieved by having a 57 mm gun fire at a 45 degree angle. The max range I have seen listed for some 40 mm guns is likewise about 12 km, but the effective range is usually listed more reasonably around three or four km.

 

[spoz]

From what I can find, most 127 mm rounds are more like 30 kg in weight.

That sounds about right from lifting the b----y things.

One final note has to do with ranges... it has been posted that the max range of a 57mm is up to 17 km, which sounds about right, but one needs to remember that there is a significant difference between max range, and effective range. IIRC that 17 km range is achieved by having a 57 mm gun fire at a 45 degree angle. The max range I have seen listed for some 40 mm guns is likewise about 12 km, but the effective range is usually listed more reasonably around three or four km.

I don't remember exactly, and can't find my notes, but I think effective for the 40 was about 8km in surface - 4 in AA - but don't quote me! It's not something manufacturers particularly like telling joe public. Effective range of the Mk45 Mod 4 is in the public arena though - somthing over 30 kms.

On a more general note, these are already bespoke ships. They look somewhat like the Bruneians on the outside but internally, and in their systems, they are quite different. To start off with, they have 9LV; the Bruneians use Thales. Different main engines and gearboxes. Diffferent sensors. Two large cranes - and it goes on. To some extent what Luerssen does is sell a hull design and their building expertise; what gets stuffed into that hull (within reason) is up to the customer.

 

[StingrayOZ]

On a more general note, these are already bespoke ships. They look somewhat like the Bruneians on the outside but internally, and in their systems, they are quite different. To start off with, they have 9LV; the Bruneians use Thales. Different main engines and gearboxes. Diffferent sensors. Two large cranes - and it goes on. To some extent what Luerssen does is sell a hull design and their building expertise; what gets stuffed into that hull (within reason) is up to the customer.

Well they will have to start from scratch if they built and optimized them for the 40mm.

The more you change up a design and adapt the more risk there is. We see it time and time again. Systems and sensors don't typically weight wildly different if they are of the same class, same as engines, might be different types but typically broadly similar dimensions. I would be surprised if they are built to exclude the 57mm gun as that is baked into the design and the slightly larger design (85) can handle the larger 76mm, the Brunei ships also carry large missiles, so it would seem the parent design has some margin.

How well the 57mm fits and the design and the RAN more broadly is a detailed question and probably won't be answered here definitively. Everyone has a favorite caliber and gun type. There are advantages and disadvantages anyway you go.

In the big world of things personally I think they should fit what ever is easiest and simplest. The OPV won't be facing serious threats. We put the slow engines in them, and the rest is fairly mid spec for an OPV.

The gun of the opv is more likely to be used to start a yacht race than fire on a Chinese destroyer.

I also don't see the point of adopting a high risk, expensive, rarely used, unintegrated, small caliber gun. I don't see the point of spending a lot of money to deliberately acquire far less capability.

 

[STURM]

There are advantages and disadvantages anyway you go.

For navies with limited budgets and which require a main gun to have a primary AA tasking; the 57mm is ideal. Armed with 3P ammo it also provides as useful capability against certain type of missiles.

 

[Volkodav]

The other angle is 40mm could potentially replace (or partially replace) 25mm and Phalanx in the RAN, 57mm is too large and heavy for that. I know RAM or some other missile option, or possibly lasers would be a Phalanx replacement, but 40mm can offer CIWS and anti-swarm capability and physically replace Typhoon and Phalanx on many platforms.

 

[DDG38]

And now a break from gun caliber discussions :
BZ to the next generation of fleet sailors (somewhere in this group may be an SSN COB) !
"The Royal Australian Navy Recruit School saw its latest recruits graduate during a parade at HMAS Cerberus on Victoria's Mornington Peninsula, south-east of Melbourne, on Friday, 22 April 2022. The 113 Rogers Division recruits started general entry course No. 398 on Monday, 21 February 2022 and 96 graduated nine weeks later. The RAN Recruit School mission is to induct the next generation of sailors into the Royal Australian Navy, enabling them to think independently and act collectively in the conduct of their core duties within Navy, and as part of a Joint force. The RAN Recruit School provides new recruits with the many skills needed to pass onto a naval career. Teamwork, self-discipline and professionalism are the key attributes developed within recruits undertaking recruit training. Recruits are expected to adopt and display in their behaviour and their attitude the Navy values of Service, Courage, Respect, Integrity and Excellence." Image Source : ADF Image Library

 

[Rock the kasbah]

And now a break from gun caliber discussions :
BZ to the next generation of fleet sailors (somewhere in this group may be an SSN COB) !
"The Royal Australian Navy Recruit School saw its latest recruits graduate during a parade at HMAS Cerberus on Victoria's Mornington Peninsula, south-east of Melbourne, on Friday, 22 April 2022. The 113 Rogers Division recruits started general entry course No. 398 on Monday, 21 February 2022 and 96 graduated nine weeks later. The RAN Recruit School mission is to induct the next generation of sailors into the Royal Australian Navy, enabling them to think independently and act collectively in the conduct of their core duties within Navy, and as part of a Joint force. The RAN Recruit School provides new recruits with the many skills needed to pass onto a naval career. Teamwork, self-discipline and professionalism are the key attributes developed within recruits undertaking recruit training. Recruits are expected to adopt and display in their behaviour and their attitude the Navy values of Service, Courage, Respect, Integrity and Excellence." Image Source : ADF Image Library
View attachment 49206

They don't expect much do they ?

 

[Rock the kasbah]

They don't expect much do they ?

I did put a smiley face after that
But no show

 

[aussienscale]

And now a break from gun caliber discussions :
BZ to the next generation of fleet sailors (somewhere in this group may be an SSN COB) !
"The Royal Australian Navy Recruit School saw its latest recruits graduate during a parade at HMAS Cerberus on Victoria's Mornington Peninsula, south-east of Melbourne, on Friday, 22 April 2022. The 113 Rogers Division recruits started general entry course No. 398 on Monday, 21 February 2022 and 96 graduated nine weeks later. The RAN Recruit School mission is to induct the next generation of sailors into the Royal Australian Navy, enabling them to think independently and act collectively in the conduct of their core duties within Navy, and as part of a Joint force. The RAN Recruit School provides new recruits with the many skills needed to pass onto a naval career. Teamwork, self-discipline and professionalism are the key attributes developed within recruits undertaking recruit training. Recruits are expected to adopt and display in their behaviour and their attitude the Navy values of Service, Courage, Respect, Integrity and Excellence." Image Source : ADF Image Library
View attachment 49206

What the GE398 !! That's it I am officially old, I was a few classes before these guys Lets just say 360+ and leave it at that shall we !!

 

[Stampede]

The other angle is 40mm could potentially replace (or partially replace) 25mm and Phalanx in the RAN, 57mm is too large and heavy for that. I know RAM or some other missile option, or possibly lasers would be a Phalanx replacement, but 40mm can offer CIWS and anti-swarm capability and physically replace Typhoon and Phalanx on many platforms.

CIWS against incoming missiles
40 mm or 57 mm?

Thoughts

Stampede