UK Defence Forum

https://en.wikipedia.org/wiki/OTO_Melara_76_mm

When we built the Peacock Class of patrol vessels to serve in Hong Kong they were built to carry the 76mm oto melara. Now with the discussions of the Enhanced role for the River II OPV and the Fictional sorry future light Frigate program the Oto Melara has been put forward as a possible armament. Since Royal Navy have already operated it it's interesting they have not put it forward again for service on any vessel built after the Peacocks.

I don't see any requirement for the 76mm gun in the Royal Navy. The 4.5 came back on the Type 22/III and the Type 23, 26 & Type 45 for the role of Naval Gunfire Support a role the 76mm is to light to properly fulfill. The 5inch gun provides a better support weapon and complicating naval gunnery by having to duplicate training and support for 2 different main weapons only adds complication and expense.

HMS Starling

Hi Mark.
Ireland has had two Peacocks for some time now. The principal effect being that they have almost completely "standardized" on the Oto Melara as OPVs principal weapon

eithne with 76mm would have been a good devlopment. There was talk of the 76mm being fitted to the Castle class OPV.

Why is it necessary? If an OPV is going up against something that it can't annihilate with a 30mm cannon then it shouldn't be there in the first place. A whole nother expensive logistics chain to support a weapons system whose only purpose would be to make our OPVs look a bit more fighty.

How about instead we concentrate on getting useful kit for our proper warships, like the strike length Mk. 41 Cells that should've been fitted to Type 45 from day one.

Engaging Strategy wrote:Why is it necessary? If an OPV is going up against something that it can't annihilate with a 30mm cannon then it shouldn't be there in the first place. A whole nother expensive logistics chain to support a weapons system whose only purpose would be to make our OPVs look a bit more fighty.

How about instead we concentrate on getting useful kit for our proper warships, like the strike length Mk. 41 Cells that should've been fitted to Type 45 from day one.

this is a system that some people think should go on the type 31 or OPV ES i'm totally with you on this the Oto melara isn't required in the Royal Navy there has only been 5 Royal Navy ships equipped with them. 2 were sold to Ireland and 3 to the Philipines (though they should have been brought back to boolster the RN patrol ship fleet maybe in the NIPS role replacing the Bird class)

Are we going to see the naval gun/Type 31/OPV discussion claim yet another topic?

RetroSicotte wrote:Are we going to see the naval gun/Type 31/OPV discussion claim yet another topic?

Obviously, it's the naval section of the forum so an unhealthy obsession with gunnery is to be expected!

Personally I favour the BL 15 inch Mk. I gun for the OPV.

Engaging Strategy wrote:Why is it necessary? If an OPV is going up against something that it can't annihilate with a 30mm cannon then it shouldn't be there in the first place. A whole nother expensive logistics chain to support a weapons system whose only purpose would be to make our OPVs look a bit more fighty.

How about instead we concentrate on getting useful kit for our proper warships, like the strike length Mk. 41 Cells that should've been fitted to Type 45 from day one.

Perfectly said!

marktigger wrote:this is a system that some people think should go on the type 31 or OPV ES i'm totally with you on this the Oto melara isn't required in the Royal Navy there has only been 5 Royal Navy ships equipped with them

It is a very mature, well supported system with advanced ammunition choices so it does seem attractive. I would say the problem is logistical. If the T45 is upgraded to a 5 inch, and the T31 is ordered in a large enough quantity, those logistical problems are reduced, and it could make sense.

do RFA's have to carry stocks of NATO standard ammunition? or would the 76mm ammo have to take up space.

shark bait wrote:If the T45 is upgraded to a 5 inch, and the T31 is ordered in a large enough quantity, those logistical problems are reduced, and it could make sense

Agreed - all OPVs should have a 5 inch gun - you know it makes sense

Engaging Strategy wrote:Personally I favour the BL 15 inch Mk. I gun for the OPV

That comment led me off into a few entertaining hours of reading about the BL18 inch and various pre-dreadnoughts. I now firmly believe that we should consider resurrecting the https://en.wikipedia.org/wiki/Lord_Clive-class_monitor. Now - that's what I call NGFS

how much 15in HE ammo did the monitors have?

not a lot as it was semi armour piercing

marktigger wrote:how much 15in HE ammo did the monitors have?

not a lot as it was semi armour piercing

Obviously the OPVs wouldn't need HE, as they won't be doing NGFS. 15" AP shells would be perfect for smugglers and skiffs. The overpressure from the warning shot would turn everyone aboard inside out!

shark bait wrote:

Engaging Strategy wrote:Why is it necessary? If an OPV is going up against something that it can't annihilate with a 30mm cannon then it shouldn't be there in the first place. A whole nother expensive logistics chain to support a weapons system whose only purpose would be to make our OPVs look a bit more fighty.

How about instead we concentrate on getting useful kit for our proper warships, like the strike length Mk. 41 Cells that should've been fitted to Type 45 from day one.

Perfectly said!

marktigger wrote:this is a system that some people think should go on the type 31 or OPV ES i'm totally with you on this the Oto melara isn't required in the Royal Navy there has only been 5 Royal Navy ships equipped with them

It is a very mature, well supported system with advanced ammunition choices so it does seem attractive. I would say the problem is logistical. If the T45 is upgraded to a 5 inch, and the T31 is ordered in a large enough quantity, those logistical problems are reduced, and it could make sense.

if we are putting an OPV somewhere it needs a 76mm Oto Melara its the wrong vessel in the wrong place! are we going to add them to RFA's just incase?

marktigger wrote:if we are putting an OPV somewhere it needs a 76mm Oto Melara its the wrong vessel in the wrong place! are we going to add them to RFA's just incase?

Just to be clear, I do not advocate putting big guns on patrol boats. I agree "wrong vessel in the wrong place".

I don't think anyone is going to send an OPV in harms way on purpose, but shit happens. Therefore, arming our new globally roaming OPVs with a gun with better self defence capability (ASuW and AAW) makes perfect sense. If a 76mm is too big, then a 57mm is about right.

The original requirement for the 76mm/62 fitted on peacock patrol craft . Was because the ton class modified mine sweepers they replaced.Fitted with two 40mm were considered under armed for Hong Kong With the projected use of R.P.G. and maritime use of light A.A. guns by none governmental vessels The original fitment was for a Breda 40h70 twin aft. The single gun variant would be a good replacement for the none U.K. tasked rivers .The castle class were fitted for but not with to because of there fishery protection role. The major problem is the cost associated with running a limited number of the guns in service.

If you add a 57mm to all OPVs and MHCs that could be a fleet of around 20+ hulls.

Repulse wrote:I don't think anyone is going to send an OPV in harms way on purpose, but shit happens.

If HMG is stupid enough to send an OPV somewhere where it can't deal with the armed threats it faces with a 30mm autocannon then it's going to get sunk, bigger gun or not.

Therefore, arming our new globally roaming OPVs with a gun with better self defence capability (ASuW and AAW) makes perfect sense.

Except a bigger gun adds almost nothing to the ship's ability to defend itself against surface and air attack in anything but the most permissive of environments. A 30mil is plenty to horrendously overmatch the capabilities of pirates and smugglers in fast boats with small arms and RPGs. It's in part why we mount a pair of them on our first rate escorts, because they're damn good for that sort of thing. Against any sort of proper warship armed with a surface to surface missile(which is pretty much all of them nowadays), your OPV is dead. Against any sort of helicopter or aircraft with a stand-off missile, or a guided bomb that can be released from outside the weapon's range you're also 100% dead. Hell, you could mount four 5" guns on the thing and it'd still be little more survivable than before.

If a 76mm is too big, then a 57mm is about right.

Why? These guns add nothing, they're not suitable for NGFS and they'd add another expensive logistical footprint. With that second point in mind you've got three choices for your RN OPV:
1. Small arms, .50 calibre machine guns and miniguns only.
2. The above plus a DS30
3. Small arms and a 5" gun.

Considering that option #1 would rightly be considered under-armed, lacking the overmatch capacity against likely enemies and option #3 would require a bigger and more expensive ship we're just left with option #2; which is perfectly adequate for what an OPV should be doing.

If you add a 57mm to all OPVs and MHCs that could be a fleet of around 20+ hulls.

Or you could stick with the DS30 and have 20+ OPVs and MHCs in addition to 19+ escorts with two fitted and whichever capital ships also get them. Face it, DS30 as the fleet wide standard light gun just makes sense.

marktigger wrote:if we are putting an OPV somewhere it needs a 76mm Oto Melara its the wrong vessel in the wrong place

The world is littered with the remains of people and ships that were in the wrong place. I doubt that the present generation will get it right any more than previous generations, despite all our advances. Would you like to be on the ship that needs a 76mm, but hasn't got one, because the "logistics are too difficult" or "it's an OPV, so it shouldn't be there"?

Repulse wrote:I don't think anyone is going to send an OPV in harms way on purpose, but shit happens. Therefore, arming our new globally roaming OPVs with a gun with better self defence capability (ASuW and AAW) makes perfect sense. If a 76mm is too big, then a 57mm is about right.

Exactly.

Caribbean wrote:

marktigger wrote:if we are putting an OPV somewhere it needs a 76mm Oto Melara its the wrong vessel in the wrong place

The world is littered with the remains of people and ships that were in the wrong place. I doubt that the present generation will get it right any more than previous generations, despite all our advances. Would you like to be on the ship that needs a 76mm, but hasn't got one, because the "logistics are too difficult" or "it's an OPV, so it shouldn't be there"?

Repulse wrote:I don't think anyone is going to send an OPV in harms way on purpose, but shit happens. Therefore, arming our new globally roaming OPVs with a gun with better self defence capability (ASuW and AAW) makes perfect sense. If a 76mm is too big, then a 57mm is about right.

Exactly.

I'd rather we were arming a globally roaming light frigate which could have to provide support to either its ships det or a landed force with an effective NGS than a round that doesn't quite do the job

Caribbean wrote:The world is littered with the remains of people and ships that were in the wrong place. I doubt that the present generation will get it right any more than previous generations, despite all our advances. Would you like to be on the ship that needs a 76mm, but hasn't got one, because the "logistics are too difficult" or "it's an OPV, so it shouldn't be there"?

This is not an argument for a bigger gun on the OPV, it's an argument against lightly armed OPVs in the first place. Anything short of a proper frigate (with a credible AAW missile system and sensors) that gets caught in your wrong place/wrong time scenario is dead. You can mess about with adding all the guns you like, but their contribution to ship survivability in such a scenario would be marginal. With this in mind, the benefits just don't justify the costs.

I think there is one story to have 76 mm guns in RN; when RN decide to buy more than 8 T26s (say 10) AND still continue to think APT-S and Kipion need "some sort of" fighting ships. In this case, RN may build another batch of River OPVs (Batch "4") in addition to the current 5 vessels, and make it 7-8, and equip 4-5 of them with 76 mm guns (and retractable Wildcat hangar).

76 mm OTO Melara series are mature, well-designed armament. It is also important to note that it is cheap, "much cheaper than 5in guns" as quoted elsewhere (ammunition is also cheap). So adopting 3in gun in "only" 4-5 vessels do not have an impact as big as having 5in gun for the same number of ships. The super-rapid system with 120 rpm fire rate is "impressive", and maybe non-negligible for Argentine air-force's Pucaras and Pampa (not su much for A-4s). Also non negligible for Merchant vessels.

How about ASMs? Super-rapid is used as a CIWS in Italian navy. But, I am not sure it is "effective enough" (question-1).

As an improvement, they provide DARTS guided ammunition projected in 1200 m/s of speed, combined with CLOS guidance system. Good. But this means it is not cheap. How expensive is it? 20 MGBP? 40 MGBP? Must be non-negligible compared to the River OPV cost as a whole, bit I am not sure how much it will increase (question-2).

On the other hand, RN has another option, 30 mm SeaHawk sigma turret. It is design to fire 5 LLMs, which is "3 inch" in its diameter. Surely it will be inferior for fight agains Merchant vessel. But, how about AAW? Can the SeaHawk Sigma system embark StarStreak SAM? (question-3)

If yes, is StarStreak SAM capable to shoot down ASMs, better than (canonical) 76mm super-rapid? (question-4a)
Then how compared to 76 mm DART ? (question-4b)

I think question-3, "can River OPVs embark StarStreak SAMs?" and question-4a, "is StarStreak better than super-rapid 76mm against ASMs?" is important. If the answers are both "yes", then it will be good to have a few up-armored River OPVs: 2x 30mm SeaHawk Sigma systems (one on the bow, another on top of the hangar), as well as a retractable Wildcat hangar.

If question-1 "76mm if effective agains ASM" is yes, and question 3 and 4s are no, then there are possibility they are equipped with a 3 inch gun on the bow, and a retractable Wildcat hangar. If DART is cheap and effective, it could be the Strales System with DART.

Anyway, RN can call them, "ocean-going light corvettes", and send them for APT-S and even Kipion. RN shall also rename them (= up armoured Rivers) as "Flowers" or "Castles".

Does the fact that the US coast guard has medium calibre guns on their vessels make them stupid. Anyone would think that the RN were in the majority, but no the RN is pretty unique in underarming ships have done for a very long time.

Engaging Strategy wrote:This is not an argument for a bigger gun on the OPV, it's an argument against lightly armed OPVs in the first place. Anything short of a proper frigate (with a credible AAW missile system and sensors) that gets caught in your wrong place/wrong time scenario is dead. You can mess about with adding all the guns you like, but their contribution to ship survivability in such a scenario would be marginal. With this in mind, the benefits just don't justify the costs.

OK, you mean scrap everything except the 19 (best case) DDs / FFs they are useless... That's one way to go I suppose

Given the current circumstances that is partly the right way to go.

The Royal Navy is at a critical mass, any fewer proper surface combatants, and it will have to begin to withdraw from its global presence and take a credibility hit.

If the cost of high end surface combatants continues to inflate faster than budget increases then something has to give, and there are 2 options;

• Maintain the best in class high end fleet, and drop the low end
• Reduce the best in class high end fleet, and maintain the low end

Which of those gives the Royal Navy the greatest credibility, and the greatest power to protect British interests around the globe?

Right now every pound spent up-gunning the low end, are pounds that should be spent ensuring we maintain the most credible fleet in the world after the Americans, something that is very much at risk now.

The 76mm Oto is a great package, mature and effective, I consider it an option for the T31, but not the Rivers. For it to make any sense on the Rivers they would also need an integrated mast, a bunch of CAMM cells, and all of a sudden we are way off scope and way over budget.

Perhaps if the gun was selected for the T31 it might strengthen the case for using it elsewhere in the Royal Navy, but I still don't think it is compelling to put it on the Rivers.

For example, assuming the 76mm Oto is chosen for the T31, would it make sense to equip the T45 with dual 76mm Oto's in a configuration similar to the French Horizon Class? Could be done at the same time as the Mk41 installation to free up more space, and removes the unique 4.5 inch from service.