DCN 100mm Naval Gun

[Lucasnz]

Happy New Year Everyone.

I've been thinking about NGS (Naval Gunfire Support). While the 76mm has a marginal NGS capability and similair range to the 100mm, I've become interested in the ability of the 100mm as a more effective NGS weapon with superior AA capability to the 114mm and 127mm.

Anyone want to venture a guess as to why the 100mm has effectivally fallen out of favour (except with the Chinese and Russian's) in western nations in the face of the Oto 76mm

I think a combination of reasons revolving around marketing by Oto Breda and the view that higher rates of fire are more effective for Anti Air defence.

 

[Tasman]

Happy New Year Everyone.

I've been thinking about NGS (Naval Gunfire Support). While the 76mm has a marginal NGS capability and similair range to the 100mm, I've become interested in the ability of the 100mm as a more effective NGS weapon with superior AA capability to the 114mm and 127mm.

Anyone want to venture a guess as to why the 100mm has effectivally fallen out of favour (except with the Chinese and Russian's) in western nations in the face of the Oto 76mm

I think a combination of reasons revolving around marketing by Oto Breda and the view that higher rates of fire are more effective for Anti Air defence.

My suggestion is that it is because the 100mm naval gun is inferior to the 76mm in the anti air role and inferior to the 127mm in the NGS and surface warfare role. Additionally I would think that the higher rate of fire of the 76mm gun makes up for the greater 'hitting power' of the 100mm in the surface warfare role, especially as most vessels equipped with this gun are likely to be packing SSMs such as Harpoon.

Cheers

 

[Lucasnz]

My suggestion is that it is because the 100mm naval gun is inferior to the 76mm in the anti air role and inferior to the 127mm in the NGS and surface warfare role. Additionally I would think that the higher rate of fire of the 76mm gun makes up for the greater 'hitting power' of the 100mm in the surface warfare role, especially as most vessels equipped with this gun are likely to be packing SSMs such as Harpoon.

Cheers

Just ran some figures for hitting power, with details as follows

Gun, Rounds per minute, Weight of Shell, Total Impact on target in Kg

• Bofors 57mm: 220: 6.38: 1403.60Kg
• Oto 76mm Compact: 85: 12.34: 1048.90Kg
• Oto 76mm Rapid: 120: 12.34: 1480.80Kg
• DCN 100mm 68 CDAM: 78: 23.50: 1833Kg

Use a 127mm is more superior to a 100 in NGS, but I'm looking a low level conflict policing operations.

 

[Whiskyjack]

Just ran some figures for hitting power, with details as follows

Gun, Rounds per minute, Weight of Shell, Total Impact on target in Kg

• Bofors 57mm: 220: 6.38: 1403.60Kg
• Oto 76mm Compact: 85: 12.34: 1048.90Kg
• Oto 76mm Rapid: 120: 12.34: 1480.80Kg
• DCN 100mm 68 CDAM: 78: 23.50: 1833Kg

Use a 127mm is more superior to a 100 in NGS, but I'm looking a low level conflict policing operations.

So as a basic scenario, the ship is 1-2 km off shore, no real threat level, and the NGS is being provided within 5 km of the beach?

 

[Tasman]

Just ran some figures for hitting power, with details as follows

Gun, Rounds per minute, Weight of Shell, Total Impact on target in Kg

• Bofors 57mm: 220: 6.38: 1403.60Kg
• Oto 76mm Compact: 85: 12.34: 1048.90Kg
• Oto 76mm Rapid: 120: 12.34: 1480.80Kg
• DCN 100mm 68 CDAM: 78: 23.50: 1833Kg

Use a 127mm is more superior to a 100 in NGS, but I'm looking a low level conflict policing operations.

For low level conflict and roles I suspect navies would want to use a general purpose gun that is ideally of the same type as used in other warships in the fleet. Both the 100mm and 57mm gun have appeal for some scenarios and some navies, like those of New Zealand and Australia for example, have nothing larger than a 25mm or 30mm gun for their patrol and mine warfare vessels. For roles where a larger gun is required a navy which already has 76mm and 127mm guns on its major combat vessels would probably be reluctant to introduce a third calibre like the 100mm. Keeping support, training and ammunition resupply as simple as possible are a few of the obvious reasons for this.

Cheers

 

[Lucasnz]

So as a basic scenario, the ship is 1-2 km off shore, no real threat level, and the NGS is being provided within 5 km of the beach?

I was thinking more a long the lines of 6-7km out, and a 10km support zone.

For low level conflict and roles I suspect navies would want to use a general purpose gun that is ideally of the same type as used in other warships in the fleet. Both the 100mm and 57mm gun have appeal for some scenarios and some navies, like those of New Zealand and Australia for example, have nothing larger than a 25mm or 30mm gun for their patrol and mine warfare vessels. For roles where a larger gun is required a navy which already has 76mm and 127mm guns on its major combat vessels would probably be reluctant to introduce a third calibre like the 100mm. Keeping support, training and ammunition resupply as simple as possible are a few of the obvious reasons for this.

True, but NZ was alreadly looking at introducing a 76mm when the orginal RFP for the OPV's was released, so looking at the 100mm isnt going to hurt. The key question is whether the 76mm is the best weapons for the job in the South Pacific.

 

[Whiskyjack]

I was thinking more a long the lines of 6-7km out, and a 10km support zone.



True, but NZ was alreadly looking at introducing a 76mm when the orginal RFP for the OPV's was released, so looking at the 100mm isnt going to hurt. The key question is whether the 76mm is the best weapons for the job in the South Pacific.

I recommend looking at www.navweaps.com, I was surprised by the difference between maximum range and effective range.

The most interesting thing is that 17km would be stretching the effective range of a lot of the systems mentioned here.

 

[Lucasnz]

I recommend looking at www.navweaps.com, I was surprised by the difference between maximum range and effective range.

The most interesting thing is that 17km would be stretching the effective range of a lot of the systems mentioned here.

Interesting: If accurate the 100mm has an effective range of 4000m more than the 76mm. Thanks for the link.

I'd still stand off at a greater distance than 1-2km, in order to avoid some items like 81mm etc.

 

[Whiskyjack]

Interesting: If accurate the 100mm has an effective range of 4000m more than the 76mm. Thanks for the link.

I'd still stand off at a greater distance than 1-2km, in order to avoid some items like 81mm etc.

Agreed.

I would still like to see something like the NLOS-LS, which can be mounted on a ship and use UAVs/FOs for targeting. It can also be unloaded to become a ground asset after the initial landings etc...

Be a joint asset Army/Navy.

The limiting factor with NGS is the lack of range. If the support is needed more than 10-15kms inland then the systems we are looking at become irrelevant. Or alternately the threat environment has the ship limited to 10 km off shore e.g. some old Soviet 122mm etc...

Of course for the Pacific Island environment, the threat is basically nil, so the ship can come to within 3-5km of the shore in most circumstances.

 

[Tasman]

I was thinking more a long the lines of 6-7km out, and a 10km support zone.



True, but NZ was alreadly looking at introducing a 76mm when the orginal RFP for the OPV's was released, so looking at the 100mm isnt going to hurt. The key question is whether the 76mm is the best weapons for the job in the South Pacific.

I think the 76mm gun is a good choice for a small navy in the South Pacific and personally I would have liked to see the NZ OPV fitted with this calibre. On the figures you have provided the 100mm would be a better NGS weapon and better in the anti shipping role but I guess NZ would have sought commonality with Australia if they had gone to a larger gun. In the pre WW2 days the 4 inch gun (close to a 100mm) was the weapon of choice on British sloops charged with policing, flag showing and dealing with low level conflict so, even then, it seems like this was seen as an ideal calibre for this sort of operation.

The 100mm would be a good choice but the desire for standardisation and limiting the number of weapon types would work against its selection.

Originally Posted by Whiskyjack
I recommend looking at www.navweaps.com, I was surprised by the difference between maximum range and effective range.

The most interesting thing is that 17km would be stretching the effective range of a lot of the systems mentioned here.

Thanks for the link Whiskyjack.
Cheers

 

[contedicavour]

Nodoby here has mentioned one key fact : France is abandoning the 100mm gun aboard both Horizon and FREMM ships... in favour of Oto Melara 76mm SR.

If France, which heavily supports its defence industry and has a long history of national procurement, has made such a decision .... ope rest in peace 100mm

cheers

 

[DoC_FouALieR]

As Contedicavour says, it is true that we are abandonning the 100mm Gun for 76mm SR, because it is more cheap to install 76mm gun that are very common, and the ammo too.
It is a question of european standardisation.

The 100mm has not be designed to land attack, but is a very effective weapon in a AAA role. Proximity and delay fuse are available, and with a high rate of fire for that caliber and a range of ~ 4 nm in AA, it is a valuable gun.
Really, as a french navy officer, I can ensure you.

 

[Mangusta CBT]

76 OTO now have guided ammo with 5 km range

http://www.otomelara.it/products/images/gallery/davide_1.jpg

And also multifunction fuze like Bofors 3P

http://www.otomelara.it/products/Images/naval_development_pfuze.jpg