Rodney + POW v Littorio and Victorio Vento

[RF]

I realise this is going off the original thread, but I don't think that the Italian strategy defined in the above post did work because right in the middle of this ''convoy duel'' was Malta. Supporting local operations should have included seizure of Malta at the point it could have been done - when Italy declared war. The Italian posture of supporting local operations appears to me to be entirely defensive and plain wrong when the need was to deprive the British of their key bases - Malta and Alexandria. The latter was of supreme importance because it was at the entrance to the Suez Canal and key to maintaining communications and supplying the Italian forces in East Africa.
We have discussed this in another thread and I think we agree that the Italian failure to wage an aggressive war in June 1940 was, in your words, ''a monumental blunder of inaction.''

[paul mercer]

One thing that puzzles me here, if the Italians has decided to have a to the last man(ship) stand up fight surely their speed would have been limited to the speeds of the slowest British ship (Rodney), given the normal ranges under which battleships would engage one another, (this would have been a similar senario had Bismarck met Rodney on her way to Brest and decided to fight) Of course the Italians might have been more manouverable due to their speed, but would that make that much difference when ships are hurling one ton shells at each other at long range? I cannot imagine POW disappearing off into the distance to take on two battleships and several cruisers on her own. Two other questions, would the training and demeanor of the crews on the opposing ships make a difference and would the presence of Ark Royal had a bearing on the battle?

[Lutscha]

How much impact would the VV's decapping system be likely to have?
This one looks to me like it could go either way. From what I recall one of the most serious flaws of the Italian BBs was their reaction to torpedos. That's unlikely to play an important part in this one.

VVs belt armour system is invulnerable at all common ranges even under 10km against her own guns.
PoWs belt is easily penetrated at all reasonable battle ranges by all the guns of the modern BBs (excluding SH).
I have often heard praise about the protected volume of the KGVs but the belt fails to keep out shells of all her contemporaries. She has no IZ against a VV which has one at least out to 25km. The belt is by far the weakest and more likely to get penetrated by hits than the TDS of her opponents. I was quite surprised to see how weak the belt is. This gives KGV the worst armour of all modern BBs imo.

Without late war FC she needs to be really lucky to not sustain critical damage while she is incapable to seriously hurt VV.

[David89]

How much impact would the VV's decapping system be likely to have?
This one looks to me like it could go either way. From what I recall one of the most serious flaws of the Italian BBs was their reaction to torpedos. That's unlikely to play an important part in this one.

VVs belt armour system is invulnerable at all common ranges even under 10km against her own guns.
PoWs belt is easily penetrated at all reasonable battle ranges by all the guns of the modern BBs (excluding SH).
I have often heard praise about the protected volume of the KGVs but the belt fails to keep out shells of all her contemporaries. She has no IZ against a VV which has one at least out to 25km. The belt is by far the weakest and more likely to get penetrated by hits than the TDS of her opponents. I was quite surprised to see how weak the belt is. This gives KGV the worst armour of all modern BBs imo.

Without late war FC she needs to be really lucky to not sustain critical damage while she is incapable to seriously hurt VV.

According to Nathan Okun, VV's belt is vulnerable to Bismarck's guns out to 17,500m taking into acount the decapping system, while KGV's belt is vulnerable out to 21,500m. On the other hand, VV's belt is shallow, annd unlike KGV's is vulnerable to plunging fire at long range. And despite the thickness of VV's deck armour, due to the extremely poor layout, she is several times as vulnerable to long range fire as KGV, who has a excellent deck which is a match for any of her contemporaries, except the Yamato. And KGV does not need late war radar, she had RDFC against Bismarck in 1941 and PoW had RDFC for the fight disscussed in this thread. So the strategy for KGV here is the same one which grants KGV superiority over Bismarck, that is hold the range open and rely on better gunnery and deck armour.

[Lutscha]

VVs belt is supported by 2 inner bulkheads which keep out the shells from her vitals. KGVs belt gets penetrated out to 25km even by her own guns. One correction though only VVs gun will still reach into the vitals of KGV at that range, the other guns penetrate (BS, R and KGV itself) the belt but are stopped before going in very deep.

Here are some nice graphics but you have to register unfortunately: http://forum-marinearchiv.de/smf/index. ... 20.30.html

[David89]

With the current version of face hard it looks different. VVs belt is supported by 2 inner bulkheads which keep out the shells from her vitals. KGVs belt gets penetrated out to 25km even by her own guns. One correction though only VVs gun will still reach into the vitals of KGV at that range, the other guns penetrate (BS, R and KGV itself) the belt but are stopped before going in very deep.

Here are some nice graphics but you have to register unfortunately: http://forum-marinearchiv.de/smf/index. ... 20.30.html

Assuming VV can get hits at over 25,000m. I think she could get hits at that range in a lenghy engagement, but VV will be a wreck before she can do any serious damage. Meanwhile KGV's shells are going through VV's deck at the same range.

[Lutscha]

How will PoW wreck VV without late war RFC at ranges over 25km before VV can reply?

[David89]

How will PoW wreck VV without late war RFC at ranges over 25km before VV can reply?

PoW and Rodney both have a comprehensive RFC setup at this point in the war. And considering how poor VV's deck is, a couple of long range hits could potentially deal out massive damage. Even without a "lucky hit" on a magazine or a crippling engine room hit, the damage will be heavy. So the Italians either try to fight at long range, in which case the better British gunnery and deck armour will really show, or they try to close the range as fast as possible, in which case either the lead ship or both will sustain major damage, and up close the two British ships will be firing as fast as they can reload, considerably faster than the VVs can fire and swamp them with fire. Remember a hit on the unarmoured fire control will severely affect fighting capability, and a turret hit would certainly knock it out at close range, even if the belt armour is inpentrable at the same range.

[Bgile]

I don't think British RFC was nearly as good in 1941 as it was late war. I know US RFC sure wasn't. I really doubt it was good enough to make a decisive difference at 30k yds or more. IMO no-one would be hitting much at that range.

[dunmunro]

VVs belt is supported by 2 inner bulkheads which keep out the shells from her vitals. KGVs belt gets penetrated out to 25km even by her own guns. One correction though only VVs gun will still reach into the vitals of KGV at that range, the other guns penetrate (BS, R and KGV itself) the belt but are stopped before going in very deep.

Here are some nice graphics but you have to register unfortunately: http://forum-marinearchiv.de/smf/index. ... 20.30.html

That graphic at marinearchiv is a bit misleading. Here's a better comparison:
http://www.sfu.ca/~dmunro/BB_comp1.jpg
You should note that VV has no longitudinal subdivision in her machinery, spaces, which was similar to USN BB design except it did not use a unit system, whereas KGV's machinery spaces are heavily subdivided. A single diving hit, as per the hit that PoW scored on Bismarck could cost VV 1/2 her machinery in a single hit. Also note that KGV's boiler rooms are protected by additional outboard compartmentation. VV has very little armoured freeboard and this is also a consideration.

Note the drawing is a bit misleading as Washington, in the drawing, appears to show a longitudinal bulkhead in Washington, but I think that was a support member of some kind and it was not a bulkhead.

Name total belt depth- depth under WL-depth above WL
King George V 7,32_____ 4,58____ 2,74
Richelieu 6,10_______ 3,96_____ 2,14
Bismarck 7,32______ 2,44_____ 4,88
Littorio 3,96_______ 2,13_____ 1,83

Bismark's above WL figure includes the 7" thick extension.

[Lutscha]

What exactly is misleading? Btw, if you have something to improve, you can post there in English.

Of how much importance is KGVs protected volume when the belt gets penetrated so easily?

[dunmunro]

What exactly is misleading? Btw, if you have something to improve, you can post there in English.

Of how much importance is KGVs protected volume when the belt gets penetrated so easily?

Several things are misleading: The drawing as presented at marinearchiv does not indicate the distance from KGV's belt to her boiler rooms and after engine rooms, nor does it indicate the higher degree of subdivision within KGV's machinery spaces. The other factor is that the penetration scenario for the RM 15" versus KGV always assume 0 obliquity, but this is unlikely in an actual action and a 20deg figure is more likely. Additionally, the RM guns are always assumed to have a new gun MV, but again this is unlikely. If we assume 20deg obliquity and some reduced MV (say 2650fps) in the RM 15" guns, then KGV will have a substantial immune zone of about 17,500 to 33,000yds. KGV is far more likely to score underwater hits, and as I've pointed out VV is very vulnerable to diving shell and would suffer severe damage from these types of hits due to her shallow belt and lack of longitudinal bulkheads in her machinery spaces.
Additionally, it is not clear to me from reading: http://www.navweaps.com/index_tech/tech-085.htm that the standoff space between VV's decapping belt and her main belt is sufficient to effectively decap KGV's 14" shells, especially at low obliquity. So VV's vulnerability is greater than assumed in the marinearchiv thread, because underwater hits are not considered, which is odd because PoW scored two on Bismarck, while KGV's vulnerability is exaggerated because unrealistic assumptions are made regarding target obliquity and gun wear, and her greater protected volume minimizes the probability of underwater hits.
Finally, VV's low armoured freeboard mean that she will be far more vulnerable to capsizing from the effects of hits above the main belt.

[Tiornu]

I have a high opinion of KGV's belt protecton. It is extremely long, extremely tall, and fully external. Inclination would be nice, but you can't have everything. We can note also the quality of C armor against large shells.
Littorio is also more susceptible to capsizing because there are no voids in the TDS available for counterflooding.

[Nlneff]

If we assume a 20 degree target angle and 95% velocity, the final obliquity on KGV's machinery belt will be 23.15 degrees at 20,000 yards. A 13.73 CA belt with .75in D backing will be penetrated in full intact bursting condition by the Victorio's gun (final velocity 1814, 95% of normal) at 20000 yards, it will still be holed at 24000 yards. How are you coming up with your numbers?

[dunmunro]

If we assume a 20 degree target angle and 95% velocity, the final obliquity on KGV's machinery belt will be 23.15 degrees at 20,000 yards. A 13.73 CA belt with .75in D backing will be penetrated in full intact bursting condition by the Victorio's gun (final velocity 1814, 95% of normal) at 20000 yards, it will still be holed at 24000 yards. How are you coming up with your numbers?

I made an error when calculating the final obliquity and you are correct that complete penetration would occur at ~20k yds. I get a final obliquity of ~25.2degs with ~1800fps striking velocity at 20k yds. The reduction in MV will also increase the angle of descent, which gets a bit tricky to calculate.