Shipbucket

Hi I'm was thinking about an AU with a different RN rearmament (many changes but more rational calibres among them)

RN guns WW2
How many types of gun do you need to arm the RN building up for WW2 ?

1) Historically you have the following in service in the 30s (DAMS/old stuff not listed)
16'
15'
8'
6'
5.5'
4.7'
(BL/QF/AA all different )
4'
(BL/QF/AA/etc all different )
2pdr
.5

2) They then built, (OTL)
14'
5.25'
4.7' (2 different new guns)
4.5'
40mm
20mm

3) How many would you really need ? Could you get away with just new Building (+ rebuilding/spares of the older guns),
6' for new CL/CAs http://navweaps.com/Weapons/WNBR_6-50_mk23.htm
4' for AA/DP an improved http://navweaps.com/Weapons/WNBR_4-45_mk16.htm
40mm http://navweaps.com/Weapons/WNUS_4cm-56_mk12.htm

I would be using all the old guns in the top section 1
I would not build most of the section 2 set
Just Build new the section 3 and rebuild/spares for some of the section 1.

This should save loads of designers (one of the big limits on RN rearmament, you only have 3 new guns to make and much fewer mounts to design/rebuild as well. (15x2(old), 6x3, 6x2(old), 4x2, 4x1, 40x8, 40x4, 40x2, 40x1(Army ?))

Do you think I can get away with using 4' as my DP gun for my light DDs (the RN ones are smaller anyway) and just not build the Tribals and build more CLs instead ? and also as my secondary gun on CVs/BBs/CLs/CAs as air is way more of a threat than surface (and you can use the main guns if you have to ?)

My main question is do I need a 4.5/4.7/5.25 thing ? or can I do with 4' and then 6' ?

Thanks JSB

IMHO the 4-inch is just too weak for surface work while the 6-inch is unsuited for AA work. OTOH the 5.25-inch wasn't really a good AA weapon.

I do see a need for something in between. I never did understand what the 4.5-inch did that the 4.7-inch couldn't, so I would go with 4.7-inch as a good surface gun as well as a DP version for those ships that need both good AA and a reasonably powerful surface gun.


And the IJN had the same problem with a lot of calibers. When the 5.5-inch gun was adopted the 6-inch guns on the Kongo's and Fuso's should have been replaced with them and those guns scrapped. I never understood the need for the 6.1-inch gun although the 3.94-inch gun was a good caliber between the 3-inch and the 4.7-inch. Again, I don't understand the need for the 5-inch, what could it do that the twin 4.7-inch gun couldn't?

An off topic explanation for the Japanese guns is in order here. Most Japanese guns quoted in the English speaking world using Imperial measures i.e 6", or 5". In metric measures 6" is 152mm, but it was rounded off into either 150mm (5.9"), or 155mm (155mm), and so we have now three different gun sizes for the same gun. The same goes for the 3.9" AA gun which is 100mm but some sources had it rounded into 4" gun (102mm), and that in turn rounded off into 105mm (4.1").
I hope this explains some of the confusion.
As for an AU armament I'd go for a middle size gun between the 6" and 4", as the 4" was indeed considered too weak for surface action and 6" was considered ineffective in AA work (too slow really). The 5.25" gun was somewhat of a compromise for DP gun the size was chosen to give the gun, more than a decent power as the main armament of a cruiser (4.7" was deemed as too small for that), and was seen as not large like the 6" gun for AA work. In fact the best AA cruisers of the Dido class were HMS Scylla and HMS Charybdis, both of them were armed with the 4.5" BD mounting.

_________________
Thank you Kim for the crest

"Never fear to try on something new. Remember that the Titanic was built by professionals, and the Ark by an amateur"

You also have the 7.5" on the Hawkins class cruisers.

And the 13.5....

I was hoping that could be forgotten under old guns (and the list on navweps is soooo long) (admittedly they would still hurt)

By the 30s the 7.5 is old and I think obsolete (single deck mount with to heavy a shell) so can be forgotten ? (and some have been removed already ?)

Thanks JSB

The problem you have with the Royal Navy especially and others as well, is that the Dreadnought revolution expanded so quickly from 11", 12", 13.4-5-8", 14", 15", 16" in less than 12 years. The ships built with the later weapons due to your beloved WNT, LNT 1&2, were to last over 20 years in service with the different guns and marks going through with them.

If you look at only the weapons (RN) that were on ships completed from 1918-27, then you go from Nelrods 16", Hood 15" (5.5"), Hawkins 7.5", D & E 6", Leaders and later VW - 4.7", S & VW 4".

Do you need any more than those sized weapons? Forget the 5.25 and 4.5, combine the work done on those weapons for high angle turrets and use the 4.7" gun size for the result. Keep the ammunition at a reasonable number of shell types. The 8" gun is the same, the only reason the RN had them is because everybody else did. The 7.5" was a good enough gun, with better loading facilities in a twin/triple turret you did not need the 8", want a bit more range increase the barrel length/calibre.

Probably the best destroyer the RN had in the Mediterranean was the L4, 4" version of the L class. When fighting Italian destroyers with gunfire it was found the volume of fire from the 4" easily made up for the smaller shell. As AA escorts they were superb. It was not by chance that the Canadians and Australians completed their later Tribals with twin 4" in place of either 4.5's or 4.7's.

My worry is that by the time the Can/Aus T got finished they where only thinking about AA fire (and maybe a sub) where as in 37 I would have to weigh up surface action a lot more, but I tend to agree (but don't have good evidence) that 4 inch (in a good mount/fire control) would be ok v a heavier gun on opposition DDs.

JSB

My Au Fleet will be as follows,

BBs - reuse the 15' twins on 35(ish ) tons with lots of 4' and 40mm
CV - big and new with 4' (8x2) and 40mm (lots)
CL- 6' (4x2) and 4' (4x2) and 40mmx6x1
DD - 4' (3x2) and 40mm (5x1)
DE - 4' (2x2) and 40mm (3x1)

I'm hoping saving on types will allow more to be made than OTL.

What do you think ?

The first ship my CL ( Plan is to just mass produce one do it all ship it may not be very strong but I will hopefully be fighting 3 v 1 )
OTL the RN built L-8 (9,740 ) A-4(6,665) T-10 (12,000) D-16 (7,000) C-11(10,800) M-3 (11000 really to late)= 49 (488,380t /8,000t= 61+ probably more due to economy's of scale ? and save on lots of scares designers and engineers)



JSB

I love the Modified Leander class, best looking CL's. I do not need to be credited for 'parts', they are available to everybody.

Next up my light DD/DE

Type I - 4' (2x2) 40mm (3x1) TT (1x4) +DCs, Turbines for 30Kn
Type II - 4' (2x2)* 40mm (3x1)* ASW (12'x3x2 ) DCs, Turbines for 30Kn
Type III - 4' (2x2)* 40mm (3x1)* ASW (12'x3x2) DCs, reciprocating steam engines for 20Kn
*some not full equipped at commissioning time.
(Type II and III may drop to single 4' at stern to make more weight/space for ASW 11'.)
(delays in 40mm production mean many ship sail without full fit)

Any comments welcome

JSB