The G3 Battlecruiser/Fast Battleship

[alspug]

I was watching one of my favourite Naval Historians on Youtube recently and he mentioned the British 16.5 inch gun in relation to the G3 class and it's potential as it is in a sweet spot as far as capability goes. Then he spoke of the 1.5 inch increase and it's comonality with British calibre advances.
It got me thinking and I went mentally back to the 12 inch gun on the Dreadnaught and then the 13.5 inch for the super dreadnaughts followed by the 15 inch on the QE class etc. The gun calibre of 14 inch was not a RN standard but one adopted when ships got taken up from building for other nations.
The proposal of the 18 inch for the N3 was in line with the 1.5 inch convention proven over the previous 15 years.

I found the proposal to be very much in line with RN procurement and also the advancement of capability. For example if you have a 15 inch gun then the 16 inch is not much of an increase in capability.

In the same talk the speed of the Nelson class was brought up and it was mentioned that the extra 1500 tons of space left in the design could have been used to add a third shaft and enough SHP to boost speed considerably. I am sure I misheard but 28 knots was mentioned. I was thinking that it would take tripling of the SHP installed to get to that kind of speed.

It is also worth noting that a RN that gets to build the 2 G3 class ships will then also have five fast ships in the fleet instead of three and enable HMS Hood for example to get her full refit.

In terms of cpability the firepower of the Nelson class was superb but her slow speed handling and ability to hold large sections of the world at risk due to mobility was low.

The R class will be seen as far more obsolete due to the Fast wing having Five 30 knot plus Battle(ship/cruise) complemented by 5 25knot Battleships that will recieve more power in order to work with the fast wing better. boosting installed power to 120,000sph would change the speed and utility greatly. How to get that power into the provided rooms is beyond me. A better bow shape would help also.

I want to know other peoples views on all of this. Was it possible to have a pair of G3 class ships built and could the British Empire build docks able to support them in enough places around the world quickly. For example the Singapore docks got completed on the eve of WW2 and worked well for the Japanese. Could Sydney Harbour and Alexandria get improved before the war etc.

 

[Dorknought]

The WNT was to stop the need to replace all the Super-Dreadnoughts with Super-Hoods, this includes the growth in supporting infrastructure. IIRC there were 5 docks in the UK that could support G3 size ships. Alexandria wouldn't be worth the investment especially if it diverted funds from Singapore. Sydney for the same reason. Singapore is really the key as the likely adversary is Japan. There was a large dock built in Esquimalt on the Canadian west coast in the 20's.

While 16.5" guns were considered for G3, the RN had only ever planned (and built) 18" after the 15" entered service. The origin was Fisher and his concept of 'plunging' on with significant calibre increases to head off competition. The Germans had understood this when they went from 12" to 15" on advice from Krupp that the RN couldn't follow as 15" was too big for wire wound guns. Perhaps the 16.5" was seen as needlessly provocative against US and Japanese 16" already in service. It was an easy decision as they wanted a new type of gun -light shell and flatter trajectory, and they had comitted to neither 16.5" or 16".

 

[Jellico]

The WNT was to stop the need to replace all the Super-Dreadnoughts with Super-Hoods, this includes the growth in supporting infrastructure. IIRC there were 5 docks in the UK that could support G3 size ships. Alexandria wouldn't be worth the investment especially if it diverted funds from Singapore. Sydney for the same reason. Singapore is really the key as the likely adversary is Japan. There was a large dock built in Esquimalt on the Canadian west coast in the 20's.

While 16.5" guns were considered for G3, the RN had only ever planned (and built) 18" after the 15" entered service. The origin was Fisher and his concept of 'plunging' on with significant calibre increases to head off competition. The Germans had understood this when they went from 12" to 15" on advice from Krupp that the RN couldn't follow as 15" was too big for wire wound guns. Perhaps the 16.5" was seen as needlessly provocative against US and Japanese 16" already in service. It was an easy decision as they wanted a new type of gun -light shell and flatter trajectory, and they had comitted to neither 16.5" or 16".

I always assumed the choice of 16" was part of the general reduction of firepower and protection to get the required speed out the fixed hull size. If the N3s were going 18" the Japanese and Americans were already provoked. You can't really go below 16" given it is the current international standard.

 

[Navigator]

Shipyard Location	Dock Name / Company	Maximum Length	Maximum Beam	Maximum Draught	(Super)Dreadnought Construction
Portsmouth	Lock D	1000	110	36	No
Portsmouth	Slipway	750	90	31	Yes
Portsmouth	13	560	82	31	No
Portsmouth	14	565	82	31	No
Portsmouth	15	563	94	31	No
Devonport	3	430	95	30	Yes
Keyham	8	659	95	31	No
Keyham	9	745	95	31	No
Keyham	10	741	95	31	No
Chatham	9	800	100	33	Yes
London	Albert Dock	1000	130	40	No
London	Albert Lock	1000	120	45	No
Tilbury	Dock extension	1300	130	45	Yes
Tilbury	Lock extension	1050	130	55	No
Sheerness	Floating Dock	680	113	33	No
Liverpool	Gladstone	1020	100	36	No
Liverpool	Canada	925	94	32	No
Birkenhead	Cammell Laird	650	90	29	Yes
Birkenhead	6	730	85	30	No
Birkenhead	7	880	95	32	No
Barrow-in-Furness	Vickers	810	100	35	Yes
Wallsend	Swan Hunter	880	108	38	Yes
High Walker	Armstrong Whitworth	1000	120	40	Yes
Hebburn	Hawthorn Leslie	700	90	28	Yes
Avonmouth	Outer	855	100	34	No
Southampton	6	860	90	33	No
Pembroke	Slipway 1	750	95	32	Yes
Pembroke	Slipway 2	750	95	32	Yes
Rosyth	1	850	110	36	No
Rosyth	2	850	110	36	No
Rosyth	3	900	110	36	No
Clydebank	John Brown	920	126	44	Yes
Renfrew	A	1020	110	40	No
Dalmuir	Beardmore	650	105	35	Yes
Govan	Fairfield	900	110	36	Yes
Govan	Harland and Wolff	550	75	36	Yes
Belfast	Harland and Wolff	950	110	40	Yes
Belfast	New	750	96	32	No
Haulbowline	1	608	94	30	No
Gibraltar	Prince of Wales	850	90	33	No
Malta	5 & 6 (renamed as 4)	770	95	32	No
Newfoundland	St John	569	85	30	No
Nova Scotia	Halifax	572	89	30	No
Simonstown	New	750	95	35	No
Bombay	Trust	500	65	30	No
Ceylon	Colombo	708	85	30	No
Singapore	Keppel 3	846	100	35	No
Hong Kong	Quarry Bay	750	88	33	No
Kau Lung (Kowloon)	1	700	86	30	No
Sydney	Woolwich	675	83	32	No
Adelaide	Commercial	500	60	32	No
Auckland	Cressey	521	80	30	No
Suez	Canal	1200	108	31	No

This table details shipbuilders and dockyards, which lie within the British Empire, for Royal Navy dreadnoughts and superdreadnoughts of at least 500' length (except Devonport), 60' beam and 28' working draught. Dimensions are given in Imperial feet and the dates of the primary source information about these facilities vary within the range 1913 to 1918.

Edit: to clarify units of measurement and to add two shipbuilders originally omitted; see posts numbered 4,504 and 4,512 for details.

A table of available dockyards from another Royal Naval discussion which has mentioned G3 and alternatives. Also see my temporarily paused thread: Two G3s instead of HMS Nelson, HMS Rodney and HMS Tiger.

Edit: Calibre reduction was to save topweight for better stability and reduction in immersed draught giving slightly higher top speed.

 

[Simon Darkshade]

That table is an excellent resource.

Would it be at all possible to please get a link to the original thread/post so that it could be linked in other thread discussions? I can think of at least two where this data would be exceptionally useful on this forum alone.

It beat me to the chase of what I was going to link to which has much the same impact - there were more than 5 docks that could take ships of 856ft x 106ft.

 

[Admiral Jellicoe]

Benbow, Victoria and Sans Pareil had 16.25inch weapons - never heard of the 1.5 inch increment before

 

[Navigator]

The link is embedded in the quote header: https://www.alternatehistory.com/forum/goto/post?id=24324741

 

[Navigator]

Benbow, Victoria and Sans Pareil had 16.25inch weapons - never heard of the 1.5 inch increment before

The 1920/1921 series of designs were originally planned around 15", 16½" and 18" calibres. The reduction took place in the late stages of the final refinement of the G3.

 

[1Big Rich]

The 1920/1921 series of designs were originally planned around 15", 16½" and 18" calibres. The reduction took place in the late stages of the final refinement of the G3.

The concepts of that era can be seen here

https://alternate-timelines.proboards.com/thread/3679/royal-navy-battleships-battlecruisers-desgins

with stats provided below in a post by myself.

IIRC, as you point out above the 16.5 was reduced as a weight-saver, but there was also talk that caliber was not liked in RN service (though one would think a new weapon wouldn't be viewed the same as a predecessor of the same caliber)

Interesting that for all the talk of docking limitations at the time, the reduction caliber in G3 to 16in was reinvested into a better ship and not a smaller ship to make the design compatible with more docks....

Regards,

 

[ArtosStark]

I was watching one of my favourite Naval Historians on Youtube recently

Which one, if you don’t mind me asking?

and he mentioned the British 16.5 inch gun in relation to the G3 class and it's potential as it is in a sweet spot as far as capability goes. Then he spoke of the 1.5 inch increase and its comonality with British calibre advances.
It got me thinking and I went mentally back to the 12 inch gun on the Dreadnaught and then the 13.5 inch for the super dreadnaughts followed by the 15 inch on the QE class etc. The gun calibre of 14 inch was not a RN standard but one adopted when ships got taken up from building for other nations.
The proposal of the 18 inch for the N3 was in line with the 1.5 inch convention proven over the previous 15 years.

I found the proposal to be very much in line with RN procurement and also the advancement of capability. For example if you have a 15 inch gun then the 16 inch is not much of an increase in capability.

According to DK Brown the 16.5” was reduced to 16” because the DNC calculated (or was told by the armament manufacturers?) that a triple 16” turret could be made the same diameter as a twin 18” while a 16.5” triple could not. This reduced cost slightly and gave the DNC more options. It wasn’t totally clear yet how the design would unfold or what units might actually be funded. Commonality would, in theory, allow the DNC to better adjust to changes in the program.

In the same talk the speed of the Nelson class was brought up and it was mentioned that the extra 1500 tons of space left in the design could have been used to add a third shaft and enough SHP to boost speed considerably. I am sure I misheard but 28 knots was mentioned. I was thinking that it would take tripling of the SHP installed to get to that kind of speed.

1500 tons extra could have been used for a lot of things. Like improving the reliability of the guns or keeping lockers and doors from buckling due to the light construction. In the actual design of O3 (which became the Nelson class) weight ran out around the time they were looking at secondary armament protection. As such those only had 1” of splinter protection. So that might be the first place they put extra weight if they realize they have it.

As to the speed, you can theoretically determine the increased requirements for a certain speed by using the cubic relationship:
28 knots /23 knots = 1.217
1.217^3 = 1.8
1.8 * 45,000 shp = 81,190 shp.

Note that this is on the exact same hull with the same properties. In reality adding in that amount of power would require changes to the hull, and would change the weight distribution, and wetted area, which would probably increase the required amount a little.

I want to know other peoples views on all of this. Was it possible to have a pair of G3 class ships built and could the British Empire build docks able to support them in enough places around the world quickly. For example the Singapore docks got completed on the eve of WW2 and worked well for the Japanese. Could Sydney Harbour and Alexandria get improved before the war etc.

Industrially possible? Yes.

The G3’s represented many of the latest technologies of the time but it was certainly within Britains industrial capacity to create. As were any expansions to docks and berths.

Financially possible? Maybe.

Britains debt has gone from 25% of GDP before the war to 135% after it with many of its traditional sources of income now being threatened (even to a modern first world state that is kind of hefty, and we have much easier sources of credit than they did). It wasn’t a surprise that the treasury was looking for spending cuts wherever they could find them. If the ships were considered to be required to maintain security then yes, they could have been paid for. However, the problem is always going to be that the Treasury, the Cabinet, and the RN are going to have different thresholds for being convinced of something being “required”. Getting them past all of them would have been a difficult task.

Diplomatically possible? Just yes.

It’s pretty likely that the G3’s were approved and sent to the builders only as a bargaining chip at Washington. However, in discussions with his opposite numbers Balfour did push them a fair bit, and actually managed to obtain acquiescence (though not enthusiasm, particularly in the case of the American delegate, Hughes) for Britain to build 2 G3’s at the cost of scrapping more of the earlier ships. Further support for them being a bargaining chip only is that, having attained this concession Balfour then almost immediately gave it up, opting instead for 2 new 35,000 ton ships (which, to be fair, was already a useful gain).

However, had the British government actually wanted the G3’s, they could have had two of them under the treaties.

Politically? Probably no.

Lloyd-George was PM at this time. He was many things, both good and bad. One of the most prominent things he was was a slimy git. One of the things he was not was a fan of military spending. Particularly when it was unpopular. And it was unpopular.

As early as 1919, Austen Chamberlain, then Chancellor of the Exchequer, had pushed for the RN to be reduced down to 15 capital ships with more cuts to follow in subsequent years. The government refused to authorize new capital ship construction and when Jellicoe had asked in June 1919 about the capital ship program he had been told that they relied on negotiations for arms limitations and that current construction was confined to completing ships at an advanced stage. The Geddes committee recommended the use of the “10 year rule” and naval estimates in 1920 dropped from £170 million to £60 million. The RN was told to plan for only a 60 percent superiority over the IJN, ignoring the USN entirely.

It was against this background that the RN proposed their £75 million program for G3’s and N3’s in 1920. It caused a bit of a public outcry when it was found that the Navy was contemplating a major building program.

In December 1920 Lloyd George told the RN that no new capital ships were to be built until a sub committee of the CID could report on wartime lessons and the future place and usefulness of the capital ship in naval operations.

Considering the mixed messages of such lessons at the time it is perhaps unsurprising that the committee came back without a firm answer either way. However, that was enough for Lloyd George to prevaricate and hold off pressure from Beatty and Churchill. Eventually, in early March 1921, Lloyd George decided to allow starting funds for 4 of the ships to be added to the estimates for 1921-1922 (Fiscal year beginning April 1). However, this was only £15 million of the £75 million total and was contingent on the Dominions chipping in (which was a big ask). And when the Admiralty went to the Treasury to get approval to order long lead items like guns and armour, they were refused. The amount had been added to the estimates but Cabinet had not actually confirmed the spending. Lloyd George had basically used his acquiescence to disperse naval pressure but would not support it when it came time to deliver. By that time the US was making noises about a disarmament conference which took priority out of the Navy’s requests.

In mid 1921 there was an Imperial conference to determine strategic requirements going forward. At this conference the RN managed to get the Dominions to agree to commit £2.2 million out of their reparations from Germany. It wasn’t a lot but it was enough for Beatty to go back to Cabinet in July 1921. This time he was allowed to start the G3’s. Partially because he got money from the Dominions, but more importantly because with the Washington conference coming up, the Government needed the bargaining chips.

(Very) Long story short, LLoyd George’s government was not interested in the cost of the G3’s. Now theoretically, if Balfour had “gone rogue” and one back with a commitment to allow for the G3’s construction then the government would have been committed to it. And they probably would have been more ok with that than with a program of 8 such ships. But there would still have been plenty of room for Cabinet to prevaricate and try to reduce the cost of the ships even with such an agreement in place.

 

[Spencersj345.346]

Which historian was it?

 

[Spherical_light]

Ah, another person who likes Dr. Alexander Clarke. At least, his WNT stream from two weeks ago roughly was what I watched and he had offered ideas on the G3s there, in addition to some interesting thoughts on some of the other ships. Granted, I also watched most of his Equitable Treaty series too last week, so I might be getting things mixed up a bit...

He's done some good videos on the WNT recently... Last weekend [previous weekend to this one] he did a stream/video lecture on what the WNT Governments were aiming for; a very interesting conclusion too. Highly advise watching it, just beware, as even the video version is around 90 minutes long. The stream/ live version is over 3 and half hours long.