Supercharged modifications to Revenge class Battleships

Hi all, late 1941 the four remaining R or Revenge class battleships were redeployed t the far East, forming the 3rd Battle Squadron, at Ceylon. The class was equipped with the 15-inch (381 mm) Mk I guns in four twin gun turrets.

The 15-inch Mk I was modified, starting sometime in the late 1930s, with two significant improvement. One, the maximum elevation of the gun was increased from 20 to 30 degrees, increasing maximum range and two, the projectiles were improved with a more streamlined ballistic cap, giving an improvement of over 5,000 yards.

The battleships and battlecruisers equipped with these guns, were given the upgrades as they underwent overhauls, but none of the R class had received them before WW2 began. Other ships were upgraded as WW2 progressed.

As an alternative improvement, the unmodified ships were given a ‘super charge’ of 490 lbs, the largest propellant charge that the guns and mountings could safely handle. Ships with the 30-degree adjustments didn’t use the ‘super charge’, as it placed additional barrel wear and mounting stress. With the supercharge, maximum ranges range improved by 5,000 yards, 300 yards short of the 30-degree ships.

Now I have some questions

I’m unclear as to whether a ship could simply be issued the 490 lb ‘Super charge’ or required some dockyard modifications to fire using one.

I think the propellants (or charges) were made up from four bags, was the ‘super charge’ simply a fifth charge. If not how easy was it to make these, was it only at the factory, or could dockyard magazines do this work?

Could the HE shell be fired with the super charge, as well as the APC version.

I don’t know of any ‘super charge’ firings, how badly did they wear the barrels and stress the mountings?

I think very limited numbers of HE shells were carried by the ships, I read that the fortress of Singapore, equipped with five of these guns, only had one HE shell. Was there a shortage of HE shells?

I think two (Royal Sovereign and Resolution) R class were enabled to use ‘super charge’ on the class sailing to the Far East in December 1941, is this the case?

These questions are based on my thoughts on the use of the R class for shore bombardment, and how far inland might they reach?

Regards
Fatboy Coxy

 

Coxy, the Wiki link gives most of the answers...
E G: " This wire-wound gun fired at a muzzle velocity of 2,450 ft/s (4 crh shell), or 2,640 ft/s (6 crh shell) with supercharge.
Weight of shell: 1,920 lbs (4 AP crh shell), 1,938 lbs (6 crh AP shell – 1937).
Weight of charge: 428 lbs cordite, 490 lbs cordite for supercharge. (I take that to mean that an extra 62lb bag was added for the "super" charge. As the Wiki animation shows, each shell had 4 bags of cordite, so for 428 lbs of charge each must weigh 107lbs - so how they made up the extra 62lb bag or approx 60% of a full size bag, is beyond me)
The firing life of a 15-inch gun was approximately 335 full charge firings using standard charges, after which it had to be re-lined.

Vanguard is probably the best example using these guns.

HMS Hood was fitted with modified mountings (Mk II) which allowed a 30 degree elevation.

Warships armed with the BL 15-inch Mark I gun:
Queen Elizabeth-class battleships (Five ships with eight guns each – 3 ships converted to Mk I (N))
Revenge-class battleships (Five ships with eight guns each)
Renown-class battlecruisers (Two ships with six guns each – 1 ship converted to Mk I (N))
HMS Hood – battlecruiser (Eight guns, Mk II mounting)
Courageous-class battlecruisers (Two ships with four guns each)
Erebus-class monitors (Two ships with two guns each)
Marshal Ney-class monitors (Two ships with two guns each)
Roberts-class monitors (Two ships with two guns each)
HMS Vanguard – battleship (Eight guns in mountings taken from Courageous and Glorious converted to Mk I (N), with additional armour, designated: Mk I (N) (RP12). The turret supports were designed to withstand supercharge firings.Vanguard was unique among British battleships in having remote power control (RPC) for her main battery turrets.
Coastal batteries
Two coastal guns ("Clem" and "Jane") were mounted near Wanstone Farm in Kent in the 1940s, and were used extensively for cross-Channel fire throughout the war.
Five guns were mounted in Singapore at Johore battery and Buona Vista Battery in the 1930s.

Hope that helps until a Naval bod comes along

 

Those guns were intended as coastal defence against battleships and therefore HE would be relatively useless. A recent history has suggested also that stories like only one shell were myth

 

PLEASE PLEASE,
I don't want to get into a discussion about the Singapore guns. I merely mentioned that as Singapore was a naval base, and as such I expected some munitions to be stored there for any contingency.

 

Hang on - why start asking questions if you don't want them answered?

 

Well thanks for the reply KevinBattle, but the Wiki link didn't really answer anything, indeed it reiterated the question over how a super charge was made up, and placed emphasises on the fact the Vanguard's turrets had been designed for supercharge firing, suggesting to me that the other older ships would be stressed when using a super charge firing. A Naval bod, or two would be most welcome

 

Super charge please Robert-w, not stuff like the guns faced the wrong way etc

 

Barrel wear in battleship guns has always been interesting to me. Just amazing engineering to get the velocities they did out of the barrel lengths used. I just looked at the wiki Kevin provided and saw that the barrel length was 650.4 inches and yielded a muzzle velocity of 2640 ft/sec with supercharge. That is the equivalent of a .30 caliber rifle with a barrel only 13" inches long, which has never been done, even with modern steels. Couple that velocity with the AP projectiles in the barrel lengths used and it's no wonder the barrel life was measured in hundreds of rounds and not thousands.

I know in the Iowa's, every shot was recorded and and range setting adjusted accordingly to allow for wear.

 

So why ask questions about HE charges?

 

Wrong.

Correct. Buono Vista Battery had 2x15" and Johore Battery had 3x15" guns. Since they were intended to repel attacks by Battleships they only had AP shells except Johore which had one HE.
SECRET CIPHER TELEGRAM
Desp. 0132 26/1/42.
Recd. 0430 27/1/42.

From:- G.O.C. Malaya
To:- The War Office
0.26 cipher 26/1.
Your 65542 (A.A.4.) 20/1
Coast Art. Maximum arc. Over Johore Mainland. Fifteen inch Johore Fort A1 067 100. A2 060 100 and 293 300. A3 75 100 and 292 315. Buona Vista B1 258 301 B2 051 061 and 253 290. 9.2 inch. Tekong. All round Arc. Except 01 limited for crest clearance even with half charge to minimum range ........ Figures each case after (A) give present maximum Arc. After (B) maximum Arc ........ At present only available 15 inch landwards projectile is one H(?E) obtained from Naval Base now at Johore Fort. Supreme Commander S.W. Pacific has been asked to supply 250 15 inch H.E. and 450 9.2 inch projectiles H.E.

The attempt to supply the requested HE failed.

On Super Charges: Extracted from 15-inch (38.1 cm) Mark I - NavWeaps
The rate at which these ships could be modernized was limited and by the start of World War II Malaya, Barham, Repulse and the five Royal Sovereign class battleships had not yet been upgraded. Royal Oak, Barham and Repulse were sunk early in the war, but the remaining unmodernized ships were given a "Super Charge" which consisted of the largest possible propellant charge that the guns and mountings could safely handle. These were issued starting in late 1941 and at the maximum elevation of 20 degrees allowed a range of 28,700 yards (26,240 m). However, from a study of the records, it would appear that no ship ever fired a shot using Super Charges, although they were used by the coastal artillery at Dover. Super Charges were not issued to ships with 30 degree mountings as the increased barrel wear and mounting stress was not considered to be acceptable. For this reason, sources which quote HMS Vanguard as having gun ranges in excess of 32,000 yards (29,260 m) are somewhat misleading, as such a range would have required the use of super charges, which she never carried.

Still trying to find out how the Super Charge was made up.

Tim

 

Re the use of the R class for bombardment purposes, at what time are you considering this?

Pre-war plans were that these ships would be decommissioned as the KGVs entered service. Even in 1939 their condition varied greatly. Royal Oak, having received a more extensive refit in the early 1930s and IIRC more armour, was the best of the bunch but of course was lost in Oct 1939. Revenge was considered the worst and remained so until sent to reserve in late 1943 after return from the Indian Ocean and being stripped of her guns.

Royal Sovereign also had problems with the handling gear in her hoists by the time she returned from the IO in late 1943 which the Admiralty didn’t want to repair. Was it repaired before her transfer to the USSR, or was that why she was chosen?

By late 1943 only Ramilles was worth retaining as a bombardment ship, principally as she had been refitted following torpedo damage at Diego Suarez in 1942.

Like Malaya, the Rs were worn out by mid WW2 and generally not considered worth doing much with.

 

timuk: Post #2 shows the weight of the super charge cordite, 490lb as opposed to the "normal" 4 x 107 lb bags of cordite for 428 lb propellant.
i.r.o. Vanguard the turrets were apparently designed for supercharge firings.

As to whether supercharge firings were ever made, why else would the propellant load be increased by such a specific amount?
There may not have been many, but if supercharged guns at 20 degrees were only slightly shorter range than 30 degree firings, that must have been done and assessed for that to be known.

But that's from Wiki, so a naval bod may have the "range" to answer more "accurately"...

 

Sorry - my post badly worded. When I said "Trying to find out how Super Charge was made up" I did not intend to refer to the quantity but rather whether it was 4x107lb (further in your previous link it actually says 108lb) + an additional 62lb bag or whether there were larger bags of 122.5lb each. For instance I know that in the artillery, certain cartridge cases contained bags which were removed or added to in order to achieve alterations to the standard charge ie: reduced or super.
As to the extract I quoted "that no ship ever fired a shot using Super Charge", assuming the quote is accurate, I presume it should be taken literally as 'no ship' rather than 'no 15" gun' as the quote goes on to mention that the 15" at Dover fired them.

Keep up the work, we'll get there in the end!

Tim

 

Just a comment as i have no knowledge of artillery aspects but.... with an additional charge, wouldn't this push the shell further into the barrel, to accommodate the extra length of the propellant charges, which would mean the rifling length would be lessened and thus affect the trajectory and accuracy?
Anyway, this is all well above my pay grade, we need someone who has deep knowledge on ballistics etc to appear.

 

That's just the problem I'm asking myself. One would think that when the shell is rammed it is pushed up against the start of the rifling and there is only a set space behind for the cartridge bags. With the artillery bags I was referring to the bags are contained within a brass cartridge so the problem doesn't occur.

Tim

 

I'm working on a alternative timeline regarding the fall (or not) of Singapore, and the fighting in the Dutch East Indies. Although the 3rd Battle Sqn was formed in March 1942 at Colombo, Ceylon, a couple of the battleships were there earlier. Specifically I was looking at a bombardment of Alor Star airfield, Kedah, northern Malaya, which lies 9 miles inland. The 15-inch gun, unmodified had a range of a bit over 13 miles (nice and accurate with the distances am I), which means she'd need to be about 4 miles off shore, a bit close to my thinking. However, if super charged, the range increased to a bit over 16 miles, a more comfortable 6-7 miles off shore.

 

The R class were used for shore bombardment,and early in the war too, although I have no idea if HE was used or not.

11th Oct 1940, HMS Revenge, the main unit in Operation Medium (not a great name eh) fired 120 rounds of 15 inch, over 18 minutes, at the harbour of Cherbourg, going after the invasion transport ships and barges, her six escorting destroyers lobbed in abother 801 rounds of 4.7 inch.

HMS Resolution bombarded German positions around Beisfjord on 1 May, and again on 13 May, in support of the landings, shelling German defences in the area.

On 15 August, HMS Ramillies bombarded the small Italian port of Bardia, in north Africa, along with the battleships Malaya and Warspite

None of these were super charged firings, indeed because they were all coastal, there wasn't the need for the greater range.

 

Do you have a date for this?

Tim

 

I have glanced through the RN Ammunition Manual BR 932 and still cannot find a definitive answer to Super Charges. All I have
found so far is the standard charge comes in 108lb bags. I can find nothing in the packaging section which indicates anything other than the 108lb (1/4 standard) charge.




For anyone who wants to look at the Manual in case I've missed something it is here: https://www.hnsa.org/wp-content/uploads/2014/08/br932.pdf

Tim

 

No specific date, but between December 1941 to February 1942 is the kind of time range