Rn vs IJN (3 Viewers)

[WARSPITER]

The RN changed strategy during the Mediterranean operations from blue water fleet type actions (Matapan etc), to convoy
attrition. This brought a whole new set of problems into play.

The fuel shortage (also known as what the hell were they thinking when they started this) became even more acute as escorts
for the convoys had to be given priority for fuel. Italy as per Japan had not done much in the way of ASW / AA / or radar
development and the price for the Axis merchant shipping was high.

The last folly came with the reinforcement of Tunisia when it was going to be impossible to keep the supplies going through.

 

[z42]

The RN changed strategy during the Mediterranean operations from blue water fleet type actions (Matapan etc), to convoy
attrition. This brought a whole new set of problems into play.

Was this a reaction to the RM fleet staying in port, or?

(also, the Axis forces did manage to extract a heavy cost on the Allied Malta convoys)

The last folly came with the reinforcement of Tunisia when it was going to be impossible to keep the supplies going through.

Yes. Maybe they could have saved more of their African forces had they started to evacuate sooner. OTOH might that have caused the African fronts to collapse faster, with the same end result?

The fuel situation is also a bit weird. They didn't have enough fuel to escort convoys, but did have enough fuel to try to supply fuel to Africa via the air?

Italy also has one of the largest coal deposits in the region (the Carbosulcis mine in Sardinia), yet in the interwar years they were dependent on imported coal. And AFAIU they had nothing like the German synthetic fuel efforts.

 

[ThomasP]

An interesting summary of the Italian oil situation in WWII can be found here:

"The Fuel Problem Of The Italian Navy in WW2"

 

[EwenS]

They were not sufficiently modernized for example with AA and ASW capabilities.

Don't be too quick to dismiss the ASW capabilities of the RM.

The RN lost 45 subs in the Med between the Italian declaration of war on 10 June 1940 and 1944 (41 prior to the Italian surrender).These losses were attributable to:

Mines - 20
Italian surface craft - 17
Italian subs - 1
German surface craft - 3 (1 possibly mined)
Rammed by an Italian merchantmen- 1
Bombed at Malta - 3

1940 - 9 (3 mined, 1 rammed & 1 loss to sub. 4 to RM surface craft)
1941 - 11 (8 mined, 2 to RM surface craft)
1942 - 13 (includes 3 lost by bombing at Malta Mar/Apr. 4 mined. 6 to RM surface craft)
1943 - 11 (8 before the Italian surrender, incl 4 to RM surface craft, and the other 3 to mines)
1944 - 1 (mined)

 

[WARSPITER]

Was this a reaction to the RM fleet staying in port, or?

(also, the Axis forces did manage to extract a heavy cost on the Allied Malta convoys)

The change in attack methods came about in part because the Italian fleet could not afford to lose it's larger vessels as they
were still a threat but were vulnerable if sailed.

The RN could not go too close to enemy held areas once they were defended by air as the risk became too high.

Somewhat of a stalemate if you like.

The change was able to come about because of Malta. By using submarines, aircraft and smaller attack vessels (force K etc)
the RN and allied units were able to concentrate on merchant shipping.

Yes. Maybe they could have saved more of their African forces had they started to evacuate sooner. OTOH might that have caused the African fronts to collapse faster, with the same end result?

I meant sending extra forces to Tunisia in the first place.

 

[EwenS]

The ability to use Malta as a base to attack enemy shipping, very much depended on how much effort the Axis put into bombing it, which in turn depended on how successful British anti-shipping operations were. A bit of a vicious circle really.

Force K (and Force B) of Cruisers and destroyers only operated from the island between Oct & Dec 1941 until losses to minefields and the increased bombing made it untenable. HMS Penelope (aka Pepperpot) only stayed until early April 1942 to escort convoys into Malta. This is how she looked after leaving for repair.

The 10th Submarine flotilla had been set up in Jan 1941 to Command the subs based at Malta. But it too was forced to withdraw to Alexandria around April 1942 for a period of time.

The availability of strike aircraft depended on what could be flown in, which depended on the ebb & flow of the Desert war. The availability of fighters depended on that and how many could be flown in from carriers at the Gibraltar end.

 

[Shortround6]

The fuel situation is also a bit weird. They didn't have enough fuel to escort convoys, but did have enough fuel to try to supply fuel to Africa via the air?

Italy also has one of the largest coal deposits in the region (the Carbosulcis mine in Sardinia), yet in the interwar years they were dependent on imported coal. And AFAIU they had nothing like the German synthetic fuel efforts.

We have to be careful of applying late 1900s technology to WW II and earlier.
Most ships ran on bunker fuel which is crude oil with a lot of the good stuff (gasoline and Kerosene) taken out.
You can bias production a bit but depending on the crude source you can only produce a certain percentage of product per ton.
Also large ships used a huge amount of fuel. The Bolzano used about 1 ton for every two nautical miles at 16kts. Escorts use a lot less but.........................
From Taranto to around 100 miles short of Tripoli is just over 1000 nm round trip. 500 tons of fuel oil if things go well.
A Me 323 might lift 16 tons of fuel (Petrol) per flight.

You need the appropriate oil products in the tanks when you start specific operations. Products sitting in rail yards outside of the refineries are several weeks/over a month away from being used.

There are 3 major types of coal. The coal produced in the Carbosulcis mine actually falls between Lignite (the lowest carbon content) and bituminous coal (the mid range). It might have been useful for 'coal' powered electric plants or for 'synthetic' fuel but it was useless for steam ships or coal fired locomotives or most coal fired industrial power plants. You need more tons of coal for the same power, you need boilers with larger grates and you need to clean out the ash more often.

Italy may not have had the industrial plant to build a synthetic fuel infrastructure. The thousands of tons of steel needed for such plants has to come from somewhere even if you have the patents/technical know how. What other infrastructure do you need? Increased electric production? increased rail traffic?
Having you material source about 275nm east of Naples also presents a problem. Do you build the synthetic fuel plant on the island of Sardinia and transport the product using tankers or do you build a lot of coal carriers and transport the much less energy dense low grade coal to the Italian mainland for processing?

 

[Shortround6]

Italy as per Japan had not done much in the way of ASW / AA / or radar
development and the price for the Axis merchant shipping was high.

Italy was more restricted.
Italy had around 25% the steel production that Japan had.
Italy was learning and did improve things somewhat although slowly.
For ASW the Italians were helped by the clearer water and calmer seas (less wave action) but that was not a real solution.

The Italians had some mediocre AA guns but not enough of the them, production may have been a problem?
The Italian 37mm

was sort of a low grade 40mm Bofors.
Which put it ahead of anything that the Japanese had under 75mm in size.
It was also better than the British pom pom on per barrel basis, but we are comparing twins to quads or octuple and that gets harder.
German early Navy 37mm AA guns are pure crap. They don't get better until 1942 or later.
Italian basic problem is there aren't enough of the them. Most of the Cruisers wound up with 4 twin mounts which for 1940-41 wasn't really that bad. They didn't get more which was bad.

Most Italian destroyers were no worse off than the British WW I and the A-I Destroyers at built. Either licensed WW I 40mm Pom Pom (two per ship) or a smattering of 13mm machine guns. Higher powered but slower firing than the British .5in guns.
Different gun action but remarkably similar in performance to the Japanese Navy 13mm AA guns. With just 2 twins per ship as built they weren't any worse than many of the Japanese destroyers as built.
Both navies swapped the 13mm guns for heaver weapons. the Japanese went for the infamous 25mm while the Italians went for the 20mm Breda gun.
The Breda used the same ammo as the German 20mm Flak 30/38 and fired about as fast the Flak 30 ( much slow than the Oerlikon).
Main practical difference was that the German guns used 20 round magazines that had to be changed and the Italian guns used a 12 round tray that feed through the gun and dropped out the other side (?) making reloading a bit easier even needing a bit quicker.
Italians often swapped a twin 20mm for a twin 13mm so the increase was a bit marginal but the Germans and British weren't doing much better in 1940-41.
Japanese waited until 1942 to upgrade many of their destroyer AA guns. Made US water cooled, belt feed .50cals look like wonder weapons
Italian twin 20mm mount.

One gunner and 4 loaders (?)s
It might have equaled a single Oerlikon gun for fire power and in 1940-41-early 42 there were not a British destroyers running around with more than 2-4 Oerlikons.

Italians may not have had the directors/fire control on the main guns that the British had on their destroyers but with the low elevation of the main guns in either navy their success was in breaking up attacks/causing planes to drop early rather than shooting anything down.

British got better in 1943 and later but we do have to be careful as to the years.

 

[Glider]

If I could add a small piece to your very informative piece. The British liked the Italian 20mm Breda. Some captured ones were mounted on British cruisers and when the ships were moved elsewhere, they transferred to any incoming replacement vessels.

 

[Peter Gunn]

Say what you will about Italian fuel, training, kit etc. but they did build some lookers, they make the KGV's look like stodgy old school marms:

 

[z42]

Say what you will about Italian fuel, training, kit etc. but they did build some lookers, they make the KGV's look like stodgy old school marms:

View attachment 771716

View attachment 771717

I think it looks slightly silly that the rear turret is so high, but yes, the Littorios are very pretty.

 

[z42]

I meant sending extra forces to Tunisia in the first place.

I understood that, yes. I was just expanding on that topic, not saying you're wrong.

Anyway, I guess it was just hard for them to switch mindset from "just a little bit more reinforcements, and we can win the campaign" to "Oh, everything is going pear shaped, we should evacuate our troops while we still can". And that delay eventually cost them several hundred thousand soldiers taken prisoner.

 

[z42]

Also large ships used a huge amount of fuel. The Bolzano used about 1 ton for every two nautical miles at 16kts. Escorts use a lot less but.........................
From Taranto to around 100 miles short of Tripoli is just over 1000 nm round trip. 500 tons of fuel oil if things go well.
A Me 323 might lift 16 tons of fuel (Petrol) per flight.

Yes, a large ship uses a lot of fuel, but they also transport a lot of stuff. They are, in fact, the most efficient form of transport on a fuel consumption per ton-mile basis.

If you're curious, I'm sure you can figure out how much fuel a Me 323 consumed on a Sicily - Tunis round trip to deliver that 16 tons vs how much fuel oil (or coal) a tanker used.

There are 3 major types of coal. The coal produced in the Carbosulcis mine actually falls between Lignite (the lowest carbon content) and bituminous coal (the mid range).

Yes, it's called 'sub-bituminous', in case anyone is curious.

It might have been useful for 'coal' powered electric plants or for 'synthetic' fuel but it was useless for steam ships or coal fired locomotives or most coal fired industrial power plants. You need more tons of coal for the same power, you need boilers with larger grates and you need to clean out the ash more often.

Italy may not have had the industrial plant to build a synthetic fuel infrastructure. The thousands of tons of steel needed for such plants has to come from somewhere even if you have the patents/technical know how. What other infrastructure do you need? Increased electric production? increased rail traffic?
Having you material source about 275nm east of Naples also presents a problem. Do you build the synthetic fuel plant on the island of Sardinia and transport the product using tankers or do you build a lot of coal carriers and transport the much less energy dense low grade coal to the Italian mainland for processing?

Yes, probably a large scale synthetic fuel program similar to the German one was unrealistic. Still, some kind of strategy for acquiring fuel would have been a good idea before going to war.

 

[Greg Boeser]

Yes, a large ship uses a lot of fuel, but they also transport a lot of stuff. They are, in fact, the most efficient form of transport on a fuel consumption per ton-mile basis.

If you're curious, I'm sure you can figure out how much fuel a Me 323 consumed on a Sicily - Tunis round trip to deliver that 16 tons vs how much fuel oil (or coal) a tanker used.



Yes, it's called 'sub-bituminous', in case anyone is curious.



Yes, probably a large scale synthetic fuel program similar to the German one was unrealistic. Still, some kind of strategy for acquiring fuel would have been a good idea before going to war.

Trouble is, most countries, when they decide to go to war, convince themselves that it will be over quickly, using the resources on hand. It doesn't always work that way.

 

[Wild_Bill_Kelso]

Yes, a large ship uses a lot of fuel, but they also transport a lot of stuff. They are, in fact, the most efficient form of transport on a fuel consumption per ton-mile basis.

If you're curious, I'm sure you can figure out how much fuel a Me 323 consumed on a Sicily - Tunis round trip to deliver that 16 tons vs how much fuel oil (or coal) a tanker used.

Fuel used by ships varies a great deal by the size and weight of a ship. Barges on rivers, and certain classes of merchant shipping are very cheap to operate, but warships not so much. Bunker fuel is also much cheaper (much less processed) than aviation fuel, particularly of the type used by WW2 aircraft (kerosene used by Jets is actually cheaper than petrol).

The reason they switched to using Ju 52s and Me 323s is because the commercial cargo ships were being routinely sunk while crossing the Mediterranean, thanks to systematic efforts by the RN and DAF, as well as the RAF on Malta.... and neither the Italians nor the Germans could figure out how to protect their shipping.

Yes, probably a large scale synthetic fuel program similar to the German one was unrealistic. Still, some kind of strategy for acquiring fuel would have been a good idea before going to war.

I think part of the goal of invading Greece was aimed toward securing oil sources in the Balkans, though they never got anywhere near that far. Middle Eastern oil was also a goal though maybe even less realistic.

 

[EwenS]

I think it looks slightly silly that the rear turret is so high, but yes, the Littorios are very pretty.

The aft turret was deliberately placed high to maximise its firing arcs.

Turret 1 - 145 degrees either side of bow.
Turret 2 - 141 degrees either side of bow
Turret 3 - 160 degrees either side of the stern.

At the extreme of the arcs turrets 2 & 3 were firing over the secondary turrets. In 1942 the elevation of all the turrets at the extreme training arcs had to be limited to prevent blast damage to the decks.

By way of comparison the US BB turrets of the Washington, SoDak & Iowa classes could all train 150 degrees either side. In a KGV it was 143 degrees each side for A turret and 135 degrees each side for B&X. In Richelieu it was 150 degrees for turret I & 156 degrees for Turret II.

Due to the experience with Littorio & Vittorio Veneto during their trials, Roma was completed with a higher bow with more sheer on the deck up to it, with a view to reducing the water being shipped over the bow in heavy seas.

 

[z42]

Fuel used by ships varies a great deal by the size and weight of a ship. Barges on rivers, and certain classes of merchant shipping are very cheap to operate, but warships not so much.

Well, warships gulp fuel when running at high speed. If they're escorting a convoy plodding along at 10kn, consumption will be much less.

Bunker fuel is also much cheaper (much less processed) than aviation fuel, particularly of the type used by WW2 aircraft (kerosene used by Jets is actually cheaper than petrol).

Yes, I know.

The reason they switched to using Ju 52s and Me 323s is because the commercial cargo ships were being routinely sunk while crossing the Mediterranean, thanks to systematic efforts by the RN and DAF, as well as the RAF on Malta.... and neither the Italians nor the Germans could figure out how to protect their shipping.

Yes, and that worked out just swell for them, didn't it. Appropriate for the time of year, see the Palm Sunday Massacre.

But lets just take a step back and appreciate the sheer scale of the problem of trying to replace shipping with air transport. A typical Italian WWII era tanker, say about 5000 GRT or ~7000 DWT would be capable of carrying on the order of 10000 tons of petrol. If the Me 323 can carry 16 tons, that means you need 625 flights to replace that one tanker!

Or in other words, when they realized they were losing the ability to supply Africa via ships, they should have put into action their emergency evacuation plans (they had those, right? Right?) rather than indulging in a fantasy of being able to rely on air transport.

I think part of the goal of invading Greece was aimed toward securing oil sources in the Balkans, though they never got anywhere near that far. Middle Eastern oil was also a goal though maybe even less realistic.

There's also the Libyan oil fields, although I don't think those were even discovered back then. Actual production started in the early 1960'ies. Kind of ironic they had rather large oil fields under their feet, had they been aware of it.

 

[EwenS]

There's also the Libyan oil fields, although I don't think those were even discovered back then. Actual production started in the early 1960'ies. Kind of ironic they had rather large oil fields under their feet, had they been aware of it.
View attachment 771758

Some traces had been found in the 1930s and some unsuccessful exploration carried out. All stopped on the outbreak of war.

The History of the Development of Libyan Gas and Oil Resources

 

[Wild_Bill_Kelso]

But there was some oil production in Persia, and they had struck oil in Iraq, Saudi Arabia and Bahrain in the 1930s. ARAMCO was established in 1943.

 

[Wild_Bill_Kelso]

Yes, and that worked out just swell for them, didn't it. Appropriate for the time of year, see the Palm Sunday Massacre.

But lets just take a step back and appreciate the sheer scale of the problem of trying to replace shipping with air transport. A typical Italian WWII era tanker, say about 5000 GRT or ~7000 DWT would be capable of carrying on the order of 10000 tons of petrol. If the Me 323 can carry 16 tons, that means you need 625 flights to replace that one tanker!

Or in other words, when they realized they were losing the ability to supply Africa via ships, they should have put into action their emergency evacuation plans (they had those, right? Right?) rather than indulging in a fantasy of being able to rely on air transport.

I never said it was a good idea lol - it was just the first thing they came up with in the midst of the crisis during the lead up to Second El Alamein. The Allies had rather suddenly become very efficient at sinking cargo ships, destroying docks, destroying trucks, and generally wiping out the Axis supply chain across the Med in the second half of 1942. It was a swiftly arriving (if predictable) crisis they were scrambling to find a solution for. There also seemed to be a serious breakdown between various elements of the German command hierarchy and the Italians - as in, they were all talking past each other.

They didn't only rely on aircraft of course, that was just one of many attempts to find a way around the problem, all ultimately doomed as we know. One other was the increased use of smaller and / or coastal shipping including sail boats (dhow, baghlah, shu'ai etc.)

I think they did briefly sortie some cruisers during Pedestal, which though risky might have paid dividends if they had come to grips with the British fleet in a surface action, but they were hampered by lack of fuel and successfully attacked by a British submarine (Unbroken).