Small Aircraft Carriers (2 Viewers)

[Howard Gibson]

Between the mid-fifteenth century and the mid-twentieth centuries, naval warfare was dominated by gunboats. In combat between gunboats, big gunsboats defeat small gunboats. The big gunboats have some combination of bigger guns, more guns, and more capacity to take punishment. Hydrodynamically, big ships are faster than small ships, although, big battleships have generally sacrificed speed for protection. In a war, it makes sense for an admiral to board his biggest, most powerful gunboat, and put is flag up, making it his flagship. The largest and most powerful gunboats are classifed as "capital ships".

This has affected our thinking about warships. We imagine ancient galleys as massive, impressive ships. Ancient galleys, at least as used in Greece, used rams as their primary weapons. The Romans were more into boarding. Ancient galleys ought not be imagined as modern capital ships. Modern fighter aircraft are a much better analogue. A ram equipped galley needs to be fast, it need high acceleration and deceleration, and it must do fast turns. A small galley is harder to hit than a big galley. You need a small, lightweight ship, packed with highly trained, muscle-bound rowers. Galley slaves were invented by the Spanish during the sixteenth century AD, and galleys quickly becamse obsolete.

During the Persian War, the Peloponnesian War, and the Punic Wars, city states built hundreds of galleys each. When storms broke out and caught galley fleets at sea, hundreds generally were wrecked. It is a very safe bet that these galleys were not Nimitz class aircraft carriers. They were small, lightly built, probably open boats. At the Battle of Salamis, Xerxes commanded from a throne located on-shore. Themistocles followed the Greco-Macedonian tradition of throwing himself into the middle of the battle.

This brings us to aircraft carriers. At the start of WWII in 1939, the Royal Navy had seven carriers, five of which would be sunk during the war. In 1941, the US Navy had eight carriers, five of which were sunk. Of ten sunken carriers, the Japanese got six. U-boats got three, and the Scharnhorst and Gneisnau got one. I did not bother to look up the Japanese. I assume that all of theirs got sunk.

Carriers have replaced battleships as capital ships. The big American carriers in particular are described as "cities at sea", with Nimitz carriers displacing over 100,000 long tons. American carrier groups seem to have one carrier only. If the Americans go up against a powerful enemy, how many of these carriers can they afford to lose?

Wouldn't it be wiser to treat carriers as consumables, make them as small as possible, and make as many as possible? Any thoughts?

 

[tomo pauk]

Wouldn't it be wiser to treat carriers as consumables, make them as small as possible, and make as many as possible? Any thoughts?

Do you have some specific era in mind, or all of the last 100+ years?

 

[EwenS]

It had a subject that has been done to death many times on many sites, especially regarding the QE class forbthe RN. This is a recent thread on the subject, if you can sort the wheat from the chaff.

NavWeaps Forums-Advantages of large vs small aircraft carriers?

Can think of a few; more planes and harder to sink. More efficient use of crew and smaller total of crew in one large vs more numerous smaller ones?

www.tapatalk.com

Development of the Queen Elizabeth class aircraft carrier – a design history | Navy Lookout

www.navylookout.com

Ultimately, today a larger carrier holds certain advantages over a number of smaller ones. It is the air is free, steel is cheap philosophy to deliver a certain level of capability. The expensive part of a carrier is the systems, mechanical and especially electronic. More ships = proportionately more cost.

 

[Shortround6]

Wouldn't it be wiser to treat carriers as consumables, make them as small as possible, and make as many as possible? Any thoughts?

There is actually economy in mass. I am stating that badly.

For 90 WW II aircraft and the desired fuel and the desired ordnance (bombs, torpedoes, depth charges, etc) you can fit a certain amount in a 30.000ton carrier.
Or at least what the navy planners think are useful amounts.
Now what can you fit into three 10,000 ton carriers, that go the same speed and have the same cruising range.
Note that the USS Independence class were actually 2 kts slower than an Essex, and had 2000miles less range. They carried more fuel per plane.
But sometimes we need to dig a little bit deeper. Essex used eight boilers and a 150,000hp power plant. The Impendence used four boilers and a 100,000hp 4 shaft power plant.
An Essex had a crew of around 2700 men, An Independence needed 1570 men. Adjust as needed for war time changes.

The Big carriers could bring more trouble to the enemy at less cost (engines and other stuff), using less fuel and a lot fewer men. The Big carries do not need 3 times the sailors to run the ship. More yes but not 3 times more.

 

[ThomasP]

Also, what type of aircraft are to be operated makes a very large difference - particularly with todays VTOL (Vertical Take-Off & Landing) airframes.

If you need the CTOL (Conventional Take-Off & Landing) capabilities, you need a ship of a minimum size - said size being dictated by the landing and take-off runs. With modern jet CTOL aircraft you can't fit that on a hull less than about 750 ft long. The RN's HMS QE and PoW new CVs are intended to carry 40x STOVL (Short Take-Off & Vertical Landing) aircraft each - under normal circumstances.

If you can use all VTOL aircraft then small carriers like HMS Invincible class (22x aircraft each) will do - at least for some missions. For ASW and Local Sea Control - the missions the Invincible class was designed for - they will allow more hulls for a given tonnage and hence a greater area of coverage.
_________________________________ Queen
__________________Invincible______Elizabeth_______Nimitz
Displacement______ 22,000________ 80,600________104,000 tons deep
Length o.a.________ 686___________ 932__________ 1,002 ft
Vmax_____________ 28____________ 32 knots______ 30+ knots
Range____________ 7,000/19_______10,000/15_____ (nuclear) nm/knots cruise
Ship's Crew_______ 650*___________700*__________3,500*
Air Wing Crew_____ 350___________ 650** _________1,500**
# of Aircraft________22xSTOVL_____40xSTOVL***___65x CTOL***
# of Sorties________170___________ 410___________1,550________F-35B internal fuel load is 12,100 lbs (or 5.85 tons)****
F-44 Avtur_________1,000_________ 2,400_________ 9,050 tons*****

* The small difference in Ship's Crew between the Invincible and QE is largely due to significant efforts in automation and reduced maintenance time. The very much larger Ship's Crew of the Nimitz is largely due to the intended significantly longer deployment endurance of the US carrier vs that of the British carriers.
** The Air Wing Crew size is as usually carried currently. This can be increased to 900 for the QE, while the Nimitz can have upto 2,500.
*** The 40 aircraft is intended as the QE's normal complement, but may be increased to 50 as designed. The Nimitz class standard air wing is currently 65 aircraft, but the carrier's total aircraft complement can be increased to as high as 85-90 through the addition of other squadron components if needed.
**** I used F-35B sorties for all of the CVs in order to compare apples-to-apples. But it should be kept in mind that aircraft such as the E-2C Hawkeye cannot be operated from smaller carriers such as the Invincible class.
***** The very great disparity between the Avtur load of the QE and the Nimitz is partly due to the Nimitz not requiring petroleum based fuel for the ships machinery.

Also, more hulls gives a greater likely-hood of having at least one available at any point in time, if one (or more) ships are out of commission - whether due to damage or planned rebuild.

 

[SaparotRob]

U.S.S. Nimitz can time travel.

 

[z42]

There are, generally, large economies of scale in ships. Larger ships need less engine power and fuel per ton of cargo, whether the cargo is containers, passengers, aircraft, or gun turrets and armor plate. Similarly, crew requirements increase much slower than the cargo capacity as you make the ship bigger.

 

[Frog]

A smaller carrier means a smaller carrier air group.

 

[GreenKnight121]

A smaller carrier means a smaller carrier air group.

And smaller and less-capable aircraft.

 

[Howard Gibson]

And smaller and less-capable aircraft.

No. Your carrier group consists of two or three carriers. A carrier group consisting of one carrier will become carrier group consisting of no carriers.

You have catapults for taking off, and arrestor hooks for landing. Do carrier based aircraft have to be big?

 

[SaparotRob]

.. Do carrier based aircraft have to be big?

For the Med perhaps not but for the Indian and Pacific Oceans? There's a necessity for long ranged aircraft. Scale everything else up to achieve long range. Then add the crew and equipment to perform its mission. These aircraft will be launched from the middle of nowhere, searching for their targets somewhere, then navigate back to a postage stamp that won't be where they left it.

 

[Shortround6]

No. Your carrier group consists of two or three carriers. A carrier group consisting of one carrier will become carrier group consisting of no carriers.

Not sure what this means. Yes you could use 2-3 small carriers to replace one. Chances of loosing both/three carriers to subs or enemy aircraft on one mission are a lot less than loosing one carrier (mission kill counts, even if the big carrier limps home it is out of service for months-year/s).
But how do you split up the air-groups? 12 fighters and 9 dive bombers and 9 torpedo bombers on each ship? or some ships have 12 fighters and either 18 dive bombers OR 19 torpedo bombers on each ship? or some other split. But now you may have problem if you lose one ship. 1/3 of your strike aircraft gone equally or most of one type gone?

You have catapults for taking off, and arrestor hooks for landing. Do carrier based aircraft have to be big?

Smaller carriers may be able to get aircraft into the air quicker. The Big carrier is only going to launch a few with catapults and the rest will just fly off, It will take a number of minutes. 3 small carriers may need to use catapults a bit longer but with 3 decks you are going to have at least 3 cats and not 2 (like some WW II carriers) you can get the same number of planes into the air in about the same time. Landing is going to be similar. the Big carrier may be a bit faster per plane but the smaller carriers can land more planes in the same amount of time.
A lot depends on hangers/ lifts/crews.
Of course with 3 small carriers you need more escorts. You needed a bigger protected space Carriers need to be several thousand yds apart). You may not need three times the escorts but you are going to need a least a few more (plus one-two more crash-rescue ships). If a tin can is doing pilot guard it is not doing sub hunting at the same time.

This is for WW II, in the late 40s and newer the big carriers could operate much bigger planes.
Douglas Sky Warrior

Douglas Skyhawk.

Now wither the Sky Warrior was a good idea or not might be a subject for another thread

But the big 1950s and newer US carriers could do things smaller carriers could not do, at all.

 

[Howard Gibson]

For the Med perhaps not but for the Indian and Pacific Oceans? There's a necessity for long ranged aircraft. Scale everything else up to achieve long range. Then add the crew and equipment to perform its mission. These aircraft will be launched from the middle of nowhere, searching for their targets somewhere, then navigate back to a postage stamp that won't be where they left it.

Long ranged aircraft are inferior in combat to short ranged aircraft. There must be a sweet spot out there. The further you fly from your carrier, the harder it will be to find it afterwards.

 

[Warspite63]

It had a subject that has been done to death many times on many sites, especially regarding the QE class forbthe RN. This is a recent thread on the subject, if you can sort the wheat from the chaff.

NavWeaps Forums-Advantages of large vs small aircraft carriers?

Can think of a few; more planes and harder to sink. More efficient use of crew and smaller total of crew in one large vs more numerous smaller ones?

www.tapatalk.com

Development of the Queen Elizabeth class aircraft carrier – a design history | Navy Lookout

www.navylookout.com

Ultimately, today a larger carrier holds certain advantages over a number of smaller ones. It is the air is free, steel is cheap philosophy to deliver a certain level of capability. The expensive part of a carrier is the systems, mechanical and especially electronic. More ships = proportionately more cost.

......on top of that, you'll also need to specialize or operate a number of small carriers as a unit in order to create balanced strike packages.

 

[Howard Gibson]

......on top of that, you'll also need to specialize or operate a number of small carriers as a unit in order to create balanced strike packages.

Do I really need to specialise? If the enemy sinks my torpedo bomber carrier, I can't torpedo bomb, and I might as well go home. The whole concept here is that war is bad for little children, puppies and aircraft carriers.

When the Royal Navy sent the HMS Victorious (USS Robin) to help the Americans in the Pacific, her arrestor wires were not up to catching Grumman TBF Avengers. They put the RN Avengers on the American carriers, and they transferred some USN Wildcats to the RN carrier. At the end of their missions,, the Americans got rum instead of ice cream. The fleet did not see a whole lot of desperate action.

 

[EwenS]

When the Royal Navy sent the HMS Victorious (USS Robin) to help the Americans in the Pacific, her arrestor wires were not up to catching Grumman TBF Avengers. They put the RN Avengers on the American carriers, and they transferred some USN Wildcats to the RN carrier. At the end of their missions,, the Americans got rum instead of ice cream. The fleet did not see a whole lot of desperate action.

That was not the reason for the cross decking for a month in June / July1943.

Victorious operated her Avengers during the trip from Norfolk to Pearl Harbor. Please note these were USN spec TBF-1 not Avengers that had been modified to meet British requirements. BUT she discovered two problems:-
1. The claw on the Avenger's arrester hook was too narrow for British arrester wires which were thicker than US ones.
2. In low winds or with Avengers at high landing weights, the pull out on the arrester wires was at its limits. They had to catch wires 1-4 (of 8) or they would end up in the barrier. By skilled coordination between the various flight deck personnel, it was found the crash barriers could be dropped in time to avoid deck accidents. However after one major crash while in the Pacific when a TBF-1 caught a wire but went over the side and burst into flames, ops were ceased until modifications could be made at PH.

When Victorious reached PH the Avengers had their arrester hooks modified. The ship herself had an extra 2 arrester wires fitted on the aft end of the flight deck on the area that had been levelled out at Norfolk.Her other wires were modified to reduce the pull out to handle Avengers better.

832 squadron took its 16 TBF-1 to Saratoga between 27 June and 24 July 1943. By then she had been firstly exercising with the USN from 29 April, sailed across the Pacific and participated in sweeps into the Coral Sea and more exercises in the region with USN ships. All the while operating her TBF-1 on searches and ASW patrols. Of course having a larger deck made operating TBF-1 easier.

Acquiring supplies of rum while she was in the Pacific was a problem. She actually ran out of it at the end of May, her CO hoping to obtain further supplies from the RAN.

The real reason for the reallocation of aircraft between the two carriers was that Victorious had better fighter direction facilities and a better trained fighter direction team. At this point in the war the RN led the USN in this area. That was a point accepted by the USN liaison officer attached to Victorious. So 24 F4F-4 were transferred from Saratoga to Victorious where they could better be controlled. Victorious left for home via PH, Panama Canal and Norfolk (Edit - at the end of July). While at Norfolk 832 swapped its TBF-1 for British spec Avenger I.

 

[Warspite63]

Do I really need to specialise? If the enemy sinks my torpedo bomber carrier, I can't torpedo bomb, and I might as well go home. The whole concept here is that war is bad for little children, puppies and aircraft carriers.

When the Royal Navy sent the HMS Victorious (USS Robin) to help the Americans in the Pacific, her arrestor wires were not up to catching Grumman TBF Avengers. They put the RN Avengers on the American carriers, and they transferred some USN Wildcats to the RN carrier. At the end of their missions,, the Americans got rum instead of ice cream. The fleet did not see a whole lot of desperate action.

I'd still say 'yes' to the specialization issue: a torpedo strike of 12 aircraft from a single squadron that lives and breathes - and more importantly - trains as a unit will be more cohesive and better coordinated than one made up of 3 flights of 4 aircraft each, coming from different vessels.

This whole conversation reminds me of an article in one of the Warship editions of the last decade about the merits/faults of the small battleship. The essential conclusion was that there is a point of diminishing returns, below which the requirements of the constant 'ship features (i.e. crew, armour plate, engine plants, etc....) outweigh the benefits of having distributed firepower across a number of hulls. I think the same principle applies here: you will need to man the ships, and 3 crews (or 2, or 4.....) will aggregate to more than the crew of a single large carrier. You will need engines, and 3 plants will take more resources to fabricate man and maintain than a single, larger one, etc.

Then there is the issue of airwing: how to build a balanced air wing for a small carrier? The RN did have a bucketload of 'small' carriers in the Colossus family. These were not built because of any inherent benefit to that compact size: they were built because Britain had a number of yards capable of pumping them out, that were not big enough to build fleet carriers

Interestingly, there is also an implied upper limit to carrier size. Besides the issues of building, berthing and maintain massive ships, there is the issue of airwing management. The USN apparently ran into that with the Midways when they were completed: 137 aircraft was simply too many to handle on a single hull. Of course, modern carriers are much larger, but so are their aircraft

 

[Howard Gibson]

This whole conversation reminds me of an article in one of the Warship editions of the last decade about the merits/faults of the small battleship. The essential conclusion was that there is a point of diminishing returns, below which the requirements of the constant 'ship features (i.e. crew, armour plate, engine plants, etc....) outweigh the benefits of having distributed firepower across a number of hulls. I think the same principle applies here: you will need to man the ships, and 3 crews (or 2, or 4.....) will aggregate to more than the crew of a single large carrier. You will need engines, and 3 plants will take more resources to fabricate man and maintain than a single, larger one, etc.

Then there is the issue of airwing: how to build a balanced air wing for a small carrier? The RN did have a bucketload of 'small' carriers in the Colossus family. These were not built because of any inherent benefit to that compact size: they were built because Britain had a number of yards capable of pumping them out, that were not big enough to build fleet carriers

I started this thread off noting the tactical advantages of being a large gunboat. Imagine the Yamato and Musashi taking on the entire pre-Iowa class US Navy, minus the aircraft carriers.

A pair or trio of small carriers should be able to launch the same aircraft as the big carrier. The Colossus class carriers carried 48 aircraft. How about 12 torpedo bombers, 12 dive bombers, and two 12 plane fighter squadrons?

 

[EwenS]

I'd still say 'yes' to the specialization issue: a torpedo strike of 12 aircraft from a single squadron that lives and breathes - and more importantly - trains as a unit will be more cohesive and better coordinated than one made up of 3 flights of 4 aircraft each, coming from different vessels.

Way back around 1920 when the RN was looking at what form its carrier force should take (I.e.after Argus was in service and the trials on Eagle had taken place, but before completion of Hermes, Eagle, and the reconstructed Furious), one of the alternatives looked at was carriers with air groups dedicated to specific roles - fighter protection of the fleet, spotting, recce and TB. It was not pursued, in part due to the number of carriers it would have required, all with relatively small air groups.

This whole conversation reminds me of an article in one of the Warship editions of the last decade about the merits/faults of the small battleship. The essential conclusion was that there is a point of diminishing returns, below which the requirements of the constant 'ship features (i.e. crew, armour plate, engine plants, etc....) outweigh the benefits of having distributed firepower across a number of hulls. I think the same principle applies here: you will need to man the ships, and 3 crews (or 2, or 4.....) will aggregate to more than the crew of a single large carrier. You will need engines, and 3 plants will take more resources to fabricate man and maintain than a single, larger one, etc.

Then there is the issue of airwing: how to build a balanced air wing for a small carrier? The RN did have a bucketload of 'small' carriers in the Colossus family. These were not built because of any inherent benefit to that compact size: they were built because Britain had a number of yards capable of pumping them out, that were not big enough to build fleet carriers

Not really. The starting point was for a small carrier to provide largely fighter protection plus some ASW for a fleet given the experience of Norway in 1940 and in the Med in 1941. The ship continued to be developed and ended up with an air group nearly double that originally envisaged through use of deck parks. Studies in 1942 produced estimates of how many of each type of carrier (fleet, light fleet & escort) would then be required with two light fleet being roughly equivalent to one fleet. Taking account of existing ships built and building the light fleet carrier order came close to meeting the overall numbers requirement.

The advantage of a Colossus v an Audacious class fleet carrier (both 1942 designs and orders) was the projected build times. In 1942 a Colossus was expected to take 24 months (first 5 wartime completions averaged 30 months), with completions planned from mid-1944 (it slipped 6 months). Time was also saved at the design stage as they used a half set of Fiji class cruiser machinery. An Audacious class fleet was expected to take 3.5 to 4 years with early predictions being in March 1946. (The first, Audacious, was only launched in March 1946).

The victim of the 1942 light carrier programme was the cruiser programme, but at the end of the day only 5 of the 16 vessels were built at 4 yards that had not previously aircraft carriers.

Interestingly, there is also an implied upper limit to carrier size. Besides the issues of building, berthing and maintain massive ships, there is the issue of airwing management. The USN apparently ran into that with the Midways when they were completed: 137 aircraft was simply too many to handle on a single hull. Of course, modern carriers are much larger, but so are their aircraft

It wasn't so much a question of not being able to handle the physical aircraft numbers as not being able to generate the same number of deck load strikes (each of roughly half the air group) in a day. That was because each half air group took longer to launch and recover as it contained more aircraft. IIRC the number of deck load strikes was thought to fall from 6 in an Essex, to 4 in a Midway. This was recognised before they completed and was the subject of much discussion within the USN.

In 1945 an Essex was carrying 100-105 aircraft, so each strike was roughly 45-50 aircraft. With the move to the Midway this was going to rise to c65.

This however arose from changed practice between when Midway was designed in 1941/42 to their completion 1945-47 and the design of the ships themselves.

Pre -war USN practice was to carry spare aircraft triced into the hangar roof space. This was found to be bad news under war conditions and was stopped so eliminating spare aircraft storage in existing ships. When the Midways were designed such storage wasn't possible due to the weight of armoured flight decks. Instead an aircraft storage space was intended for the area aft of the after lift. When it was decided not to carry spare aircraft, the aircraft storage area became an additional hangar area for operational aircraft so allowing an increase in the effective air group size.

The difference in the inteneed use of the main hangar and the aircraft storage area is highlighted in the design of the Midway. The three horizontal armour layers (flight deck, hangar deck & protective deck) in the Midway ran roughly between the forward and after lifts so protecting the main hangar and the machinery spaces beneath. The aft hangar space however (originally the aircraft storage area) was left without such protection.

 

[EwenS]

I started this thread off noting the tactical advantages of being a large gunboat. Imagine the Yamato and Musashi taking on the entire pre-Iowa class US Navy, minus the aircraft carriers.

A pair or trio of small carriers should be able to launch the same aircraft as the big carrier. The Colossus class carriers carried 48 aircraft. How about 12 torpedo bombers, 12 dive bombers, and two 12 plane fighter squadrons?

The Colossus air group contemplated changed between 1942 & 1944 partly due to the move from the intended compact Seafires to the physically larger Corsairs. As completed the first 4 carried 21-24 Corsairs and 18 Barracuda TBR (Combining the TB and DB roles) for a total air group of 39-42 in 1945. IIRC Korean War air groups maxed out around the same size when they operated Fireflies and Sea Furies.

The largest RN air group in 1945 was on Implacable consisting of 48 Seafire III, 12 Fireflies and 21 Avengers. The narrow folded width of Seafires and Fireflies helped push up numbers.