Wif challenge- design a " simple" Aircraft carrier circa 1980s for RAN

[roughneck06]

I read today that the Aussie Govt considered approaching the USA and GB to design and possibly build a simple aircraft carrier capable of operating F/A 18s. This was after the Melborne was decommissioned and the sale of HMS Invincible was cancelled. What " simple" or airgroup was not specified.

My thoughts-

Something Foch sized, electronics/  radar minimized- dependant of DDGs to  provide what is not installed on the CV. Defensive weapons- CIWS only. Again- DDGs provide defense.

Also- VSS III- a reverse angled enlarged SCS.

Ideas/thoughts appreciated!!!!

[dy031101]

Electronics to the standard indeed no more than that of a DDG, hull built to merchant standard?

[rickshaw]

MMm, large tanker hull, with double hull.  Increased compartmentalisation as well (can't just have big fuel tanks not very useful).  Angled flight deck.   Diesel engined.  Need catapults.   Island on the right side.  Deck edge elevators only.   Electronics - it should have a powerful air search radar and sufficient ECM to withstand most threats (it won't be designed to face the fUSSR).  Armament should be kept to a minimum.   RBS-70s and Phalanx.  Provision to fit Sea Sparrow later.  It should have as large an air compliment as possible.   It should rely upon being a part of a task force rather than a stand alone unit.  The other task force members are there to protect it and it they.

[GTX]

I read today that the Aussie Govt considered approaching the USA and GB to design and possibly build a simple aircraft carrier capable of operating F/A 18s. This was after the Melborne was decommissioned and the sale of HMS Invincible was cancelled. What " simple" or airgroup was not specified.

Where did you read this if I may ask?  My sources indicate that both the Labor and Coalition (though Labor always gets the total blame) had given up on Carriers in '82/'83.

Prior to this though, the following options were considered:

• Invincible Class - originally to be Invincible and then briefly Hermes pending the building of a new carrier;
• Spanish SCS - essentially what became the Príncipe de Asturias;
• Italian Giuseppe Garibaldi class;
• Litton Ingalls derivation of the Tarawa class LHA  - this one may have, with some serious redesign have handled CTOL aircraft;
• Vickers conceptual design for a 12800 tonne Macship;
• Vosper Thornycroft conceptual design for a 8000 tonne Harrier Carrier;
• French DTCN PH75 Conceptual design of 18100 tonnes;
• Gibbs & Cox SCS conceptual design similar to the Príncipe de Asturias;
• Modicattion of the LHA but of 53800 tonnes rather than 39900 tonnes - this one would have been the biggest on offer by far and possibly with some serious redesign could have handled CTOL aircraft;
• Spruance (DD-963) modification;
• John McMullen conceptual VSTOL carrier of 20800 tonnes;
• Rosenblatt & Son variation on 14800 tonne SCS; and
• Yard Ltd Protean modular design based on a merchant ship hull and machinery.

Here is a brief comparison of the options:



Regards,

Greg

[roughneck06]

As the reference for the " simple carrier"- I read that in Wikipedia -HMAS Melbourne- I found it interesting as I had never read anything about it before.

[Jschmus]

As the reference for the " simple carrier"- I read that in Wikipedia -HMAS Melbourne- I found it interesting as I had never read anything about it before.

The citation for that is listed as Australian Carrier Decisions: the acquisition of HMA Ships Albatross, Sydney and Melbourne, by Anthony Wright, collected in "Australian Maritime Affairs (No 4)".

[rickshaw]

As the reference for the " simple carrier"- I read that in Wikipedia -HMAS Melbourne- I found it interesting as I had never read anything about it before.

The citation for that is listed as Australian Carrier Decisions: the acquisition of HMA Ships Albatross, Sydney and Melbourne, by Anthony Wright, collected in "Australian Maritime Affairs (No 4)".

Available here - http://www.navy.gov.au/w/images/PIAMA04.pdf

[Hobbes]

MMm, large tanker hull, with double hull. 

You'd have to install ungodly amounts of power to get a decent speed out of such a hull. Consider this: A Nimitz-class carrier has 1/5 the displacement of cargo ships the same length.

[Weaver]

Hmm - well why not take one step back and consider the requirement: what exactly is an Aussie carrier for?

If it's for air-defence of the fleet, then what is the fleet for?

If it's for power-projection, then bear in mind that seriously bombing another country from the sea requires a certain critical mass of force: a bare-minimum ship with, say, 12x F-18s might not cut it.

Define the requirement first, then see how that affects design considerations.



Couple of detailed design points though: you'd struggle to power a decent-sized ship capable of military speeds (i.e. 30ish knots) with diesels. Gas turbines are almost de-rigeur for Harrier-carriers, and if you want steam catapults, you have to have some means of generating steam. This can be done without a steam propulsion plant (it's being considered for the new RN carriers) but it's never been done, so it would be a high-risk developmental item, rather out of step with the "cheap and simple" concept.

[GTX]

As the reference for the " simple carrier"- I read that in Wikipedia -HMAS Melbourne- I found it interesting as I had never read anything about it before.

The citation for that is listed as Australian Carrier Decisions: the acquisition of HMA Ships Albatross, Sydney and Melbourne, by Anthony Wright, collected in "Australian Maritime Affairs (No 4)".

Available here - http://www.navy.gov.au/w/images/PIAMA04.pdf

Interesting read.  I don't see anything in relation to the "Govt ...approaching the USA and GB to design and possibly build a simple aircraft carrier capable of operating F/A 18...after the Melbourne was decommissioned and the sale of HMS Invincible was cancelled" though.  Note the following Ministerial statements though:




I'm curious to know more of this second highlighted comment.  I suspect though that it refers to one of the proposals to develop a modified LHA.

Regards,

Greg

[rickshaw]

MMm, large tanker hull, with double hull. 

You'd have to install ungodly amounts of power to get a decent speed out of such a hull. Consider this: A Nimitz-class carrier has 1/5 the displacement of cargo ships the same length.

Define "decent speed" and then justify a requirement for it.  As the purpose of this craft would be power projection within our AO, it wouldn't need to necessarily be very fast.  However, once it got there, it would need sufficient air power to control the airspace around it.

[rickshaw]

Interesting read.  I don't see anything in relation to the "Govt ...approaching the USA and GB to design and possibly build a simple aircraft carrier capable of operating F/A 18...after the Melbourne was decommissioned and the sale of HMS Invincible was cancelled" though. 

I still believe the largest determinant of cost of such a ship is the manning issue.  They are invariably large complements and that costs shitloads of dosh.  Actual ship steel is a fraction of that cost over the life of any ship.

[Weaver]

Well one reason for speed in a carrier is wind-over-deck. If your maximum speed is 15 kts rather than 30kts, then you either have to have cats that are longer and stronger enough to generate the extra 15kts, or you have to accept lower MTO weights for your aircraft.

[rickshaw]

Well one reason for speed in a carrier is wind-over-deck. If your maximum speed is 15 kts rather than 30kts, then you either have to have cats that are longer and stronger enough to generate the extra 15kts, or you have to accept lower MTO weights for your aircraft.

Or have a ski-jump.

I've often wondered why they make ski-jumps permanent structures.  I'd make it a collapsible one.

Wind over deck helped with early aviation.  Nowadays you have sufficient thrust to not need it to the same degree.

[Weaver]

Well one reason for speed in a carrier is wind-over-deck. If your maximum speed is 15 kts rather than 30kts, then you either have to have cats that are longer and stronger enough to generate the extra 15kts, or you have to accept lower MTO weights for your aircraft.

Or have a ski-jump.

I've often wondered why they make ski-jumps permanent structures.  I'd make it a collapsible one.

Wind over deck helped with early aviation.  Nowadays you have sufficient thrust to not need it to the same degree.

Wind over deck prevented the 25 de Mayo from launching Skyhawks in the Falklands. It all depends on how big your aircraft are relative to your catapults. One of the arguments made against having more smaller carriers in the USN in the 1970s was that, as you made the deck smaller, the cats didn't shrink with it, and so began to impact adversely on other deck activities. To some extent, considerations like this condition the size of a CTOL carrier more than the size of the air group. By the time you've got cats and wires that can launch and recover useful and available aircraft, the deck is so big that the hanger underneath it can easily accomodate 40-60 aircraft.

Harrier carriers scale up and down more freely, the lower limit being the size of an operationally efficient air group (six Harriers) and the upper limit being the point where you can operate more effective CTOL aircraft. The availability of a "Super Harrier" would move the latter point significantly upwards. Harrier carriers have cheaper ship-cost-per-aircraft within this range than CTOL carriers because they don't need arrestor wires, catapults or steam. They can also launch and recover aircraft in a wider range of weather conditions than a CTOL and have a better safety record due to the "stop then land" nature of recovery rather than the risky "land then stop" CTOL approach. On the other hand, the payload-range of the aircraft is low, and bring-back weights are non-negotiable: if you can't get the weight below the thrust level for landing then that £1m missile IS getting dumped in the drink.

I can see your point about a moveable ski-jump for a multi-role ship that might need to operate the maximum number of helos in some configurations. Some of the the test ramps used to prove the ski-jump concept had flexible decks and variable height, so it must be doable. The Invincibles use the space under the ski jump for storage and some accomodation.

To my mind, the best Harrier carrier would be a "New Hermes", that is to say, a 30,000 ton simple carrier with no fancy weapons and maximum air group. 12 SHARs, 12 ASW Sea Kings, 4 AEW Sea Kings and 2 plane-guard/CSAR Sea Kings should be perfectly doable, with any excess being used for more SHARs. Such a carrier would be a formidable ASW asset, could add a valuable layer of extra air defence to a fleet, and conduct effective anti-shipping strikes. It's power-projection capabilities would be limited however, since the range and payload of even a dozen SHARs is probably not good enough to support a significant operation. It all goes back to my original question: what exactly do you want it for? I can easily justify it in a NATO/RN GIUK gap scenario, but I'm less familiar with Australian naval theory and strategy.