Sunday, 29 November 2009

Small Versatile Carrier

The carriers produced in the largest numbers ever where the United States Escort Carriers of the Second World war. Today several carriers of this size still exist the smallest is Thailand's HTMS Chakri Naruebet,  which operates 6 Harriers and 6 Helicopter, and is based on US Sea Control Ship design, that was never built.
At 11,485 this is only some 3500 tons heavier than the new Type 45 destroyers.
A next generation Small Carrier would carry F-35 Lightning II and V22 Osprey or perhaps UAV, such a ship is under consideration for the Royal Navy as the UXV Combatant based on the Type 45 destroyer and carrying UCAVs
Whilst the UXV combatant seems like an interesting concept it seem to be to small to offer a truly flexible ship capable of multiple roles. The ship would be designed to perform several major roles depending on the composition of the air wing carried. Whilst the Casablanca class of WWII carried 28 aircraft, the increased size and weight of modern aircraft means that i operation a modern carrier in the same class would carry between 12 and 18 aircraft.
This embarked air wing would be split into two parts, the permanent defence of the ship would be based about the on board defensive air wing that would primary be based around anti submarine and AEW aircraft. It is likely that each of these roles could be filled by 3 aircraft. The mission equipment would take up the rest of the ships capacity and could either be used for addition aircraft of other equipment.
The Royal Navies current AEW capability is provided by Sea King ASaC7 helicopter. The Royal Navy has plans to replace the Sea Kings for the next generation of carriers the candidates include systems based on the Merlin helicopter and the V22 Osprey.
The ship will need to have the basic ability to defend itself including a CIWS and a SAM installation.
This size of carrier has served in large numbers escorting convoys and supporting other operations in world war to it's great advantage in these cases is the ability to build them quickly. That quality is essential for any future ships of this size, like HMS Ocean the ships should be built to commercial standards and the basic design should be kept up to date allowing production to start quickly should a major threat emerge which requires the escort role to be performed in large quantities.
The inclusion of a large stern door would allow access to the large volume of the hangar deck allowing the ship to ferry equipment and act as a defended transport. The use of containerised accommodation in the hangar deck and on the flight deck would allow the vehicle to act as a  troop carrier still with a large flight deck of moving the personnel on and off.
In addition to these roles the smaller carriers can be but more in harms way providing close support as they did in the pacific theatre during WWII and providing platforms for the delivery of relief supplies in the event of natural disaster.

Carrier Classes

Escort Carrier
Cassablanca class 10,902 tons loaded
HTMS Chakri Naruebet 11,485 tons loaded 
Giuseppe Garibaldi (551) 13,850 tons loaded
Sea Control Ship 13,736 tons (full load)
Spanish aircraft carrier Principe de Asturias 16,700 tons loaded

Light Carrier
Invincible class 20,710 tons loaded
Spanish ship Juan Carlos I (L61) 27,079 tonnes
Centaur class 28,700 tons loaded
Italian Cavour 27,100 tonnes.

Medium Carrier
Essex class  36.830 tons loaded
Charles_de_Gaulle 42,000 tons full loaded

Heavy Carrier
Audacious class 53,950 tons full loaded
Queen Elizabeth class 65,000 tons full loaded

Super Carrier
Nimitz Class  103,000 tons full loaded
Gerald R. Ford class 100,000 long tons

Hyper Carriers
Project Habakkuk

Big Carrier Blues

During world war II it was not the Audacious class carriers like Ark Royal or the smaller Majestic class that served the Royal Navy best but the adhoc escort carriers.

The large carriers serve the role of force projection, you can have a small airfield within range of any point on earth without the need for someone else's permission. Very useful in the right circumstances as Eisenhower said "talk gently and carry a big stick" the big carriers are the big stick. Is that a role that the UK can justifiably take or afford? When was the last time that they were the only option? When was the Invincible Class to small for the job?

They can however only be in a limited number of places at any one time so no matter how small the fight you're in, you have only one choice and that is to deploy a force that is a far larger than is needed. They are incredibly vulnerable. In international waters a Chinese submarine got within torpedo range of a US carrier without being detected.

Wednesday, 25 November 2009

Why the UK should scrap trident.

Replacing trident is set to cost £10 billion pounds for no real return. I'd like to suggest an alternative. Currently the RAF posses an aircraft with greater range than the Vulcan and with the ability to carry a larger payload.

The US may sell us AGM 86 ALCM for $1.16 million a time, or the more advanced AGM 129 ACM at $4.0 million or planned Anglo French Storm Shadow Naval at a similar cost. The aircraft in question has the weight capacity to carry 8 of these things, though I'm not sure they would all fit in the bomb bay. Until 1992 it was armed with nuclear weapons.

The name of this aircraft, if you hadn't already guessed is the Nimrod. Though as any large aircraft can have cruise missiles under the wigs on pylons just about anything will do. 
If and when the government finances pick up the we can build a dedicated bomber say the Vulcan B4 or Victor B3 which given an avionics suite from the Nimrod would allow 2 man operation. The Engines from the F-35 Lightning II, either the Pratt_&_Whitney_F135 or the General Electric/Rolls-Royce F136 produce enough power are over a meter shorter and only 8 cm of greater diameter. The all up package should cost no more than the MR4A even with updated materials and manufacturing. The Vulcan was always known for it's relative stealth, which could easily be improved by attention to detail and if needed the replacement of the single tail fin with a pair of canted fins removing the right angle.

The Times claims the estimate for replacing Trident is £20 billion other places estimate the cost at up to £150 billion over the 20 year life time of the project. All for a system that will hopefully never be used. With the current reduced number of MR4A Nimrods being ordered the unit cost is about £400 million. So for £5 billion you get 12 aircraft plus over 100 of the more advance cruise missile.

In reality of course the bulk savings would mean that the aircraft cost less the 400m more like somewhere between 250 and 300 billion. That would include all the Maritime Patrol Equipment which might be removed and perhaps replaced with a simpler avionics fit derived from the F35. Either way the aircraft would have a useful secondary task of either patrol or conventional bomber.

Of course the current generation of hunter killer subs can launch BGM-109 Tomahawk cruise missiles which while not usually Nuclear armed could be. Further extending the range of Nuclear strikes, though as the place on earth furthest from the see is some 2,648 km from the sea current the longest range Tomahawk the Block II TLAM-A has a range of only 2,500 km.

The Russian Graney class submarine with it's mix of long range cruise missiles and more traditional hunter killer equipment would seem to be the Russian equivalent of a Nuclear platform without the immense cost of the trident system.