Why the size of the Queen Elizabeth class aircraft carriers makes them a ‘conventional deterrent’

So great is the impact of larger aircraft carriers as a visible deterrent, they’re often used as a geopolitical chess piece.

Earlier in the year, speaking as Assault Stations were successfully completed for the first time, the Ship’s Amphibious Operations Officer, Lieutenant Colonel Mark Searight Royal Marines, explained the importance of HMS Queen Elizabeth and her capabilities.

“HMS Queen Elizabeth will maintain the United Kingdom’s ability to have a forward-based strategic conventional deterrent which has the ability not only to conduct strike operations with the F-35B, which is its primary role, but also to have an Embarked Military Force that is fully trained and ready to be projected ashore to conduct tasks that might arise.

That might be soft power for defence engagement, all the way through to humanitarian and disaster relief and war fighting. This training is part of the initial work-up to achieve that. The training has gone really well. It’s been an education to the Ship’s Company on what the LPH role will entail, and there has also been education to those who assist me to achieve aviation assault operations: Assault guides, FLYCO, the Logistics department who make sure they can sustain the operation and troops sufficiently; the ammunition personnel in the Air Engineering Department who make sure we have got the right ammunition. It’s a complex process.”

The view of the deterrent effect these vessels will have has been expressed frequently in defence circles, with the First Sea Lord last year stating that the Queen Elizabeth class supercarriers will represent a “powerful and important strategic conventional deterrent”.

The ships former commanding officer, Captain Simon Petitt, rightfully pointed out that there is a lot of symbolism in modern warfare and that having a ship the size of HMS Queen Elizabeth, which will be the navy’s biggest ever, was significant. The sight of a heavily equipped 70,000 tonne carrier, which is almost 300 metres long, heading towards a potential enemy had a deterrent effect that is essential if the UK wants to project influence across the world Petitt claims.

“It is massively visible, you can range back in history and see the value of this. Everything from Nelson deterring Admiral Villeneuve from leaving Cadiz all the way to the big battleships of early 20th century, to what we are doing now.

The Americans use it all the time. We currently haven’t got this level of carrier capability. The bigger the capability the more influence you have to bear.”

So great is the impact of larger vessels as a deterrent, they’re often used as a geopolitical chess piece. American governments have, since the second world war, moved aircraft carriers around to demonstrate American resolve.

There’s historical precedent for the UK utilising this capability, in 1972 British Honduras was threatened with imminent invasion by Guatemalan paratroops. Britain’s response had to be immediate and decisive but there was only one deterrent the government could offer: HMS Ark Royal and her air wing. They were used successfully to deter invasion of the territory.

The particular benefits of using carriers in this way are that they operate on the high seas, where permission is not needed from other countries. Indeed, since modern US carriers are large and imposing they “show the flag” to great effect due to their sheer size alone. Equally, it is often argued that had the Royal Navy had two full sized carriers in 1982 it is more than possible that Argentina would not have attempted to take the Falklands in the first place.

Larger carriers don’t have to be packed to bursting point with aircraft to achieve their greatest effectiveness, even with fewer aircraft on board, a ship with a large flight deck can rearm and refuel aircraft much more quickly, this is typically why they allow for much higher sortie generation rates than smaller vessels.

The more crowded the flight deck, the slower the turn-around of each aircraft, the lower the sortie generation rate.

Size also offers greater storage capacity, larger vessels do not have to be resupplied as often, impacting both the effectiveness of the carrier and her vulnerability. Because a carrier is more vulnerable when being replenished, the vessel typically withdraws from station for that function. Much of the time lost is the time spent heading away from station and returning. The smaller the carrier, the more time lost and a bigger logistics chain required in support.

A larger ship is likely to survive damage that will sink or disable a smaller one. The smaller the proportion of a ship that gets damaged, the better the chance that the ship can survive the damage and keep on fighting. It takes sheer size to provide enough protection against all the weapons likely to be used against a carrier, from bombs to cruise missiles to torpedoes.

This lesson comes from the second world war, where lessons learned from operations with the large converted battlecruisers in comparison with the smaller purpose-built aircraft carriers had taught both the Royal and US Navies that large carriers were more survivable than smaller ones due primarily to the large number of watertight compartments.

If a complement of aircraft that would typically be found on one large carrier is split among several smaller carriers, then each vessel needs its own escorts unless they operate together. This would require more resources to operate effectively. It might be argued that splitting up a carrier force would make it more difficult for an enemy to deal with all of it at once but the price paid in escorting ships would be high, making it unfeasible for most navies. Indeed, the most significant effect this would have would be requiring more smaller carriers to do the job of one large vessel, further increasing costs.

Each of the smaller carriers in the group is less survivable, more wasteful and less effective than a single larger ship.