HMS Duncan

HMS Duncan: What Capabilities Does The Warship Bring To The Gulf?

HMS Duncan

The UK Government announced it would the warship to the Gulf amid escalating tensions with Iran (Picture: MOD).

HMS Duncan, which has been diverted to the Gulf, is the sixth and final Type 45 destroyer built for the Royal Navy, being commissioned into the fleet in 2013.

The Navy describes the Type 45 as "one of the most advanced warships ever built" and they are significantly more capable than their predecessor, the Type 42 class.

Duncan measures 500 feet in length, with a top speed of 30 knots and a 7,000-mile nautical range.

With her Royal Navy crew, she brings formidable, varied and adaptable abilities to her patrol role in the Gulf, which her adversaries will know about and respect.

HMS Duncan 250419 CREDIT Royal Navy.jpg
HMS Duncan has been referred to as "one of the most advanced warships ever built" (Picture: Royal Navy).

Weapons and Primary Role

The Type 45 is primarily designed to be an anti-aircraft and anti-missile platform – protecting themselves and crucially the broader fleet.

In the near future, these ships will help protect the Queen Elizabeth-class aircraft carriers.

They are equipped with the Sea Viper Missile System, which can knock moving targets out of the sky from 70 miles away.

This missile system uses the SAMPSON active electronically scanned array multi-function radar.

This means thousands of items, even those travelling at supersonic speeds, can be tracked at any one time and destroyed if needed.

Sea Viper can launch eight missiles in 10 seconds and simultaneously guide up to 16 missiles at a time. The Royal Navy says on its website "airborne threats don't stand a chance".

Other Roles

Aside from air defence, the Type 45 can deliver many other capabilities, including tackling pirates and providing humanitarian aid.

The ships weapons systems also equip the Type 45 with the ability to tackle the threat posed by traditional or asymmetric warfare.

The destroyer is mounted with a traditional 4.5-inch naval gun, alongside two 30mm small calibre guns and two 7.62mm miniguns.

Two Phalanx close-in weapons systems are also on board, using a radar cannon mounted on a swivel base, to counter missiles and helicopters.

A Phalanx weapons system being used on a US vessel
HMS Duncan is equipped with two Phalanx weapons systems to counter missiles and aircraft (Picture: US Department of Defense).

Design Benefits

The Type 45 looks significantly different from her predecessors. This is all to do with radar, specifically reducing the 'signature' of the ship, making it harder to detect.

Things like lifeboats, deck equipment and life-rafts are hidden from view.

There is no 'mid-ships' passage like on the Type 42s and there are a lot of flat surfaces, giving the vessel a slab-sided appearance.

In radar parlance, this all gives the Type 45 a 'clean' appearance, making her trickier to spot and identify on radar operators' screens.

The onboard Seagnat system aids her 'stealth ship' characteristics. It is a decoy system that uses radar jamming and radar deception (projecting a false signature) to help disguise the ship and crucially fool missiles.


Having an advanced warship is great, but any platform is only as good as those operating it.

One hundred and ninety-one Royal Navy sailors and officers make up the standard Type 45 crew – although they can accommodate up to 285.

Many of these crew members will have served multiple times on Type 45s as they have been in service for a decade.

They will have the training and experience to do their job as the situation demands.

HMS Duncan on Exercise Mare Aperto
HMS Duncan can accommodate up to 285 crew members (Picture: Royal Navy).


There's ongoing concern about the Type 45's propulsion system. It is highly advanced, enabling a 7,000 nautical mile range.

However, it has failed on several deployments. HMS Duncan reportedly suffering propulsion failure in 2016.

It is understood the ship's intercoolers can fail in extreme temperatures and an engine replacement programme is in progress.

What Does This Mean?

Even the United States acknowledges that the Type 45 is about as good as it gets, worldwide, in air-defence destroyer terms. They are remarkably advanced and pack a punch far bigger than any predecessor or competitor.

They also come equipped with a Royal Navy crew – in short professionals respected and admired the world over.

Engines aside, it would be hard to think of a better class of ship to be protecting Britain's interests in the Gulf region, at this difficult time.