Summary and Key Points: A Type 45 destroyer costs Britain over £1,000,000,000 and stops working when the water gets warm. Above roughly 28 degrees Celsius, the intercoolers on the ship’s two Rolls-Royce WR-21 gas turbines do not lose efficiency gradually the way the designers intended — they fail outright and trip the turbines, at which point the entire electrical load of an 8,500-ton warship drops onto two diesel generators that were never sized to carry it, and they collapse in sequence. On a ship with fully integrated electric propulsion, that is not a breakdown in the ordinary sense. Everything goes off at once: propulsion, sensors, weapons, navigation. A destroyer floating blind. And the water warm enough to spring the trap is the water Britain most needs these ships to patrol.
The Type 45 Destroyer Challenge Is No Joke
In the summer of 2016, HMS Duncan, the Royal Navy’s newest destroyer, lost power and had to be towed back to port, and by then nobody in Britain was surprised. Her sister Daring had gone dark in the mid-Atlantic in 2010 and limped to Canada for repairs, then failed again off Kuwait in 2012.
Dauntless had broken down in 2014. Parliament had opened inquiries, the newspapers had their photographs of a row of billion-pound warships tied up together in Portsmouth, and the Type 45, on paper the finest air-defense destroyer in Europe, had become shorthand for everything wrong with British defense procurement.
The full story is better and worse than the caricature: better, because the ship’s weapons and radar delivered exactly the leap they promised and the class has since fought and won real battles; worse, because the failures traced to decisions made before the first hull touched water, and because Britain had cut the fleet so deep that there was no slack left to absorb them.
Understanding the Type 45 means starting where the trouble began, not in the engine room.
HMS Daring Type 45 Destroyer Royal Navy.
It was in the requirements.
A Ship Born From a Failed Marriage
The Type 45 exists because a three-way European partnership collapsed.
After an earlier NATO frigate project died, Britain, France, and Italy issued a joint requirement in 1992 and signed a 1993 memorandum of understanding for the Common New Generation Frigate, a shared air-defense warship known as Project Horizon, with Britain planning to buy twelve to replace its Cold War-era Type 42 destroyers.
The three navies wanted different ships, the industrial workshare fights never ended, and in April 1999 the United Kingdom walked away to build a national destroyer instead, with the collaborative program formally terminated that October. Britain kept the piece of Horizon that worked, the jointly developed Principal Anti-Air Missile System, and designed a new ship around it.
The goal was written in the Royal Navy’s institutional memory of the Falklands, where Argentine jets and sea-skimming missiles had overwhelmed the fleet’s defenses and sunk its ships: the new destroyer would exist to shield a carrier group or amphibious force from saturation air attack, tracking and killing dozens of threats at once.
The resulting Sea Viper system paired the SAMPSON multifunction radar, an actively scanned array atop the mast tracking hundreds of contacts out to roughly 400 kilometers, with the S1850M long-range surveillance radar and a 48-cell Sylver vertical launcher firing Aster 15 and Aster 30 missiles covering everything from point defense to engagements beyond 100 kilometers. Wrapped around that combat system was the largest escort the Royal Navy had ever built, about 152 meters and 8,500 tons, stealthy in its shaping, crewed by roughly 190 sailors with berths for many more.
HMS Daring (D32), a stealth design of area defence anti-aircraft destroyer of the Royal Navy, outward bound from Portsmouth Naval Base, UK.
Against the measure the ship was designed for, the design succeeded completely. The failures came from everywhere else.
What the Program Cost, and What Each Ship Cost After the Cuts
The original national plan projected around £7 billion for twelve ships. Post-Cold War budgets then went to work: twelve became eight, and in 2008 eight became six, the final class of Daring, Dauntless, Diamond, Dragon, Defender, and Duncan.
The National Audit Office assessed the delivered six-ship program at approximately £6.46 billion, meaning Britain paid over £ 1 billion per destroyer for half the fleet it had planned, nearly the full price of the original dozen.
The mechanism is brutal and general. The costs of developing a warship’s radar, combat system, missiles, and design are fixed whether one hull is built or twenty, so halving the production run does not halve the bill; it concentrates the same development mountain onto fewer ships, roughly doubling the cost of each one. The cut had a second consequence that would prove even more expensive than the arithmetic.
Six ships is the bare minimum for a national air-defense force once maintenance cycles, training, and refits are counted, which meant the Royal Navy had purchased a fleet with no redundancy at all.
Every hull was load-bearing. A class with no spare capacity cannot afford a design flaw, and the Type 45 was carrying one below the waterline the whole time.
The Flaw Below the Waterline
The Type 45 was among the first major warships in the world built with fully integrated electric propulsion, a single electrical system feeding everything aboard, with motors turning the shafts and power running the radar, weapons, and computers alike.
The concept was correct and is now the direction of warship design everywhere, but the decision came relatively late in the design process, and the system went into the lead ship without the exhaustive shore testing such a novel arrangement demanded. At its heart sat two Rolls-Royce WR-21 gas turbines fitted with an intercooler and recuperator, an efficiency system that manages and recycles heat, with the intercooler units designed by Northrop Grumman, and backed by only two modest diesel generators.
The trap was thermal. In waters warmer than roughly 28 degrees Celsius, the intercooler system did not lose efficiency gradually as intended; it failed outright, tripping the turbines, at which point the full electrical load of an 8,500-ton warship dropped onto two diesels never sized to carry it, and they collapsed in cascade. On an integrated-electric ship, the result is not a breakdown in the ordinary sense.
It is a total electric failure, everything off at once, propulsion, sensors, weapons, and navigation; a destroyer floating blind and defenseless, the condition the Ministry of Defence itself eventually acknowledged left the ships vulnerable to blackout. And the waters warm enough to spring the trap were precisely the waters Britain most needed the ships to patrol, the Persian Gulf.
Rolls-Royce’s position, that the intercoolers were built exactly to the supplied specification and that Gulf conditions fell outside those specifications, located the fault with precision: the requirement itself had been written for a gentler ocean than the one the Royal Navy actually operates in.
The breakdown log made the flaw famous, Daring in the Atlantic and off Kuwait, Dauntless in 2014, Duncan in 2016, and the parliamentary inquiries that followed turned an engineering defect into a national embarrassment.
The Availability Crisis
With workarounds and operating restrictions developed under an Equipment Improvement Plan, the destroyers could and did deploy, including to the Gulf, and the popular image of a class permanently welded to the pier was never accurate. What was accurate was worse in slow motion: a six-ship class in which any given moment found ships under repair, under restriction, awaiting refit, or deep inside the fix program left the Royal Navy struggling, year after year, to keep more than one or two Type 45s genuinely ready, out of a national destroyer force that was the Type 45s and nothing else.
The lead ship became the emblem. HMS Daring entered a maintenance and upgrade period that stretched across the better part of eight years, among the longest absences of a front-line warship in modern British history, a first-of-class that spent more of the 2020s in Birkenhead than at sea.
The strategic picture magnified every one of those dockyard days, because Britain’s whole escort fleet had contracted to nineteen destroyers and frigates, so each unavailable Type 45 subtracted a meaningful share of the nation’s entire high-end naval capability, the same unforgiving arithmetic that governs any navy operating small numbers of capital ships. The bitter irony is that when the ships sailed, they were superb. HMS Diamond spent the Red Sea crisis of 2023 and 2024 shooting down Houthi drones and missiles in the first sustained saturation air defense the Royal Navy had fought since the Falklands, the exact scenario the class was designed for, performed under fire, successfully, by a destroyer from the most mocked warship program in the country. The Type 45 never had a fighting problem. It had a showing-up problem.
Cutting Open the Hulls
Under Project Napier, launched in 2014 and costed by the government at roughly £280 million overall, the Royal Navy pursued immediate reliability measures and then the definitive remedy, the Power Improvement Project, contracted to BAE Systems in 2018 at £160 million, which removes each ship’s two inadequate diesel generators and installs three far more powerful sets able to run the destroyer’s propulsion and systems without leaning on the WR-21s at all. Executing it requires surgery: each destroyer is withdrawn from service and taken to Cammell Laird at Birkenhead, where engineers cut openings through a finished warship to extract machinery buried at its core and thread the new generators in, one of the most invasive refit programs the Royal Navy has ever run.
Ship by ship, it has worked.
As of early 2026, Dauntless, Dragon, and Duncan are through the program and operational, Defender and Diamond are in refit, and Daring has completed her conversion and is working through testing and training before rejoining the fleet, with the class-wide effort running toward the end of the decade.
A decade of dockyard time and hundreds of millions of pounds, spent to retrofit the resilience that thorough shore testing of the propulsion system might have built in before HMS Daring ever launched.
The Future of the Six
The class emerging from the repair yards will be more dangerous than the one that entered them, which is the underappreciated half of the Type 45’s future. Under the Sea Viper Evolution program the Ministry of Defence announced in May 2022, the six ships are receiving upgraded Aster 30 Block 1 missiles alongside improvements to the SAMPSON radar and command system, giving the class a defense against anti-ship ballistic missiles, the threat now proliferating from the Red Sea to the Pacific, with the work running across the second half of this decade; a parallel effort adds Sea Ceptor missiles to deepen each ship’s magazine.
A powered, reliable, ballistic-missile-capable Type 45 will anchor British and allied carrier defense into the late 2030s, when the planned Type 83 destroyer is intended to replace it, and the fixed ships have already banked the combat record that vindicates the design’s core.
About the Author: Harry J. Kazianis
Harry J. Kazianis (@Grecianformula) was the former Senior Director of National Security Affairs at the Center for the National Interest (CFTNI), a foreign policy think tank founded by Richard Nixon based in Washington, DC. Harry has over a decade of experience in think tanks and national security publishing. His ideas have been published in the NY Times, The Washington Post, The Wall Street Journal, CNN, and many other outlets. He has held positions at CSIS, the Heritage Foundation, the University of Nottingham, and several other institutions related to national security research and studies. He is the former Executive Editor of the National Interest and the Diplomat. He holds a Master’s degree focusing on international affairs from Harvard University.
