Harpoon Missile Malfunction On Danish Frigate Closes Part Of Baltic Strait

The Harpoon missile glitch comes amid fallout from other technical failures aboard another Danish frigate that was operating in the Red Sea.

byThomas Newdick|
The Royal Danish Navy’s recent woes are continuing, with the service today having declared a missile failure aboard one of its frigates, the Niels Juel, at a harbor in the Baltic Sea. As well forcing the closure of Denmark’s most important strait connecting the Baltic Sea and the Atlantic Ocean, the incident comes one day after the sacking of the head of the Danish Armed Forces, amid the fallout of weapons failures aboard another of its frigates, which was protecting Red Sea shipping against Houthi attacks.
Mark König/Wikimedia Commons


The Royal Danish Navy’s recent woes are continuing, with the service today having declared a missile malfunction aboard one of its frigates. The activation of the booster motor on a live Harpoon anti-ship missile while the warship was in port forced a precautionary closure of part of Denmark’s most important strait connecting the Baltic Sea and the Atlantic Ocean. The incident comes one day after the sacking of the head of the Danish Armed Forces, amid the fallout of weapons failures aboard another of its frigates of the same class, which was protecting Red Sea shipping against Houthi attacks. You can read all about those issues in our recent report linked here.

The Danish Armed Forces announced today a “technical problem” involving a Harpoon onboard the frigate Niels Juel, which is currently in harbor at Naval Station Korsør, on the Danish island of Zealand.

The frigate Niels Juel docked at Naval Station Korsør. Danish Armed Forces

According to a statement from the Armed Forces: “The problem has arisen in connection with a mandatory test where the launcher, the booster, is activated and cannot currently be deactivated.”

The missile’s solid-fuel rocket booster is responsible for the initial launch of the weapon, but it detaches when expended, after which the main turbojet continues for the rest of its flight. The warship is normally fitted with eight tube-launched Harpoon missiles amidships, although a maximum load of 16 can be carried, at the expense of other weapons.

“Until the booster is disabled, there is a risk that the missile could launch and fly several kilometers away,” the statement continued, adding that specialists were on their way to solve the problem.

A Harpoon Block 1C anti-ship missile is launched from the USS Coronado (LCS-4), an Independence variant Littoral Combat Ship, on July 19, 2016. U.S. Navy photo by Mass Communication Specialist 2nd Class Michaela Garrison/Released

While the Harpoon missile involved is a live example, the Danish Armed Forces says there is no danger of the warhead detonating, or its turbojet main engine starting, which could carry it potentially around 75 nautical miles.

This is due to the fact that only the booster was activated for this particular test. This was reportedly being run as part of a wider exercise, which began in March and is due to end on Friday.

Inadvertent launches of anti-ship missiles are extremely rare, but they have occurred before, with disastrous results.

Nevertheless, with the possibility that the missile’s booster could still be inadvertently fired, the Danish military has declared a danger area extending around 5-7 kilometers (3.1-4.3 miles) southwest of Naval Station Korsør up to a height of approximately 1,000 meters (3,280 feet) above the water.

A map of the danger area, southwest of Naval Station Korsør, released by the Danish military today. Danish Armed Forces

The Armed Forces say that the danger area does not cover the Great Belt Bridge, a major road and rail connection crossing the Great Belt strait between the Danish islands of Zealand and Funen. Located around 2.5 miles north of the danger area, the bridge remains open to traffic.

“The police and the Danish Maritime Authority are informed, and ships in the direction of the danger zone are being notified and asked to wait for the problem to be resolved,” the Armed Forces said. The airspace over the danger area has also been closed.

The Great Belt Bridge is seen from Zealand as waves crashes ashore, Denmark, on December 22, 2023. Photo by THOMAS TRAASDAHL/Ritzau Scanpix/AFP via Getty Images

In turn, the Danish Maritime Authority has issued a warning for vessels to avoid the affected part of the Great Belt strait, citing a risk of “falling missile fragments” and requesting that ships drop anchor if necessary.

The Niels Juel is one of the three frigates of the Iver Huitfeldt class, which are homebased at Korsør. These modern vessels are primarily air defense warships, and all entered Royal Danish Navy service in 2011.

Costing around $325 million each, the Iver Huitfeldt class frigates are 455 feet long, 65 feet in beam, and have a draft of nearly 21 feet. They displace 6,540 tons fully loaded. As well as the aforementioned Harpoons, the ships’ missile armament comprises a 32-cell Mark 41 Vertical Launching System (VLS) for up to 32 Standard SM-2 Block IIIA surface-to-air missiles, and Mk 56 VLS for up to 48 RIM-162 Evolved Sea Sparrow Missiles (ESSM).

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Today’s incident could hardly come at a worse time for the Danish Ministry of Defense.

Yesterday, the chief of defense, Gen. Flemming Lentfer, was sacked for failing to report malfunctioning weapons systems on another Danish frigate, the Iver Huitfeldt, in the Red Sea.

The Iver Huitfeldt was deployed to the region to help protect commercial maritime traffic from Houthi drone and missile attacks, part of a major campaign that was launched soon after Israel began its latest offensive in Gaza, last October.

According to reports, Lentfer failed to inform the defense ministry that radar and missile systems aboard the Iver Huitfeldt had failed during a Houthi drone attack. You can read our initial analysis of that incident in this previous report.

In particular, it was reported that the warship was unable to fire its ESSM air defense missiles for a half-hour period, while “up to half” of the rounds fired from the twin 76mm guns detonated too early and close to the ship.

Nevertheless, the Iver Huitfeldt was able to shoot down four of the incoming drones, while the remainder were tackled by other vessels. Once the ESSM was back on line, the Danish frigate used three missiles and 50-100 rounds of 76mm ammunition to defeat the four drones, with a video of the engagement seen below.

The Danish Minister of Defense, Troels Lund Poulsen, announced the decision:

“I have lost confidence in the Chief of the Armed Forces. Therefore, I have decided that he will no longer lead the Danish Armed Forces. We are facing a historic and necessary strengthening of the Danish Armed Forces. This places great demands on our organization and the military advice we provide to the political level.”

Maj Gen. Michael Hyldgaard has been appointed as acting Chief of the Armed Forces.

While mishaps and technical failures are part of military operations, in peacetime and in conflicts, this dismal week for the Royal Danish Navy, in particular, will lead to questions asked about the credibility of the wider Danish Armed Forces.

Seen during his time as Commander Special Operations Command Denmark, Maj. Gen. Michael Hyldgaard is now the acting Chief of the Danish Armed Forces. Photo by IDA MARIE ODGAARD/Ritzau Scanpix/AFP via Getty Images

Some may argue that the Danish Armed Forces is overstretched, having joined the multinational task force assembled in the Red Sea at the same time as its more usual Baltic area of operations is seeing rising tensions between NATO and Russia.

In the skies over the Baltic, meanwhile, NATO intercepts of Russian aircraft are common and airspace violations are certainly not unheard of. These have, in the past, also directly affected Denmark, including the incident in 2020 when a Russian Su-27 intercepted a U.S. Air Force B-52 as it was approaching Denmark’s Bornholm Island, before following the bomber “well into Danish airspace over the island,” according to NATO.

A still picture of a Russian Su-27 flying alongside a B-52 as it approached Bornholm Island on August 28, 2020. NATO

Meanwhile, the strategic relevance of Greenland, a Danish autonomous territory, has also greatly increased against the backdrop of the deterioration in East-West relations, which further stretches available resources.

While we await further fallout of these two latest embarrassing incidents to affect the Royal Danish Navy, the service will surely be thankful that neither of them resulted in any harm to the ships or their crew — or any other third parties.

Contact the author: thomas@thewarzone.com