Here's What You Need To Remember: Each U.S attack proceeded as if by the rules of a 19th-century duel. The U.S. ships radioed to the Iranians their intent to destroy the platform, and gave them five minutes to abandon ship. Most of the panicked crew fled on two tugs—but some stayed behind and manned the guns.

The orders from the Joint Chiefs of Staff were clear: the Iranian frigate Sabalan must die.

On April 14, 1988, the frigate USS Samuel B. Roberts had run into an Iranian mine while attempting to extricate herself from a minefield. The blast tore open a 21-foot long hole in her hull and wounded ten sailors. Only a heroic damage control effort kept the frigate afloat.

This was deemed the last straw after ten months of skirmishes between U.S. ships and Iranian forces in the Persian Gulf.

It was by then the eighth bloody year of the Iran-Iraq War, in which Iran had taken to attacking commercial shipping in the Gulf in retaliation for Arab support for Iraq. 

Starting in June 1987, U.S. ships began escorting commercial convoys in the Gulf under operation “Earnest Will.”  Meanwhile, special operators in helicopters caught an Iranian ship at night laying mines and captured a logbook proving Iranian involvement—as recounted in this earlier article.

Following the Roberts mining, President Reagan wanted to launch a more punishing retaliation. Attacks on actual Iranian soil were deemed too escalatory. Instead, for Operation Praying Mantis two Iranian oil platforms—used to surveil commercial shipping with their radars and stage motorboat attacks—were marked for termination.  And the Sabalan.

The 1,500-ton Saam-class frigate was one of three built by Vosper in the UK for Iran during the 1970s, and was armed with a rapid-firing 4.5” gun and Italian-built Sea Killer cruise missiles on a stern-mounted launcher (picture here).  Using an Iranian modification of the outdated Sea Killer called the Sea Dawn, the frigates had struck six Iraqi merchant ships in a five-month period in 1986-1987.

However, the Sabalan’s captain Abdollah Manavi achieved particular notoriety as David Crist recounts in his book The Twilight War:

“This odious skipper had earned the nickname “Captain Nasty” due to the ship’s infamous reputation for deliberately attacking the crew quarters of neutral shipping  Even when his command in Bandar Abbas directed Captain Nasty not to attack a tanker, he often disregarded the order openly to his superior, seemingly delighting in aiming the ship’s gunfire at the crewmen and their lifeboats.  Then Sabalan would transmit to the helpless tanker “Have a nice day.”

On the morning of April 18, three U.S. Navy Surface Action Groups (SAGs) assembled for their mission.  The frigate USS Gary remained in reserve. Marine Sea Cobra gunships and Navy SH-2 SeaSprite helicopters fanned out across the Persian Gulf, keeping tabs on the movement of Iranian and commercial shipping alike to avoid friendly fire incidents in the narrow and crowded waterway.

SAG Bravo consisted of the Spruance-class destroyer USS Merill, the older missile destroyer Lynde McCormick, and the amphibious landing dock Trenton, carrying helicopters from Marine Air Group 2-88.

At 8 AM, Bravo approached within three miles of the Iranian oil platform Sassan, which was defended by four ZU-23 23-millimeter flak cannons and SA-7 surface to air missiles.

Each U.S attack proceeded as if by the rules of a 19th-century duel. The U.S. ships radioed to the Iranians their intent to destroy the platform, and gave them five minutes to abandon ship. Most of the panicked crew fled on two tugs—but some stayed behind and manned the guns.

Captain J.B. Perkins III recalled the moment in “Praying Mantis: The Surface View” in Proceedings:

“At 0804, we told the inhabitants that their time was up and commenced firing at the gun emplacement. This was not a classic Naval Gun Fire Support mission; I had decided on airbursts over the GOSP [Gas Oil Separation Plant] to pin down personnel and destroy command-and-control antennae, but to avoid holing potential helo landing surfaces.

At the first muzzle flash from the Merrill's 5-inch mount 51, the Iranian 23-mm. gun mount opened up, getting the attention of the ship's bridge and topside watchstanders. The Merrill immediately silenced the Iranian gun with a direct hit, and encountered no further opposition.”

Marine Sea Cobra gunships also began picking off the guns with TOW anti-tank missiles.

Perkins continues:

After about 50 rounds had exploded over the southern half of the GOSP, a large crowd of converted martyrs gathered at the northern end. At this point, we checked fire and permitted a tug to return and pick up what appeared to be the rest of the Sassan GOSP occupants.

Following further bombardment, at 9:25 Huey and CH-46 helicopters swooped over the burning platform and deposited two platoons of Marines via fast rope. In the next two hours the leathernecks scooped up intelligence and rigged the platform with 1,500 pounds of explosives.  Seven minutes after the Marines lifted off, Sassan erupted in a massive explosion.

A Cobra helicopter then detected what appeared to be a possible Saam-class frigate approaching SAG Bravo from the northeast. Had the Sabalan emerged from her lair?

Merill readied a Harpoon missile to strike.  Fortunately, Perkins recounts that prudence averted an international incident:

“We then asked for further descriptive information and ultimately for a hull number. The contact turned out to be a Soviet Sovremennyy-class guided-missile destroyer.

The skipper, when asked his intention, replied with a heavy accent, "I vant to take peectures for heestory."

Meanwhile, SAG Charlie—consisting of missile cruiser Wainwright and the frigates Simpson and Bagley—began its attack on the Sirri-D platform.

Again, most of the crew evacuated, though a few manned the platform’s loan ZU-23 gun.  As the warships began bombarding Sirri, a shell ignited a compressed gas tank, consuming the entire platform in a deadly blaze.  Plans to land a platoon of Navy SEALs were deemed unnecessary.  After the war, the platforms’ scorched remains had to be demolished and rebuilt by French and Russian oil companies.

At ten minutes till noon, the cruiser Wainwright suddenly detected a vessel approaching.  This was the Iranian Joshan, a German-built La Commandante-class fast attack boat displaced a mere 234 tons, compared to the nearly 8,000 tons of the Wainwright. Joshan had just one Harpoon missile on her two twin-rail launchers, and was under orders not to fire.

As if in Wild West showdown, the three American warships formed a line abreast formation as the plucky missile boat and its crew of thirty advanced towards them at 30 knots.

After the Joshan ignored several requests to turn around, Wainwright signaled “Stop your engines, abandon ship, I intend to sink you".

According to American accounts, Joshan abruptly launched its radar-guided Harpoon missile from 15 miles away. 

As the sea-skimming weapon and its deadly 500-pound warhead soared towards the Wainwright at over 500 miles per hour, the Belknap-class cruiser performed evasive maneuvers while SH-2 helicopters overhead released clouds of radar-reflective chaff in the air. The missile—its radar seeker possibly malfunctioning—rocketed past Wainwright’s starboard side.

However, the Joshan’s Captain Malek insists he obeyed orders and never fired at the American ships.  Instead, he claims that a chief petty officer fired a shoulder-launched SA-7 missile at a U.S. helicopter.

Wainwright and Simpson retaliated with a barrage of six smaller SM-1 missiles which demolished Joshan’s engine room.  A subsequent Harpoon missile missed as the blazing Joshan nosed into the water. SAG Charlie closed with the foundering missile boat, pummeling her with 5” shells until Joshan sank with the loss of eleven crew.

All that remained was for the three ships in SAG Delta to locate and destroy the Sablan. 

But where was infamous Iranian frigate?  And did Tehran plan to counter attack?

The answer to these questions, and the events of the frantic air-sea battle that unfolded that afternoon are detailed in a companion article.

Sébastien Roblin writes on the technical, historical and political aspects of international security and conflict for publications including The National Interest, NBC News, Forbes.com and War is Boring.  He holds a Master’s degree from Georgetown University and served with the Peace Corps in China. You can follow his articles on Twitter. This article first appeared last year.

Image: Wikipedia.