Thunder on the Pacific: USS Missouri’s Mark 7 Guns Unleash Fury at RimPac ’90

Smoke roiling skyward, a volcanic blast at the heart of steel and sea—the awesome power of battleship artillery, captured forever in a split second, is rarely so viscerally displayed as in a photograph of USS Missouri (BB-63) during exercise RimPac ‘90. Here, aboard “Mighty Mo,” the Mark 7 16-inch/50-caliber guns bellow in near-unison, sending not only smoke and shockwaves across the Pacific but also a reminder of a vanished era when big guns ruled the waves.

Evolution of a Naval Titan

Commissioned in 1944, Missouri was the final battleship completed for the United States Navy—a floating fortress designed to project power, absorb punishment, and deliver devastating blows miles beyond the horizon. Her main batteries, the Mark 7 16-inch/50-caliber guns, formed the backbone of this lethal promise.

Each of her three main turrets housed three such monsters: nine in all, each barrel stretching more than 66 feet and weighing over 267,000 pounds. Firing a one-ton shell up to 23 miles, these weapons were designed to smash enemy ships into flotsam or obliterate hardened shore targets at will. Standing on her deck when a salvo was loosed, you could feel the concussion ripple through your chest, even as the horizon blossomed with the flash and thunder of high explosives.

RimPac ’90: The Last Salvos of a Naval Age

By the summer of 1990, the world had changed. The Cold War was ending, missile technology was ascendant, and battleships were more symbols of history than tools of war. Yet during RimPac—the world’s largest maritime exercise, held biennially in the Pacific—the Missouri was very much alive. Crewed by nearly 1,800 sailors, bristling with modern missile and electronics upgrades from her 1980s recommissioning, she was as formidable and awe-inspiring as ever.

During the gunnery phase near Hawaii’s sparkling blue waters, Missouri’s gunnery crews swung into action. In a precision dance of muscle and machinery, each turret was loaded and trained toward the imaginary threat on the far horizon. At the order, all nine of the Mark 7s fired in tightly timed succession.

Instantly, the muzzles erupted, belching volcanic clouds of orange and black smoke. Shockwaves rippled across the surface. The deck shuddered, and a sound like a peal of thunder split the sky. Sailors—some Navy veterans, some the latest generation entrusted with the ship’s legacy—watched and grinned, knowing full well they were witnessing the living power of a bygone era.

Anatomy of a Mark 7 Salvo

Operating these guns was a feat of mechanical choreography and human teamwork. Below decks, enormous powder bags were hoisted and rammed home behind a massive, armorpiercing or high-explosive projectile. A complex system of hydraulic lifts, gears, and finely tuned sights synchronized to ensure each shot was accurate—never a simple task when the “target” was, at times, over the horizon.

When a full broadside was unleashed, the force was so immense that it was said the ship would shift sideways in the water—though the 57,000-ton behemoth remained unbowed. Each gun’s barrel would glow with heat after repeated firing; each shell’s flight was a fiery arc, the vanguard of American naval power.

The Modern Missouri: Past and Future

During RimPac ’90, Missouri’s giant guns were matched with Tomahawk cruise missile launchers and Harpoon anti-ship missiles, a fusion of old and new. But it was the thunder of the 16-inchers that captured the hearts of onlookers—naval personnel, journalists, and photographers alike. The awe inspired by their thunderous voice was a direct link back to the mighty fleet actions of World War II, Korea, and the opening salvos of Operation Desert Storm, where Missouri would fire her guns in anger one last time only a few months later.

Missouri’s last salvos at RimPac were more than a demonstration—they were a pageant, a memory, and a tribute rolled into one. Watching those plumes of smoke waft skyward, one could almost hear the ghosts of history: the surrender ceremonies in Tokyo Bay that took place on her decks in 1945, the flashing guns at Inchon, and the pounding fire-support off the coasts of Kuwait and Iraq.

A Symbol, Yesterday and Today

The image of Missouri’s triple turrets firing in 1990 captures the paradoxical end of an era. Here was a ship every bit as technologically fearsome as she was beautiful, her big guns unbowed even as the world left behind their thunder for the silent arc of guided missiles.

Today, USS Missouri rests at Pearl Harbor, a floating museum moored within sight of the sunken USS Arizona. Visitors who walk her decks can look down the vast barrels of her Mark 7s, imagine the roar and shock of those RimPac salvos, and know they are standing on the very steel where global history turned.

As smoke rose and the sound faded into the vast Pacific, those firing moments during RimPac ’90 were a salute from the Missouri—a last, proud roar from a lion whose age had passed, but whose legacy will thunder through history forever.