USS White River: How the US Navy transformed a landing vessel into a legendary rocket artillery ship

• Today's US Navy may be poorly equipped to support a landing force, but that wasn't the case decades ago.
• A unique and little-known ship packed a formidable punch in the Korean and Vietnam wars.
• This is how the USS White River earned its fearsome reputation.

With the war in Ukraine waging through a third year, one of the greatest lessons of the conflict has been the importance of mass firepower, with as much as 80% of casualties on both sides attributable to artillery .

Some of that firepower can be carried by ships. This is especially true in the close-shore hotspots across the Indo-Pacific region, where the US Defense Department is refocusing its attention.

Today's ships armed with long-range cruise missiles and carrier-based fighters may be poorly equipped to support a landing force with massive shore bombardment and calls for immediate direct fire.

What the Navy could really use for these operations is a new version of the USS White River , a unique yet little-known ship that served as a workhorse for the US Navy in two wars.

Designed from a landing ship meant to drop troops and supplies off at beachheads, the USS White River's 25 years of service didn't see the ship drop off a single soldier or vehicle into combat. Instead, the ship acted as a floating battery, raining hundreds of thousands of rockets, mortars, and gun rounds on enemy targets.

Its deployment into any given area always raised the morale of the soldiers it supported, wrought havoc on entire enemy units, and demonstrated the importance of naval fire support.

More than half a century after the White River's decommissioning, the US Navy is looking to build a new generation of medium-sized landing ships, some of which could become modern versions of the White River.

'Rocket ships'

USS White River's design was the product of an evolving way to address the needs of shore bombardment during World War II .

Allied assaults on the beaches of the Pacific, Africa, and Europe had proved the need for massive firepower to destroy fortified fighting positions and minefields. The deck guns of battleships , cruisers, and even destroyers were sometimes too slow to provide accurate fire or too powerful in the immediacy of troop landings.

The best solution was, for lack of a better term, rocket ships : Small vessels porcupined with rocket launchers able to fire dozens or even thousands of rockets en masse.

Rather than building an entirely new vessel, it was decided to modify medium-sized landing ships (classified as LSMs for 'Landing Ship Medium'). Originally designed to carry troops, vehicles, and supplies directly onto beachheads, the vessels proved to be quite versatile, with many models being reconfigured for various uses.

Given the designation "LSMR" for "Landing Ship Medium – Rocket," their size and cargo space enabled the ships to carry thousands of rockets at a time, and their shallow draft enabled them to sail up to the shore, giving them the ability to fire rockets further inland.

The first rocket fire support ships the US Navy operated, like the British-made Landing Craft Tank (Rocket) and the LSMR-188-class , though useful, had issues that hampered their effectiveness.

Although equipped with thousands of rockets, the launchers were welded in place facing forward, forcing the ship to point towards its target for all salvos — a difficult task in high winds, changing tides, or choppy seas. Additionally, it took hours to reload all of the launchers for a full salvo, and the crew had to be confined below deck during firing, as the exhaust from the rockets was toxic.

The solutions were the LSMR-401 and follow-on LSMR-501-classes; these designs modified from the LSMR-188 featured a better layout — the superstructure housing the bridge, for example, was moved aft and the 5-inch gun turret placed directly in front of it.

The armament was also further upgraded, with two 40mm and four 20mm anti-aircraft guns (which could be pointed horizontally to fire at land-based targets), four 4-inch mortars, and, depending on the layout, eight to ten Mark 102 double-barreled rocket launchers. The LSMR-501 class's armament was slightly larger, with four 40mm and eight 20mm anti-aircraft guns.

The cornerstone of the ships' armament, the Mark 102 rocket launcher, fired two 5.0-inch spin-stabilized rockets within one second, after which it was automatically reloaded within three seconds, enabling each launcher to fire about 30 rockets per minute — a blistering rate for rocket artillery systems .

Four types of rockets could be fired, with warheads ranging from 1.7 to 12 pounds and ranges of 1.4 to 5.6 miles. Depending on the makeup of the loadout, a ship could carry anywhere from 1,500 to 5,000 rockets.

The destructive potential of a single LSMR-401/501-class ship was large enough that the Navy boasted that it had as much firepower as five destroyers.

In action

Laid down in June of 1945, USS White River was one of 36 ships of the LSMR-501-class, and originally only referred to by its hull number, LSMR-536.

Launched on July 14 and commissioned on November 28, the ship, like the rest of the vessels in its class, arrived too late for World War II. Absent hostilities, it was decommissioned less than a year later on July 31, 1946 and placed in the Atlantic Reserve Fleet.

Recommissioned on September 16, 1950 as a result of the outbreak of war on the Korean Peninsula, it was refitted, crewed, and joined the Pacific Fleet in early 1951. After training stints in California and Japan, LSMR-536 arrived off North Korean-controlled island of Ch'o-do on July 16, 1952.

The ship would patrol along the western North Korean coastline intermittently (in one case providing night illumination fire on Ch'o-do) for the remainder of the war's hostilities, and would also patrol the South Korean coast afterwards until 1954. Officially renamed USS White River in 1955, the ship was decommissioned again in 1956.

White River would remain in the Pacific Reserve Fleet in San Diego for nine years until it was recommissioned again in 1965, this time for service in Vietnam, where it made a name for itself.

Arriving off South Vietnam's Quảng Ngãi Province on May 25, 1966, White River was immediately involved in shore bombardment that very day. Two days later, the ship provided fire support for South Vietnamese Army units (ARVN) operating in the vicinity, doing so intermittently for the next two months while also supporting three other US military operations in the area, including one involving an amphibious landing.

Part of Inshore Fire Support Division 93 , USS White River sailed all along South Vietnam, from the Vietnamese DMZ to the Cambodian border in the Gulf of Thailand. It was even able to sail inland up the Mekong River Delta — an area rife with Viet Cong strongholds — because of its shallow draft.

Over the next four years, USS White River took part in at least 11 named operations, supported American, Australian, South Korean, and South Vietnamese soldiers, and was responsible for destroying hundreds of Viet Cong ammo dumps, bunkers, structures, and boats used by the guerrillas.

"A love affair developed, and advisers in the outposts told us they couldn't sleep at night unless we were there. It would take six destroyers to replace us," Lt. Cmdr. Roy E. McCoy, the commander of Inshore Fire Support Division 93, told TIME in 1966.

"Usually, depending on the missions, with 5,000 rockets, we could go through them in a week, or we could go through them in three days." Chris Page, a crewman who sailed on the White River in Vietnam, recalled . "It just depends how many missions we had to shoot. But usually, at the longest, it would be seven days and we'd be back again loading them."

That arsenal, and White River's ability to stay on station for days, was a godsend to allies and a death sentence for enemies. On January 27, 1969, responding to a call for help by ARVN soldiers after an attack on VC positions in Quảng Ngãi province resulted in 15 friendly KIAs, White River unleashed a two-hour bombardment that destroyed 24 structures and started five secondary fires.

A day later, White River blasted a VC staging area half a mile away, killing 15 VC and destroying 63 more structures (including nine bunkers) and 35 meters of trails. A day after that, White River fired on a nearby VC anti-aircraft site, destroying it and killing or wounding 11 guerillas.

White River was even deadlier with the assistance of aerial spotters. While supporting Australian soldiers in Phuoc Tuy Province from October 22-27, the ship destroyed 97 structures and two weapons sites that triggered 13 secondary explosions, resulting in at least 18 VC killed and 17 wounded.

White River's last mission, on March 17, 1970, saw it sail 18 miles upriver into the Rung Sat Special Zone in the Mekong Delta — then the deepest penetration inland of a naval gunfire support ship. Over the course of five hours, it fired 2,526 rockets. Thick swamp and foliage prevented a full damage assessment, but at least 10 secondary fires were seen burning.

Future shore bombardment and LSMs

Despite its value and firepower, by 1970, White River was showing its age. It was ultimately deemed unfit for service that May and decommissioned and stricken from the Naval Vessel Register. The following November, the ship was sold for scrap.

In the decades since White River's service, the Navy has largely replaced naval guns and rockets with cruise missiles and airstrikes from carriers as the service moved towards precision strikes, with less emphasis on volume of fire. In fact, with the decommissioning of the battleship USS Missouri in 1992, no gun on any ship in the US Navy is larger than 5 inches (a reference to the gun barrel's diameter).

The role of shore bombardment and naval gun support more broadly was supposed to be handed over to 32 Zumwalt-class destroyers, each of which would be equipped with two 6-inch guns of the Advanced Gun System capable of firing Long-Range Land Attack Projectiles : rocket-assisted precision 155mm rounds that were envisioned to glide out to targets up to 80 miles away.

But development issues and cost overruns on the ships proved cost prohibitive, so much so that the planned order of 32 ships was reduced to just three. Consequently, the cost of the guided gliding shells jumped to as much as $800,000 per round .

In 2021, the Navy decided to replace the AGS guns on the existing Zumwalts with hypersonic missiles , effectively changing their shore bombardment role to that of an anti-ship surface combatant. In 2020, the USS Zumwalt successfully launched SM-2 anti-aircraft missiles from the newly installed MK 57 Vertical Launching System as well.

The fleet's cruisers and destroyers are loaded with dozens of $2 million Tomahawk cruise missiles , but they too lack the volume of fire and reload capacity of a rocket artillery ship like the decommissioned White River.

Meanwhile, the Navy is also looking at rebuilding LSMs — a type of vessel that hasn't been in the US Navy inventory for decades.

Originally proposed by the Marine Corps in 2022 and called the Light Amphibious Warship program, the Navy has since agreed on the need for smaller amphibious ships as a way to help lessen the reliance on the large Landing Helicopter Assault and Landing Platform Dock ships that make up the entirety of the amphibious ship force.

Now known as the Medium Landing Ship program , the Navy hopes to acquire 18 to 35 of the vessels. The ships would help the Navy and Marine Corps implement their Distributed Maritime Operations concept, which calls for US naval assets to disperse over large areas to reduce the risk of catastrophic losses from an enemy attack.

The Corps wants the new ships to be able to beach and unload Marines and their gear essential to setting up small expeditionary bases across the Pacific , but they're also expected to be useful in noncombat operations or situations where there are no port facilities.

If the Navy ever decides to modify one of these future LSMs for deep fire support, it should look no further than the example set by the White River.

Benjamin Brimelow is a freelance journalist covering international military and defense issues. He holds a master's degree in Global Affairs with a concentration in international security from the Fletcher School of Law and Diplomacy. His work has appeared in Business Insider and the Modern War Institute at West Point.