A Casualty of Leyte- October 25, 1944

In quiet repose within the collection of the museum rests the pristine model of a feared and deadly class of enemy warship.  Its namesake, IJS Mogami, slipped beneath the waters of Surigao Strait, Philippines, at a little after 1 pm local time, October 25, 1944.  After being rendered dead in the water by American shells and bombs overnight, it was scuttled with a Type-93 “Long-Lance” torpedo by destroyer IJN Akebono during the retreat from the Battle of Surigao Strait, part of the larger Battle of Leyte Gulf.   

Both the model and the real Mogami began construction at the Kure Naval Arsenal almost 13 years before the battle, ostensibly under armament and displacement limits set by the London Naval Treaty of 1930.  Although Japan was a signatory to the treaty, which set displacement for cruisers at 10,000 tons, the Mogami-class “light-cruisers” not only weighed in at more than 13,000 tons when launched, but were designed from the beginning to be upgraded with heavier deck guns.  The design emphasizing such heavy armament on a relatively light hull resulted in warpage and stability issues during trials, to the extent that she and her sister ship Mikuma, both launched in 1934, had to return to the dry docks at Kure for an extensive refit.

Here we see turret three as it would have appeared until the end of the decade, like the four others of Mogami, equipped with three 155 mm guns each (Only the third and fourth turrets were equipped with rangefinders).  The turret rings were conveniently designed for swapping-out with turrets housing two 203mm guns each, which was accomplished before the war with America began.  

Mogami and Mikuma scored their deadliest victory against American and Australian (and, ironically, Japanese) forces when they helped sink the Newport News-constructed heavy cruiser USS Houston (CA-30) and light cruiser HMAS Perth (D-29) in the Battle of the Sunda Strait (depicted above) on the night of February 28-March 1 1942.  After-action analysis determined that torpedoes from Mikuma and destroyer IJS Fubuki also sank or disabled four of the Japanese troop transport vessels the Allied ships were trying to attack in the first place.  

The sister ships encountered further misfortune when attempting to escort Vice Admiral Nobutake Kondo’s invasion force to Midway Island in June 1942.  In the ensuing debacle, Mogami collided with Mikuma on June 5 when the latter executed an emergency turn before the former could respond.  Mogami’s bow was crushed, cutting its top speed by over half, and one of Mikuma’s main fuel tanks was punctured, leaving an oil slick any aircraft could follow, and follow they did.  

Over the next 24 hours, Marine, Army, and finally Navy planes followed the trail.  Dive bombers from USS Enterprise (CV-6 ) and Hornet (CV-8), both made in Newport News, left Mikuma a smoking ruin after five direct hits set off unexploded ordnance, particularly the Type-93 torpedoes.  Although the most advanced torpedo in the world at the time in terms of range, speed, and firepower, the Long Lance would ultimately prove fatal to three of the four ships of the class because of the compressed oxygen they carried.  

Mogami would have suffered the same fate had it not been for its damage control officer, Lieutenant Commander Masayushi Saruwatari, who ordered all remaining torpedoes and depth charges jettisoned after the collision when it became clear that aerial attack was inevitable.  The dive bombers only scored two significant hits, but one forced Saruwatari, in his words, to take the “apparently unmerciful step” of sealing off the sickbay to keep a conflagration there from spreading to the rest of the ship.  Those within not killed by the bomb perished in the flames. “I trembled with great sorrow toward them,” recalled Saruwatari. 

Mogami survived to fight another day, but when it did resume the fight, it had undergone quite a metamorphosis.  After essential repairs at the island of Truk southwest of Midway, Mogami made it back to Sasebo on the southern Japanese island of Kyushu in August 1942 where engineers worked feverishly to reinvent the warship to cope with a combat environment drastically changed from the one it was designed to fight in.  Mogami’s fourth and fifth turrets ( the "light cruiser" kind shown in the model above, the heavy cruiser replacements in the illustration immediately below) were removed and a flight deck and rail system supporting up to 11 reconnaissance floatplanes was installed. 

Its dual 25mm anti air emplacements (on either side of the searchlight in the photo above) were replaced with 10 triple-mount 25mm guns along with an air-defense radar.  During two subsequent refits back in Kure, four more triple-mount and 18 more single-mount 25mm AA guns were installed along with two more radar targeting systems.  By the time it was assigned to help repel the American invasion of the Philippines as part of the Southern Force, the “aircraft cruiser” Mogami had more than 17 times the number of 25mm anti-aircraft guns than it had at the start of the war.  

But in the end, Mogami and 192 of its crew of 850 would perish in the last sea battle decided by old-fashioned gunplay.  Four well-placed 8-inch shells lobbed by Rear Admiral Jessie Oldendorf’s task group defending Leyte destroyed Mogami’s bridge and its air defense center.  As the surviving vessels of the Southern Force attempted to withdraw back through the strait amid the smoke and darkness, the cruiser IJN Nachi collided with the crippled Mogami.  This time, there was no time to jettison the volatile torpedoes and five exploded, knocking out Mogami’s starboard engine.  More 6 and 8-inch shells rained down from the pursuing cruisers USS Denver (CL-58), USS Louisville (CA-28), and USS Portland (CA-33), and the cruiser’s port engine then failed.  Now adrift in the morning light, Mogami was hit by two 500-pound bombs from a group of 17 TBF Avengers which attacked shortly after 9 am.  The crew started abandoning ship around two hours later, and two hours after that, Akebono struck the final blow. 

Coincidentally, at almost the same time on October 25, Mogami’s sister ship Suzuya also succumbed after aerial attack by the planes of Task Unit 77.4.3 (“Taffy 3”) off Samar.  The ship sustained no direct hits, but indirect damage caused its Long Lance torpedoes to explode.  The final ship of the class, IJS Kumano, survived the Battle off Samar despite sustaining the loss of her bow to a torpedo from USS Johnston (DD-557), but she was sunk exactly one month later by aircraft from the Newport News-made USS Ticonderoga (CV-14) as the ship underwent repairs in Dasol Bay, around 175 miles north of Manila.

The model remains an intricately-fashioned but mute reminder of the grand plans and desperate measures other navies have undertaken to win supremacy of the seas, only to be stopped by the mighty United States Navy.

(Sources: Gordon W. Prange, Donald Goldstein and Katherine Dillon, Miracle at Midway (New York: McGraw-Hill), 339-340; "Japan's Light/Heavy Cruiser Mogami," worldofwarships.com; combined fleet.com.  Special thinks to HRNM Registrar Katherine Renfrew)

5-Inch Guns at the Battle of Leyte Gulf

On the morning of October 25, 1944, the escort carrier group “Taffy 3” was surprised by a large Japanese force which included cruisers and the heaviest battleship in the world, the Yamato.  This small group of escort carriers and “tin can” destroyers was all that stood between the Japanese and the American invasion force at Leyte in the Philippines.  In part of what was to be called the Battle of Leyte Gulf, a handful of destroyers and destroyer escorts protected “jeep carriers” (CVEs) in a suicidal run against a vastly superior Japanese force.  The names USS Johnston (DD-557), USS Hoel (DD-533), USS Heermann (DD-532) and USS Samuel B. Roberts (DE-413) are among those of naval lore for their actions in this battle as they tried to screen the carriers. Of note in these tales of bravery are the stories of the men who kept firing their comparatively small five inch guns against heavily armored Japanese vessels after their ships had been severely damaged or they were out of ammunition.  

Note the five 5-inch turrets on the Fletcher-class destroyers.

The 5-inch gun was not the main weapon in a WWII-era USN destroyer’s arsenal. That honor belonged to the Mk 15 torpedo.  A Fletcher-class destroyer usually mounted ten, while a destroyer escort such as Samuel B. Roberts had three. Yet after these were fired, they could not be reloaded at sea, and the 5-inch guns became a ship’s primary weapon. The Mk 30 single mounted 5-inch/.38 caliber gun was the largest cannon on these ships. Widely regarded as the best dual purpose gun in WWII, it was put on almost everything afloat in the U.S. Navy.

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During the battle, the heaviest guns that the escort carrier group Taffy 3 had at their disposal were the 5-inch ones. Besides the destroyers’ guns, each CVE had a single 5-inch gun in an open mount.  As the group desperately tried to run from the shocking appearance of the Japanese fleet, American sailors and pilots tried to throw everything they could to delay the onslaught.

 The Mk 30 5-inch gun fired a round which weighed 55 lbs.  For comparison, the 16-inch guns on an Iowa-class battleship fired shells weighing 2,700lbs, and the Yamato fired shells weighing over 3,000lbs out of her 18.1-inch guns. In addition, the small shells fired by the American destroyers could not penetrate the armor on the heavy cruisers that were at the front of the fleet overtaking the American carriers.  Even with these facts, the small ships, led by Johnston, engaged the heavier Japanese ships, firing hundreds of shells during the course of the battle.  Samuel B. Roberts reportedly fired over 600 rounds in just over a half hour, which is astounding as there were only two guns onboard the ship.  Numerous Japanese ships were hit in the barrage flying from the guns of the American ships.  The accuracy of the destroyer’s gunfire was helped by the proximity of combat, the superior American radar guided fire control system, and the sheer size of their foes.

In this David versus Goliath drama, the courage and determination of the “small boys” proved decisive in slowing down and confusing the Japanese fleet.  In the end, the Japanese admiral called off his fleet and Taffy 3, as well as the invasion fleet, were saved.  The men on the destroyer screening force paid dearly as several ships were lost, but their sacrifice helped prevent further disaster.