On April 16, 1989 there was an explosion in a gun turret on the U.S.S. Iowa. 47 men were killed. This need not have happened. It was a foreseeable result of lack of training and the running of unnecessary risks by persons both on the ship and at the highest level of the Navy command.
In this multi-part series, I will explore this disaster, which has its roots in the ridiculous worship of an obsolete weapons system, the battleship, by persons who damn well should have known better, starting with John Lehman, secretary of the Navy.
As I shall show, not only should Lehman and the Navy command known these ships were both obsolete and dangerous, they were actually told so. Even so, they were placed into service and kept in service -- I believe primarily for political reasons, as the ships had long since ceased to be efficient weapons platforms.
Below the fold, I give some basics of the primary weapons system of these ships as originally designed. Although obsolete no later than the 1950s, these weapons systems were the primary reason for the reactivation of the ships in the 1980s.
The Iowa class ships.
The Iowa-class battleships were designed in the late 1930s and finished in the early 1940s, during World War II. Their primary mission was to engage in combat with, and destroy, enemy battleships of similar size, armament and protection. They were also capable of use for bombardment of on-shore targets.
To these purposes, the Iowa class carried a main armament of nine large rifled guns. The inside of the gun barrels is called the bore, which in the Iowa class was 16 inches wide. These were called "50 caliber" guns because the gun barrel was 66 feet long, or 50 times the bore diameter.
Wiki Commons / Voytek S
Three guns were mounted in each of the ships' three turrets. The turrets were numbered from bow to stern. Each gun was capable of being fired independently and at different elevations (and hence different ranges) than the other two in the turret.
The multi-story turrets which carried these guns were themselves possibly the most complex and heaviest weapons systems ever mounted in a naval vessel. They extended from the top deck of the ship, with the visible part being called the "gun house", clear to the lower deck of the ship. The rotating shaft of the turret was armored to protect against hits from enemy battleships.
Within the turret, ammunition and propellent, in the form of pre-measured gun powder bags, was sent up by lifts to the gun house. To protect against loss of the ship due to an explosion in the gun house, elaborate systems of screening were employed.
There were two basic types of projectiles used, armor-piercing and high explosive. The armor-piecing shells were designed to penetrate the high-quality steel alloy armor used by other navies to protect their own battleships. These shells weighed 2,700 pounds. The kinetic energy alone from a hit on an enemy ship would be enormous.
Beyond that however, the armor piercing shells contained a bursting charge of about 50 pounds of explosive, which was fused to go off with a short delay following the impact, by which time the shell would, or so it was hoped, have penetrated to the interior of the enemy vessel.
The high-explosive shells weighed less, 1900 pounds, and contained a greater amount of bursting charge, 150 pounds. Their purpose was to create the maximum possible explosive power against ground targets, such as buildings.
Firing the main armament
To fire the guns, it was necessary to open the breach (that is, the end of the gun inside the turret), blow compressed air into the gun to flush out the gun muzzle any flaming debris from any previous discharge, and then insert, using a hydraulic ram, the projectile into the gun barrel. After that, bags of gun power would be placed into the gun, again, they would be slid into the breech using the hydraulic ram. Here's a US Navy training film which explains in detail the procedure, as well as giving some idea of the complexity of the turret structure.
The primer for this massive charge was a simple .30 caliber rifle cartridge. This would be inserted into the breech block (the large seal for the breach, this looks and works somewhat like the door on a bank vault). When the gun was ready to fire, the gunnery control officers would be informed. The gun could be discharged either by the turret commander or by a central gunnery control command station. Once the decision to fire was made, an electrical signal would fire the primer into the power bags, causing them to explode and expelling the shell out of the muzzle of the gun toward the target. (See here for a basic animation showing how a gun turret worked.)
Ideally each gun could be discharged twice a minute, or maybe a little faster. Combat with an opposing battleship might last only a few salvos, so it was essential to place as many shells downrange towards the target as quickly as possible.
Thus, in the 1941 Battle of the Denmark Strait, the largest British ship, the battlecruiser Hood was sunk after just five minutes firing by the German ships. During these five minutes Bismarck, the principal German warship, had fired 93 armor-piercing projectiles from its 8 main guns, also approximately 2 salvos per minute.
A battleship was capable of doing enormous destruction, but it was also quite dangerous to operate. In combat conditions, particularly on early battleships, a turret fire, caused generally by a hit from an enemy shell, could reach the magazine and cause an explosion which would destroy the whole ship. But even in non-combat conditions, a ship could be destroyed or seriously damaged by its own munitions.
For example, in 1943, the Japanese battleship Mutsu was destroyed at anchor by an explosion in the magazine of one its main turrets. Two Italian battleships were destroyed in World War I by internal explosions, supposedly the result of enemy sabotage, but one wonders.
In our own Navy there had been six prior instances of turret fires on battleships, most were from before World War 1, but two were later, both on the same ship, USS MIssissippi. 48 men were killed on June 12, 1924 as a result of an explosion in the ship's number 2 main gun turret during target practice. Just over 20 years later, on November 2, 1944, another turret explosion occurred while the ship was conducting shore bombardment. This time 45 men were killed.
Heavy cruisers, which are smaller vessels than battleships, but which were still significant warships, also suffered turret fires, as their main armament (8 inch guns) was operated similarly to the large battleship guns. On April 21, 1951, there was a turret explosion on heavy cruiser St. Paul while the ship was engaged in shore bombardment of the Korean peninsula.
In May 1972, the heavy cruiser USS Newport News suffered a premature shell detonation in the barrel of one of the ship's 8 inch guns, which like the Iowa-class main armament, was mounted in a turret. The resulting explosion killed 20 men and injured 36 more.
Internal fire barriers prevented these fires from reaching the magazines and destroying the ships on which they occurred. But there was never any certainty that the internal protections would always work, and so, on all the Iowa class ships, there were provisions made to permit the magazines to be flooded with seawater to prevent a disastrous magazine explosion.
The need for such a fail-safe measure had been established in 1916 at the Battle of Jutland when a combat-caused turret fire on the battlecruiser HMS Lion threatened to spread to ignite the magazine of the ship's central turret, with the danger only being averted by the last-minute flooding of the magazine.
First retirement of the Iowa class
Returning to the Iowa class ships, all were removed from service in the 1950s when relatively new.
Missouri was withdrawn from service in 1956 and placed into reserve, as were Iowa and Wisconsin in 1958. New Jersey was decommissioned following the Korean War, but was returned to service in 1968 during the Vietnam War and used for shore bombardment before being removed again from service in December 1968.
And so these ships remained, quietly sitting alongside piers for an entire generation. All the ships they had been intended to fight had been sunk or scrapped long before. It was possible to tour the Missouri at Bremerton, Washington, which I remember doing as a child. You could only walk around the main deck, but it was impressive enough even so.
Reagan Administration reactivates the battleships
This situation continued decade after decade, until the mid-1980s, when the Reagan Administration came up with its idea of having a 600-ship navy, and decided to reactivate the Iowa battleships. With the exception of the New Jersey's brief reactivation in 1968, the main armament of these ships had not been fired since the 1950s.
The technology of course dated from the late 1930s. Almost no one in the Navy had any actual experience of serving on a battleship. Much of the ammunition and propellent bags for the main armament dated back to the 1940s.
Part 2: Dubious decision-making, incomplete renovation work, and underfunding leads to needless risks on the reactivated battleships.