The crack.

There have been many rumors and sea stories about the crack in the armored barbette of turret III on the USS Missouri. Most rumors claim it was caused by the ship's grounding in Hampton Roads. Not hardly, since the ship's hull was bogged down in a sand bar several hundred feet forward. There were also rumors that not all of the hull repairs for the grounding were completed, thus restricting her speed. All of these rumors are untrue and this article is being offered to clear the whole mess up.

In 1982 I was assigned to be the Hull Configuration Manager at Long Beach Naval Shipyard for the reactivation of Missouri and to inspect and compare configuration control on all four ships of the class. I was responsible to monitor, inspect, advise and design all structural modifications and repairs to the ship's hulls, superstructure and armor. So what you are about to read comes directly from "the horse's mouth".

In 1982 and in 1983 we did shipchecks of Missouri as she was still laid up in Reserve in Bremerton, Washington. On the first trip I photographed the crack in the starboard side of the barbette.

Prior to that, NAVSEA had also inspected the crack and cut a rectangular coupon out of it for analysis. I wish they had called me first because I had all the manufacturer's specs as to the analytical content of the class A armor (thanks to Nathan Okun in Oxnard, California for supplying them). That coupon cut with the square corners to concentrate stresses was just asking for more cracks to emanate from the corners.

Sketch of the crack. Made by Richard A. Landgraff.

Additionally, NAVSEA also X-rayed the barbette panel to see how deep the crack went. Their readings were still written on the side and I copied them all down. I also measured the exact shape and size of the crack using grid dimensions from the aft panel butt and down from the underside of the main deck.

Upon return to Long Beach, I then developed a repair procedure for the crack. Actually, it wasn't repair, but cosmetic cover up. Primarily, we had to cut out a couple of large chunks of the separated armor surface to eliminate the square corners of the coupon cut. Then we merely filled it in with underwater hull smoothing epoxy resin. After painting, you cannot tell where the crack is.

Now, for the cause of the crack. It is actually a laminar separation of the heat treated face of the class A armor. The face was carburized and hardened to a 540 Brinnel hardness up to 40% of the depth of the plate. The barbette panel is 17.3 inches thick and the laminar separation went no more than 6 inches deep, thus proving it was within the outer 40% heat treated depth.

Actually, throughout the entire ship, examples of laminar separation, starting near the edge of an armor panel, are quite common. During modernization at the shipyard, I got called out several times by ship's officers to inspect (and alleviate their fears) "cracks" in the class A armor. But this was only on the Missouri and not the other three ships of the class.

Checking the Basic C&R (Construction & Repair) drawings still on microfilm, drawing number 351465 "BARBETTE-III-ARMOR, PLATE- III-B-4" gives the most obvious clue as to why only Missouri has the most obvious evidence of laminar separation over her sisters.

The drawing lists which manufacturers were to make which armor for which ship. Bethlehem Steel Co. made the class A armor for the Iowa and New Jersey. Carnegie-Illinois Steel Co. made the class A armor for the Wisconsin, Illinois and Kentucky. But Missouris class A armor was made by The Midvale Co.

I checked with Nathan Okun, and he confirmed through his personal research that Midvale used a different carburizing and heat treating method than either Bethlehem or Carnegie. Midvale's method probably quenched the surface too quickly and caused many cases of laminar separation. But, as long as the heat treated surface stayed there, it would still do its job to break up a projectile casing of incoming artillery.

You see, it's pretty tricky face hardening 12 to 17 inch thick nickel-chrome steel and still leave the edges "soft" for machining of keyways that would lock the panels together. Generally, the armor panel would be lying with its back side down on a flat car of wet sand and the edges would be wrapped in wet asbestos while the face was heated for its final treatment. When the top 40% of the panel was hot enough, it was then cooled with water sprays. If it cooled too fast, then some areas would start to peel away, usually beginning along an edge that was kept "cool" with the wet asbestos shielding.

As for interior damage up forward remaining from the grounding, I personally inspected the decks and bulkheads in that area and found no residual damage. When the ship was drydocked in Long Beach, I went down into the dock, before all the water was even out yet, and it took some time but I finally found the welds of the shell insert where she was repaired. That general area also required the installation of new sea water intakes and discharges for modernization era air conditioning plants. I had the shipfitter's report back to me if they found any damaged areas that still needed repair. After a few weeks, I was getting concerned since I received no reports. Interviewing the shipfitters and their supervisors, they said that nothing needed further repair. They were able to identify how far into the ship's framing the repairs went and discovered that all repairs were A-1 in quality and completeness.

In summary, the crack in panel III-B-4 of Barbette III was caused by laminar separation during heat treatment at the foundry. Repairs by Norfolk Naval Shipyard of the hull from the grounding were thorough and expertly done.

Also, speed restriction of the ship to only 26 or 28 knots are also anti-Battleship biased. I was on Missouris high speed trial run in 1986 and that old gal kicked up a rooster tail you wouldn't believe at 32 knots for 4 hours without a waiver. Then we did a full "Crash Back" by changing the props from full forward to full reverse in just seconds. The momentum of 50,000 plus tons still carried the ship forward for over a mile. But the reversal of props never even sent the slightest vibration through her. I was about midships down on Broadway at the time. Then we ran full throttle in reverse for another 2 hours. Then we went full forward again at 32 knots and did dozens of high speed turns with the rudders hard over.

Crack? I dare you to find it.

Grounding hull damage? You need diving gear to find the repair welds, maybe.

Speed restriction? HAH!

So there.