On October 22nd, 1941 Battleship Arizona was hit by Battleship Oklahoma during exercises in the Pacific Ocean. The two ships (along with Nevada) were operating as Battleship Division One of the US Navy's Battle Fleet. There were no injuries and damage was comparitively slight for the armored battlewagons; however the incident put both ships in drydock for a short period of time. Below is information gleaned from various records at the US National Archives in College Park, Maryland, that may help the reader gain a better understanding of the event.

Using the Booklet of General plans for both Arizona and Oklahoma, we can show the comparative size and layouts of the two ships in the areas of the collision: Documentation A Memo from CINCPAC (Commander in Chief, Pacific Fleet) to the office of the Chief of Naval Operations with basic information.   Pearl Harbor Navy Yard photo 541-41, showing the damage to the port-side blister from about frame 70 to frame 77 (a distance of about 28 feet or 8.5 meters). The top of the damage is about four feet (1.25 meters) below the waterline and none of the sailors would have been able to directly see this until the ship was drydocked.   Pearl Harbor Navy Yard photo 542-41 taken near the time that 541-41 was, showing the damage from frames 70 to 78 (about 32 feet) with a shipyard worker standing on the bilge keel near the turn of the blister's bottom. All of the ship's shell in this area is anti-torpedo blister structure added during a modernization from 1929 to 1931. The blisters were separated into 22 segments lengthwise with an upper and lower compartment to each segment. This damage spans both upper and lower blister compartments of two segments with a total of five void compartments and four fuel compartments opened to the sea.      The Navy memo the two photos above were attched to stated, "damage below the waterline on the port side near frame 76, involving the following compartments:" Voids, outer compartments: B-4-LB, B-6-LB B-6-UB B-8-LB B-8-UB Fuel tanks, inboard of the voids: B-116-AF B-118-AF C-114-AF C-116-AF      Using this and plans we have available, we can build a graphic representation of the collision. But first. we should spend some time describing Arizona's structure so the reader has a better understanding of what they are examining. Before the US entry into the First World War, the US Navy had standardized a structure known as a "torpedo defense system" that consisted of separate compartments filled with air ("voids") and liquid (fuel oil). Much like a crush zone in a modern car, this system of compartments would absorb the concussive explosion of a torpedo and prevent much of the damage from reaching inside the important machinery sections of this ship while requiring less weight that an extension of the thick armor belt above.      Pulling up what is known as a "transverse section" drawing that is set at Frame 75, the center of the damage, we see the following, with color added to make the separate compartments more understandable: - Click to enlarge -      The memo states that both upper and lower blisters at this frame were punctured and B-118-AF damaged and open to the sea as well. Overhead views of the decks show how forward and aft the sea water extended: - Click to Enlarge - The above plan is the "First Platform," which was a few feet under the waterline and is essentially where the inclined ladder drawn in the transverse section drawing above topped out at. Seawater only penetrated two compartments in from the outer shell of the ship, but it is interesting to note that it extended forward one blister compartment below this (See the "Hold" Deck plan below) and TWO fuel compartments aft. C-114-AF is perhaps not surprising given it's close proximity to the damage and forces exerted on the structures there, but the aft compartment C-116-AF presumably was fouled due to valve settings or some other issue not related to puncturing of the structure.

SOURCES:
National Archives & Records Administration, College Park:
Second floor, Textual records: Record Group 19, Bureau of Ships General Correspondence Files 1940-45, BAC-BYTL
Third floor, Cartographic records: ships' plans

Transcribed by RESEARCHER @ LARGE. Formatting & Comments Copyright R@L.

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