USS Oglala (CM-4) - Report of December 31, 1941

U.S.S. Oglala (CM4)
CM4/A16-3/S81-3/ (0103) 10/cam

Pearl Harbor, T.H.
December 31, 1941

1. In accordance with reference (a), the following report of the action of December 7, 1941, is submitted:

a. NARRATIVE. At the time of the attack, the ship was moored port side to U.S.S. Helena at berth B-2, Ten Ten Dock, Navy Yard, Pearl Harbor, with a distance between ships of about eight feet. The weather was clear with high visibility. General Quarters was sounded about 0755 at the start of the attack by the enemy. While going to general quarters, a torpedo-plane was seen approaching the ship, and when close aboard, about abeam on the starboard side, dropped a torpedo. At about 0757 a violent detonation occurred, which lifted up the fireroom floor plates and ruptured the hull on the port side. Fireroom started flooding rapidly; personnel secured the boiler fires, closed watertight doors and abandoned the fireroom. At about the same time, (0757), several planes strafed the ship with machine gun fire. At about 0800 a bomb from an enemy dive bomber fell between the Oglala and the Helena and exploded outboard in the vicinity of the fireroom, or perhaps a little forward thereof. The effect of this explosion was probably to augment the damage previously done by the torpedo.

At about 0830 extensive flooding of the engineroom was reported and the ship took a 5° list. Investigation revealed that the ship was dry forward of the fireroom but was flooding rapidly aft. As all power was off the ship, there were no pumping facilities and it was evident that the ship could not be kept afloat much longer.

It was decided to tow the ship clear of the Helena in order to secure her to the dock and also clear the battery of the Helena. Two small tugs were commandeered and they assisted in pulling the ship clear. At about 0900, the ship was secured to Ten Ten Dock astern of the Helena. All possible lines were gotten out to the dock but the list to port continued to increase.

At about 0930, when the list had increased to about 20° and service of the guns could not be continued, the machine guns were removed and the order given to "Abandon Ship". Shortly before 1000 the ship had finally turned over and came to rest on the bottom on her port side in about 6 fathoms of water.

b. The ship suffered no direct hits by projectiles or bombs, except machine gun bullets (strafing attack).

c. UNDERWATER EXPLOSIONS.

1. The torpedo fired at the ship at 0757 passed under the hull from starboard to port and exploded under the bottom on the port side, probably upon striking the starboard side of the Helena. Since the Helena has nearly the same draft as the Oglala, it seems likely that the torpedo porpoised under the Oglala, came up and struck the Helena on the starboard side. It is possible also that it was a magnetic torpedo and exploded under the bottoms of the two ships without stricking. However, the large damage to Helena and the undoubtedly lesser damage to Oglala inclines to the former view.

This torpedo explosion centered at the fireroom, lifting up the fireroom floor plates and rupturing the port side. A large inrush of water resulted, and personnel immediately secured the fires, closed watertight doors, and abandoned the fireroom. The noise of the explosion was loud and shock effect serious, such that the circuit breaker of operating generator was thrown out, the port flushing pump in the engineroom was broken loose from its foundations, and men were thrown out of their bunks. No flash, flame, or smoke was noted. A general flexural vibration of the ship was noted. Engineroom also commenced to flood forward on the port side.

2. The bomb which fell at 0800 between the Helena and Oglala caused a second violent detonation, raising a geyser of oil and water which fell on deck. The explosion centered on the port side, approximately abreast of the fireroom or a little forward thereof. it appears that this bomb caused no new flooding but increased the flooding of both firerooms and engineroom. in this case also, the noise of the explosion was loud and the shock effect serious. No flash, flame, or smoke was noted. A general flexural vibration of the ship was noted.

d. Prior to abandoning ship, the condition of flooding was as follows:- port bunker storeroom, which runs full length and outboard of fireroom flooded; fireroom, flooded; engineroom flooded; #3 hold, partially flooded and filling slowly. Other space aft of engineroom, such as shaft alleys, #4 hold, etc., may have flooded but were not examined either because of impossibility of access or lack of time. It was evident that the ship was settling by the stern as well as healing to port. The two new bunk compartments forward of the fireroom were dry when last examined, as were other forward compartments. However it is probable that these compartments flooded later through the open vent system. The magazines were not flooded. No voluntary flooding, or counter-flooding was accomplished. No rupture of bulkheads due to flooding pressure was noted.

e. At the time of the raid, the ship was in a modified material condition "Baker", such ports and hatches as requeired for the comfort of the crew were left open. When general quarters was sounded, material condition "Afirm" was set. It is probable that in the haste and confusion the setting of material condition "Afirm" was not adequately accomplished; several ports in an office on the starboard side were left open.

f. This ship had refueled on December 5, 1941, and had approximately 232,600 gal. fuel oil on board when sunk. The head of oil had been taken off the C1-C2 double bottom fuel oil tanks under engineroom and from A103 fuel oil tank adjacent to fore peak and chain locker.

g. All fresh water tanks were full, total capacity about 45,000 gallons. All feed tanks were nearly full; total feed water on hand about 52,000 gallons.

h. It is not believed that the ship had suffered extensive structural damage. However this cannot be definitely determined until ship is righted. The immediate loss of all pumping facilities, poor compartmentation, and lack of watertightness, made it impossible to control the inflow of water and made the sinking of the ship inevitable.

[signed]
R.E. KRAUSE.

Copy:

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