U-boat Archive - U-505 - Analysis of Attack

UNITED STATES FLEET

HEADQUARTERS OF THE COMMANDER IN CHIEF

NAVY DEPARTMENT

WASHINGTON 25, D. C.

Incident No. 6313

ANALYSIS OF ANTI-SUBMARINE ACTION BY USS CHATELAIN (DE149)

Employment. . . . . . . . . . . . . . . .	CVE Killer Group
Time. . . . . . . . . . . . . . . . . . . . . .	1109 GCT, 4 June 1944
Position. . . . . . . . . . . . . . . . . . .	21-30N/19-10W
Weather. . . . . . . . . . . . . . . . . . .	Clear; Visibility excellent; Sea Smooth; Wind force 1
Depth of Water. . . . . . . . . . . . .	1700 fathoms
Contact first made by. . . . . . . . .	Sonar
Range. . . . . . . . . . . . . . . . . . . .	800 yards
Sonar conditions. . . . . . . . . . . . .	Long 90/15 Mike
Number of Attacks. . . . . . . . . . .	2

BRIEF OF NARRATIVE.

(a) While on position in anti-submarine screen of the GUADALCANAL, CHATELAIN at 1109 GCT, 4 June, obtained sonar contact at range of about 800 yards. Range closed too rapidly to fire on first approach, so CHATELAIN changed course to open out. Due to proximity of carrier, range was opened only 700 yards, at which point she proceeded to attack. At 1116 hedgehogs were fired with negative results. Contact was lost at approximately 50 yards, indicating very shallow target.

(b) CHATELAIN regained contact immediately and opened the range for reattack. Fighter planes from GUADALCANAL sighted the U-boat running close to the surface and fired machine gun bursts to indicate its position. At 1121 CHATELAIN fired 14 depth charges, shallow setting , which resulted in the immediate appearance of an oil slick. At 1123 submarine surfaced and was immediately taken under fire by CHATELAIN, JENKS, PILLSBURY and two fighter planes. At 1125 CHATELAIN fired one torpedo, which missed 50 to 100 yards ahead of the submarine. THe submarine crew was observed abandoning ship and orders were received to cease fire.

(c) CHATELAIN and JENKS recovered the survivors of the U-boat while the PILLSBURY put a salvage party aboard and succeeded in preventing the U-boat from sinking. The U-boat (U-505) was subsequently taken in tow by GUADALCANAL, and was later delivered to Bermuda.

EVALUATION OF TARGET

(a) U-505

EVIDENCE OF DAMAGE

(a) Submarine forced to surface and abandon ship. Submarine and crew captured.

UNITED STATES FLEET

HEADQUARTERS OF THE COMMANDER IN CHIEF

NAVY DEPARTMENT

WASHINGTON 25, D. C.

ANALYSIS OF ATTACKS.

CHATELAIN First Attack

	Time	1116
	Range at which contact was gained	800 yards
	Range at which contact was lost	50 yards
	H. E.	None
	Doppler	Slight down
	Target Movement	Right
	Number of Charges	24
	Depth Setting	Hedgehog

This attack was commenced from too short a range to permit accurate evaluation of target. At time of firing bearing movement was noted to be changing from the left to the right. Results negative.

CHATELAIN Second Attack

	Time	1121
	Range at which contact was gained	100 yards (opened to 500 yards)
	Range at which contact was lost	Approximately 100 yards
	H. E.	None
	Doppler	Slight up
	Target Movement	Left
	Number of Charges	14
	Depth Setting	75'-150'

This attack was also commenced from very short range. However, very shallow depth of submarine reduced the problem of lead. An immediate oil slick resulted, and the submarine surfaced in the center of the depth charge boil.

It is interesting to note that despite the shallow depth of the maneuvering submarine and the low ranges of lost contact no hydrophone effects were heard at any time.

- 2 -



	UNITED STATES FLEET
	HEADQUARTERS OF THE COMMANDER IN CHIEF
	NAVY DEPARTMENT
	WASHINGTON 25, D. C.

	OPINIONS

	Plotting Room Opinion not requested.

	Tactical Analysis Officer

	(a) U505 was captured by the GUADALCANAL group, and subsequently brought into port. It is recommended that this incident be assessed "A".

	(b) CHATELAIN gained initial contact and carried out two attacks causing the U-boat to surface. It is recommended that she be given principal credit. Two fighter planes from GUADALCANAL, F-1 and F-7, (pilots Ensign J. W. Cadle and Lieutenant W. W. Roberts) gave material aid in the form of accurate information of the U-boat's movements during attacks, and these planes took the U-boat under fire upon its surfacing. It is recommended that they receive contributory credit.

	(c) In addition to CHATELAIN, the JENKS and PILLSBURY engaged the surfaced U-boat with gunfire until it was abandoned. It is recommended that JENKS and PILLSBURY receive contributory credit.

	(d) The assignment of credit for subsequent salvage of U-505 is considered to be in the province of the Fleet Commander (CincLant).






	- 3 -