U.S. NAVAL
TECHNICAL MISSION IN EUROPE
c/o Fleet Post
Office
New York, N.Y.
File: A9-16(3)
(10/Hn)
Serial: 0958
29 August 1945
CONFIDENTIAL
From: Chief, U.S.
Naval Technical Mission in Europe.
To: Chief of Naval
Operations (OP-16-PT)
Subject: U.S. Naval Technical Mission in
Europe Technical Report No. 222-45, Loss of the German Battleship Tirpitz on 12
November 1945 – Forwarding of.
Enclosures:
(A) (HW) Complete
copies Nos. 1 and 2 of subject report as listed in distribution.
(B) (HW) Six (6)
copies Nos. 20-25, without photographs, as listed in distribution.
(C) (HW) Copy No.
26 without photographs, with one set of negatives of photographs in subject
report.
1. Enclosures (A),
(B) and (C) are forwarded herewith.
2. CNO (OP-16-PT) is requested to make
complete additional copies of this report for such other agencies as may be
interested.
[Signed]
HARRY D. HOFFMAN,
Captain, U.S.N., Acting
DISTRIBUTION To:
CNO
(OP-16-PT) Copy Nos. 1 – 2
COMINCH
(Readiness) Copy No. 3
CIOS,
APO 413 Copy No. 4
BuShips
Copy No. 5
BuShips
(Code 400) Copy Nos. 6 – 7
BuOrd
Copy No. 8
BuAer
(TIL Section) Copy No. 9
ComNavEu
Copy No. 10
ComNavEu
for Admiralty Copy No. 11
BuPors
(Training Division) Copy No. 12
CINCPAC
Copy No. 13
ComSerFor,
Pac. (Fleet Maint.) Copy No. 14
Naval
Damage Control Training Center Copy No. 15
NTS
(Damage Control) Copy No. 16
U.S.
Naval Academy, Post Grad. School Copy No. 17
U.S.
Naval Academy Copy No. 18
Office
of Research and Invention Copy No. 19
CON
(OP-16-PT) w/o photographs Copy Nos. 20 –25
CON
(OP-16-PT) w/enclosure C Copy No. 26
Table of Contents
1. Introduction
2. Narrative
3. Discussion
4. Conclusion
Appendix: Loss of the German Battleship Tirpitz on 12 November
1944
References:
ComNavEu A16-3, Memo T-25:PC of 9 July.
Admiralty Battle Summary No. 27 (1945)
CB-3081(20), “Naval A/C Attack on TIRPITZ,” (Operation “Tungsten”) on 3 April,
1944.
British Air Ministry Operational Research
Section (Bomber Command) Report S.218 “Results of Attacks with 12,000 M.C.
(“Tallboy”) Bombs,” dated 2 May 1945.
Official German Reports Concerning Loss of
TIRPITZ (included with translations as Appendix “A”).
Principal Characteristics of Tirpitz
L.B.P. - 790 feet
L.O.A. - 821.5
feet
Beam (moulded) -
118.0 feet
Drafts - 29.0 feet
forward; 29.0 feet aft
Displacement -
42,000 tons
GM - 12.0 feet
1. Introduction.
This report on the loss of the German
battleship “Tirpitz” is based primarily on the references. Supplementary
information was obtained by an interrogation of Fregatten Kapitan (Ing.)
[Alfred] Eichler, who had been through earlier attacks on “Tirpitz” as Chief
Engineer. Although not present at the time of the sinking, Eichler, had talked
with survivors concerning the damage control aspects of the attack.
“Tirpitz” had been subjected to a number of
air and submarine attacks which resulted in minor damage only (references (a),
(b), and (c)). During a raid on 3 April 1944, she was struck by a total of 16
bombs, ranging 500-pound general purpose bombs with instantaneous fuses to
1600-pound armor piercing with 0.8 seconds delay in the fuze. There was
extensive non-vital damage to portions of the superstructure and other spaces
in the upper watertight part of the ship, but only a dud pierced the armoured
deck. During an attack on 15 September, 1944, the following damage was
incurred: (1) the forward 100 feet of the bow was destroyed and the bottom
shell plating ruptured or buckled for about 50 feet further aft: (2) the bow
was flooded from the forward end for about 120 feet below the upper platform
and for about 80 feet on the upper platform. Furthermore, the starboard
propeller shaft tunnel and shell plating in the immediate vicinity were
ruptured during a midget submarine attack causing the flooding of several small
spaces low in the ship at the stern. None of this underwater damage at the bow
and stern was repaired.
2. Narrative.
On the morning of 12 November, 1944,
“Tirpitz” was lying at anchor in Tromsoe Fiord, located in the northern part of
Norway. The fuel and fresh water on board amounted to only about 3,000 tons,
approximately 30 percent of full load. The vessel was without trim, but had a
list of one degree to port. Stern and bow anchors were out to deep her from
swinging into unfavorable defensive positions. A torpedo net enclosed the ship
as protection against submarines and other types of sneak craft. An air raid
watch had been stationed at daybreak. The weather was fair, skies clear and
visibility excellent. The wind was from SSW force 1.
0800 - The first warning was received
concerning single bombers in the vicinity of Bodoe. “Tirpitz” was connected
immediately to the main air raid warning station at Tromsoe.
Note: All times may be slightly in error.
0815 - An additional warning was received
that 3 Lancasters with Mosquito fighter escort had been sighted at 0737 flying
in on an easterly course. More Lancasters were reported approaching on a north-easterly
course. Fighter protection was requested by “Tirpitz” but no acknowledgment was
received.
0854 - An air raid alarm was sounded for the
ship and the city of Tromsoe. It was apparently at this time that battle
stations were manned, closures set and the vessel made ready for action. One
boiler in the starboard forward fireroom (Kesselraum Stbd. v.) furnished steam
to the turbo generator in generator room No. 3 (E. Masch. R3). Steam for the
turbo generator in generator room No. 4 (E. Masch. R4) probably came from a
boiler in the after port fireroom (Kesselraum Bb.h.). The battle electrical
load was split between the two generators in accordance with established procedure.
0915 - A formation of about 18 British
aircraft was sighted approaching at an estimated range of 75 miles. At a range
of about 55 miles these planes headed directly toward “Tirpitz.” Shortly
thereafter a second formation of about 12 planes was sighted by “Tirpltz.” The
altitude of both flights was 12,500 to 16,500 feet.
0920 - The request for fighter protection
was repeated by the Commanding Officer of “Tirpitz” and the fighters took off
immediately.
0927 - At a distance of approximately 30
miles from Tromsoe, the first bomber formation in response to a smoke signal
split into groups of 4 to 5 planes and started in on an attack course. The
planes came from the direction of the sun and the course, in contrast to
previous tactics was athwartships.
0934 - Heavy AA guns opened tire at a range
of about 7 miles, causing only a slight breaking up of the formation, the
bombers joining together again immediately.
0936 - Medium AA and machine guns opened
fire but the bombers continued straight through. One plane was observed to fall
during the approach. Note: Not shown on plates, located on lower platform,
starboard and port respectively, outboard, between frames 145.6 and 154.5.
0938 - A closed bomb carpet of 29 “Tallboy”
12,000 pound bombs was dropped on “Tirpitz.” There was one confirmed direct hit
and probably two others (Plate I). All hits were on the port side. Numbering
these bombs for convenience from forward, No. 1 (classified as “probable”)
according to reference (d), struck near turret “Bruno.” No. 2 made a confirmed
direct hit near the aircraft stowage detonating in a wing tank outboard of the
port engine room (Turbineraum Bb.), (Plate II). According to reference (a) Bomb
No. 3 (the second probable) struck abaft of and to port of turret “Caesar.” No.
3 was reported to have caused a fire. There were no reports or indications of any
other direct hits.
In addition to the direct hits,
approximately 7 other bombs landed to port of “Tirpitz” within the torpedo net,
2 or 3 very close to the ship’s side. (Plate III). Ten borne craters in the sea
bottom were visible from the air. There were no reports of any bombs landing to
starboard of the centerline, either on the ship or nearby.
Large quantities of water swept into and
over the “Tirpitz.” She listed rapidly to an angle of about 35 degrees. AA fire
decreased sharply. At the start of the list the order was given to
counterflood. It was discovered later that the flooding controls had been
abandoned. It is not known whether these controls were abandoned before the
valves could be opened. The main drainage pumps were not used. Personnel were
instructed to evacuate the lower decks. The port side of the superstructure
dock went under and the list increased to about 60 degrees, remaining there
briefly.
0945 - Turret “Caesar” exploded, cause
unknown,. all rotating structure reportedly being hurdled about 25 yards
through the air. The immediate effect of the explosion was to increase the list
so that the ship capsized, approximately 7 minutes after the first bombs
landed. “Tirpitz” came to rest on the floor of the anchorage at an angle of about
135 degrees with the superstructure embedded in the mud.
Electricity was furnished by the turbo
generator in generator room until the very end. There were no indications of
panic during or after the capsizing. About 1,200 officers and men were lost,
and about 600 saved.
3. Discussion.
(a) Type of Bombs.
According to references (a) and (c), the,
bombs used against “Tirpitz” on 12 November 1944, were the “Tallboy” type. Two
previous attacks had been made against “Tirpitz” using “Tallboy” bombs.
However, smoke, screens had then prevented any serious damage. “Tallboy” has a
total weight of 12,000 pounds, including 5,200 pounds of Torpex. filling. There
are 3 fuzes and 3 exploders of special design in the tail, giving a range of,
fuze settings from instantaneous to one-half to one hour delay. For attacks on
shipping a 0.07 and 0.05 second delay have been used.
Eighteen of the bombers used S.A.B.S. Mk.
IIa Tachometric sights, while 12 planes were equipped with Mark XIV vector
sights. Analyses pf the most recent daylight attacks with S.A.B.S. at altitudes
averaging 13,000 test indicate about 5 percent gross errors and an average
radial error of 195 yards. “Tallboy” was not designed for armored targets but
for deep penetration into the ground and for maximum earth shock. It is
interesting to note that a “Tallboy” bomb contains about 5 times the weight of
explosive carried by the largest torpedo used by any Navy during this war. It
is reported in reference (a) that the detonation of one of these bombs in the
water about 60 feet from “Lutzow” led to the loss of that vessel.
(b) Structural
Damage.
Information concerning the structural damage
is only partially complete, being based on divers’ inspections which were
halted due to dangerous working conditions (reference (d)). None of the bombs
apparently caused any damage on the starboard side outboard or in the large
interior spaces on the starboard side.
On the port side from stern to frame 98
there was no apparent damage except for shrapnel bolas in the vicinity of frame
98. Between frames 98 and 132 the outer skin was torn away. Probably a
considerable portion of the torpedo bulkhead was ruptured in this area, the
torpedo defense system on “Tirpitz” being designed to withstand only about 660
pounds [300 kg] of German hexanite. Forward of frame 132 there were no signs of
damage except for shrapnel holes near frame 132 and the damage from a previous
attack mentioned in paragraph 1,b.
Damage occurred to port of the centerline in
the following parts of the ship, at least (Plate III):
For about 15
frames in the middle engine room. (Turbineraum m) and Section IX.
Port engine room,
in Section X (Turbineraum Bb.)
Port fireroom No.
1, in Section XI (Kesselraum, Bb.h.)
Section XII
Port fireroom No.
2, in Section XIII (Kesselraum Bb.v.)
Section XIV
The most severe damage of all seems to have
resulted from the detonation of Bomb No. 2. This bomb went through all decks
and armor, detonating in a filled wing tank near the torpedo bulkhead of the
port engine room (Plate II). In way of the port engine room (for about
one-third the ship’s breadth) the bilge keel, shell plating and inclined armor
were demolished. In this location the edges of the shell were spread outward
and the edges of the torpedo bulkhead bent inward and torn wide open.
(c) Explosion of
Turret “Caesar.”
Turret “Caesar” exploded from an unknown
cause about 7 minutes after the first bombs landed (paragraph 2). Fregatten
Kapitan (Ing.) Eichler stated that while, the ship was listed to 60 degrees all
the rotating structure, weighing about 1,000 tons, suddenly was hurled out of
the barbette and through the air about 25 yards.
The reason for this explosion is not known
definitely. The results of an interrogation referred to in reference (a)
indicate that a bomb may have struck the ship abaft and to port of Turret
“Caesar,” causing a fire. Such a fire could have led to the explosion. The
divers’ examinations apparently did not interior of the ship in the
neighborhood of Turret “Caesar.”
On the other hand, Eichler claimed that the
ship was not hit by a bomb in the vicinity of turret “Caesar.” According to
him, “Tirpitz” had in her magazines an unusually large amount of powder.
Although regulations in the German Navy, based on war experiences and
underwater tests, required that such ammunition be stowed horizontally and
longitudinally, some powder had to be stowed transversely. Eichler’s theory was
that a non-contact detonation had forced in the ship’s side sufficiently to cause
some of the transversely stowed powder bags to be ignited, However, the divers’
reports indicate that, the shell plating is intact from frame 98 to the stern.
It seems quite improbable that powder protected by a torpedo system could be damaged
seriously enough to cause an explosion if the shell plating were not badly ruptured.
Short circuits of electrical equipment
caused by the shock of detonations within and close to the ship may have
started fires in the magazines.
(d) Number and Locations of Direct Hits.
Reference (d) mentioned only two direct
hits, one, near turret “Bruno” and a second amidships near the plane stowage.
Since the divers’ examinations were halted before bomb hit No. 1 could be
verified, this bomb, is classified as “probable” (Plate I). The damage incurred
by No. 2 was reported by the divers. References (a) and (b) state that there
were three direct hits altogether. As mentioned in the section on the explosion
of turret “Caesar,” an interrogation referred to in reference (a) indicates
that a bomb detonation near turret “Caesar” resulted in the explosion of that
turret. On the other hand, the, interrogation of Fregatten Kapitan (Ing)
Eichler indicates that a bomb may not have struck near turret “Caesar” and
there may have been another factor causing the explosion. Since there appears
to be a reasonable doubt, Bomb No. 3 is considered a “probable.”
(e) Flooding, Stability and Damage Control.
As mentioned in paragraph 1, damage from
previous attacks had resulted in a number of spaces in the bow and stern of
“Tirpitz” still being flooded prior to the attack of 12 November. The fuel and
fresh water on board were about 30 percent of full load (paragraph 2).
Calculations indicate that under the above condition of loading and with the
minor flooding in the bow and stern, the displacement prior to the final attack
was about 42,000 tons, at a corresponding mean draft of about 29.0 feet and a
GM of about 12.0 feet. In order not to reduce the reserve buoyancy, the one
degree port list had not been removed by counterflooding.
The spaces flooded immediately, therefore,
may have included at least the after engine room (Turbineraum m.h.), the after
middle fireroom (Kesselraum m.h.) and all spaces between frames 83 and 154.5
beneath the armored deck and to port of the centreline. In addition, the
detonation of Bomb No. 2 undoubtedly destroyed the watertight integrity of
upper deck spaces in the immediate vicinity.
The capsizing took place in three stages:
approximately 35, 60 and finally 135 degrees. The immediate flooding was
sufficient to cause the vessel to list rapidly to about 35 degrees. The initial
stability of “Tirpitz” undoubtedly had been impaired somewhat by the fact that
the amount of fuel oil and fresh water, stored in tanks low in the ship, was
about 7,000 tons less than for full load. Since it was not customary to ballast
fuel oil tanks with seawater, no compensation had been made for the fuel oil
removed. Also, the torpedo protection system for German battleships is designed
with the empty tanks used for counterflooding outboard of the wing liquid
storage tanks (Plate II). When some of the empty counterflooding tanks on the
port side of “Tirpitz” were ruptured, the listing moment was much greater than
if they were inboard of the wing storage tanks. Furthermore, some of these wing
storage tanks, likewise unballasted, probably were empty or partially empty
prior to rupture, and their flooding may have added considerably to the port
listing moment.
At an angle of 35 degrees a balance was reached
between the listing moment created by the sea water in the port spaces and a
righting moment produced by the inherent stability characteristics of the ship,
possibly assisted by the reaction of the mud on the floor of the anchorage.
Even though counterflooding were to result
in loss by bodily sinkage, salvage of “Tirpitz” resting upright on the floor of
the anchorage would have been much easier than raising her after capsizing. For
this reason, at the start of the list orders were issued to counterflood.
Although communications to some stations may have been disrupted, the Repair
Parties had standing instructions to open the sea valves to all counterflooding
tanks on the side opposite a list as soon as the list reached 5 degrees. It was
discovered later that the counterflooding valves had been abandoned. It appears
unlikely that well trained men would leave their stations before opening the
valves. Moreover, there were no indications of panic among the crew.
It would appear that the counterflooding system
was not designed to check such a rapidly increasing list. Undoubtedly, there
was some delay in manning the various flooding stations and in turning the
reach roads to open the sea valves. In addition, it is quite possible that the
valves had openings too small to handle rapidly enough the required amount of
water. By the time “Tirpitz” had been inclined to an angle of 35 degrees, the
sea connections to the starboard counterflooding, tanks might have been out of
the water. (Plate II).
Although the time is not known definitely,
it is probable that while the list was still steady at about 35 degrees the
orders to evacuate the lower decks were issued. The resultant loss in
water-tight integrity caused by the opening of accesses during the evacuation
seems to have been the cause for increasing the list to 60 degrees. Calculations
indicate that after the evacuation was underway there may have been as much as
17,000 tons of sea water in “Tirpitz,” causing a listing moment of about
450,000 foot tons. Normally, the ship would have continued on over. However, a
balance was reached at 60 degrees, apparently because the ship’ s bottom was
resting against firmer soil.
While “Tirpitz” was inclined at 60 degrees,
turret “Caesar” suddenly exploded, the whole rotating structure being hurled
out of the barbette. The reaction from this explosion upset the balance and the
ship capsized.
4. Conclusions.
The loss of “Tirpitz” indicates the
effectiveness against large combatant vessels of giant bombs properly fuzed and
containing massive explosive charges.
The circumstances were extremely favorable
for a successful attack. The visibility and wind conditions were excellent.
Altogether, twenty-nine 12,000 pound bombs, each with a 5,200 pound Torpex
filler, were dropped on a single target lying at anchor. All bombs apparently
landed on one side of the ship’s centerline.
“Tirpitz” incurred severe structural damage
on the port side. There was at least one direct hit and probably two others. In
addition, bombs detonating in the water close to the ship broke down the
torpedo protection system and were a vital factor in the capsizing. There was
no evidence of damage to the starboard side from this attack.
A sudden, tremendous inflow of water filled
a major portion of the port side, causing the vessel to list rapidly to about
35 degrees.
The missing 7,000 tons of fuel oil and fresh
water had the same detrimental effect on the initial stability as the removal
of a corresponding low weight. Liquid ballasting was not added to compensate for
the fuel consumed.
That part of the listing moment caused by
the flooding of ruptured port counterflooding tanks was much greater than if
these tanks had been located inboard of the wing storage tanks.
A considerable part of the listing moment
may have been caused by the flooding of unballasted wing liquid storage tanks.
Counterflooding was ineffective, possibly
because the sea valves were opened too slowly and when opened were too small to
handle rapidly enough the enormous amount of water required to check the list.
The breakdown of the watertight integrity,
resulting from the order to evacuate the lower decks, eliminated all
possibility of keeping the ship afloat.
Prepared by:
T. G. SPRINGER, Comdr., USN
E. B. HITCHCOCK, Lt (jg), USNR
Translation of
Captured German Documents
Note: This translation avoids the dispatch
style of the originals for the sake of clarity.
Appendix (A-1)
From: OKM
To: CPVA (Chemical Physical Research
Institute)
Re: Sinking of “Tirpitz”
Enclosed data concerning the sinking of
“Tirpitz” are returned as being under your cognizance. A copy of the data is to
be sent to this office (FEP).
By Direction
Appendix (A-2) (Dated 19 November 1944)
This report is based on eyewitness accounts
and weather forecasts. Weather: clear, visibility very good. The attack was
made from the direction of the sun as the sun rose: wind SSW, force 1. A watch
had been set aboard ship since daylight.
0800 - Received first warning concerning
single bombers around Bodoe. Ship was connected immediately to the main air
raid warning station at Tromsoe (direct connection).
0815 - Received further warning from FMZ
that 3 Lancasters (tactical time 0737) with Mosquito fighter escort were flying
in on an easterly course. More Lancasters were reported coming in on a
northeasterly course so that the ship command expected a repetition of the
attack of 29 October (Swedish Territory). Fighter protection was requested
through FMZ. No acknowledgement so far.
0850 - Report received from warning station
of an HMB north of Tromsoe coming into TEMOS, Sector Z, Course west. Since the
report came from north of Tromsoe, it was considered unreliable.
0854 - An air raid alarm was sounded for the
ship and the city of Tromsoe. No further report was received from the warning
station until the sighting of the bomber formation.
0915 - Enemy formation of approximately 20
to 25 aircraft was sighted approaching. (AA Post reported 19 planes; range 120
kilometers). At a range of 90 kilometers the planes headed toward “Tirpitz.” At
this time, the warning station at Tromsoe reported the approach of a second
formation. Shortly thereafter, this second formation was sighted from “Tirpitz”
also. (AA post reported 14 planes). The altitude of both flights was
approximately 300 meters.
0920 - The request for fighter protection
was o repeated o by order of the Commanding Officer of “Tirpitz.” The fighters
took off immediately.
0927 - At a distance of 50 kilometers from
Tromsoe the first bomber formation, in response to a smoke signal, split up
into groups of 4 to 5 planes and started in on an attack course. In contrast to
previous tactics, the course was athwartships.
0934 - Heavy AA guns opened fire at a range
of 12 kilometers and consequently caused only a slight breaking up of the
formation. The bombers immediately resumed formation.
0936 - Medium AA and machine guns opened
fire. The enemy planes continued straight through. During the approach one
plane was seen to fall.
0938 - A closed bomb carpet was dropped on a
single target, “Tirpitz.” Included were many hits by heavy caliber bombs within
the torpedo net on the port side and two direct hits on the port side of the
ship, one of which hit near turret “Bruno” (Lt. Fasbender in charge). Large
quantities of water swept over the ship, accompanied by an increasing list
until the port side of the superstructure deck was under water. There resulted
also a decrease in AA fire and a number of personnel and material casualties.
At the start of the list, the command was given to counter-flood. This order
probably was not carried out as it was later discovered that the flooding controls
no longer were manned. Further bomb hits were not clearly observed.
0945 - “Caesar” turret exploded, cause
unknown. The immediate effect was to increase the list and start the ship to
capsize to a final angle of 135 degrees. Shortly before the explosion, the
order was given to evacuate the lower decks. As a result the watertight integrity
of the entire ship was broken, thereby influencing the subsequent capsizing.
All the times mentioned above may be slightly in error.
Conduct of the
Crew
The commanding officer told the crew before
the attack that another major raid was imminent and that the crew of “Tirpitz”
would stand fast, show their teeth to the enemy and repulse the attack. As the
list increased, a further command was given: “Fire everything possible!” The
crew carried on bravely in spite of the tremendous effect of the bombing and
heavy casualties. The conduct was completely disciplined. There was no panic
during or after the capsizing.
SOPA Tromsoe
Appendix (A-3) (dated 23 November 1944)
In connection with
the attack on “Tirpitz,” it is reported further:
(1) Nearly 46 tons
of the heaviest type of bombs landed within the torpedo net close to the port
side of “Tirpitz.” There were definitely two bomb hits on the port side of the
ship, and no bombs or near misses on the starboard side.
(2) According, to
results of investigation, there was no damage (except for older known damage)
on the starboard side outboard or in the large interior spaces on the starboard
side.
(3) “Tirpitz” had
a list of one degree to port before the start of the attack. In order to prevent
a loss of reserve buoyancy, this list was not eliminated by counterflooding.
(4) On 12 November
the supply of fuel oil and water on board was approximately 3,000 tons; this is
compared with a full load value of about 10,000 tons.
(5) The ship’s
watertight integrity was probably broken down by the order to clear the lower
decks.
(6) The probable
cause of capsizing was the combined effect of (1) to (5).
(7) A sudden,
tremendous inflow of water nearly filled the entire port side of the ship.
(8) The beginning
turning moment to port was accelerated by the buoyancy of the starboard side
and reinforced by the 7,000 tons of liquid not on board.
(9) It is to be
presumed that great changes took place on the bottom of the cage (? - probably
floor of anchorage) as confirmed after the raid of 29 October.
(10) Concluding
observations: preservation of the ship was made possible only by placing the
ship in very calm water, while recognizing the known disadvantages, including
the risk of the most severe damage. In anchoring in shallow water, the ship
would only sink to an upright position if flooding were equal on both sides of
the ship. The dynamic effect of such a one-sided mass of water was beyond human
imagination and unknown at the time of planning and building the ship.
The experience at Scapa Flow may be
mentioned: all the large warships (“Seydlitz,” “Moltke”) capsized without
exterior damage in calm water, except “Hindenburg” which also was in calm water
and took two hours to sink.
ADM. POLARK, COMMAND
Appendix (A-4) (dated 24 November 1944)
The fact that the supply of water and fuel
oil on board was 7,000 tons less than full load (mentioned in the supplementary
dispatch of Comm. Adm. POLARK, dated 22 November concerning the attack on
“Tirpitz” would increase the freeboard approximately 1.2 meters according to
today’s discussion. It is not known why counterflooding of empty tanks to reach
a balance, was not undertaken by the command.
Signed MOK, Norway
Appendix (A-5) (dated 10 December 1944)
The diver’s investigation of the bottom and
port side of “Tirpitz” was halted because of the danger to the diver in
penetrating further into the torn shell plating and also because of the short
period of daylight.
The investigation revealed considerable
information concerning the damage. The lower edge of the port waterline armor
projects slightly out of the mud. From the stern to frame 98, there is no
damage except for shrapnel holes in the vicinity of frame 98. Between frames 98
and 132 the outer skin is torn away. Forward of frame 132 there is no damage
except for shrapnel holes near frame 132 and previously confirmed damage at the
bow.
Damage occurred in
the following parts of the ship:
(a)
About 15 frames in the middle turbine room and Section IX.
(b)
Frame 98 to 112, Section X (port turbine room).
(c)
Frames 112 to 127, Section XI (Boiler room No.1).
(d)
Frames 127 to 132, Section XII (Boiler auxiliary machinery room).
(e)
Approximately 15 Frames comprising Section XIII (Boiler room No. 2).
(f)
Electric Generator Room No. 4.
The most severe damage of all seems to have
resulted from direct hits on the ship near the plane stowage, a location
checked by shore observation. In that location a bomb went through all decks
and armor, detonating in a filled wing tank near the torpedo bulkhead of the
port turbine room. In way of the port turbine room (for about one-third of the
ship’ s breadth) the shell plating and waterline armor had completely
disappeared, and the bilge keel and ship’s bottom were also missing up to the
cooling-water discharge sea chest. In this location the edges of the longitudinal
bulkhead (probably torpedo bulkhead) bent inward and torn wide open. According
to observers, the capsizing took place in three stages, the ship listing to
35°, 60° and 135°. This progression probably was due to the flooding of the
additional spaces opened up by bomb hits, pierced bulkheads, and incomplete
closures (caused by evacuation of lower decks). The above conclusion is
difficult to prove, because the damaged locations will never be accessible, due
to reasons mentioned earlier.
Endorsement by Adm. POLARK
The investigation confirms the previous
belief that the opening of the port side at an important location was the
deciding factor in the loss.
Adm. POLARK,
Command
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| Drawing showing the path of Bomb No. 2 and the spaces established later by divers’ inspections as having been damaged. |
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| This drawing illustrates the estimated point of detonation of Bomb No. 2 in a wing tank on the port side, and the different listing angles, 1º, 35º, 60º, and 135º. |
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| Estimated point of detonation of Bomb No. 3 abaft of and to port of turret “Caesar.” |
