U-boat Archive - U-boat KTB

Armament

Target Identification

Identifying the target was important for applying the rules of engagement, firing calculations, intelligence accounting, and for submitting the correct claim for tonnage. If the tactical situation allowed, the CO would observe the target, noting the ship's characteristics while First Watch Officer or Obersteuermann refered to Dr. Erich Gröner's Die Handelsflotten der Welt. This compact publication privided details of all merchant ships known to the German Navy.

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	Excerpt from Dr. Erich Gröner's Die Handelsflotten der Welt

Torpedo Tubes

Referred to in KTBs by Roman numbers. Tube (Rohr) I, II, III, IV, V, VI – bow tubes numbered 1, 2, 3, 4, stern tubes numbered 5 and 6. All German U-Boat torpedo tubes were 53.3 cm/21" in diameter and 7.16 meters long. A piston weighing 75 lbs. was placed behind the torpedo after loading. For submerged firing the torpedo was fired by compressed air at a pressure of approximately 24 atmospheres acting against the piston which forced the torpedo from the tube at a speed of 10 meters/second. A relief valve automatically opened at the back of the tube and water pressure would force the piston back to its original position venting the compressed air back into the boat. For surfaced firing the compressed air was directed behind the torpedo, not the piston by means of a change-over cock which also locked the piston to the tube. The forward inner tube door was then closed and the water drained into the bilge. The tube was then ready for loading. Type VII and IX U-boats had four bow torpedo tubes. Type VII had one stern tube while Type IX had two. There were a few exceptions for both types though and special purpose boats such as supply boats, torpedo carriers and mine layers had different configurations.

Torpedo Types

Often referred to in KTBs as simply Ato or Eto (A for Air and E for Electric) further details were left to the torpedo firing report (Schussmeldung). The Ato burned a mixture of compressed air, water and Decalin in a radial engine for propulsion leaving a visible bubble trail on the surface. The Eto used a battery for propulsion and left no bubble trail on the surface. The table below provides information on the most common types of torpedoes carried aboard U-boats.

	Type	Date in Service	Guidance	Pistol	Propulsion	Weight (kg)	Range (km)	Speed (knots)
T I	G7a	1938	Straight	Pi 1 or TZ3 with Pi 3	4-cycle gas/steam	1,538	7.5/12	40/30
T I Fat I	G7a	late 1942	Fat	Pi 1 or TZ3 with Pi 3	4-cycle gas/steam	1,538	7.5/12	40/30
T I Lut I/II	G7a	late 1944	Lut	Pi 1 or TZ3 with Pi 3	4-cycle gas/steam	1,538	7.5/12	40/30
T II	G7e	1939	Straight	Pi 1	Electric	1,608	5.0	30
T III	G7e	late 1942	Straight	Pi 2	Electric	1,608	5.0	30
T III Fat	G7e	mid 1943	Fat	Pi 2	Electric	1,700	5.0	30
T IIIa Fat II	G7e	early 1944	Fat	Pi 2	Electric	1,620	7.5	30
T IIIa Lut I/II	G7e	early 1944	Lut	Pi 2	Electric	1,760	7.5	30
T IV Falke	G7es	early 1943	Acoustic homing	Pi 4a	Electric	1,400	7.5	20
T V Zaunkönig	G7es	late 1943	Acoustic homing	TZ 5 with Pi 4c	Electric	1,495	5.7	24

Note: Torpedoes could be directed to turn up to 90° off initial course in 1° increments (later changed to 135°). Depth settings were 0-12 and later 0-15 meters in one meter increments. Torpedoes were designed to sink at the end of the run without detonating. To obtain optimum performance from G7e torpedoes batteries had to be withdrawn from the torpedo tubes and serviced every few days and the battery had to be heated to 30°C/85°F just prior to firing (if not only 28 knots at 3,300 meters could be obtained).

Fat and Lut Steering Mechanisms

Fat, short for Federapparat Torpedo, was a steering mechanism which enabled the torpedo to begin a ladder pattern at a preset point of a normal run. The Fat I torpedo could be set to turn 180° right or left on short (900 yds/820 meters) or long (1,640 yds/1500 meter) legs. The speed of advance when set for short legs was 7 knots and for long legs 5 knots. The Fat II, in tended as a self defense weapon, could be set to describe a long loop or a circle (always to the left) at a preset point in its initial normal run. The Lut, short for Lagenunabhängiger Torpedo, could be set for an additional course change after the initial normal run. This allowed the U-boat to launch from any position relative to the target. The Lut I enabled the length of the ladder legs to be set between 0 and 1500 meters. Thus the speed of advance could be varied between 5 and 21 knots. The Lut II enabled the left or right turns to be set at angles less than 180° See the following excerpt from the Admiralty Cumulative Edition for additional information on Fat and Lut torpedoes.

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	Excerpt on Torpedoes from the Cumulative Edition - CB 04051(103) The Admiralty's appreciation of the German U-boat force as of June 1944

Torpedo Pistols

	Date in Service	Fuse	Used with
Pi G7a	from 1920's	Both Impact (AZ) and Magnetic (MZ) (Modified in October 1939 to allow firing in AZ only) - the MZ feature had 17 zones (0-16) to compensate for variation in the strength of the earth's magnetic field. A dedicated chart was consulted to select the zone (0 for Norway's North Cape to 16 for the Bay of Biscay) which was set by means of a movable ring on the front of the pistol. Outside the areas shown on the chart the MZ feature of the PiG7a was innefective.	G7a and G7e
Pi 1 (A-B)	November 1939	A modification of the Pi 1 pistol designed to reduce the possibility of premature detonation	G7a and G7e
Pi 1 (Pi G7H)	Summer 1940	A Pi 1 pistol with the MZ feature removed. This was the standard German pistol from the summer of 1940 until the end of 1942.	G7a and G7e
Pi 2 (Pi 39H)	December 1942	Selectable impact and magnetic or impact alone (new German designed magnetic detonator - impact mechanism same as Pi1)	G7e TIII
TZ3 with Pi 3	Late 1943	Selectable impact and magnetic or impact alone (TZ3 based on the Italian SIC magnetic pistol - impact mechanism same as Pi 1)	G7a
Pi 4	late 1943	Inertia	T IV
TZ5	early 1943	Magnetic	T V together with Pi 4

Note: Pi 1, 2, and 3 pistols armed the torpedo after it had travelled 250 meters from the U-boat. T IV and T V torpedoes also armed 250 meters after firing.

Torpedo Warheads

G7a and G7e torpedoes were fitted with a warhead weighing 617 lbs/280 kg The explosive was a mixture of hexanitrophenylamine (NHD) and trinitrotoluene (TNT) mixed 25% by weight with aluminum (Al) or TNT/HND/AI for short. The T IV and T V torpedoes had a slightly smaller warhead, 604 lbs/274 kgt, to accommodate the acoustic homing mechanism in the nose and the cavity for the pistol.

Torpedo Firing Reports

Each time a torpedo was fired the Commander was required to submit a torpedo firing report. The purpose of the report was to enable the Torpedo Inspectorate (Torpedoinspektion (T.J.)) to analyze and track torpedo performance. The form was usually filled out by the First Watch Officer who also served as Weapons Officer. The report included a description of the weather and target; type of torpedo and pistol, torpedo tube and ejection method; source of firing data, aim point and firing values; all torpedo and pistol settings; the position of the boat relative to the target; and the observed performance of the torpedo. On the reverse of the report there was a narrative description of the tactical situation and often a diagram depicting the position of the boat relative to the target at firing and the track of the boat up to firing. These reports were included as an attachment to the KTB and are a valuable supplement to the brief description of an attack typically found there. See the following page for more information on torpedo firing reports.

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	Torpedo Firing reports - Keys, notes and examples

Torpedo and Mine Vocabulary

General Terms

Aal	Eel - torpedo (slang)
Abdeckblech	Cover plate (torpedo)
Abfeuerschalter	Firing switch
Abfeuerungshebel	Firing lever
Abladekommando	Unloading detail
Ablaufgerüste	Depth charge chutes/racks
Abstandspistole	Remote pistol (magnetic arming pistol)
Abwehrschuß	An attack on an approaching target/defensive shot
Achterstich	An attack on a receding target/from astern
Akustischer Torpedo	Acoustic torpedo
Alte Art	Old style (refering to type of torpedo pistol)
Angaben	Data
Angriffssehrohr (ASR)	Attack periscope
Art	Type (eg. of torpedo)
Art der Aptierung	Type of adaptation/modification
Atmosphärisch angetriebener Torpedo (Ato or A-to)	A torpedo using compressed air as an oxidant and Decalin as a fuel with water to create steam for propulsion
Aufladekommando	Loading detail
Aufschlagzünder (AZ)	Impact detonator
Aufschlagzündung	Impact firing (for torpedoes)
Aufschlagzündung	Contact detonation (of torpedoes or mines)
Auftriebskörper	Buoyancy chamber
Ausstoßart	Ejection method (for torpedoes - with or without piston)
Ausstossrohr	Exit tube, Ejection tube
Behälter	Container(s)
Bodenverschluss	Rear door of torpedo tube
Bootsschacht	Encasing for the periscope
Bugrohr	Bow tube
Bugschuss	Bow shot
Decalin	Decahydronaphthalene - The G7a torpedo burned a mixture of compressed air, water and Decalin in a radial engine for propulsion leaving a visible bubble trail on the surface
Eingestellte	Preset/adjusted
Einstellung	Setting
Einzelschuss	Single shot
Elektrisch angetriebener Torpedo (Eto or E-to)	A torpedo using a battery powered electric motor for propulsion
Elektrische Abfeuerung	Electric firing mechanism normally used to fire torpedoes - as a backup, torpedoes could be fired manually by a lever on the torpedo tube.
Entfernung schätzen	To estimate range
Fächer	Fan as in a "Zweifächer", "Dreifächer" or "Vierfächer" - a two-fan, three-fan or four-fan torpedo attack as opposed to independently aimed shots.
Fächerschuß	Fan shot or spread shot
Falke	Code name for the T IV acoustic homing torpedo
Fangschuss	Coup de grace/Finishing shot - A torpedo fired at a stopped or crippled vessel to finish it off.
FAT-Warnung	Warning given to other U-boat that a FAT had been fired
Federapparat (FAT)	Steering mechanism which enabled the torpedo to begin a ladder pattern at a preset point of a normal run
Federapparat Torpedo (Fat.)	Spring mechanism torpedo
Fehlzünder	Misfire, premature detonation
Fertig	Ready
Feste Werte	Set value (as for a torpedo pistol)
Feuerleitanlage	Fire control system
Feuerleitübungen	Fire control exercises
Feuerleitung	Fire control
Flutvorrichtung	Decoy launcher
Frontausrüstung	Loading ammunition for a war patrol
Füllventil	Charging valve
Geber	Transmitter
Gefechtskopf	Warhead
Gefechtspistolen	Contact pistol - detonating mechanism
Geleitzugtorpedos	Convoy torpedoes (FAT or LUT)
Gerade (ger.) Kurs	Straight (course)
Geschätzt	Estimated
Gewehr	Gun
Gezielte	Deliberate (as for deliberate shot)
Gradlaufkreisel	Directional Gyroscope
Gröner	Author of a reference book used to identify targets. The book listed all known merchant ships of the world, many of them with side views/silhouettes.
Grundeinstellung	Basic setting
Heckschuss	Stern shot
Hecktorpedorohr (Hechrohr)	Stern torpedo tube
Herausgesprungen	Broached (literally jumped out - as for a torpedo)
K.Sehr	Main periscope
Kieissäge	Circular saw (sound made by towed counter acoustic torpedo noise makers)
Klargemacht	Made ready (as for torpedo tubes or guns for firing)
Knacken	To 'knock off" or sink a ship by action
Kolbenschiessen	Piston firing - test firing the torpedo tube with only a piston installed
Kreiseltochter	Gyro subsystem
Kreiselunformer	Gyro motor
Kreisläufe	Circular runner from gyro failure
Ladegut	Payload (decoy)
Lagenunabhängiger Torpedo (LUT)	Steering mechanism which like the FAT enabled the torpedo to begin a ladder pattern at a preset point of a normal run and which could be set for an additional course change after the initial normal run
Lageunabhängiger Torpedo (Lut.)	Bearing independent torpedo
Lampentafel	Light board
Laufbahn	Torpedo track
Laufende Nummer (Lfd.Nr.)	Serial number
Laufstrecke	Change definition to running distance
Laufstreckenmarkenrad	Range-setting wheel
Linsensystems	Lens system
Losehebel	Firing lever
Luftzeilsehrohr	Air search periscope
Magnetischerzündung	Magnetic detonation (of torpedoes or mines)
Magnetzünder (MZ)	Magnetic detonator
Mit Kolben (m.K.)	With piston - firing a torpedo by compressed air behind the piston forcing the piston and the torpedo down the tube (usually employed when firing submerged)
Müllschuss	Garbage shot - ejecting garbage through the torpedo tube
Mündungsklappe(n)	Bow cap(s) of torpedo tube(s)
Mündungsrohr	Torpedo tube
Nachladen	To reload
Nachschuss	Follow up shot
Nachtzielsehrohr	Night periscope
Nahschuss (NS.)	Near shot - setting for TV torpedo for receding targets. If torpedo loses acoustic target it will circle once in position and then resume initial course until target is reaquired or exhaustion.
Oberdecksaal	Above deck torpedo (slang)
Oberdecksbehältern	Upper deck containers used to store ATO torpedoes
Ohne Kolben (o.K.)	Without piston - firing a torpedo by compressed air between the torpedo and the piston leaving the piston in place behind the torpedo (usually employed when firing on the surface)
Okularteiles	Eyepiece section of periscope
Optiken	Optical elements in periscope
Opunkt	Aiming point
Peildiopter	Telescopic bearing sight (placed over gyrocompass)
Pistole (Pi)	Pistol torpedo detonating mechanism
Rechengerät	Computer (eg. firing control computer)
Reichentfernung	Range
Rohr	Torpedo tube
Rudersperrung	Rudder lock - this is set to keep the torpedo from broaching or hitting the bottom in shallow water when it first comes out of the torpedo tube
Rundblick	Panorama/view from periscope sweep
Säule	Column, post
Schachtmine A (SMA)	Shaft Mine A
Schachtrohr	Encasing tube (periscope)
Scharfschüsse	Shot from an acute angle
Schießendes	Shooting
Schießtabellen	Firing table
Schiesstechnik	Firing technique
Schussabgabe	Firing
Schußentfernung	Firing distance
Schussgelegenheit	Shooting/firing opportunity
Schussgelegenheiten	Shooting opportunities
Schussmeldung	Firing report
Schussrichtung	Direction of fire
Schußweite	Firing range
Schußwinkelempfänger	Gyro angle receivers
Schusswinkelempfänger	Angle Shot Receiver - located on the side of each torpedo tube it receives gyro angle from the torpedo data computer and applies it to the torpedo
Schwanzstück	Tail of torpedo
Seeröhr(e)	Periscope(s)
Seerohrfahrstuhl	Periscope control seat
Seerohrwinde	Periscope winch
Sehrohrkranzbeleuchtung	Periscope azimuth circle
Seite	Bearing/aspect/side/page
Seitenwinkel	Relative bearing
Sicherheitsstrecke	Safety distance (arming distance for torpedoes)
Sicherheitsstreckenpropeller	Arming distance propeller
Sicherheitsstreckenteil	Safety distance mechanism
Sonnenblende	Lens hood
Spiegelwagens	Reflecting mirror carriage in periscope
Spitzer Winkel	Acute angle
Standsehrohrer	Fixed eye level periscope/Attack periscope
Steckschuss	A dud torpedo lodged in the target
Stellzeuge	Control and regulators
Steuerkasten	Control box
Stoppen	To time with a stopwatch
Strichplatte	Graticule plate of the periscope
Stumpfer Winkel	Obtuse angle - an angle which is greater than 90° and less than 180°.
Teilscheibe	Graduated scale
Tiefensteuerung	Depth control (for torpedo)
Torpedo Erprobungs Kommando (T.E.K.)	Torpedo Test Command
Torpedo Los!	Fire! - Firing command
Torpedo untertriebzelle	Poppet tanks (Type XXI)
Torpedoausstossrohr	Torpedo tube
Torpedoausstoszpatrone	Torpedo impulse tank
Torpedodatencomputer	Torpedo fire-control apparatus, electro-mechanical deflection calculator that produced settings for torpedo firing.
Torpedoeinführluk	Torpedo loading hatch
Torpedoeinführluke	Torpedo loading hatch
Torpedoerprobungskommand (T.E.K.)	Torpedo Testing Command
Torpedoflutuhren	torpedo flood control clock
Torpedoinspektion (T.J.)	Torpedo Inspectorate - Responsible for overall development and supply of torpedoes
Torpedoklappenantrieb	Torpedo shutter mechanism
Torpedolaufbahn	Wake of torpedo
Torpedoluk	Torpedo hatch
Torpedomine (TMA, TMB, TMC)	Torpedo mine - TMA, TMB, TMC models
Torpedomunitionsbehälter	Torpedo stowage
Torpedorichtungsweiseranlage (T.R.W.)	Torpedo Direction Computing Installation
Torpedorohr(e) (T.R.)	Torpedo tube(s)
Torpedoschießen	Torpedo firing practice
Torpedoübernahmegerätes	Torpedo loading device
Torpedounterwasser-zielapparat (TUZA)	Aiming apparatus for night firing - this name was replaced by UZO
Torpedoversuchsanatalt (T.V.A)	Torpedo Experimental Establishment - These were located at Gotenhafen and Exkenförde
Torpedoversuchsanstalt	Torpedo Test Establishment
Trägheitspistolen	Inertia pistol (for torpedoes)
Transportschiene	Transport rail
Trefferaussicht	Expectation of hit
Treffpunkt	Point of impact
T-Schußwinkelempfänger	Torpedo gyro angle receivers
Überwasserzieloptik (U.Z.O.)	Literally “above water target optics”. Consisted of special heavy, pressure-proof binoculars mounted on a pedestal on the U-boat’s bridge which in turn was connected to the Torpedo Data Computer (TDC) usually mounted in the conning tower. The operator (usually the IWO ) lined up the crosshairs with the target ship and the bearing to the target would be transmitted to the TDC. The CO usually manned the periscope which worked the same way for underwater shots.
Übungskopf	Practice warhead
Umladen	To unload (as for upper-deck torpedo containers)
Untergeschnitten	Undercut/dipped periscope under
Unterwasserangriff	Attack submerged
Unzuverlässige Angaben	Uncertain data
Vergrößerungswechsel	Magnification selector
Verkleidungsklappe	Outer door fairing
Verriegelungsmagnet	Locking magnet
Verschossen	To be out of (torpedoes)
Vorhalterechner	Torpedo fire-control apparatus, electro-mechanical deflection calculator that produced settings for torpedo firing.
Wasserfahne	Periscope feather
Wasserschlagklappe	Water pressure flap (holds arming distance propeller from turning until after launch)
Wasserschwall	Swell/disturbance at expulsion of torpedo
Weitschuss (WS.)	Distant shot - setting for TV torpedo for approaching targets. If torpedo loses acoustic target it will circle in position until target is reaquired or exhaustion.
Wendeschuß	The term Wendeschuß [reversal-shot] is used in firing reports and KTBs to refer to the firing of acoustic torpedoes. The term may have been derived from the idea that acoustic torpedoes were intended to counter escort vessels, turning the tactical situation in favor of the U-boat.
Winkeleinstellung	Gyro angling gear
Zaunkönig	Code name for the T V acoustic homing torpedo
Zeitschalter	Timer, time switch
Ziel	Target
Zielen	To aim
Zielgenau	Accurate, precise, on target
Zielrichtung	Line of sight
Zielrichtungsgeber (T.Z.R.)	Target angle sender
Zielschiff	Target ship
Zielsehrohr	Target (attack) periscope
Zielstelle	Targeting device (for torpedoes periscope or U.Z.O.)
Zuverlässige Angaben	Reliable data

Firing Calculations

Abkommpunkt	Aim point
Auswanderung	Bearing shift
Delta (symbol = delta δ)	Change in torpedo course required to compensate for the straight ahead distance traveled after firing and turn to the preset gyro angle
Drehgeschwindigkeit	Rate of turn
E-Änderung	Range change
Eigener Kurs (E.K.)	Own course (at the time of torpedo firing)
Eingestellte Werte	Final values
Entfernung (E)	Estimated range in meters
Fahrtverschätzung	Speed estimate
Gefechtstorpedoköpfe	Torpedo warheads
Gegnerfahrt (Vg or simply Fahrt)	Target speed in knots
Gegnerlage (symbol = Gamma γ)	Target angle - the relative bearing of the U-boat from the target - usually given in degrees green (grün - gr.) meaning starboard or red (rot- r.) meaning port or Bug links/rechts (bow left/right)
Geradauslaufstrecke	Straight distance (for Fat or Lut torpedoes)
Geschätzt	Estimated (range)
Lage laufend	Corrected Inclinations; i.e. corrected according to changes of relative bearing up to the moment of firing.
Lagenwinkel (symbol = Gamma γ)	Angle on the bow/Target angle - One of the three angles of the firing triangle
Laufstrecke	Maximum range
Laufzeit des Torpedo 30 k = 15.43 m/s 40 k = 20.58 m/s	Torpedo Run - Time of the torpedo run was recorded and used after the fact to determine the actual distance to the target. The KTB might read “After 28 seconds (432 m) hit aft of the bridge” meaning the torpedo was set to run at 30 knots and did so for 28 seconds therefore the actual distance to the target was 432 meters (G7a was usually fired at 40 knots - G7e at 30 knots). Some commanders simply noted “hit after 28 seconds” and didn’t do the calculation as there was a separate firing report (Schussmeldung) used for that data.
Schätzen	To estimate
Schätzung	Estimation
Schiffspeilung	Target bearing relative to the bow of the U-boat in degrees (0-359) (symbol = psi - φ)
Schliefe	Loop - leg of a Fat or Lut torpedo
Schneidungswinkel (symbol = Alpha α)	Crossing/impact angle - One of the three angles of the firing triangle
Schussdreieck	Firing triangle
Schußunterlagen	Firing data
Schusswinkel (symbol = sigma - ς)	Torpedo course relative to the heading of the U-boat in degrees (0-359)
Sekond (Sek.)	Second
Strefbefehl	Time in seconds between salvo torpedo launch
Streubreite	Spread width - expressed in meters (as for a fan of torpedoes)
Streuwinkel	Angle of spread
Tiefeneinstellung	Depth setting
Torpedokurs	Corse of the torpedo (not relative to the boat)
V-Lut	Advance (speed of advance of Fat or Lut torpedoes)
Vorhaltewinkel (Vorhalt/Beta/β)	Leading angle - One of the three angles of the firing triangle
Vorlauf	Length of initial run of Fat or Lut torpedoes
Zeittakt	Time interval between torpedoes in a fan shot (usually automatically set at 2.3 seconds)
Zeitzünder	Time delay detonator

Firing results

Abrotzen	Founder
Absacken	To settle
Achterlastig	Down by the stern
Aufschlag	Impact
Auseinandergeplatzt	Broke in two
Blindgänger	Dud
Bricht auseinander	Break apart
Detonationsdruck	Blast pressure
Detonationswelle	Shock wave
Detonationswolke	Explosion plume
Drehmotor	Hydralic training motor (for attack periscope)
Durchgebrochen	Sagged (as would a ship with its keel broken)
Eingeknickt	Buckled
Einschlag	Impact
Erschütterung	Concussion, shock
Explosion	Explosion
Fehlschuss	Miss
Feuer	Fire
Feuerschein	Fiery glow
Flammensäule	Column of fire
Gekenterte	Upturned
Geschwindigkeitsminderer	Speed control for periscopes
Gesunken	Sunk
Grunddetonierer	Torpedo that detonated when it hit the bottom
Grundgänger	Torpedo that hit the bottom
Hecktorpedoraum	Aft torpedo compartment
Hochgehen	To go off, explode
Keine Wirkung	No (visible) effect
Kentern	To capsize, overturn
Kentert	Capsizes
Kesselexplosion	Boiler explosion
Knall	Detonation, loud, sharp noise
Luftzielsehrohr	Navigation/air search/night periscope
Oberflächenläufer	A torpedo that runs on the surface
Pilz	Mushroom cloud
Rauch	Smoke
Rauchpilz	Mushroom cloud
Rohrläufer	Tube runner - a torpedo running in the torpedo tube
Rohrstecker	Torpedo that is stuck in the torpedo tube (not necessarily running)
Rohrversager	Torpedo which does not leave the tube upon firing
Schlagseite	List
Schlagseite bekommen	To list
Sinkgeräusche	Sinking noises
Sprengsäule	Explosion plume
Sprengwolke	Cloud from an explosion
Stichflamme	Flash
Stichflammen	Tounges/spurts of flame
Torpediert	Torpedoed
Torpedoaufschlag	Torpedo impact
Torpedoversager	Torpedo failure, malfunction
Treffer	Hit
Trümmerfeld	Debris field
Untergangsstelle	Sinking location
Untergegangen	Went down/sank
Untersteuerte	Passed under the target
Versenkungsstelle	Sinking/scuttling location
Wegsacken	To sink, to settle
Wrack	Wreck
Wrackteile	Wreckage
Wracktrümmer	Wreckage
Zünden	To ignite

Guns

The table below provides information on guns carried aboard U-boats.

Caliber	Type - Mount	Breech/ Clip	Practical rate of fire	Maximum Elevation	Effective Range	Gun's Crew	Weight of Projectile

Deck guns
105 mm (4.14")	SK C/32U - U-boat L C/32U	Single-shot	15	35°	12,000 m.	6	51.4lbs/23.3kg
105 mm (4.14")	SK C/32U - 88mm Marine Pivot L C/30D	Single-shot	15	30°	12,000 m.	6	51.4lbs/23.3kg
				30°
88 mm (3.46")	SK C/30U - U-boat L C/30U	Single-shot	15-18	80°	11,000 m.	6	30.11lbs/13.7kg
88 mm (3.46")	SK C/35 - U-boat L C/35U	Single-shot	15-18	30°	11,000 m.	6	30.11lbs/13.7kg

Anti-aircraft guns
37 mm (1.46")	SK C/30U - Ubts. LC 39	Single-shot	12	85°	2,500 m	3/4	1.6lbs/730g
37 mm (1.46")	M42 U - LM 43 U	Automatic 8-round	40	80°	2,500 m	3/4	1.6lbs/730g
Twin 37 mm (1.46")	Zwilling M 42 U - LM 42	Automatic 8-round	80	80°	2,500 m	3/4	1.6lbs/730g

30 mm for Type XXI	Flak M 44 - LM 44	Automatic

20 mm (0.79")	AMG C/30 - L 30	Automatic 20-round	120	90°	1,500 m	2/4	0.7 lbs/320g
20 mm (0.79")	MG C/30 - L 30/37	Automatic 20-round	120	90°	1,500 m	2/4	0.7 lbs/320g
20 mm (0.79")	Flak C/38 - L 30/37	Automatic 20-round	220	90°	1,500 m	2/4	0.7 lbs/320g
Twin 20 mm (0.79")	Flak Zwilling C/38 II - M 43 U	Automatic 20-round	440	90°	1,500 m	2/4	0.7 lbs/320g
Quadruple 20 mm (0.79")	Flak Vierling C38/43 - M 43 U	Automatic 20-round	880	90°	1,500 m	2/4	0.7 lbs/320g

Twin 13.2 mm (0.52")	Breda 1931 - retractable into water-tight housing	Automatic 30-round	400	85°	1,000 m	2/4	0.28 lbs. 125g

Self defense guns
7.92 mm	MG15	Automatic 50/75 round	800-900	90°	750 m	1-2	12.8g
7.92 mm	MG34	Automatic 50/75 round	600-700	90°	750 m	1-2	12.8g
Twin 7.92 mm	MG81Z	Automatic Belt fed	2,200	90°	750 m	1-2	12.8g
Additionally a variety of small arms were carried, typically 5-10 Mauser 7.65 mm pistols, 5-10 rifles, submachine guns (MP-40 - 9 mm), hand grenades, and 2 signal pistols.

Gun Vocabulary

Abdrücken	To fire
Abfeuern	To pull trigger
Abfeuerungsvorrichtung	Firing mechanism
Abmontieren	To dismount (gun from ship)
Abprallen	To ricochet
Abwehrerfolg	Defensive success
Abwehrgeschütz	Defensive gun
Abwehrwaffe	Defensive weapon
Ansprache	Designation of a target
Anspruch	Claim
Anwärmeschuss	Warming up shot
Anzielen	To sight, aim
Artillerieeinschlag	Shell hit
Artilleriefeuer	Gunfire
Artilleriemaat	Gunner's Mate
Artillerieoffizier (A.O.)	Gunnery Officer
Aufsatzwinkel	Elevation
Aufschlagpunkt	Point of impact, objective point
Aufschlagzünder	Impact fuse
Aufstellung	Mounting/deployment/formation/table/schedule
Aus nächster Nähe	At close range
Ausgehoben	Silenced (gun)
Automatischem	Automatic
Bereitschaftsmunition	Ready-use ammunition
Beschießt	To fire at
Beschießung	Shelling/bombardment
Bewaffnung	Armament
Bodenstück	Breech
Bordgeschütz	Gun
Brandkerngeschoss	Incendiary bullet
Bremsvorrichtung	Recoil buffer
Doppellafette	Double-barreled mount
Doppelläufig	Double-barreled
Durchladen	To load
Eingabeln	Bracketing
Einladen	To load
Einläufig	Single-barreled
Einschiessen	Sighting shot (for range)
Entsichert	Ready for firing/off safety
Fadenkreuz	Cross-wires (of gunsight)
Fertig!	Ready!
Fest	Secured as for the cannon or flak weapons
Feuer einstellen!	Cease fire!
Feuer frei!	Fire!
Feuer erwidern	Return fire
Feuererlaubnis!	Fire!
Feuereröffnung	Opening fire
Feuerpause!	Cease firing!
Feuerüberfall	Armed attack
Flakabwehr	Anti-aircraft defense
Flakbedienung	Anti-aircraft gun crew
Flakbereitschaft	Anti-aircraft readiness
Flakbeschuss	Flak fire
Flakfeuer	Anti-aircraft fire
Flakmaschinengewehr (Fla.M.W.)	Anti-aircraft machine gun
Flakschiessen	Anti-aircraft fire
Flaktreffer	Hit by anti-aircraft fire
Flakvierling	Anti-aircraft quadruple
Flakzwilling	Anti-aircraft twin
Flugabwehr	Anti-aircraft defense
Flugzeugabwehrkanone (Flak)	Anti-aircraft weapon
Frühzunder	Premature burst
Funktionsschießen	Firing operation
Gehäuse	Casing (of gun)
Geleitetes Schiessen	Controlled fire
Geschütz	Cannon
Geschützbedienung	Gun crew
Geschützführer	Gun captain
Geschützmannschaft	Gun crew
Geschützmunition	Cannon/gun ammunition
Gesichert	On safety
Gespannt	Cocked
Granathülse	Shell case
Gutliegendes	Well aimed
Hemmung	Jam, stoppage
Hülsen	Case
Hülsenböden	Case base
Kaliberanlauf	Gunnery practice
Kanone	Gun
Kleinkampfmittel	Small weapons
Knallerei	Fireworks
Küstenbatterie	Coastal battery
Ladekanonier	Gun-loader
Ladestörung	Stoppage in loading mechanism
Lafette (L)	Gun carriage or mount
Lauf	Barrel, breech, chamber
Leuchtgeschoss	Star-shell
Leuchtgranate (LG)	Star shell
Leuchtspur	Tracer (as for machine gun fire)
Luftabwehr	Anti-aircraft defense
Luftangriff	Aircraft attack
Luftballon	Balloon as for anti-aircraft training
Luger 08	Standard German military pistol
Magazinfeuer	Automatic fire
Maschinenfeuerwaffen	Machine gun
Maschinengewehr (MG)	Machine gun
Mundpfropfen	Tampion (muzzle plug)
Mündungsfeuerdämpfer	Muzzle
Mündungsfropf	Tompion
Mündungsklappe	Tompion
Munition	Ammunition
Munitionsaufzug	Ammunition hoist
Munitionsbehälter	Magazine
Munitionsbestand	Stock of ammunition
Munitionskammer	Magazine
Panzersprengmunition	Anti-armour munition
Patronen	Cartridge
Patronenlager	Cartridge chamber
Richtanlage	Training mechanism
Rohrkrepierer	Barrel burst
Rückstoß	Recoil
Schieber	Sight slide (adjusting gunsight)
Schießerei	Gunfire/shooting
Schiessfertigkeit	Marksmanship
Schießt	Fires/shoots
Schiffskanone (SK)	Ship's Cannon
Schnellfeuerkanone	Quick firing gun
Schuss	Round of ammunition, shot
Schuss!	Fire
Schussbahn	Line of fire
Schusswaffe	Firearm
Schussweite	Range
Schutzschilde	Shields - as for the anti-aircraft guns
Seelenrohr	Liner (of gun barrel)
Signalpatronen	Signal cartridges
Spannhebel	Cocking handle
Splitterregen	Splinter rain
Sprengbüchsen	Demolition block (in container)
Sprenggranate	High explosive shell
Sprengmunition	Exploding munition
Sprengung	Demolition
Stellbecher	Mechanism to set time fuse of shells
Stockung	Delay (in bringing ammunition to guns)
Stopfen!	Suspend firing!
Strich	Mil (used in gunnery - 1 mil subtends 1 meter at 1000 meters distance)
Tragweite	Range
Treffer verzeichnen	To register hits
Treffergenauigkeit	Accuracy of hits
Treffsicher	Well aimed, accurate in firing
Trommel	Range drum
Unklar	Out of action, not ready
Versager	Dud, misfire
Verschossen	Winchester (out of ammunition/torpedoes)
Voller Flakbereitschaft	Full anti-aircraft readiness
Volltreffer	Direct hit
Waffen	Weapons
Waffeneinsatz	Use of weapons
Waffenmannschaft	Gun crew
Warnschuss	Warning shot
Wirkungsfeuer	Fire for effect
Zielkreis	Aiming circle
Zonenfeuer	Barrage fire
Zurrung	Locking mechanism

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