Naval Automatic Guns: Part 2 - Bofors, Oerlikon and similar calibre guns

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In part 2 of this topic, we cover the development of the heavier automatic guns that were the Bofors, Oerlikon, Breda and similar calibre guns, notable of the German Navy. As the performance of attacking aircraft improved so it became necessary to have guns with a greater stopping power in terms of range and explosive charge.

Catalogue number 21001

20mm Oerlikon gun

The single 20mm Oerlikon was the standard close range weapon for British and American navies at the beginning of the Second World War. Even if it's ability to hit and bring down high performance aircraft was limited, it was better than the 0.5-inch Vickers machine gun. The gun was on a free-swinging mounting and the sight was a bead and reticule type marked off with 300, 200 and 100 knots rings. Spring-loaded ammunition drums existed for 58, 60 and later 80 rounds, the metal clip belts had to be kept well-greased to avoid blockages. The gun shown here has a splinter screen.

Verso : " Opening fire on a mine 1945 Atlantic " in French and in black ink

5.6cm x 8cm Gelatin silver print


Catalogue number 27001

Firing a twin Oerlikon, L'Impetueux

This is a twin-barrelled Oerlikon but only one magazine is in place. Training is by the shoulder straps and handle bars, the left handle bar seen here also includes the trigger. Below the white round trunnion pivot is the cam limit stop mechanism that prevents the gun being fired into a part of the ship's structure. The French warship L'Impetueux was an American-built submarine chaser launched in 1943 and was handed over to France in 1950 being based in Saigon until it was transferred to the Cambodian Navy in 1953.

Verso: "Impetueux 1953" in light pencil

11cm x 8cm Gelatin silver print


Catalogue number 65045

Details of an Oerlikon gun

This bird's eye view of a 20mm Oerlikon gun on a U.S. Navy PT boat clearly shows the different parts of the gun - from the top of the photograph down, air-cooled barrel (note the cooling fins showing just out of the casing), barrel spring in its vented casing, barrel spring (to cock the gun, these strong springs had to be manually pulled back to the firing position), magazine support shoulder, magazine catch lever (coming up from the gun and bending to the right), trigger housing with the trigger stub to the left and just after the mounting fixture and finally, the hand grip. This gun is not fitted with the gunner's body strap and shoulder rests.

Verso: "Transfer of wounded sailors aboard a PT boat to be carried to a hospital ship off Southern coast of France. 16 Aug 1944"

Credit: Official U.S. Navy photograph

11cm x 8cm Gelatin silver print


Catalogue number 105085

The Bofors 40mm gun

The story of the development of the Bofors 40mm gun is one of a repeated search to replace an existing naval anti-aircraft gun. The first was when after purchasing a certain number of Vickers 2-pounder Pom-Pom guns - the standard naval anti-aircraft gun at the time - in the late 1920s the Swedish Navy began discussions with the Bofors company to find a more efficient replacement, less prone to stoppages and jams. Design and modifications followed with a series of prototypes leading to the 40 mm L/60 Model 1936 rapid firing automatic gun which equipped the Swedish Army and Navy. The second was when at the onset of the Second World War, the British and American navies were seeking a more powerful rapid-firing replacement for the 20mm Oerlikon to fight off attacks by the latest Axis aircraft. The successor was the air-cooled and later the water-cooled 40mm single and twin Bofors gun firing high explosive rounds.

Verso: "U.S. Coast Guard gunners protect convoys from enemy air attacks. 3/31/44"

Credit: U.S. Authority

17cm x 11.7cm Gelatin silver print


Catalogue number 65050

Bofors-armed patrol boat

This photograph shows a single 40mm Bofors on a Danish patrol boat. Sitting on the left of the gun is the gun trainer with his open sight and to the right is the gun layer, each following the target with manual hand cranks. Between the two is the gun loader holding a four-round ammunition clip.

16.3cm x 20.5cm Gelatin silver print


Catalogue number 64016

Single Bofors gun mount

We can see the gun auto-loader guides towards the rear of the gun and the three-segment gun sights. Firing was triggered by the gun layer's foot pedal.

17.8cm x 12.7cm Gelatin silver print


Catalogue number 107063

Powered Bofors mounts

The following two photographs are good views of a twin 40mm Bofors gun on a hydraulic powered mounting.

7.9cm x 5.4cm Gelatin silver print


Catalogue number 57063

Bofors guns on H.M.S. Warrior

This is a photograph of one of the four twin 40mm Bofors mounts on the aircraft carrier H.M.S. Warrior. Note how the barrels shine and the flash shields are bright and shiny! It is one of 20 photographs illustrating a visit of H.M.S. Warrior in Malta.

12.8cm x 9cm Gelatin silver print


Catalogue number 57063

Modern Bofors mount

This is a modern powered single gun mounting, note the gun sights are not in place, the letter box type ammunition holder on mounting and ready-use ammunition racks all around the gun shield. There is a stand for gun loader. The gun breach is protected by a black cover.


Catalogue number 48149

A full outfit of anti-aircraft guns

This landing support craft of the Italian Navy (Alano, ex-LSSL34 U.S. Navy, launched 1944) has a comprehensive outfit of Oelikan and Bofors guns. There are twin Bofors fore and aft with a single Bofors right forward. Shielded Oelikan guns port and starboard can be seen forward of the superstructure, on the bridge wings and just aft of the bridge structure.

Credit: Stato Maggiore Della Marina

18.2cm x 13.1cm Gelatin silver print


Catalogue number 111075

Target ranging on a Bofors mount

This gun mounting is probably at the French Navy firing range at St Mandrier.The dish is part of the target range detection radar. Otherwise, the set-up remains the same for a twin 40mm Bofors mounting.

Credit: Groupe des Ecoles de la Méditerranée

23cm x 17.3cm Gelatin silver print


Catalogue number 56064

A modern Oerlikon gun and mount 1

Time has moved on and so has the appearance of this Oerlikon with the well-tried 20mm KAA gun on a British-made A41/820 manually-controlled mounting which, not having a height adjusting trunnion, still requires the gunner to be strapped into the shoulder supports to avoid falling over backwards at even modest degrees of elevation. The sight looks like the mark 14 gunsight with two air-driven gyroscopes that give the correct lead angle (or aim-off) for a given range, tracers helping to find the correct range. The experience of the Royal Navy during low level aircraft attacks in the Falklands War and the rise in terrorist attacks by fast boats has led to a renewed interest in light machine guns.

17.8cm x 12.7cm Gelatin silver print


Catalogue number 111075

A modern Oerlikon gun and mount 2

17.8cm x 12cm Gelatin silver print


Catalogue number 29044

German Navy anti-aircraft guns

This photograph shows two types of automatic guns used by the German Navy in World War Two. In the foreground is a 2cm Flak 38 gun on a single mounting. To the right, we can see the basket to receive empty cartridge cases (to recuperate much-need brass metal) and behind the gun is the loader with a 20-round magazine. To the far left is the gunner with the shoulder rests for free training and elevation. The gun seems to have some kind of special sight. In the background is a twin 3.7cm SKC/30 single-shot gun with a gyro cross-levelling sight.

12.8cm x 9cm Gelatin silver print


Catalogue number 113154

2cm German automatic gun

This 2cm Flak gun could be raised or lowered by the gun number using the elevating hand wheel on the pedestal which avoided the gunner having to lean far back - note the elaborate shoulder rest, the spare magazines in trays on the mounting and the bin for used cartridge cases. Once again, there is a 3.7 cm SKC/30 gun in the background.

Verso: "Enemy aircraft in sight - maximum alert ! A group of fast motor launches comes back from the Kerch Strait. After battling with Soviet gunboats, the fight with enemy aircraft is coming. Everything is ready. The gun crew follows the approach of enemy aircraft with the utmost attention. 1-1-44" in German and in French.

16.9cm x 12.1cm Gelatin silver print


Catalogue number 113152

German coastal flak ship, 1943

Here are two single 2cm Flak 38 mounting on what appears to be a converted anti-aircraft armed trawler. There is a crew member on the elevating hand wheel and directions are taken from the number right background in communication with the bridge. Note the counterbalance on each mounting.

Verso: "A steel greeting for the Tommy. As soon as the enemy aircraft approach the German coast, the men of the patrol boats send their steel greetings to the Tommies. 18-3-43" in German and in French.

23cm x 17.3cm Gelatin silver print


Catalogue number 113153

The "Vierling" quadruple 2cm flak mounting

Two quadruple 2cm Flak 38 mountings are shown in this photograph on board a ship in the Arctic Ocean, hence the sheepskin overcoats and hats. In the German Navy, this mounting was known as the Vierlings L38/43 and according to Campbell in "Naval Weapons of World War Two" "was probably the best of such weapons". Training and elevation were by hand wheels and here the guns appear to have the 40-round magazines. Is it spare barrels in the tubes on the outside of the gun platform?

Verso: "On a German ship in Northern Arctic Ocean 10-7-44." In German and in French.

16.9cm x 12cm Gelatin silver print


Catalogue number 54072

German Navy 3.7cm anti-aircraft gun

The 3.7cm/83 SK c/30 was a semi-automatic gun with the major disadvantage of being manually loaded and firing single shots, the effective rate of fire was about 30 rounds per minute - we can see a loader holding a shell on the extreme left of the photograph. Note crew members with hand-held rangefinders upper left.

Verso: "3.7cm Double Flak on Gneisenau Über… 08/1938" in German and in pencil. The same photograph is given as "3.7 cm/83 SK C/30 guns on Bismarck" on Tony DiGiulian's excellent website Navweaps

13.9cm x 9.6cm Gelatin silver print


Catalogue number 108099

Training on a 3.7cm gun

The twin 3.7cm SKC/30 mounting was triaxial with not only training and elevation by hand wheels but also correction for rolling or pitch - see crew member at the centre of the mounting.

Credit: Bundesarchiv Bild

17.2cm x 11cm Photograph


Catalogue number 18026

Anti-aircraft gun on board Prinz Eugen, 1942

The 3.7cm gun had a high angle of elevation, 80°, as can be seen here but this made hand-loading difficult. The crew member to the far right is holding one of the 0.748 kg shells.

14.7cm x 10.2cm Photograph


Catalogue number 68008

French Navy 3.7cm gun, 1925 model

This gun was hand-loaded which gave it a slow rate of fire for an anti-aircraft weapon when it came into service in 1936. The practical rate of fire has been given as between 15 and 21 rounds per minute and the effective range was 5,000m. This photograph is part of a series of 45 photographs taken during a 1930s cruise of the French cruiser Dupleix.

6.1cm x 10.7cm Gelatin silver print

Catalogue number 112054

An Italian anti-aircraft gun, the Breda 37mm gun

This Breda 37mm gun was water-cooled and used six-round clips but the gun and mounting were heavy and required a solid base. Also only the breech recoiled and not the barrel which produced vibrations that affected accuracy. Rate of fire was relatively low with 60 to 120 rounds per minute.

5.5cm x 5.2cm Gelatin silver print


Catalogue number 48168

Breda 37mm guns on an Italian motor torpedo boat

The Breda 40mm/70 type 107 guns shown here on Folgore had a 32-round automatic feed and also could use four-round clips.

Credit: Stato Maggiore della Marina

18.1cm x 13cm Gelatin silver print

Catalogue number 48172

The Italian motor gun boat Lampo

Three 40mm Breda guns with automatic feeds can be seen in this view of Lampo.

Credit: Interconair

17.7cm x 12.7cm Gelatin silver print