Unknown AA-Guns

[Kuno]

Colleagues; did not know, where to post these pics else. Obviously a AA gun. Would say postwar - maybe of British origin? Who has an idea resp. could provide a reference photo?

[ted angus]

look like bofors L40/70

[antarmike]

Bofors L40/70

Edited September 28, 2008 by antarmike

[david052]

Yup, I would agree. Where was the green photo taken - RAF Leuchars?

[antarmike]

It might be waddington??

[Kuno]

Was this a newer model of the famous Bofors AA gun of WW2; yes?

[REME 245]

This was the post-war version with the long barrel and powered mount.

[Kuno]

Many thanks for your information!

[antarmike]

The new model had a much greater rate of fire, Aircraft speed had increased conciderably during the war and it was only possible to get a few shots at the faster planes with the older Bofors, so the higher fire rate L40/70 was introduced.

Edited September 30, 2008 by antarmike

[antarmike]

By the end of World War II, jet aircraft had so increased the speed of attack that the Bofors simply could not get enough rounds into the air to counter the aircraft before it had already flown out of range. In order to counter these threats, the gun would have to have longer range and a higher rate of fire, thereby increasing the number of rounds fired over the period of an engagement. Bofors considered either updating the 40 mm, or alternately making a much more powerful 57 mm design, and in the end did both.

 

The new 40 mm design used a larger 40 × 364R round firing a slightly lighter 870g shell at a much higher 1,030 m/s muzzle velocity. The rate of fire was increased to 240 rounds per minute (4.0 Hz), unusually high for such a large round. Additionally the carriage was modified to be power-laid, the power being supplied by a generator placed on the front of the carriage. The first version was produced in 1947, accepted in 1948 as the 40 mm lvakan m/48, and entered Swedish service in 1951. Additional changes over the years have improved the firing rate first to 300 rpm (5.0 Hz), and later to 330 rpm (5.5 Hz).

 

Foreign sales started, as they had in the past, with Holland and Great Britain. In November 1953 it was accepted as the NATO standard anti-aircraft gun, and was soon produced in the thousands. The L/70 was also used as the basis for a number of SPAAGs, notably the U.S. Army's proposed M247 Sergeant York.

 

(wikpedia)

 

The rate of fire of the earlier L60 had been 120 rounds per minute. (2 Hz)

 

 

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Shell 40x311mmR (1.57 in)

Caliber 40 mm L/60 (actual calibre is 56)

Carriage 522 kg

Elevation L/60: -5°/+90°(55°/s)

L/70: -20°/+80°(57°/s)

Traverse 360°

L/60: 50°/s

L/70: 92°/s

Rate of fire L/60: 120 round/min

L/70: 330 round/min

Muzzle velocity L/60: 881 m/s (2,890 ft/s)

L/70: 1,012 m/s (3,320 ft/s)

Maximum range L/60: 7,160 m (23,491 ft)

L/70: 12,500 m (41,010 ft)

Edited September 30, 2008 by antarmike