Posts Tagged: 1960

Memo regarding considerations for series production of akv 151 (KV 155)

Original title: PM rörande akv 151, överarbetning av konstruktionen med hänsyn till planerad tillverkning i serie

This memo (dated 1960-01-04) discusses series production of the akv 151 SPG (aka. KV 155, the bkan 1 prototype) and some of the project history. The author notes that since the original suggestion in the second quarter of 1949, eleven years have passed and series production has not yet started. A number of reasons for this is mentioned (lack of engineers, changes in the specification, doubts whether the project is viable at all). The author concludes that because of the changes in the specification and the fact that the current prototype is based on a chassis (the Krv) that is not likely to be mass produced, the vehicle (and its chassis in particular) will need to be reworked before it can enter series production.

The author also mentions that it would be desirable to reduce the weight of the vehicle; the prototype weighs 45 metric tons but according to a 1958 report Swedish AFV’s should weigh no more than 37 metric tons, and if possible weigh less than 25 tons. A note in the margin exclaims “-18% !” in red next to this paragraph; someone who read the memo probably doubts that this is possible (and they would be right, because the series production version turned out to weigh 52 metric tons in the end).

Finally, four alternatives are presented; two conventional and two using the suspension to help with gun elevation. The weight for all four alternatives is claimed to be less than 37 tons, which seems like a pipe dream in retrospect. Rough drawings of the alternatives are attached.

Archive reference: SE/KrA/0266/002/01:H/F I/43

105 mm tracked SPG project, contract and technical specification

An agreement (dated 1960-03-22) between KATF and Bofors, authorizing the latter to complete certain development work on a 105mm tracked SPG. As an appendix to the agreement is a rough technical specification for the SPG; this is the interesting part.

Archive reference: SE/KrA/0266/002/01:H/F I/40

Report on live fire trials against a strv 74 turret

A report from the Royal Military Academy, dated 1960-11-30, regarding live fire trials conducted against a strv 74 turret in August of 1960.

Weapons used:

  • 20 mm “tube cannon” for strv 74 (a smaller gun barrel inserted into the full-size one for practice purposes), firing 20 mm spårljuspansarprojektil m/42 (a full-caliber AP tracer round)
  • 37 mm anti-tank gun m/34 firing 37 mm spårljuspansarprojektil m/49 (a sub-caliber AP tracer round with a 24 mm penetrator)
  • 75 mm tank gun for strv 74, firing 7,5 cm spårljuspansarprojektil m/49 (a sub-caliber AP tracer round with a 50 mm penetrator)

The report concludes that the 20 mm rounds will reliably penetrate the turret side at distances less than 300 meters, with possible penetrations up to 670 meters. The 37 mm sub-caliber rounds will reliably penetrate most of the turret except an area within 20 degrees to either side of the gun barrel at distances under 750 meters, and may be able to penetrate the gun mantlet at distances up to about 850 meters. The 75 mm sub-caliber rounds will reliably penetrate the gun mantlet with considerable behind-armor effects at distances up to at least 1400 meters and most likely significantly longer distances as well, but that has not been tested.

Archive reference: SE/KrA/0266/002/01:H/F I/43