Posts Tagged: 1958

Report (May 1958) from the 2nd Equipment Planning Study Group

Original title: Rapport maj 1958 från studiegrupp 2 för fortsatt tygmaterielplanering

The 2nd study group for further equipment planning was responsible for figuring out what kind of requirements would be reasonable to expect from next-generation direct-fire AFV’s (tanks and APC’s, mostly) that were to enter service around 1965. In order to do this, the group considered what the Soviets were doing, what everyone else was doing, current bleeding edge research, where tank development was right now and where it was heading. In May of 1958 the group issued this report, which is a bit over 90 pages long.

The report discusses current trends in tank development, and designates three general lines of development called the A-tank, the T-tank and the S-tank.

  • The A-tank (A for America, probably) is the expected result from current US and UK design philosophy. It weighs about 40-45 metric tons and is frontally protected against sub-caliber kinetic penetrators fired from guns of up to 120 mm caliber, with mobility somewhat impaired by its weight. (In reality, this alternative later resulted in the M60 Patton and the Chieftain.)
  • The T-tank (T for Tyskland – Germany) is the expected result from current German and French design philosophy. It weighs about 30-35 metric tons and has very high specific engine power (25-30 hp/t or more), but only has frontal protection against (the equivalent of) 57 mm guns. (In reality, this alternative later resulted the Leopard 1 and the AMX-30.)
  • The S-tank (S for Sweden) is a proposed turretless Swedish design that has the same protection as the A-tank against kinetic weapons, while weighing only about 30 metric tons. Additionally, since the gun is fixed in the chassis, it can be fitted with screens or lattices that will protect it from all currently known anti-tank missiles and other HEAT penetrators.

The report then goes on to reason about the importance of low tank weight with regards to strategic mobility. For Swedish conditions, tanks should ideally weigh less than 37 metric tons. Based on this and other factors, the authors argue that the army should not purchase upgunned Centurions from the UK, as they are too heavy and an insufficient upgrade over the 84 mm variant. Instead, it is recommended that future Swedish tank development should focus on a) testing the S-tank concept in practice to see if it’s a workable solution, b) start development on a domestic A-tank equivalent (reusing the existing Krv chassis for experiments as necessary), using an autoloader instead of a manual loader to keep the weight down, and c) keep an eye on developments in the US and UK with the intention of purchasing complete tanks if something better/cheaper than the domestic alternatives comes up.

The report also features about a metric ton of appendices, which I have photographed but not published here because they are mainly used as support for the recommendations outlined in the main report and thus not really all that interesting on their own. If you see one you want in the table of contents, leave a comment and ask for it and I’ll post it.

Archive reference: SE/KrA/0266/002/01:H/F III/1

Aberdeen Proving Grounds test report for an AMX-13 prototype

A report in English from the Aberdeen Proving Grounds, covering their initial evaluation of what seems to be an AMX-13 prototype (the report just calls it “French light tank”). Original project number is TT 2-674.

The report seems to have wandered a long and winding road to end up in the archive where I found it. It’s originally dated 1951-02-17, and mentions that the testing was done in October to December of 1950. Somehow, it then ends up in the Top Secret (“kvalificerat hemligt”, of particular importance to the safety of the realm, cannot be shown to anyone without the approval of the head of the Department of Defense) archive of the Swedish Royal Army Ordnance Administration, the Vehicle Bureau, in late November of 1951. It sits there for a few years until it’s eventually downgraded to “regular” secret and discussed at the Vehicle Bureau in October of 1958, and that’s where I found it.

The photo appendices are sadly of a very bad quality; they seem to have copied them using some arcane machine that gave terrible quality. Appendices D, E and G are missing, either because they were illegible because of said copying machine, or because they weren’t included in the archive.

Archive reference: SE/KrA/0266/002/01:H/F I/19

Evaluation of later mark Centurion tanks, 1958

Two travel reports from delegations sent to the UK in September and October of 1958 with the intent of evaluating the improvements done by the British in their later mark Centurion tanks (mk 7-10). Lots of interesting reading in general, revealing how the Swedish and the British armies of the time thought about their tanks.

Archive reference: SE/KrA/0266/002/01:H/F I/19

Summary of penetration data for various projectiles (1958)

Original title: Sammanställning av data för genomslag av pansar
Author: Ann Littke-Persson, research engineer 1st class

A research report from FOA 2 (defense research agency, bureau 2), dated 1958-08-01, regarding the penetration capabilities of various projectiles of different kinds. The report is mainly theoretical in nature, but it extrapolates values for planned projectiles from empirical data obtained from various test firings, both Swedish and foreign.

Page 36 has a convenient reference of terms used in the report.

Archive reference: SE/KrA/0266/002/01:H/F I/19

Preliminary plans for guns, autoloaders and ammunition for strv A and strv S

Two documents from 1958 describing early developments in tank gun specifications, intended for two alternatives for a future Swedish tank. The alternatives are called “stridsvagn typ A” and “stridsvagn typ S” where A is a conventional turreted design and S is a very early S-tank (at this point they haven’t yet decided if the S-tank’s hydraulic gun laying system is technically feasible or not, so they plan for both alternatives).

Archive reference: SE/KrA/0266/002/01:H/F I/20

Memo regarding the procurement status of SPG, SPAAG and tanks

Original title: PM ang. akv, lvkv och strv enligt tygmaterielplan 1958/66

A memo from the Vehicle Bureau dated 1958-05-02, discussing the procurement status of current SPG’s, SPAAG’s and tanks (well, one of each, really). The SPG (akv 151) is built on a Krv chassis but now it seems like the Krv project will be cancelled, which is problematic. The Krv project itself is likely to get cancelled because of problems with the ammunition; options for keeping it alive is simply purchasing a new gun plus ammunition for it off-the-shelf abroad. There are two SPAAG alternatives; one is to purchase a “Grantham” SPAAG off-the-shelf, the other is doing something with the indigenous lvkv fm/49 (aka. lvkv 42).

Archive reference: SE/KrA/0266/002/01:H/F I/19

Memo regarding 105mm tracked SPG

Original title: VPM ang. 10,5 cm artilleripjäs i bandlavettage

A memo (dated 1958-06-13) from the Bureau of Weapons regarding tracked 105mm SPG’s. Bofors already has two alternatives based on the VAK 40 (aka. lvkv fm/49) chassis drawn up, one with the gun in the open but space available for the crew to sit under armor while the vehicle is moving, and one with the entire gun installation under 8-10 mm armor. The memo then goes on to discuss the current status of similar foreign projects and mentions a French project with a 105 mm gun on an AMX 13 chassis as well as three American projects (M37, M52 and an experimental T195).

Finally, the memo lists some technical requirements that would seem reasonable for such a weapon system.

Archive reference: SE/KrA/0266/002/01:H/F I/19