These two documents, originating at Bofors in March and December of 1952 respectively, describe the plans for developing a working prototype of the 15 cm self-propelled artillery piece that was originally proposed in 1949, variously called 15 cm kv fm/49, akv 1949 and VK 152 S 49 (the latter being the internal Bofors designation). Initially, three alternatives for the track assembly and drive train are proposed: one using the existing drive train from the strv m/42 (Volvo A8B engine uprated to 450 HP and VL 420 gearbox), one a purely experimental project based on a Sherman’s gearbox and drive train, and one possible “merge” with the drive train and gearbox of a future tank being developed by KAFT (which is obviously project EMIL, but it was very much a paper project at this point).
The decision described in these documents is to go with the strv m/42 option, but this must’ve been changed to the third alternative at some point because eventually what ended up happening was that the project EMIL chassis and engine were used.
Archive reference: SE/KrA/0062/D/01/016:H/F I/28
Minutes of a meeting held at Bofors on May 30th and 31st 1951, regarding current projects. Most interestingly, a “new tank gun” is discussed, with some different alternatives presented.
Archive reference: SE/KrA/0062/D/01/016:H/F I/24
In the same 1949 army headquarters memo mentioned in the previous post, the army also saw the need for a 15 cm self-propelled autoloaded artillery gun (the 10,5 cm gun was intended for smaller formations, while the 15 cm SPG would be a division or corps-level asset). Development of this artillery piece was contracted to Bofors, with deliveries planned to start in spring 1956 (in reality, the production version of this SPG finally entered service in 1967, delayed over 10 years).
These documents describe the original intentions and requirements for the SPG, and a preliminary drawing is attached. It was originally intended to weigh 30 tons; the production version would eventually enter service weighing 52 tons. A large part of the increased weight was due to a requirement added later, namely that the entire fighting compartment and the external ammunition storage must be armor protected and sealed against NBC weapons.
Archive reference: SE/KrA/0062/D/01/016:H/F I/17 and SE/KrA/0062/D/01/016:H/F I/18
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
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
Minutes from two meetings at Bofors (on 1954-09-22 and 1954-12-08) discussing the status of various projects. More specifically:
Archive reference: SE/KrA/0266/002/01:H/F I/1
Minutes from a meeting (1954-05-04) at the arms administration’s vehicle bureau regarding the status of current projects. Mentions the “tankette” (project 6400 aka. the KRV), kv 155 (a SPG prototype that would eventually become akv 151 and then eventually bkan 1), lvkv fm/49 (a SPAAG) and the upgunning of strv m/42.
Archive reference: SE/KrA/0266/002/01:H/F I/1