Author: Renhanxue and sp15

Hello everyone,

yet another brand new tank was found in the Swedish archives – and yes, it’s a proposed upgrade of the m/41 (TNH-Sv) light tank, originally manufactured in Czechoslovakia.

Renhanxue:

In mid-1943, the strv m/41 (TNH-S) and strv m/42 deliveries were in progress but judging by disturbing intelligence reports from Finland and Germany, they really weren’t up to the latest modern standards. Some army people had been allowed to study captured Soviet T-34′s in Finland and were particularly impressed by its powerful diesel engine and heavily sloped armor. A successor to the Swedish tanks then in production was needed, and soon. Some people at the Royal Artillery and Ordnance Administration were convinced that it was necessary to lift the 22 tonne weight limit (imposed for the sake of strategic mobility, since most Swedish bridges could not tolerate any greater mass), but it was also recognised that lighter tanks had a role to play.

Because of the need for a speedy development process and to avoid re-tooling existing production lines, Scania-Vabis (which was ordinarily a manufacturer of trucks and buses, but also contracted to license build the strv m/41) was asked to investigate in which ways the strv m/41 could be improved without losing too much time. The result was described in a letter dated July 21st, 1943, which contains the two photos above.

Scania-Vabis (seemingly inspired by the T-34 and similar modern designs) proposed two hull alternatives (1 and 2) and two turret alternatives (a and b); the turrets were compatible with both proposed hulls. Hull 1 (the first photo) attempted to keep parts commonality with the existing strv m/41 as far as possible; the main changes were slightly wider tracks and road wheels, sloping the armor, switching to welded seams in many of places and improving the driver’s position in a few ways (better periscope and a bit more room). The resulting tank was calculated to weigh 13 tonnes, two more than the strv m/41.

Hull 2 was essentially a new tank; the chassis had been redesigned to be able to fit a new 8-cylinder engine capable of producing 220 HP. The hull armor was improved and the tank was calculated to weigh 15 tonnes. The road wheel arrangement had also been modified, and the bottom plate of the tank was curved to help protect against mines. Scania-Vabis admitted that in order to get production of this proposal going, quite some engineering effort and retooling would be required.

The turrets were similar to each other, the main difference being that turret b had a rounded mantlet and the machine gun fixed in a coaxial position, while on turret a aiming the machine gun independently was possible. In the end neither proposal was accepted, although I haven’t been able to find the exact reasoning for why in the archives just yet.

Alternative 1

Armor (Hull)
Upper front: 35mm at 30dg
Armor joint between LFP and UFP: 65mm
Lower front: 30mm at 26dg
Floor: 15mm
Lower side: 30mm at 78dg
Upper side: 30mm at 55dg
Rear: 15mm at 77dg
Drivers hatch: 60mm (rounded)
Floor armor above tracks: 10mm

Armor (Turret)
Front: 50mm at 60dg
Front roof: 25mm at 30dg
middle roof: 13mm
Rear roof: 15mm at 30dg
Gun mantlet: 25mm at 45dg (rounded)
Turret rear: 30mm at 60dg (rounded)
Turret floor: 13mm

Armament: 57mm L/50,5 Pvkan m/43
Ammo capacity: 80 rounds
Weight: 13 ton
Top speed circa: 45kph

Alternative 2

Armor (Hull)
Upper front: 40mm at 27dg
Armor joint between LFP and UFP: 65mm (rounded)
Lower front: 40mm at 30dg
Floor: 15mm
Roof: 13mm
Lower side: 35mm at 78dg
Upper side: 35mm at 55dg
Rear: 20mm at 75dg
Drivers hatch: 60mm (rounded)
Floor armor above tracks: 10mm

Armor (Turret)
Front: 50mm (rounded)
Front roof: 20mm at 20dg
Roof: 13mm
Gun mantlet: 35mm at 70dg
Turret rear: 35mm at 70dg
Turret floor: 13mm

Armament: 57mm L/50,5 Pvkan m/43
Weight: 15 ton
Top speed circa: 45kph
Track width: 380mm
Roadwheel diameter: 800mm
Fuel capacity: 400 liters
Engine: Scania-Vabis 8 cylinder (220hp)