Swedish tanks: Strv m/38 – m/40k

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Author: SP15

The strv m/38, m/39, m/40L & m/40k were Swedish light tanks that served with the Swedish army troughout and beyond ww2. At one point they were some of the most advanced tanks in the world but after the war they would be religated to the role of reconnaissance vehicles.

 

Background

In the mid 1930s as tensions were starting to rise in mainland Europe the Swedish army began looking at the acquisition of new tanks for its first tank battalion. The Swedish army had since 1922 operated an experimental tank battalion at Göta livgarde which had allowed them to gain experience with operating tanks. The tanks used by the Göta livgarde tank battalion were however severely outdated and due to a lack of spare parts half of the vehicles ended up being cannibalized.

Several attempts were made to find a replacement in the late 20’s – early 30’s but despite testing numerous potential designs and even funding the development of a domestic tank design (the strv m/31) mediocre trial results and a lack of funds forced the army to delay the purchase. I wont go into detail about those attempts here but If you want to know more about them I have an article on the Strv m/31’s development.

Strv m/31

It wouldn’t be until the 6th of April 1936 that the Swedish army was finally granted the funding to purchase new tanks. The funds were intended to be used to create two tank battalions with two tank companies each. Unfortunately with the 4,5 million Kr the army had been had been granted there wouldn’t be enough for that. Instead they would have to settle for a single tank battalion, which to maximize the number of vehicles would be equipped primarily with machinegun armed tankettes. A small number of modern light tanks would make up the remainder of the battalion.

 

Development

Since early 1936 the army had been looking at designs from both the Czech CKD and Swedish Landsverk companies as both were able to offer excellent designs with a comparable performance and price.

Landsverk’s designs (the L-60 and L-120) would be slightly more expensive and more importantly they had a longer delivery time. Due to this CKD’s offer was preferred, however it was rightfully reasoned that it might not be the best idea to completely rely on foreign companies in case of war, because of this it was decided to split the order. CKD would deliver 48 AH-IV-S tankettes and Landsverk would be contracted for 16 of their latest pattern L-60 tanks.

 

Irish L-60’s

Landsverk’s L-60 had originally been developed in the early 30’s as one of Landsverk’s export offerings. In 1934 the tank would be successfully pitched to the Irish military which would purchase 2 vehicles that were delivered in 1935 – 36.

It was during this time that the Swedish military became interested in the project. One of the Irish vehicles came to be tested alongside the Strv m/31 where the L-60 was found to have superior mobility, optics and accuracy while showing no major drawbacks. Having been impressed by the results the Swedish army would order the construction of two improved prototypes in July of 1936.

In some respects the The L-60 was a design well ahead of its time. Like its larger brother the L-10 or Strv m/31 the L-60 had a modern fully welded hull which also made extensive use of sloped armor. As was typical of light tanks of this period the L-60’s armor was only intended to protect against machine gun caliber rounds, reaching a maximum thickness of 15 mm at the turret front. This had made some sense back in 1931-35 when the tank was designed as cannon armed tanks were less common, but this poor protection would be one of the first things addressed when the vehicle entered production.

Thanks to suspension and drivetrain improvements the L-60 was not only faster but more reliable than earlier designs. During its development the L-60 had been redesigned with a front mounted transmission to avoid the track tensioning problems that the Strv m/31 had suffered from. In addition the suspension was also redesigned from the spring system seen on the m/31 to a torsion bar suspension. In fact the L-60 was the first tank ever to be fitted (and later produced) with a torsion bar suspension. The Original L-60 as well as the Hungarian license produced version (M38 Toldi) was powered by a German Bussig NAG gasoline engine which produced 155 – 160 hp, this gave the 7 ton tank a top speed of around 45-50 kph on roads.

L-60-S prototype

The Swedish L-60 prototypes differed substantially from earlier models. These vehicles were fitted with the Swedish built Scania-Vabis 1664 engine, which while less powerful than the German one (at 142 – 145 hp) avoided the problem of having to import spare parts. A feature only present on the 2nd Swedish prototype (pictured above) was a redesigned hull front where an extra step in the armor was added to the upper portion of the front glacis and the main headlight housing moved down.

As requested by KAFT (the army ordinance board) a new turret with room for a radio set and equipped with a commanders cupola was fitted. This turret had actually been taken from the Landsverk Lynx armored car. Like earlier L-60’s the armament consisted of a 20 mm Madsen autocannon paired with a 8 mm MG. However because Swedish army was not satisfied by the Madsen’s performance, or with having to import a new gun and its ammunition the 37 mm bofors gun was chosen for the production version. This in turn necessitated the use of a larger turret, so an existing Landsverk L-180 armored car turret ended up being used. The result of these changes was a 8,5 ton vehicle that came to be known as the Strv m/38 in Swedish service.

Strv m/38

Deliveries of the 16 Strv m/38’s took place between November 1938 and august 1939. They were the only operational tanks in the Swedish army with any anti tank capability At the outbreak of ww2, a fact that would remain unchanged until 1941. Ironically the m/38’s ended up only briefly serving with the Göta livgarde tank battalion as it was by this point in the process of shutting down, they would end up being transferred to the I9 and I10 infantry regiments.

Strv m/39

Remember that 2nd tank battalion requested back in 1936? Well on the 28th of November 1939 (only days before the Soviet invasion of Finland) the Swedish government finally granted another 4 million Kr for the acquisition of 20 additional tanks. Negotiations between KAFT and landsverk on a 2nd series of tanks had begun already in may 1939 well before deliveries of the Strv m/38 were completed. The Strv m/39 as it was designated would be delivered in the spring of 1941 after several months of delays due to shortage of 37 mm guns.

Video of Strv m/38 & Strv m/39 in action (skip to 4:00)

These tanks would remain largely unchanged but they would introduce a new turret design, a re-designed engine deck and replace the steering wheel used on the m/38 with steering levers. The new turret which was an evolution of the Lynx turret used on the prototype, moved the main gun to a smaller mantlet mounted on the left side of the turret front. This allowed the installation of a 2nd machinegun and allowed both MG’s to be aimed independently of the main gun. The gun depression was also increased from -10 degrees to -15 degrees.

Like the m/38 the Strv m/39 ended up being sent to I9 and I10 – later with the formation of the Swedish armored corps in 1942 renamed P4 and P3 respectively. Some m/39’s also ended up being transferred to the K2 regiment for use as training vehicles.

Strv m/40L

Of course 20 tanks would not be enough to equip another tank battalion therefore another 100 L-60’s were ordered in October of 1940. Originally this order was meant to go to CKD (who had after the German occupation been renamed BMM) but the order ended up being canceled by the Germans and the tanks originally meant for Sweden would end up being used as the Pz.38t Aufs S which saw use in the German invasion of France, and later the operation Barbarossa.

The m/40L differed very little from the m/39. Besides a completely redesigned engine compartment the only major difference was the introduction of an automatic gearbox, which replaced the German FAK-55 used on earlier models. One of the stranger things added to some strv m/40L’s was mounting points for a mortar on the engine deck.

 

The largest improvement introduced with this version was an applique armor package, which increased the armor thickness of the turret and hull front to 40-50 mm. To reduce the wear and tear on the suspension only the turret received a permanent armor increase, the full applique armor would only be mounted in the field. Like the m/39 before it the m/40L suffered from a number of delays, the final of the 100 Strv m/40L was delivered in march 1942 over four months after the estimated date. The tank ended up serving with the P3, P4 and K2 regiments.

Applique armor package for Strv m/39 & m/40L

Having seen incredible success of the German tank corps in Poland and France the role of the tank in the Swedish army came to be re-evaluated. It was decided that from 1942 onwards the army would field three armor brigades with two armor battalions each containing 199 vehicles. 76 medium tanks, 105 light tanks, 6 tank destroyers & 12 self propelled anti aircraft guns would make up these 199 vehicles.

This meant that the army needed to acquire an additional 202 light tanks. The order would end up being split between Scania-Vabis (who had been granted a license for the production of the TNH/Pz 38.t) and Karlstad’s Mekaniska Werkstad which took over the assembly of the L-60 from Landsverk as they were focusing on the production of medium tanks.

 

 

 

Strv m/40K

 

The L-60 design received a final overhaul and the suspension was Improved to the point where the applique armor could be built in from the start. Other than that the hull was extended to fit the new more powerful 162 hp Scania-Vabis L 603 engine. Despite this the power to weight ratio remained a rather mediocre 15 hp/t due to the increased weight.

 

To save on production time lot of the smaller features on the Strv m/40k such as the headlights and antenna were standardized with those of the Strv m/42 medium tank. A total of 80 Strv m/40K’s were produced between 1943 and 1944. The majority of these tanks would end up serving with the P2 regiment.

Strv m/40K with mortar

 

Impact and legacy

I don’t think the importance of the Landsverk L-60 can be overstated. In many ways it was the right tank at the right time. It provided the Swedish army with a option when no other tank could be built or imported, and it would serve as the backbone of the Swedish armored corps for the majority of ww2.

It introduced the world to several technical innovations like the first use of torsion bar suspension and automatic gearboxes on tanks. And as the first Swedish mass produced tank it showed that Sweden did not need to rely on foreign vehicles. It also marked the start of a indigenous tank and AFV industry that is still going strong to this day with designs like the CV90 IFV and Archer SPG.

Well over 400 vehicles would be produced and these would end up being used all over the world from Ireland to the Dominican republic. The L-60 would also end up seeing extensive combat use by Hungarian forces on the Eastern front and former Swedish Strv m/40L’s in the hands of Dominican rebels would end up fighting the US marines in the 60’s.

Dominican Strv m/40L destroyed by a US 106 mm recoilles rifle

That said the L-60 was still a product of its time and like many pre war designs it was not able to keep up with the pace of tank development during ww2. Despite several upgrades the tank would suffer from a lack of firepower that never really ended up being solved, and as the use of medium and heavy tanks became more prevalent the L-60 ended up taking more of a secondary role as a support/reconnaissance vehicle.

The L’60’s In Swedish service would be retired one by one starting with the strv m/39 & m/40L in 1957 and ending with the Strv m/40K in 1960. Their turrets however would remain in service as part of costal fortifications and airfield defences until the 90’s.

 

Versions

Over the years there would be a number of different projects which were based on or attempted to upgrade the L-60. Here I will give a short description of some of them.

 

Finnish L-62 ANTI II

Already before the L-60’s development Landsverk was experimenting with designs mounting the bofors 40 mm gun on a tank chassis. In 1938 they constructed a prototype based on a extended L-60 chassis which they named the L-62 ANTI. A modified version of this vehicle known as the Nimrod would end up being adopted alongside the L-60 by the Hungarians. A 2nd generation version based on the Strv m/40L chassis also ended up being produced by landsverk for Finland during ww2.

 

Lvkv fm/43

The Swedish army had shown some interest in the L-62 but they would go trough a number of iterations of a 20 mm armed SPAAG before ultimately coming back to the idea of an improved L-62. This version was designed with a new low profile hull based on the Strv m/40k and with a turret mounting dual 40 mm guns. It was meant to go into production in 1945 but deliveries would end up being delayed untill 1946-47.$

 

L-60-S with 7,5 cm kan m/02

15 cm Stormpjäs fm/43

1942 one of the L-60-S prototypes would be converted into an experimental assault gun. The turret was removed and replaced by a superstructure in which a 7,5 cm m/02 gun was mounted. This vehicle would also be tested with the longer 7,5 cm kan m/40. In 1943 this project would be moved to the Strv m/41 chassis due to the insufficient armor protection of the L-60 platform.

Also in 1943 a 15 cm recoilless rifle was fitted and the vehicle was re-designated as 15 cm Stormpjäs fm/43. The gun used was based on a converted fortress gun and was able to fire a 34 kg HE shell at 305 m/s. In 1944 this project was also moved to the Strv m/41 chassis.

 

Terro (1941)

Terro (1942)

 

In 1940 Landsverk had started planning for a next generation of L-60 which they named the L-60-IV “Terro”. The tank would have shared its major components with the Landsverk Lago medium tank and it would have weighed 12-14 tons. It would have had a crew of 4 and featured increased armor protection, improved engine performance and the possibility of mounting a 57 mm gun.

The proposal was dismissed by KAFT as the tank was only marginally better than the improved versions of the standard L-60, Landsverk would also have needed several months to retool and switch production to the “Terro”. The Swiss military actually ended up showing some interest in the Terro in 1942 but by that point Landsverk was preoccupied with the production of tanks for the Swedish army.

Strv m/40L or m/39 with Smoke launchers

In the late 40’s the Swedish army tested several vehicles with experimental smoke launchers including the L-60. These never ended up being adopted, probably because the tanks were thoroughly obsolete at the point they were tested.

L-60 m/48

In 1948 as part of landsverk’s post war export attempts drawings were made for an improved L-60 model 1948. The tank would have had an improved engine and would have been armed with a high caliber autocannon equipped with a Littlejohn adaptor. Sadly as with all landsverk’s projects from this time it never ended up being built.

Pvkv IV “Värjan”

The Pvkv IV “Värjan” was an attempt to up gun the L-60 platform in the early 50’s. A single Strv m/40L was converted & tested in 1952 but the vehicle was rejected in favor of another conversion based on the Strv m/41 (TNH) chassis.

 

Strv m/40L with racks for Rb 51 (SS10)

A few years later in 1954 another attempt was made at re-arming the Swedish L-60’s. A strv m/40L chassis ended up being fitted with a mounting rack for the French SS10 anti tank guided missile during Swedish trials with said missile.

 

Technical data

Landsverk L-60

Combat weight: 6,8 ton

Crew: Commander/Radioman/loader, Driver, Gunner/Machinegunner

Length: 4660 mm

Width: 2110 mm

Height: 1850 mm

Top speed: 48 Kph

Gradient: 40 dg

Side slope: 30 dg

Trench: 1,75 m

Ground clerance: 350 mm

Track width: 286 mm

Ground contact length: 2440 mm

Ground pressure: 0,52 kg/cm^2

Turning radius: 4,5 m

Vertical step: 0,7 m

Fording: 0,7 m

Engine: Büssing-NAG type L8 V/36 TR (Gasoline 160 hp at 2700 rpm)

Power to weight ratio: 23 hp/t

 

Armor (turret)

Front: 13 mm

Side: 13 mm

Rear: 13 mm

Roof: 6 mm

 

Armor (hull)

Front: 13 mm

Side: 13 mm

Rear: 13 mm

Roof: 5-9 mm

Floor: 8 mm

Armor scheme:

Main armament: 20 mm akan m/Madsen

Secondary armament: 8 mm ksp m/36 strv

Gun elevation/depression: +30/-10 dg

Ammo: 240 rounds 20 mm, 3000 rounds 8 mm

 

Strv m/38

Combat weight: 8,525 ton

Crew: Commander/Radioman/loader, Driver, Gunner/Machinegunner

Length: 4800 mm

Width: 2075 mm

Height: 2050 mm

Top speed: 46 Kph (-5,3)

Gradient: 40 dg

Side slope: 30 dg

Trench: 1,75 m

Ground clerance: 350 mm

Track width: 286 mm

Ground contact length: 2440 mm

Ground pressure: 0,52 kg/cm^2

Turning radius: 4,7 m

Vertical step: 0,7 m

Fording: 0,7 m

Engine: Scania-Vabis 1664 (Gasoline 145 hp at 2300 rpm)

Power to weight ratio: 17 hp/t

 

Armor (turret)

Front: 15 mm

Side: 13 mm

Rear: 13 mm

Roof: 6 mm

 

Armor (hull)

Front: 13 mm

Side: 13 mm

Rear: 13 mm

Roof: 5-9 mm

Floor: 8 mm

Armor scheme (ignore black numbers/text):

View post on imgur.com

Main armament: 37 mm kan m/38 strv

Secondary armament: 8 mm ksp m/36 strv

Gun elevation/depression: +20/-10 dg

Ammo: 100 rounds 37 mm, 2250 rounds 8 mm

 

Strv m/39

Weight (excluding crew): 8,695 ton (applique 9,2 ton)

Crew: Commander/Radioman/loader, Driver, Gunner/Machinegunner

Length: 4800 mm

Width: 2075 mm

Height: 2050 mm

Top speed: 45 Kph

Gradient: 40 dg

Side slope: 30 dg

Trench: 1,75 m

Ground clerance: 350 mm

Track width: 286 mm

Ground contact length: 2440 mm

Ground pressure: 0,52 kg/cm^2

Turning radius: 4,7 m

Vertical step: 0,7 m

Fording: 0,7 m

Engine: Scania-Vabis 1664 (Gasoline 145 hp at 2300 rpm)

Power to weight ratio: 16,6 hp/t (15,7 hp/t)

 

Armor (turret)

Front: 15 mm

Side: 13 mm

Rear: 13 mm

Roof: 5 mm

 

Armor (hull)

Front: 13 mm

Side: 13 mm

Rear: 13 mm

Roof: 5-9 mm

Floor: 8-5 mm

 

Base armor scheme:

View post on imgur.com

Applique armor scheme:

View post on imgur.com

Main armament: 37 mm kan m/38 strv

Secondary armament: 2x 8 mm ksp m/39 strv

Gun elevation/depression: +20/-15 dg

Ammo: 100 rounds 37 mm, 2250 rounds 8 mm

 

Strv m/40L

Weight (excluding crew): 8,93 (applique 9,36 ton)

Crew: Commander/Radioman/loader, Driver, Gunner/Machinegunner

Length: 4800 mm (4900 mm including gun)

Width: 2075 mm

Height: 2050 mm

Top speed: 45 Kph

Gradient: 40 dg

Side slope: 30 dg

Trench: 1,75 m

Ground clerance: 350 mm

Track width: 286 mm

Ground contact length: 2290 mm

Ground pressure: 0,73 kg/cm^2

Turning radius: 4,7 m

Vertical step: 0,7 m

Fording: 0,7 m

Engine: Scania-Vabis 1664 (Gasoline 145 hp at 2300 rpm)

Power to weight ratio: 15,9 hp/t (15,2 hp/t)

 

Armor (turret)

Front: 15 mm

Side: 13 mm

Rear: 13 mm

Roof: 5 mm

 

Armor (hull)

Front: 13 mm

Side: 13 mm

Rear: 13 mm

Roof: 5-9 mm

Floor: 8-5 mm

Base armor scheme:

View post on imgur.com

Applique armor scheme:

View post on imgur.com

Main armament: 37 mm kan m/38 strv

Secondary armament: 2x 8 mm ksp m/39 strv

Gun elevation/depression: +20/-15 dg

Ammo: 100 rounds 37 mm, 3500 rounds 8 mm

 

Strv m/40K

Combat weight: 10,95 ton

Crew: Commander/Radioman/loader, Driver, Gunner/Machinegunner

Length: 4970 mm

Width: 2080 mm

Height: 2140 mm

Top speed: 45 Kph (-5)

Gradient: 40 dg

Side slope: 30 dg

Trench: 1,75 m

Ground clerance: 340 mm

Track width: 286 mm

Ground contact length: 2690 mm

Ground pressure: 0,71 kg/cm^2

Turning radius: 6,5 m

Vertical step: 0,7 m

Fording: 0,7 m

Engine: Scania-Vabis L 603/3 (Gasoline 165 hp at 2320 rpm)

Power to weight ratio: 15 hp/t

 

Armor (turret)

Front: 50 mm

Side: 20 mm

Rear: 35 mm

Roof: 5 mm

 

Armor (hull)

Front: 35 mm

Side: 18 mm

Rear: 13 mm

Roof: 5-9 mm

Floor: 12 mm

Armor scheme drawing:

View post on imgur.com

Main armament: 37 mm kan m/38 strv

Secondary armament: 2x 8 mm ksp m/39 strv

Gun elevation/depression: +20/-15 dg

Ammo: 100 rounds 37 mm, 3500 rounds 8 mm

 

Drawings

Landsverk L-60

Strv m/38

Strv m/40L & m/39 turret

Strv m/40L & m/39 turret

Strv m/40L turret with applique armor

Hull applique armor

Strv m/40K

Strv m/40k turret

Internal layout Strv m/40K

Measurement drawing Strv m/40K

 

Source’s & Historical Refrences

–  Manual Strv m/38

– Manual Strv m/38, m/39,m/40L & m/40K

– Strv m/40L datasheet

– Datasheets strv m/38 – m40k

– Comparative data of swedish tanks (1946)

– Technical description of Landsverk L-60

– Landsverk Blueprint archive (Part of Krigsarkivet in Stockholm)

– Svenskt pansar: 90 år av svensk stridsfordonsutveckling – By Rickard O. Lindström & Carl-Gustaf Svantesson

– Private archive – SPHF (Swedish historical armor association)

– Pansar Magazine – issue 1-3 (2013)

 

For more articles and tidbits on swedish tanks and tank development in general you can check out my blog: https://fromtheswedisharchives.wordpress.com/

This article is part of the Swedish tech tree project for War thunder. If you want a swedish tech tree in War Thunder check out the  Swedish ground forces thread ( https://forum.warthunder.com/index.php?/topic/417466-standalone-swedish-ground-forces-tree/ ) on the official forum. Thank you for reading!

2 comments on “Swedish tanks: Strv m/38 – m/40k

  1. Sturmi0545 says:

    I like the IKEA applique armor package the most 🙂

    1
  2. Tristan Boileau says:

    Värjan for tier 5!

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