Lago 1, the first Medium tank of the Swedish TT
In 1938 the Hungarian military had signed a deal with Landsverk for the license to produce the L-60 light tank and L-62 SPAAG, these vehicles would become known as the Toldi and Nimrod In Hungarian service. Around the same time the Hungary had been looking to acquire a medium tank. The Italian M13/39 the Czechoslovak koda T-21 and Praga V-8-H were all under consideration but in addition an order was placed with Landsverk for a soft steel Lago prototype to be delivered by 1940.
To adapt the Lago design to fit Hungarian requirements a number of changes were made including increasing the elevation of the rear turret mg to serve as an anti aircraft weapon, adding a ejection system for spent shell casings to the hull floor and changing the main gun to an Hungarian 40 mm gun. In addition to the three 8 mm machineguns a 12,7 mm mg was added to tanks hull, an alternative design with a turret mounted 12,7 mm was also discussed but dropped since this gun already took up more space than the main gun.
Lago I drawing
The prototype called Lago I was finished in May 1941. By this time Hungary had already moved on and adopted the Skoda T-21 as the Turán I, but luckily for Landsverk the Swedish army was now very interested in getting a medium tank of its own. The decision was made to develop a new 21 ton medium tank with 70 mm of armor protection and a 75 mm gun based on the existing Lago prototype. The Lago I itself would be used to test various various elements in preparation for the production model.
Despite lacking much of the intended equipment the prototype ended up with a weight of 18,3 tons, a significant increase from the original 15 ton estimated weight. Despite this the tank proved to have good mobility in both snow and mud, being able to reach a top speed of 45 kph on roads. Since the tank was mostly used for mobility testing the only armament mounted on the Lago I was its 40 mm cannon, though the possibility of mounting a 57 mm naval gun was discussed.
The Lago I was Initially equipped with a German electromagnetic gearbox and a pair of Scania-Vabis 1664 engines outputting 284 hp. Not wanting to be reliant on foreign components however the tank was refitted with a Swedish produced hydraulic gearbox from Atlas Diesel. In preparation for the increased weight of the production version a more modern pair of Scania-Vabis L 603 engines were fitted in 1942. To fit both the new engines and gearbox the engine compartment was completely rebuilt and the tank renamed Lago I H. During testing with the new powertrain the Lago I H was able to achieve a sustained top speed of 55 Kph, though it was later limited to 45 kph as the gearbox proved unreliable at higher speeds.
So to conclude:
Data: Lago I
Crew: 5
Weight: 18,3 ton
Length: 6 m
Width: 2,32 m
Height: 2,45 m
Ground clearence: 0,4 m
Armament (secondary): 3x 8 mm Ksp m/39
Armament (main): 40 mm Kan Strv
Depression/elevation: -10°/+25°
Armor: 34/34/20 mm
Engine: x2 Scania-Vabis 1664 (142 hp, Gasoline), x2 Scania-Vabis L 603 (162 hp, Gasoline)
Top speed: 55 kph
Ground pressure: 0,5m/cm^2
Trench: 2,4-2,8 m
Fording: 1 m
Sources:
Landsverk Blueprint archive (Part of Krigsarkivet in Stockholm) Täby (Arninge-Krigsarkivet) - Riksarkivet
Book - Svenskt pansar: 90 år av svensk stridsfordonsutveckling - By Rickard O. Lindström & Carl-Gustaf
Swedish tanks: Landsverk Lago – From the swedish archives
Book - Landsverk i Landskrona https://i.imgur.com/tJ6dJBv.jpg
SPHF’s (swedish historical armor association) private archive
Most of the original sources and information was correct however the fact the Lago 1 was equipped with a 37mm Bofors gun, is false.
WE have a bug report, as old as swedens TT and its yet to be resolved.