Sweden had been the only northern European nation to have not been actively in combat. That was not due to the triumph of Swedish diplomacy nor the strength of the Swedish military, but rather the luck of geopolitics. Like all its neighbours Sweden had embarked on a military expansion programme in the late 1930’s, both with domestic design and production and international purchases, and had instituted a national draft in 1938, and created the Hemvärnet Home Guard in May 1940.
Although no longer an imperial power, both Finland and Norway had very close history and ties to Sweden. The Soviet invasion of Finland was treated with great concern in Sweden, and although the Swedes were technically neutrals in the conflicts in Europe, they more realistically maintained a position as non-combatants in the Winter War; supplying both equipment and manpower to Finland. This extended to a complete air force unit, Flight Regiment 19, comprising 25 Swedish aircraft and all operational and support crews operating as volunteers. The Gloster Gladiators of F 19 claimed 12 Soviet aircraft for the loss of only 2 aircraft in combat and 4 to accidents in 2 months of operations. With the cessation of hostilities the aircraft and crews returned to Sweden.
Both the German invasion of Norway and the planned British invasion were centred on the supply of Swedish steel to Germany through the Norwegian port of Narvik. The German plan was just to hold and secure Narvik, while the British plan was to capture Narvik and push onwards into Sweden to capture the ore mining district of Sweden and the Swedish Baltic port of Lule, using the justification of defending the supply line for war matériel through to Finland. At the time Sweden was unaware of this British plan, but were suspicious that a British occupation of Narvik in neutral Norway, and “securing” the Malmbanan railway corridor would lead to an unacceptable British occupation of Swedish territory, while provoking both Germany and the Soviets to enter combat on Swedish soil. With the Finno-Soviet armistice the dubious British justification for action into Sweden was removed, but in London the planning for British action into Sweden continued. Then in a quirk of fate, both the British and German actions against Norway were launched simultaneously, with the British navy mining the waters of Norway in Operation Wilfred as the start of their invasion plan on the 8th April 1940, while the Germans landed troops before dawn on the 9th in Operation Weserübung.
The Germans had managed to capture and hold Narvik, although combined armies from Britain, France, Poland and Norway had been at the point of liberating the town before the Armistice. With the German withdrawal and the establishment of the Samling government in southern Norway the export abilities of the port at Narvik were secured to allow unrestricted iron exports. Now with the Soviets calmed by their Armistice with the Finns and distracted by their assimilation of the Baltic States, and with the Anglo-German Armistice lowering the threat from those nations, Sweden continued her armaments programme, aware that the international situation was still very volatile, and that they were surrounded by potential threats.
With the German invasion of Denmark, the Swedes had impounded an undelivered order of 15 Landsverk Lynx armoured cars, and impressed them as Pansarbil m/39’s. A further order for an additional 30 vehicles for the Swedish Army was placed with Volvo, as Landsverk was already committed to domestic tank production. This second batch of vehicles became m/40’s with slightly higher powered Volvo engines and a Bofors gun. In the immediate aftermath of the German assault on the west Volvo attempted to export additional vehicles, but the only order was for licence construction of the m/39 model in Belgium.
Landsverk had been too committed with production and development of the L-60 S light tank and new designs. Already batches of L-60’s had been delivered as the m/38 and m/39 and with the escalation of international tensions in 1940 an additional order as the m/40L was on the construction line. But even this was not enough for Swedish needs, and in March 1940 an order was placed for 90 Czech TNH tanks, which were delivered after the Armistice and served as the Stridsvagn m/40T. The armament was soon changed out for the same 37mm Bofors gun equipping the m/40, with the regunned vehicles redesignated as the m/41T.
In the early 1930’s Landsverk had designed a family of self-propelled anti-aircraft guns, but the lack of an adequate armoured chassis meant the vehicles were not progressed. With the battles in the Low Countries the effect of airpower on massed armour had been demonstrated, and now the need for tanks able to defend themselves against aircraft was obvious. With the L-60 already in production Landsverk now had a viable vehicle to use as the gun carriage, and with a request for an anti-aircraft tank from Finland, a customer willing to actually pay for that development expedited the process.
Landsverk had designed the L-62, -63, -64, and -65 as similar vehicles differing in the anti-aircraft gun fitted. The Finns required a vehicle fitted with their version of the Bofors L/60 autocannon, which had been included in the original L-62 design. The L-60 chassis was lengthened by adding a road-wheel to allow the fitment of a newly designed circular turret for the gun for the new L-62. Simultaneously Landsverk worked on a version for domestic use, utilising a dual mount of the Swedish naval Bofors m/32 autocannon, upgrading the L-63 to become the Kanonvagn m/40.
Sweden had also investigated foreign aircraft purchases and licence building to bolster its air force. From the United States the Northrop A-17 had been selected as a light bomber to be licence-built in Sweden by ASJA. Before the prototypes had been delivered to Sweden, Northrop had become Douglas – and changes in Sweden led to ASJA being taken over by SAAB shortly after. With the need for skis to be fitted for winter operations, Sweden specified that their version of the aircraft be fitted with fixed undercarriage, enabling an easy transfer to skis for winter operations, most notably the Swedes chose to install a domed canopy above the pilot and fitted local guns and radios. By the end of ASJA’s production run in 1940 63 aircraft had been constructed as B 5B’s, while future construction was under the name of SAAB.
Looking for new fighter aircraft as well, Seversky had flown its EP-1-68, a modified AP-7 racing aircraft, itself a modified P-35 fighter, to Sweden as a demonstrator in 1939. By the German invasion of Poland 60 aircraft had been ordered, with another order for a further 60 being placed in January of 1940 before the first aircraft had even been delivered. The initial batch of aircraft were shipped to Trondheim in northern Norway and, still crated, trained to Sweden for final assembly as J 9 fighters. After the German withdrawal from Norway the port of Trondheim remained in royal Norwegian control, and so the import of the second batch of fighters was able to continue in late 1940.
Seversky had also developed a 2-seat variant of the P-35, the 2PA-204A “convoy fighter”, and Sweden also ordered 52 as the B 6 light bomber. Only 2 aircraft were delivered with the initial J 9 shipments through the Kingdom of Norway, with the remaining aircraft being delivered with the second batch of J 9’s in late 1940.
SAAB had also been working on designing a single seat fighter. In September 1939 in response to a Swedish Air Board request for tender, SAAB presented plans for the L-12 powered by a Bristol Taurus engine. Production was ordered as the J 19 for a first flight by July 1941 and delivery by 1943. An inability of the British to supply the engines, and with SAAB already being committed to developing the B 17 and B 18 designs led to the cancelation of the project in December 1940.
Instead Sweden concentrated its efforts on purchasing foreign fighters, and in February 1940 the Swedish government signed an order for the purchase of 144 Vultee J 10 fighters. Delays in construction for this brand new design, caused by engine cooling and controllability issues meant that the first flight of the production prototype only occurred in September, with delivery only envisioned for late 1941.
European manufacturers had also featured in Sweden’s aircraft shopping spree. After the Armistice, and in an effort to rebuild friendships and gain foreign currency, Germany honoured its export agreement for 18 Dornier Do 215B-2 bombers starting in August 1940. Becoming the S 11 in Swedish service, the aircraft were deployed over the Baltic monitoring the forced integration of the former Baltic republics into the Soviet Union.
The more modest Bréguet 694 had been ordered from Belgian manufacture, and with the inability of French engine manufacturers to supply foreign orders the 12 aircraft ordered as S 10’s were constructed to 694bis standard with American engines with delivery starting in late 1940.
Before the German advance westwards, Sweden had purchased 18 Fokker G.I light bombers as an interim aircraft to provide coverage until the SAAB B 18 bomber entered service. The Dutch had embargoed export delivery to ensure their own defence, and with the German withdrawal continued production with all aircraft allocated to the Dutch Air Force. However a production line had been setup in Denmark for licence production of Fokkers for Danish service before the German invasion of Denmark. After their liberation the Danes had restarted construction of their aircraft, only to have the political decision made to no longer operate combat aircraft. With no aircraft available from Dutch manufacture, Sweden took the opportunity to instead purchase aircraft constructed in Denmark. Thirty-six aircraft were ordered as B 7 attack aircraft, with delivery scheduled for early 1941 after the initial order for Finland was completed. With their mission including dive bombing, the B 7’s included the fitment of the dive brakes trialled originally by Fokker.