The construction of Hallinkangas in Kuorevesi is a fine example of true Finnish grit. The factory and its airport were built in the middle of the forest, far from any habitation, and without modern tools. Initially, the only power sources available were agricultural combustion engines and fuel generators. The overhead power lines from Mänttä to Halli were completed in early spring 1940. At the same time, Finland was honourably defending its eastern border against a big push from the Soviet Union.

Text: Otavamedia/ Tuomas Lehtonen according to the story told by Jussi Karhumäki (Valto Karhumäki’s son) and Pekka Karhumäki (Niilo Karhumäki’s son) Photos: Tommi Anttonen

Relations between Finland and the Soviet Union became strained during the 1930s. As the likelihood of war increased, Finland began to consider how to disperse its air force operations and aircraft production. A new base was required in the middle of the country, far from any habitation.

Pekka Karhumäki
Pekka Karhumäki, son of Niilo Karhumäki.

In 1938, Field Marshal C.G.E. Mannerheim visited Keljo in Jyväskylä, where the Karhumäki brothers Niilo, Valto and Uuno ran an aircraft repair shop. Mannerheim was accompanied by General of the Infantry Rudolf Walden, Secretary of the Defence Council Colonel Aksel Fredrik Airo, and a host of other high-ranking officers. The brothers had been servicing Finnish Air Force planes at their shop since 1934. Mannerheim and Niilo Karhumäki discussed increasing cooperation between the government and the brothers’ repair shop.

During the winter following the Marshal’s visit, majors Koskiala and Kuusinen (from the engineering corps) visited Keljo as representatives of the Finnish Air Force and Ministry of Defence. The gentlemen suggested a new cooperation agreement. The brothers were offered the chance to increase their workshop operations tenfold. The proposal was to station repair operations in a new location where an airport would also be built. The Karhumäki brothers seized this opportunity.

Contract for building an aircraft factory in Halli

Image removed.As the brothers also excelled in aerial photography, they were tasked with finding a suitable location for the government’s aviation hub. It needed to be located west of the Turku-Tampere-Jyväskylä line. On the basis of surveillance flights made in 1938, the brothers suggested almost 30 potential locations for the airport and repair shop. Hallinkangas in Kuorevesi turned out to be the best.

Halli’s flat forested terrain was an optimal landing and takeoff platform for aircraft, and the nearby Lake Kolhinselkä provided an easy landing spot for seaplanes, which were still very important for the Air Force at that time.

Jussi Karhumäki
Jussi Karhumäki in the former office building (now the Wanha Konttori museum).

In June 1939, the Karhumäki brothers signed an agreement with the Ministry of Defence to build an aircraft factory in Halli. The partnership that had been established in 1933 (Avoin yhtiö Veljekset Karhumäki) was converted into a limited liability company, Veljekset Karhumäki Oy. Halli’s gravel airstrip, along with the Karhumäki brothers’ redbrick aircraft hangar and office building (now the Wanha Konttori museum), were quickly completed. Construction work began in 1939 and was finished by the following spring.

The first Viima aircraft that arrived for repairs landed on the newly built runway on 5 July 1940. Later that year, the State Aircraft Factory (the predecessor to both Valmet and Patria) was completed in Halli, along with some of the operations of the Tampere aviation depot. The construction of Fokker fighters was then transferred from Vilppula to Halli.

A pioneer village

The Kuorevesi area (now part of the City of Jämsä) underwent a huge change in 1939–40. This forested and sparsely populated rural area grew from 2,500 to 5,000 inhabitants within a year. A huge construction project was carried out in Halli over the space of that year: forest was felled, roads were built, sewers and waterpipes were laid, an electrical grid was established, and the first buildings were constructed.

In addition to their aircraft repair operations, the Karhumäki brothers also played an important role in supplying Kuorevesi with water and electricity. The brothers established Kuoreveden Sähkö Oy, which built overhead power lines from Mänttä to Kuorevesi, a distance of some 20 kilometres. Kuoreveden Sähkö began to maintain the municipality’s electrical grid and manage electricity transmission. During the first few decades, the brothers were also responsible for the area’s water supply. Water was initially directed from a pumping station on top of the hill to a pressure station on the second floor of the office building (Wanha Konttori), from where it was distributed throughout the area.

At first, the aircraft factory construction workers lived in farmhouses and granaries. They later moved into the housing that was completed for the aircraft factory’s future staff in autumn 1939. Meals were eaten in field kitchens. Before the village shop, Hokka and restaurant building were finished in 1940, the shop operated out of a huge wooden box next to the Hietala farmhouse. This box had been used to transport a Cessna C-37 aircraft that had been purchased from the USA. 

Building the area really was good old-fashioned pioneer work that required plenty of man- and horsepower – and cars powered by wood gas generators. Construction work was hindered by both the war and an extremely cold winter, as men, trucks and vans were also needed at the front. They were tough times in many ways and, for example, the man who had plastered Valto Karhumäki’s house died in a wartime submarine accident. However, there were enough people available to build Halli, which had become central to Finland’s security, and a great many of them came from Veteli in Central Ostrobothnia. At that time, it was playfully said that, for Veteli pioneers, Halli was the America of Finland.