The story of Finnish tanks during the Second World War isn't exactly a happy one. From a manpower point of view they did extremely well, with tank crews showing high levels of skill and courage. On the equipment side of things however the situation was dire. Finland had ordered 32 Vickers 6 ton MK.E's before the war, but to save money they'd been ordered without lots of fittings or equipment. They lacked any guns or sights, any radios, even the drivers seats were missing. By the time the Winter War broke out 26 tanks had been delivered. During the summer of 1939 the tanks were briefly armed with the 37mm guns loaned from Finland's FT-17's, so the Vickers tanks could be used in war games.
After this time the FT-17's got their guns back and a program to arm the Vickers started. The tanks were fitted with a 37mm Bofors gun and water-cooled Maxim, both with improvised sights which reduced their accuracy. The driver curiously had a 9mm Suomi SMG fitted that he could use in place of a hull machine gun. This rearmament program continued during the Winter War. By late February 1940 thirteen tanks had been armed, and it was decided to send them into action. What followed was the one Finish tank attack of the Winter War.
Next to Lake Naykkijarvi (my spell checker just gave up and cried when I entered that name) lies the town of Honkaniemi. The attacking Soviets had pushed through the town, using the lake to screen their right flank. So it was decided that the 13 armed tanks which formed the 4th Tank Company would be launched into the salient and cut off the exposed Russians. Finnish Jaeger infantry was trucked to a site three km short of the assembly point at Jukkala. The infantry then skied the remaining distance arriving at 0400. The tanks were transferred by train to the front then unloaded and road marched 50 km to a staging area, arriving at 0430. However during that road march the Fins suffered their first losses. Five of the tanks had their fuel contaminated by water and broke down on the way. At the staging area a further two were put out of action with mechanical troubles. This left just six tanks for the attack.

The attack with several companies of infantry and two battalions of artillery in support was to cross a band of swampy terrain and slam into the Soviet front-line, tearing the top off the salient. Then the Finish infantry battalion at the head of the salient would pass through the counter attacking force and stop the penetration of Russian forces attempting to recapture the town. Don't be fooled by the description of "town", despite being the second largest settlement in the area it was mostly a combination of wooded areas and open cultivated fields with houses dotted about.
The attack was scheduled for 0500 February 26th 1940, however communication issues with the supporting units meant the attack was postponed for an hour and fifteen minutes. Then when the artillery bombardment did begin some of the rounds landed short causing causalities in the Finnish force. Despite this the first ever Finnish armoured attack crossed its start line.
It failed to get off to a very auspicious start when tank 644 drove into a ditch and damaged the turret. Unable to fight the tank had to return to base.
Note the T-28 in the background. Likely a Vehicle Collection Point after the battle on the Soviet side.
Of the five remaining tanks all were destroyed, several whilst trying to inspire the infantry to follow them into close assaults. Three were destroyed in the lightly wooded areas. One, commanded by the platoon leader managed to reach a point where he could see the frozen lake on the other side of field. However his tank was hit and the crew forced to bail out. In return the Soviets lost at least three tanks, although the Soviet High Command claimed to have destroyed six enemy tanks for no loss.

Image credits: