The Vesikko was built in Finland, commissioned by a Dutch company that was actually a front for the German government after the end of WWI when the country was barred from building submarines. In 1936, she started sailing for the Finnish Navy.
This is one of the smallest subs I've toured. The interior diameter of the pressure hull is 13 feet, or 4 meters. When you're standing on the deck it's easy to reach out and touch the ceiling and walls.
Apparently, the engines needed constant lubrication while running. The engineers had to brace themselves with one hand so they wouldn't slip on the floor while oiling the engine. During operation this compartment would have been deafeningly loud and swelteringly hot.
Running on the surface, the Vesikko had a range of about 1,550 miles (2,500 km), though that would depend how often she needed to submerge. Range underwater on a full charge of her batteries was around 46 miles (74 km) at 4.6 mph (7.4 km/h).
The Lembit, in her long life, lost her torpedo tube covers. One was found before the most recent restoration. The others were reconstructed using plans discovered at the Vickers and Armstrongs shipyard in the UK.
Originally the Lembit had two 600 hp diesels for surface running and recharging the batteries. One is now missing. Two 395 hp electric motors that provided propulsion underwater are at the other end of this compartment.