The Fram was built with the following specifications: length 39 m, beam 11m, draught 5.5m and displacement 800 tons loaded. Both the bow and thecstern were particularly strengthened, with a 1.25m thickness of oak in the bow. The sides were 70-80 cm thick and had three layers: the two inner ones of oak and the outer one of greenheart. There was only 30-40 cm between the ribs of naturally-grown knee-shaped oak bolted together in pairs. There were 400 such knees in the construction. The spaces between were filled with a mixture of pitch, tar and sawdust. The interior was in all ways supported with beams in oak and pitchpine joined with iron. The Fram was designed as a 3-masted schooner with a 34m high main mast of pitchpine. A triple expansion steam engine of 220 hp gave a speed of 6-7 nm/hour in calm seas.
The Construction of the Fram
Fridtjof Nansen’s plan deliberately to let a ship freeze into the dreaded ice in the Arctic Ocean was revolutionary. The idea was thought to be suicidal as no ship could withstand the ice pressure.The Fram proved this wrong, but then the construction was exceptional. The main innovation was the rounded hull with smooth sides so tie ice could not get a grip to press the ship down, but on the contrary would press it upwards like a round nut squeezed between two fingers.The wooden materials were stronger, thicker and more closely spaced than on any ship before.The rudder and propeller could be hoisted up inside a well in the stern to protect them from ice damage, and the ship was short, for manoeuvrability in the ice as well as for extra strength.
Source: Onsite informationboard