Before the introduction of high strength steels manufactured using Thermo-Mechanical processes, welded joints such as those found in Jacket node assemblies over 50mm thick required to be heat treated after welding. This “Post Weld Heat Treatment” was required to release any stresses in the steel affected by the heat induced during welding.
The Stress Furnace or Oven was housed within a 20 m long x 10 m wide x 10 m high building with an elevating door arrangement enabling entry and exit for the transport trolley which supported items to be treated. The Furnace could handle loads up to 250 Tonnes for post weld heat treatment of fabricated components up to 650°C. Individual large nodes or several smaller nodes are loaded on to one of the two bogies and pulled through into the oven.
During the early 1990’s the introduction of thicker steels which were not subject to the effects of stress induced by welding resulted in the Stress Furnace becoming used on fewer occasions.