Method of welding in deep joints

A method of welding for joining two metallic components, the method comprising:

• arranging a first metallic component of the two metallic components and a second metallic component of the two metallic components for a zero gap portion and a non-zero gap portion therebetween;
• joining the two metallic components at the zero gap portion with a root weld;
• joining the two metallic components at the non-zero gap portion with a fill up weld;
• melting the two metallic components in a weld region of the root weld and the fill up weld into a molten state to form a weld pool through an energy input by directing at least one first source of energy on the two metallic components to join the two metallic components;
• and
• focusing at least one second source of energy to heat a heating region, which heating region surrounds the weld pool from all sides, to reduce cooling rate and extend solidification time of the weld pool,
• wherein the at least one second source of energy is adapted to be focused in multiple positions of the heating region via multiple heat sources, the multiple positions including:
• at least one leading pre-heating position in front of the weld pool,
• at least one trailing post-heating position behind the weld pool,
• at least one first side position on the first metallic component, the at least one first side position adjacent the weld pool and between the at least one leading pre-heating position and the at least one trailing post-heating position, and
• at least one second side position on the second metallic component, the at least one second side position adjacent the weld pool and between the at least one leading pre-heating position and the at least one trailing post-heating position.