Lisbon's Vasco da Gama Bridge is the longest in Europe, spanning a total distance of 10.7 miles. Taking three years to complete, the bridge opened for traffic in 1998 to celebrate the 500th anniversary of Vasco da Dama's discovery of the maritime route from Europe to India.
The arc temperature may be upto 20,000 K. Although TIG welding produces the highest quality welds, it is a slow and expensive process. Metal inert gas welding process (MIG) is economical with consumable electrode fed at a predetermined rate. Plasma arc welding (PAW) has made substantial progress in utilising the high heat energy of an ionised gas stream.
Gas Metal Arc Welding. The process of Gas Metal Arc Welding (GMAW), created in the 1940âs, is another automatic welding process. This method consists of the use of a welding gun which automatically feeds the weld metal through the gun for use. The weld gun also automatically distributes a protective gas as a shield from the natural elements. This process saves a lot of time and is best for a large quantity of welding work.