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.
SMAW, or stick welding, is the most common form of arc welding. In the process, a stick or electrode is placed at the end of a holder. Using electricity from the power source, an arc is struck between the tip of the electrode and the metal welding surface. The heat of the arc melts the tip of the electrode creating the filler material that is deposited as the electrode is consumed.