Welding System which enhances the productivity several times for welding of oil storage tanks, liners for reactor building of nuclear power stations. Submerged Arc welding (SAW) or Gas Metal Arc welding (GMAW) processes are used. The operator sits comfortably in the cage and supervises the weld quality in situ. Flux, flux recovery system, wire spool etc. are kept in the moving cage. Welding power source is kept on the ground. Welding power is supplied through welding cable to the welding head. The cage moves on the top edge of the circular plate with the help of special designed roller.