A comparison is made of different submerged arc welding processes, that is ones using singlewire, twin-wire and triple-wire electrodes, applied to welding of two webs consisting of L sections 16x90x4100 mm in size. Experimental welding, measurement of welding parameters, calculation of the melting rate, measurement and calculation of shielding flux consumption, a visual examination of the welds made, an analysis of macro sections, and an economic calculation of the respective total cost of the welding processes using single-wire, twin-wire and triple-wire electrodes were performed in order to make a comparative analysis of the processes concerned. The experimental results obtained showed that high quality welded joints could be produced using two wires or three wires, i.e. the twin- or triple-wire electrode, in a joint contact tube in submerged arc welding. The calculation of the cost-effectiveness of welding, including personnel, materials, overheads and other costs, showed that welding with the twin-wire electrode cuts the costs by 20% and welding with the triple-wire electrode by around 30%. Submerged arc welding with a triple-wire electrode is a new welding process variant suitable for thick and long workpieces and in cases where a larger quantity of the molten filler material is required. Three wires in a joint contact tube can be arranged in a line or in the shape of a triangle optionally with long sides depending on the shape of the joint assembly and the weld shape desired. Although this procedure is highly efficient and shows numerous advantages over welding with a single-wire electrode, it has not been established in practice yet.