Abstract: A tube wall for a metallurgical furnace is mainly formed by an array of generally parallel tubes centered on respective tube axes and each having two widened open tube ends one of which projects laterally from the respective tube in one radial direction and the other of which projects laterally from the respective tube in the opposite radial direction. Each tube end laterally engages the tube end of an adjacent tube and the tubes are laterally spaced between their ends. Respective caps each cover two adjacent tube ends and interconnect same so that the interiors of the tubes and caps form a sinuous passage. Finally, respective welds secure the tube ends and caps together hermetically to seal off the passage. Thus appropriate means can circulate a coolant through the array. Such construction is sufficiently rigid to do away with webs laterally interconnecting the tube sections, thereby eliminating the cost of their manufacture and installation.