3 'ropes' hammer welded or rolled into a 'ribband'

Helical welding; the previous barrel production technique folded 'iron plate' or 'cold rolled steel' over a mandrel then welded the two edges longitudinally. 'Engines Of War: or, Historical and Experimental Observations on Ancient And Modern Warlike Machines And Implements, Including the Manufacture of Guns, Gunpowder, and Swords with remarks on Bronze, Iron, Steel, &c.' Henry Wilkinson, 1841 - "The iron called Damascus, from it’s resemblance to the celebrated Oriental barrels and swordblades, is now manufactured in great perfection in this country, as well as in France and Germany, and may be varied in fineness or pattern to almost any extent, according to the various manipulations it may undergo. One method is to unite, by welding 25 bars of iron and mild steel alternately, each about 2 feet long, 2 inches wide, and ¼ of an inch thick; and having drawn the whole mass into a long bar, or rod, 3/8 of an inch square, it is then cut into proper lengths of from five to six feet; one of these pieces being made red hot is held firmly in a vice, or in a square hole, to prevent it from turning, while the other end is twisted by a brace, or by machinery, taking care that the turns are regular, and holding those parts which turn closer than others with a pair of tongs, the rod is by this means shortened to half it’s original length, and made quite round. If only two pieces are employed to form the riband, one is turned to the right, and the other to the left; these being laid parallel to each other are united by welding and then flattened; but if three square rods are used, the centre one is turned in a contrary direction to the outside ones, and this produces the handsomest figure. By these operations the alterations of iron and steel change places at every half revolution of the square rod composed of twenty-five laminae; the external layers winding round the interior ones, thus forming when flattened into a riband, irregular concentric ovals or circles. The fineness of the Damascus depends on the number and thickness of alterations; but when wound into spiral form, and united on its edges by jumping, the edges bend round and the figure is completed."