to achieve the aforesaid effect also in accordance with the method of the invention the fallen wire 2a is elevated by means of the clamping device 10 as indicated in dotted lines in fig2 since the fallen wire 2a is rotated over about 90 u00b0 at the height of the thread opening 6 relative to its normal position re threading can be carried out relatively easily either manually or automatically since this threading can occur along a direction 19 fig5 which is parallel to the direction of the warp thread 7 during the upwards movement the wire 2a involved preferably will be rotated back to its normal warp detection position in order to avoid excess friction occurring between the twisted wire 2a and the corresponding electrode 8 and so that the clamping device is not unnecessarily heavily loaded and or damaged before the re threading is carried out however the clamping device 10 is brought back to its rotated position while the fallen drop wire is held at its elevated position e g see fig6 since possibly a threading element i e a thread needle must pass along the support elements 9 as well as through the thread opening 6 during the re threading the fallen wire 2a involved must be put in its highest position i e higher than during the normal suspension to the warp thread 7 this is indicated.