are dependent upon the operation of palletizing machine 1 so as to displace interlacing gantry 11 automatically and alternately from one side to the other of transport pallet 7 as the rows of tubes 2 are deposited on this transport pallet 7 and according to a predetermined interlacing pattern one example of which is shown in fig5 how this interlacing pattern is accomplished is explained with reference to fig4 a and 4b in these drawings interlacing gantry 11 is shown in its two end positions its departure position is shown by a dotted line and its arrival position by a solid line in addition in these drawings girder 5 for gripping tubes 2 is shown in two positions an upper position by a solid line and a lower position by a dotted line said gripping girder 5 comprises three air vent systems 5 u2032 allowing it to carry a maximum of three tubes 2 at the beginning of a palletizing cycle interlacing gantry 11 is displaced from the left to the right of transport pallet 7 cf fig4 b to place interlacing ties 12 u2032 on pallet 7 letting the ends overhang so knots can be tied at the end of the palletizing process a first row of eight tubes 2 is deposited on pallet 7 while placing interlacing tie 12 u2032 on transport pallet 7 this first row may be formed by a first and a second series s 1 s 2 of three tubes 2 and then a third series s 3 of two tubes 2 deposited side by side interlacing gantry 11 is displaced from the right to the left of transport pallet 7 cf fig4 a before a fourth and a fifth series s 4 s 5 of.