Since similar anchor had not been developed prior to the project, smallest feasible dimensions in terms of hole-sizes according to calculations were carried out and then altered after short tests. The holes were in ten rows of three at 120° degree angle apart so that the first row had holes at 0°, 120° and 240°, while second row had holes at 60°, 180° and 300°. They were first 2 mm diameter since this resulted in acceptable flow rate according to calculations in Appendix I, but these were quickly changed to 2.6 mm diameter to experimentally see if it increased the grip further. The process of creating the holes is shown from Figure 17 to Figure 22.
