Hole straightness
Anchoring of immersed tunnels involves drilling long holes with strict accuracy requirements. The water-powered DTH hammer from Wassara has a proven track record of its ability to drill long straight holes.
High drilling performance
A Wassara water-powered DTH hammer will maintain a high rate of penetration in most kind of formations. The Wassara hammer performance is unaffected by water in the formation, even at high back pressure.
High quality borehole surface
Water-powered DTH drilling gives an optimal borehole surface for the anchoring process. The borehole surface needs to be clean and have enough roughness to ensure successful grouting of the anchor.