I found this at the bottom of a chest belonging to an old carpenter and joiner from Raglan.
The tool is 3 ft long and the end is sharp, so presumably it is a morticer of some kind.
But I cannot work out what it was used for and why it has a cranked handle. I could not find it in Salaman but I may be looking under the wrong heading!
It is hard to believe it has taken 5 years for someone (David Kilgour of New Zealand) to identify this as a Slater's ripper!!