Ned...essentially a design name/theme taken up by two Companies
A VPP is a controllable pitch propeller - same concept, fundamentals - same principals - slightly different control systems
Some 45 years ago, I was involved in the Lloyds Survey on the Dutch Lipps brand manufacturedVPP's on Australian flagged Ro-Ro's
Extremely reliable......hydraulic fluid cleanliness was nearest to the Almighty......very reliable
I understand Lipps were bought out and into Wartsila Group in the late 60's?
Lipps and Kamewa were rival manufacturers of complete VPP packages
Derek