Abstract: The pitch setting of a machine controllable pitch propeller is indicated with a high accuracy by comparing the positions of the portions within the vessel hull of a translating member fastened to the pitch change mechanism within the propeller hub and a non-translating member fastened adjacent one end to the hub and extending essentially free of axial load through the propeller shaft into the vessel hull.

Abstract: A controllable pitch marine propeller comprises a hub body carrying a plurality of propeller blades for rotation about pivot axes disposed radially of the hub axis, a force rod extending into the hub body from the propeller shaft, and a cross-head affixed to the force rod and coupled to each propeller blade by a pin and slideway such that the propeller pitch is controlled by fore and aft movements of the force rod. The hub body has a tubular mount spigot that receives the aft end of the shaft with the shaft and mount spigot terminating aftward of the pivot axes of the blades. The cross-head is generally cup-shaped, having a base portion affixed to the force rod aftward of the pivot axes of the blades and a tubular portion extending forewardly from the base portion and surrounding aftward portions of the spigot in telescoping relation. The cross-head in supported in plain bearing relation by the hub body for fore and aft movements.