Abstract: A blow out preventer includes a main body with a main passage arranged therethrough, a ram movable between a first ram position in which the ram is spaced from the main passage and a second ram position in which the ram at least partly interrupts the main passage, and a bonnet releasably secured to the main body. The bonnet includes a hydraulic ram actuator coupled to the ram. The hydraulic ram actuator includes a primary piston arranged within a primary cylinder and fixed to a piston rod, and a secondary piston arranged within a secondary cylinder to be slidable on the piston rod. The primary piston and the secondary piston are each arranged to actuate the ram via the piston rod. The primary piston and the secondary piston each comprise a stroke length, the stroke length of the secondary piston being shorter than the stroke length of the primary piston.

Abstract: A rod locking apparatus includes a housing which includes a first tubular passage and a second tubular passage which are arranged to intersect with each other, the first tubular passage including a serrated locking surface, and a wedge piston slidably arranged in the first tubular passage. The wedge piston includes a front side which includes a wedge surface which engages an end surface of a rod to be locked, and a serrated rear side which engages with the serrated locking surface.