Snorkel mast for a semi-submersible vehicle

Abstract

There is described a snorkel mast for a submersible vehicle. The mast terminates at the upper end in an inverted U-shaped snorkel head pipe section closed by a butterfly valve. The butterfly valve is operated by a bell-crank lever having a float at one end and a water impact flap at the other. Operation of the bell-crank lever by water level action against the float or by water impact action on the flap if a wave washes over the top of the snorkel mast acts to close the butterfly valve. The mast carries a fairing which comprises a number of fairing elements of airfoil cross-section, vertically spaced on the mast so as to be freely rotatable thereon in water lubricated bearings. The segmented fairings on the snorkel mast maintains hydrodynamic stability during high speed turns.

Dependencies are inferred from the claim text.