tabernacle
n. countablen. a special hinged base for a boat's mast. It allows you to lower the mast easily when you need to go under a bridge.
n. a hinged socket or post designed to support a mast on the deck of a vessel. It facilitates the lowering of the mast for maintenance or for passing beneath overhead obstructions.
The sailor lowered the mast using the tabernacle.
Because the river has several low stone bridges, the sailboat is equipped with a tabernacle to lower the mast quickly.
The structural integrity of the tabernacle is paramount, as it must withstand the significant lateral forces exerted on the mast while remaining flexible enough to pivot when the locking pin is removed.
From Middle English tabernacle (14th century), from Old French tabernacle, from Latin tabernāculum (“tent, booth, shed”), the diminutive of taberna (“hut, shed”).
In a nautical context, it refers specifically to the mast-step mechanism rather than a religious structure.