Sailing to Windward: Tacking a Ship Against the Wind
Diagrams of the sail, yard and rudder, with instructions for coming about (folio 124r)
Folio 124r treats the working of a sailing ship's rig and how to come about against the wind. Small overhead diagrams show the sail with its yard (antenna), mast and the sliding fitting Leonardo calls the carro, labelled with letters a, b, o and named parts (poppa/prua, stern/bow). The long note on the left explains, step by step, how to reverse course under the same wind by shifting the rudder from a to b and moving the sail's carro from stern to bow. A brief heading names close-hauled sailing ('di burina overo orza').
On this page
The rig: yard, mast, rudder and the sliding carro
Leonardo fixes the geometry of the rig: the tip of the yard (antenna) always stays toward the stern and the carro toward the bow. The overhead figures are lettered a, b, o and marked poppa (stern) and prua (bow). To change tack the carro is run up over the bow and drawn back to the stern over ropes made fast from the foot of the mast.
Coming about under the same wind
With the north-east wind (greco) Leonardo has run toward the south-west (libeccio); to return on the same wind he first turns the rudder from a to b, then, bow to the south-west, changes the sail and swings the bow to the north-west (maestro), setting the rudder in line with the keel to hold the new course. The maneuver couples rudder action, sail change and wind direction.
Sailing close-hauled
A short label names the point of sail: 'andare di burina overo orza', to sail by the bowline, that is, luffing or close-hauled against the wind.