rotating mast, spanner length

[simonfraser.97]

10 mast, 35m big roach main.
going to control the rotation with spanner, rope led to 10:1 winch.
spanner 3x depth of the mast ??
tnx for your input

[Munter]

The length of spanner required also depends on the rotation point of the mast and whether a vang or a traveller is being used to control the main.

I found that moving the rotation point of the mast to the rear of the mast made rotation significantly easier as the boom wasn't being forced rearward each time the mast rotated.
If you are using a vang (cats or wide monos may not) then this calls for a longer lever than without as the vang pushes the mast out to full rotation.

Although at a completely different scale to yours I used a lever that was 35-40cm long on a mast with 10cm chord length on a rig that used lots of vang for roach control. I hope this helps some.

[simonfraser.97]

tnx munter, nice boat too !