ships wheel to a wooden bolt

Hi
I have been asked to make a gate with a ships wheel that you would use to turn to move the bolt in and out to open it
has anyone ever done this and how would i work out the ratio of cogs to the long wooden bolt
any help greatly received
cy

Without getting into the complexity of pitch diameters of gears, here's an approximation that will get you in the ball park.

Assume

L = distance bolt must retract to allow gate to be opened
N = desired number of revolutions of wheel needed to retract bolt

Then the circumference of the gear attached to the wheel, C, must be approximately

C = L / N

and the diameter of the gear, D, must be

D = C/pi

Rack and pinion assemblies are commercially available but they are likely to be expensive. Think about making your own.