Tiller pilot

[lustyd]

no information has surfaced regarding vessel tonnage

Tiller pilots and vessel tonnage are not related. There are light boats with poor rudder design and there are heavy boats with good rudder design. It’s the rudder you’re pushing against.

 

[Tranona]

Having read through these numerous and informative posts, no information has surfaced regarding vessel tonnage.
My 35ft tiller-steered timber gaffer displaces approx 14 tonnes. Even temporarily securing the tiller with lines enabling me (when flying solo) to venture out of the cockpit if but only for a few minutes is inviting trouble.
Does anyone have any info regarding a tiller-pilot heavy duty enough to allow me some respite?

The simple answer is no. Vessel displacement is often used a a proxy for the size of boat for which an autopilot might be suitable. In general modern tiller steered boats tend to be well under 5 tonnes displacement and the most powerful unit that is readily available is suggested for up to 4.5 tons, although the US made Pelagic claims higher, maybe up to 6 tonnes. as others have pointed out it is only a guide as it is primarily the loads that are an issue rather than the weight of the boat and the style and design of the boat is also important plus how well the boat can be balanced under sail.

A boat such as you describe generates high loads on the tiller which as you know can be a challenge for a human pilot so not surprising a small electric motor is also challenged. All is not lost though as it is possible to use the power of a wind vane steering gear to enhance a tiller pilot and there are several examples of how this has been done. However if the boat is under sail the windvane will do a better job than any tiller pilot. where such an arrangement does work well is under motor where the tiller pilot will steer to a good compass course.

I am afraid if you want a boat off that size to steer itself using an autopilot you need a different design of boat, almost certainly with wheel steering as there are autopilots powerful enough to handle such boats.

 

[bluerm166]

Suggest the OP fits a simple rain cover to whichever model he buys if he wants to use it on a boat.

 

[Plum]

Having read through these numerous and informative posts, no information has surfaced regarding vessel tonnage.
My 35ft tiller-steered timber gaffer displaces approx 14 tonnes. Even temporarily securing the tiller with lines enabling me (when flying solo) to venture out of the cockpit if but only for a few minutes is inviting trouble.
Does anyone have any info regarding a tiller-pilot heavy duty enough to allow me some respite?

Assuming your gaffer has a long keel I am surprised you can only set up the rig and tiller to give only a few minutes away from the helm. If the helm is balanced then I ydon't see why a "5 tonne" tillerpilot would not work (other than down wind). If you need more time, as Sandy said, heave-to.