How to build a jinker for a monohull?

[Steve Bean]

I'm with UNCIVILIZED here. Go primitive!! More details about the geography would help tune up the strategy. Exactly how far do you need to transport the boat from the waterfront? Do you have access to trees that you could cut ? They might be easier to get / cheaper than telephone poles or pilings. Are you any good with an axe or chainsaw? Are bananas available cheap in case you want to use greased boards?
"Engineer approved" may be an obstacle for some of these ideas...

[UNCIVILIZED]

In terms of towing or pulling power, a long length of line & several stout, low friction blocks go a long way towards helping. For example if your windlass can muster 1,000lb of pull, & you can rig up a 4:1 block & tackle... Let alone if you use a 4x4 instead of the windlass with the same amount of purchase.

Or if you can find it, a tow truck with a winch, or some heavy duty construction machinery. Particularly something which has hydraulically powered features. And even the average bumper winch on a 4x4 has a huge amount of pulling power (several tons).

One other option, if you have blocks that are strong enough, & a long line, is to anchor the block to something heavy & fixed onshore. And have a commercial boat with lots of torque in the harbor hook onto one end of the line, with the other end on your vessel. I can't imagine that not giving you enough power to haul her out.

And many of the above tools for motive power can be used in conjunction with one another. Just remember to keep people out of the danger sectors should a towing line part & snap back. As well as to use energy dampeners on the towing lines to mitigate this should it happen.


PS: You can make a cheap, industrial power winch by bolting an empty tire rim onto a truck that has a solid rear axle or locking differential, & anchoring the vehicle to something heavy on land. Thus the only limiting factors are the strength of the rope used, ditto the vehicle's chassis, & the stall limit of the engine. And needs be, you can use something of a smaller diameter attached to the rim to increase the power ratio of things.

[Fore and Aft]

Can you get a whole truck chassis? We got an old truck chassis and welded a frame on top of it so we could launch a 40 foot power cat into the river. We just had to cross a farm paddock to get to the boat ramp. The cat wobbled around a bit but slow and steady worked fine. I think we kept the steering wheel to help steer the contraption?
Cheers

[HankOnthewater]

Here are some photos of jinkers, all boats at this sailing club are pulled out that way, all jinkers are home made, and I think no engineer came ever close to any of them. Most boats range from 20 to 36 ft.

The first jinker is for a 30 ft wooden boat, the other 2 photos are from a jinker with a 'Custom 30' yacht, with a displacement of approx 4.5 tonnes.
Sorry, the last photo is shown on its side, don't know what happened there.