Peak Halyard take up tackle

[Richvee]

I'm in the process of rigging the main gaff on the Kate Cory. I have a question regarding the peak halyard, in particular, the take up tackle. The Peak Halyard is rove through the two single blocks on the gaff, through the triple block on the mast as shown.

 

The hauling end simple belays to the pin rail, starboard side.  The take up fall runs through single block at the rail, and through the double upper block and belays in the rail, port side.

So, I'm having a little difficulty working the mechanics of this through rig in my head.  Do you "pull" the hauling end down to raise the gaff?? And in turn, does raising the gaff bring the take up tackle blocks closer together, or farther apart? 

 

Another way to ask what I'm looking to find out....If I rig the gaff in the raised position, should there be a big distance between the take up tackle blocks as shown in the plans, or should the upper block be down closer to the pin rial block? 

[popeye2sea]

My guess is that it is rigged this way because the treble block at the mast head is fixed.  As the gaff is lowered to the boom the peak halyard will have to extend, be payed out, along with it. At some point the upper block of the tackle on the port side will jamb up against the treble block.  At this point the hauling end can be payed out to give more length to the peak halyard.

 

The reverse should be true for raising the gaff.  Haul away on the hauling end at the same time as the throat halyard while tending the tackle on the port side so that it does not jamb.  When the gaff nears the top the upper tackle block on the port side should be nearer the top, which would give you the needed room to haul the gaff the remaining distance and top up the gaff as necessary to fully extend the sail.  The tackle blocks would be getting closer together during this final haul.  

 

Again this is all a guess on my part, but that is what I would do if saw something like that.

 

Of course, all of those complications could be avoided by simply rigging the peak halyard so that the standing end starts from a becket on the treble block (actually, I think you would only need a double block).  Then the hauling end would be coming down singly on one side only.

 

My two cents.

Regards,

[Richvee]

Thanks. That makes sense. After rigging the contraption, and playing with the lines a bit, the two ends seem to work in conjunction with each other. Pull down the hauling end, Starboard side, and the take up tackle, port side simultaneously,  (along with the throat halyard) and the gaff would raise, decreasing the distance between the tackle blocks as the gaff rises. 

 

That said, since I'm rigging the gaff in the raised position without a sail ...and that's not very realistic to begin with, why fret over the distance between the tackle blocks? So I took a little artistic licence and kept a rather large of space between the blocks. I think it looks a little more dramatic.  

 

[michaelmys]

The only experience I have of this rig was on a Brixham sailing trawler from the 19th century, which had been restored, and was sailworthy. At the start of raising the gaff, the take up tackle is in the extended, position and made fast, until the gaff is nearly completely hoisted. The peak is hoisted largely by the hauling end of the halyard, as high as it will go (At the same time as raising the throat, with the throat halyard). As the gaff nears the top, though , the mechanical advantage of the upper blocks is poor, and it's difficult to get the peak of the gaff to its optimum height. Once you've gone as far as you can go with the hauling halyard, it's made fast. The the take up tackle is used. this brings an extra  purchase into play, increasing the raising power of the halyard by a factor of four in the case of your model. This gives significant extra power to get the top of the gaff in its optimum position. It's a manouevre known as "peaking up the gaff". The upper block is set quite high at the start of the hoist , because of the high mechanical advantage. You need to pull a lot of rope to move the gaff a little bit. On the boat I sailed on, once the gaff had been peaked up, the uppr block was between half and two thirds of the way down, depending on how hard the crew had worked with the hauling end of the halyard.

 

Cheers!

Michael

[Richvee]

Thanks Michael for the great explanation. It's fun for me to learn the workings of this ship as I build it.

 

So, by dumb luck, and just liking the position I achieved for the upper block , I ended up with the block just about halfway up. Fairly close to accurate.  Sometimes even a blind squirrel finds a nut. 😎