Using a sheave on a double block as a becket???

[Captain Al]

Has anyone ever heard of or seen a rigging where one of the sheaves of a double block is used as a becket?  On my photos in my Bounty kit, it shows the tackle belayed to a sheave on a double block, then running up to a double block, back down to the remaining sheave on the double deck block, up to the second sheave above, and then finally down to be belayed to an eyebolt on the deck.  I have never seen such a thing and wonder why a single block with becket is not being used on the deck.  Can anyone shed light?  I haven't installed these deck blocks and think I should simply use the single below and the double above. 

[Tallshiptragic]

The standing part of the line should attach to the rope strop around the block - or a 'becket with thimble' if you're looking at modern blocks.

 

Also the only part of a 'tackle' that's made fast to an eyelet on deck would be the standing part of the tackle line. The running part (what you pull on) would usually be belayed to a cleat or pin.

Edited April 13, 2015 by Tallshiptragic

[JerryTodd]

I have seen a stopper knot at the sheave, and the line rove through the 2 doubles then to a belaying pin.  In this case the original becket block failed (the phenolic sheave split) and they only had a double block handy.  (this was on a real vessel, not a model).

 

To me, a line made off to a eye-bolt implies that the belay at the other end is the working end and that second sheave is used but the line is made-off at the block.

[Jim Lad]

I've seen a photo of just that being done on a pearling lugger, but I can't find the photo at the moment.

 

It looks a very unseamanlike way of doing things.

 

John

[popeye2sea]

Seems like it would throw the block out of alignment with the line and make the block jam easier.

[JerseyCity Frankie]

Sounds like you are describing a Two Fold Purchase that has been configured as a Luff Tackle, but why use the wrong block?  I can't think of a reason to use a double block as a single unless as a stop gap with no single blocks aboard ( as mentioned above) But its hard to imagine a vessel like Bounty short of single blocks. In the diagram you have, is the line made off on the lower block sheave with a loop knot, or a splice? If its a splice I would have to throw my hands in the air and say its crazy, since this would imply its intended to stay this way whereas a knot could be cast off easily. But the use of a knot still leaves the question of why a double.

[Captain Al]

Thank you all for your replies.  You've all shed a lot of light on the subject and brought me to the conclusion that either I am seeing the photo incorrectly (things do get vague when there's 5 parts of line and you can't make out where they each start and stop) or its another case of A.L.'s poor examples.  In many cases, this being one of them, I would rather have them not show an example than show one so poorly defined or plainly wrong.