Block and tackle

[Phil Patrick]

Does anyone here about have any good photos or info on the construction of wooden block and tackle? (aka snatch blocks to some). I have an opening to make quite a few but I am still sorting out a few details.
Goals:
Wooden body.
Wooden sheeves
Steel hooks and appropriate tackle.

Any help will be appreciated!!!

[Glenn]

The construction would depend on the load being lifted, materials available, size of the blocks, numbers of ropes, cables, etc and many other things. One multiple block can be used or several single blocks can be ganged together to do the same job.

Ships rigging uses blocks with a much different design from the land based blocks I am more familiar with using. I would suggest you refine your search to the type and style of block used for your application. Look at what is available now and build to match.

Please consider the responsibility for making such a device. If human life is involved, have this designed approved by those that KNOW the limitations of the materials, the design, and the application. Engineering specs are minimum specifications of the materials, applications, and design, so you may want to improve on all areas to get above minimums.

I have seen hooks straightened out, blocks fail, and connections fail. There can be large loads involved very quickly. Then there is the shock loading to consider which can be well in excess of anything you ever dreamed about.

[Phil Patrick]

Glenn,
Trust me, I have no intention whatsoever of moving forward without sorting out all the fine details. I rigged and moved machinery for the last 15 years and saw too much shoddy equipment and gear to satisfy me.
This project is not for faint of heart. I just need a few more details to finalize my plans. Also, these are not going to be sold to an unwary public. My father and I are building him a horse barn, timber framed. I need some specific rigging to effect some of lifts when we raise it.
This will be the second full barn we have done and are refining some of our techniques.

[JamesBBrauer]

I thumbed through a couple of google books, and this one looks like it might have some specific info:

Machine design: hoists, derricks, cranes - Google Book Search

And I always thought a snatch block had independent side pieces along the pulley so it could be placed along the line, without having to feed the end through the pulley. But I guess there are different terms for things in different places. I set up some rigging last week with a couple of these to get some logs off the mountain and into the trailer to take to the sawmill.

[markb]

I googled , blockand tackle images


Thats not what you asked for, i know, I have a wooden block, I'll take a pic, I think it has metal wheels, I have a metal body wooden wheel also. I'll post this evening.

[arftist]

My father use to repair wood blocks when I was a child. If I remember correctly, they had wood bodys but metal shieves or pulleys. I remember him taking them apart and putting them back together, but not the actual repair. He probably just replaced the bearings and shafts. If you can wait a few days, I may be able to find one and take it apart and post some pictures.

[Mike Ameling]

A couple books that could help:

The Ashley Book of Knots
The Arts of th eSailor by Hervey Smith
Moving Heavy Things by Jan Adkins

Plus a good timber framing or log home building book should have some pretty good info in them.

Mikey

[Phil Patrick]

Thanks alot everybody!

[kasper]

just a note of safety,if it were me i would go to a wire rope store and purchase the blocks and riggin with the proper safe working load for the task in hand,blocks don,t break they explod,heavy things drop,bights of line whip not pretty,anyway be safe and the best of luck.