Am in the process of building a small timber frame cabin with half loft. Will be a small building say 16X16ish with a half loft. My question comes into the raising. I will be doing this mostly alone, well with my wife, but she is 5' and 90lbs, so mostly alone. :D I've read about mechanical advantages, tackle blocks, capstans and want to develop a system I can use to raise my bents. I'm leaning more to the type of framing where the bent includes the rafters so no plates need to be lifted, or rafter frames hauled up into place. Can anyone help me with size of rope I should use in my block (thinking a 3 sheave block) and a workable idea of a capstan and Gin pole set up?
The first problem is to specify the shape, the weight and the lift before getting to figuring the gear. To generally inform yourself on rigging, I suggest downloading an US Army field manual on rigging, its free, just google. When it becomes time to raise do yourself a favor and get competent friends to help out, manning the lift, taglines, and receiving is not a one person affair.
You can also use NSTM589 for information on rigging.
Read it here:
http://www.public.navy.mil/comnavsafecen/documents/afloat/surface/dckar/d_ref/589cranes.pdf (http://www.public.navy.mil/comnavsafecen/documents/afloat/surface/dckar/d_ref/589cranes.pdf)
This is a pretty good example showing a raising with limited people using an A-frame, block and tackle, come-along, chain fall, etc...
https://www.youtube.com/watch?v=dDfFjP1No-Q (https://www.youtube.com/watch?v=dDfFjP1No-Q)
And welcome to the Forum!
Aeneas61,
I, too, was faced with a similar question...How does one man in the woods install a 30 foot ridge pole on his cabin, and live?
And, oh, yeah, the one man had never rigged anything in his life.
I settled on two words...FM-125 and McMaster-Carr
I talked with many folks who were self-proclaimed experts, I researched rigging on the internet, and I spent hours scouring our library for information and techniques. I even looked at building a road to my cabin so I could rent a crane and hire out the rigging. In the end, I went back to the basics. The FM-125, ARMY rigging manual (attached to this post) was easy to understand and does a very good job of detailing out loads, beam strength, rigging practices, etc. Then, between McMaster-Carr and keeping my eyes open at antique stores, auctions, and farm sales, I was able to acquire the equipment I needed.
I've found that if you think things through, plan properly, and execute your plan in deliberate manner, one person can accomplish some difficult tasks. Keep in mind, it is going to take longer and, in my case, working alone, I had to plan for things that might go wrong and how to get word to someone if they did. If you happen to have another set of hands available for your project, you can cut your time by about 70% and reduce the risk significantly.
Over the last few years, I tend to rely on two techniques to accomplish most of what I need - Gin Pole and Lifting Shear. They can be set up and operated by one person, and in general, my loads are 500-1000 lbs so the equipment is sized such that you can lug it around.
Rigging equipment.
(https://forestryforum.com/gallery/albums/userpics/17998/DSC00422.JPG)
(https://forestryforum.com/gallery/albums/userpics/17998/DSC02548.JPG)
Installation of the Stump Ranch ridge (30') and center post; installed by one man with a couple of Spruce poles....and a whole lot of thinking and head scratching.
(https://forestryforum.com/gallery/albums/userpics/17998/DSC00419.JPG)
(https://forestryforum.com/gallery/albums/userpics/17998/DSC00417.JPG)
(https://forestryforum.com/gallery/albums/userpics/17998/1998/ff.JPG)
(https://forestryforum.com/gallery/albums/userpics/17998/DSC00360_28229.jpg)
(https://forestryforum.com/gallery/albums/userpics/17998/2073/DSC00354.JPG)
(https://forestryforum.com/gallery/albums/userpics/17998/2073/DSC00365.JPG)
(https://forestryforum.com/gallery/albums/userpics/17998/2073/DSC00399.JPG)
Raising a frame with a lifting shear made from 4 x 4s purchased at Menards; frame was installed by two men.
(https://forestryforum.com/gallery/albums/userpics/17998/ff2.jpg)
A temporary gin pole - designed to be moved and set up by one man. I sketched up this design and had a local welder fabricate the metal parts for me.
(https://forestryforum.com/gallery/albums/userpics/17998/DSC01963.JPG)
(https://forestryforum.com/gallery/albums/userpics/17998/DSC01969.JPG)
Installing logs on the walls with Spruce pole shear - this was a one man operation.
(https://forestryforum.com/gallery/albums/userpics/17998/1998/DSC02470.JPG)
Interesting topic and good to see some options being used out there and I'll throw in mine. I favor tripods for lifting. They are just so stable and can be operated by one person. The chain hoist hook can be used as a plumb bob to position it dead center before lifting simply by shifting the legs a bit. And if a little more height is needed in a pinch then just push the legs in to get it. I use bamboo for scaffolding and lifting equipment because it is common and freely available in my area. Below is a pic to give a flavor of a 9 meter tripod that just set down a plate on a teak frame.
(https://forestryforum.com/gallery/albums/userpics/21063/tripod~0.jpg)
Thanks for the replies everyone! Im feeling more confident now this is doable. If I understand this correctly, a gin pole with two triple sheave blocks gives a 6 to 1 advantage, then a capstan with a 8" axle and 8' arms gives another 12 point advantage, then I need to calculate my advantage minus my friction of 40%? Does that sound about right? I also need some way to calculate bent weight in order to figure one rope size, and tackle block size. Anyone know a good green wood beam calculator or other way to calculate up a bent weight? IM leaning more toward 3/4 manila as my rope, seeing as it will always have 6 strands pulling anything with two triple blocks, even with a working load of only 600ish lbs, that would work out boat least 3500lbs of safe work load, I don't imagine a bent being that heavy for my small cabin....
Use the forum tool box (left column, red box) to calculate weights.
What capstan winch are you looking at?
I took the Raising and Rigging workshop at The Heartwood School in 2010. It is taught be Grigg Mullen from the Virginia Military Institute. It covers all of these options for raising timber frames. It was a very valuable course. Parts of the book that we got were from the Army rigging manual. I think that manual will give you a lot of the information you need to safely raise your frame.
That was a good video Brian. Patrick Moore was in it, and he was one of the students in the Raising and Rigging workshop with me.
Beenthere,
Wow we have a tool box! ;D I feel like I just realized my house has a fridge! 8)
As to the capstan, Im not sure yet, seems a length of oak log hewn to look like a curvy woman for keeping the rope centered, then tenoned to fit in a cross pice of the frame....I think i can figure that out, Ill def put up pics and video of our raising, though I would advise against breath holding as I will need to cut, hew, and joint everything with hand tools, should be a few months, but I will put up progress shots for all to enjoy. Luckily I have more patience (or is it stubbornness) than brains or cash!
I lift the load with a chainfall. To boom the load I've only needed double sheeved blocks. Tripple's get spendy.
A couple more ideas....
Rope Pullers, I love these things.
(https://forestryforum.com/gallery/albums/userpics/17998/1998/%5BDSC00346.jpg)
The beast, made this from an electric winch. Hard to move around, but when you need some power in a hard to get at location, well this is the ticket.
(https://forestryforum.com/gallery/albums/userpics/17998/DSC02467.JPG)
Raising a frame at the Northhouse School with a lifting shear made from Pine.
(https://forestryforum.com/gallery/albums/userpics/17998/DSC02435.JPG)
I've gotten all my blocks on ebay. You can find some really solid used stuff absurdly cheap there. Especially if you don't mind using something like 3/4" to 1" Manila rope. New tackle blocks can get really pricey! Good luck with it!