Our Second BIG Timber Frame Bent Raising (With Video)

by ziggy on September 8, 2011 -- 0 comments -- Follow

bigbent-standing01

The mighty central bent in the Wabi-sabi kitchen

A bit over a week ago, we raised our mighty giant of a bent for the kitchen. It’s the bent we’ve been working on for weeks and weeks – an assembly of three posts, and a beam with a scarf joint. The beam in question is a gigantic, curving sycamore joined to a cannon of an oak, supported on the south side by a stout poplar, in the middle an oak with a coped shoulder and through tenon (that runs through the scarf), and on the south another oak post. Put together, we guessed that the bent weighed in around 1800 pounds. No joke!

bigbent-raising-layout

Getting a tight fit between post and beam

Assembling the Post and Beams

As with our first bent, the first project was moving the individual pieces over to the foundation, leveling them, and joining them together as tightly as possible. We set up bunks (wood supports to get the timbers off the ground) and set about joining them and leveling all of the posts and beams. This was actually the first time we had fully assembled everything. In the above photo, you can see the ratcheting strap we used to get the middle post joined to the beam as snug as we could.

bigbent-raising-layout1

The bent gets bracing

Once we were happy with the bent being level, square, and tight, we then braced the whole assembly extremely thoroughly. We didn’t want any movement as the bent would soon be raised off the ground. Perhaps most important was making a so-called strongback for the scarf joint — basically attaching a stout 2×6 across the scarf and beyond on either side on the back. This would prevent any forces from splitting the scarf and ruining hours of layout and joinery work.

bigbent-ginpole

Gin pole with triple wheel pulley

Preparing to Raise the Bent By Hand

Next came the rigging. With two pulleys we rigged up a fancy block and tackle system to decrease the load we’d we lifting by at least a factor of five or six. (This part of the process I’m still a bit iffy on – I don’t have my head around all of the engineering.)

At the heart of the rigging was a stout gin pole, buried two feet deep, guyed out on three sides to keep the pole straight and stable. At the top we placed a triple wheel pulley. The rope (1/2 in. braided nylon, 100 foot length) ran through this pulley to a double wheel pulley on a sling attached to the beam. Look below to see what I mean.

bigbent-sling

Sling with double wheel pulley

The rope then ran through a redirect pulley at the bottom of the gin pole, so that we could pull the rope straight, instead of at an angle from the top of the gin pole. Nifty! It took a couple of tries to run the rope right so that the pulley at the top of the gin pole would stay vertical and not twist, causing the rope to rub.

bigbent-riggingready00

The bent raised up several degrees & checking the rigging

After all that rigging business was said and done, we took the opportunity to (very laboriously) lift the bent by hand onto increasingly higher sets of bunks, to increase the angle of the assembly, and to get the post ends in line with the holes, and actually resting on the surface of the sill. Since our foundation is not level, the post heights are different, and they did not all want to rest at the same level super easily, but we got several degrees off the ground and called it good. Major workout!

bigbent-buttalignment

Post ends in alignment with holes

Raising the Bent to Vertical by Hand!

Now for the real fun — the actual raising! It ended up taking a good 10 people on the rope, pulling with all of their might, to get the bent up, and up. We put a few folks on the back end with pike poles (long 2x4s in this case) to help push the bent upward, too. Actually, the raising went quite quickly, and as we approached 90 degrees, we stopped the action to check the alignment of the pegs with the holes in the sills.

Not surprisingly, we had to coax the pegs into the holes with a big ol’ commander mallet. (A.K.A. persuader, Ringo, bigass hammer, backbreaker, etc.) With a few strikes, we got all three posts to seat in the holes, and we continued with the pulling of the rope.

Next came something a bit frightening — the bent moved so easily at this point that we nearly went overboard! Thank goodness for the emergency tie-off on the opposite end, keeping the bent from completely tipping forward, destroying everything in its path. I’ll admit, I was damn scared that that would happen…

Once we wiped the sweat off our brows, we got out the drill and quickly braced the beast, and viola! Our bent was fully upright.

The rest of the afternoon, we cleaned up and stared up at what we had done… what a delight to see our work standing tall in the waning afternoon sun.

bigbent-standing02

The end

 

Send Me More Updates Like This!

Previous post:

Next post: