Sunday, April 5, 2015

Gateway (83)

Post 83 in an ongoing series describing the design and construction of a kabukimon, a type of Japanese gate. This is a project for the Museum of Fine Arts in Boston. Post 1 in this series can be found here if you'd like to start at the beginning. Each post links to the next at the bottom of the page. Recent installments also to be found in the 'Blog archive' index to the right of the page.

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The second of three installments describing the gate's installation at site. Previous post.

April 1st ended with the main frame assembly (main posts, magusa, kabuki, and nose pieces) all set and ready to go with the main doors also mounted. Many blankets covered the pile and our hope was that upon return the following morning we wouldn't find someone sleeping underneath. The rear posts were positioned on their plinths.

April 2nd.

Originally the crane was scheduled for 7:30 am, however there turned out to be a couple of other tasks for which it was needed on the other side of the Museum, so it in fact rolled in at 9:30 am. That was fine, as it gave us a little more time to set up. It was nice to have a certain easing of pressure. We started by removing the main doors and re-stacking them with padding.

One thing to get ready were the stretchers, nuki, connecting the rear posts to the front posts. Matt J helped me out with this work:




I should mention that Matt J, who also helped during the foundation work on this project last year, works for a collective of sorts called Byggmeister, specializing in remodeling and energy efficient retrofits in the greater Boston area. I learn a lot from him about recent advances in technology in that area. I met him a few years back when he attended a workshop I taught in Japanese joinery.

The nuki required a bit of persuasion to slide through the post mortises, nothing too strenuous, and after they were in we could set the rear posts back up again, using a pair of sawhorses and beams as temporary support:


 All ready for the crane now, hardhats and all:


I'm a little nervous at this point, and more than a little fatigued, both mentally and physically. Hard to give a real smile in such a situation.

The crane rolled in and set up:


As mentioned in yesterday's post, I had rigged the frame assembly for the lift in such a way as to minimize any chance that the lifting straps could damage the stainless strips for the kabuki's copper roof cap. The crane operator, Ken, looked at it and said the rigging approach might not result in a plumb hang of the assembly after the lift. We could give it a lift though to see how things looked.

Several people had now rolled into the scene. A security guy or two came in to control pedestrian traffic, and a few photographers also, cameras dangling. The MFA's project coordinator was there. One photographer was from the Boston Herald, one was from the Boston Globe, and another from the MFA. It was exciting to have photographers there, in one sense, terrifying in another.

The Boston Globe photographer, Lane Turner, snapped the following picture upon our initial lift:


Image from: Getty images (link)

So, that wasn't going to fly - the posts were too tilted for installing. So, we set the unit back down again and re-did the slings, configuring them as chokes. We tried a second lift, which then required a slight tweaking of the slings, and then had another go. This time we had it hanging more or less plumb. Nowhere to go but up, up, and away:





That was something to see. My wife took all the video by the way. The professional photographers had to get in there as the gate got close to touchdown, so the last few moments of the lift could not be captured on film.

Funny enough, I wasn't especially nervous about lifting the assembly, which I had worked many months upon, up so high. While I have seen my share of harrowing crane disaster videos on Youtube, the lifting conditions here were entirely safe, the operator was experienced at working for the MFA, and the slings were brand new and several multiples stronger then the load they would bear. Fact is, if the slings failed with the gate a few feet off the ground, the assembly would likely be ruined, and putting it 100 feet or so into the air was not going to change that.

What I was a little nervous about was the mounting and connection onto the foundation and to the stretchers. While I had fit the stretchers individually to both the main posts and rear posts in the shop, I had never set up the entire assembly in my shop (due to a lack of space and lifting equipment) to check that the whole works went together. Remember, complicating things is that the rear posts are spaced further apart than the mains, are parallelogram shaped (as are the upper stretchers), and if there was any mistake in the angling of the mortises, or appreciable differences in heights of the foundation points, etc., there could be issues. That there could be issues, and some of them might be disastrous, was one thing giving me pause. On many jobs, you bring the cut assembly from the shop and install it to field conditions, the fitting often requiring a couple of tries and adjustments. Here, I had been the one to set the granite (last summer), so I had some control over the resulting precision of that install. Still, it is almost to be expected that there be some sort of hitch or glitch.

Adding to my anxiety was that there were a battery of photographers and other people taking video while the assembly was being fitted for the first time. What if it came down into place and something was out of whack, and we had to pull it off again? That might look like the dreaded 'something was wrong'. Partly I was nervous about looking bad in such a public manner (I could imagine the news headline and accompanying pics), partly I feared that something might be sufficiently out of whack that the assembly could not in fact be fitted. That was worst case, and though I generally thought it an unlikely outcome, however it was flickering across the back of my mind as a possibility.

Anyway, things went about as well as they could possibly go. The main posts came down exactly as planned:


And the stretchers fit as intended. Setting the right lower stretcher first:


I can't tell you how odd it is to be a bit stressed out by the whole process and not totally sure how it all will be coming together, and meanwhile in the background you hear the whirr of motor drives and the repeated 'clicks' of several cameras with every move:



Putting a ratchet strap on between the front posts and rear support posts as a temporary measure:


Again, Mike (in red) and Matt were such big help to me during this process.

Surveying the situation...


Everything was looking copacetic, so it was time to remove the straps and say goodbye to the crane:


Here, I'm chatting a little with the photographers, and hoping that their notes and observations, when they come into print, are reflecting the project in a way that is similar to how I perceive it:


I was so relieved everything had just fit perfectly! It was one of those moments in life I'll always remember.

Tightening down one of the nuts onto the 1-1/8" stainless threaded rods:


A look at one of the main post corners showing the copper protection and bronze hinge components:


With the gate's main frame locked down and in good alignment, I thought the next task should be to get the main doors on there. The sooner they were hung the sooner they were out of the way, and therefore no longer needing as much attention in terms of protection or secure storage. One issue stood in the way however.

A primary change I had made in the new gate from the old was in the foundation system. The old gate used welded metal 'shoes' to support the structure, and the posts themselves went down below the granite pavers. As a consequence, the bottoms of the posts had thoroughly rotted out. The new gate I designed employs granite plinths and sills to keep the wood several inches away from the soil, and all the post plinths were slightly larger pads than the post sections which were to sit upon them. It's logical that a support pad have a larger footprint than the part it supports, generally speaking, and having an offset in size masks any discrepancies that might result from the wood swelling or shrinking relative to the stone.

The doors hang, as is traditional practice with these structures, not within a frame but outside of it and the hinge stile's inner arris more or less meets the nearby post's arris. Since the door stile extends down below the bottom of the post, you end up with a corner of the plinth which interferes with the door stile - indicated by the black marked lines in this pic:


Now, there were several ways to potentially solve this issue. One could have narrowed the spacing between the main posts so that the post corners could be aligned tight to the plinth corner. However the problem with that is then you end up with an uneven reveal around the plinth. The plinth could have been made so as to be the same size as the post section, however that is both structurally a little illogical, and would have banked upon the post sections ending up exactly at target dimension, which, as regular readers of this blog will know, was certainly not a given with the somewhat unpredictable results obtained through the saw-milling and wood drying processes many months ago. The posts did actually end up about 1/8" under target dimension for width and thickness.

It may seem as well that it would be expedient to simply remove a portion of the door stile so that it would clear the plinth corner. That might have been possible were it not for one crucial fact, and that it that the doors to this gate are normally in the open position, and thus those adjustments to the stiles would have been clear to view and have looked a bit odd.

So, that left the best solution as one which seemed on its face to be difficult to achieve: cutting a rebate in the granite to clear the door stile. As I was aware of this issue many months ago, I had come up with an idea as to how to tackle this problem, and then I made some calls to various granite fabricators to ask them what they thought of my potential solution. They said they thought it would work. I did too, but wasn't 100% confident about it as I am not a granite fabricator. Mike and Matt were skeptical, giving me the raised eyebrow and all, and that's okay, I'm used to that.

My approach to cutting the rebate was to slice down both sides and across the bottom corner using a diamond tipped saw blade in a water-cooled circular saw. I picked up a Makita 4101RH for this, a 4.5" saw. It had good on-line reviews, people only complaining about the price, and I have generally been pleased with most Makita products. After the slicing, my idea was to break off the waste and chip any chunks out, and then clean up using a diamond coated router bit. I obtained the router bits from a specialist stone masonry company up in Vermont.

I figured these tools would get the job done, however having no experience with them, wasn't sure exactly how onerous the task was going to be. As it turned out, it was like slicing up butter -I couldn't believe how easy it went:



I was really happy to get through that without any hassles!

With those rebates cut, it was time to hang the doors, however the wind had really picked up. Given that the doors are rather large and heavy, it seemed prudent to put off the door hanging until a later time. So we moved onto other things - I'll be back tomorrow with another post to describe all that. Thanks for coming by the Carpentry Way. Next up is post 84.

26 comments:

  1. Chris,
    Going too look forward to making a visit to the Boston MFA to see this gate as the results of your dedicated Work Skills... Thank for your blog....

    Joe

    ReplyDelete
  2. One thing is for sure:
    If I could read only one blog on the whole internet, for whatever reason, it would be definitely "The carpentry way".
    The words to describe what I feel were all said in past comments, but I would love to repeat. Your work is really epic, impressive, inspiring, awesome, wow, beautiful and .......... (please type in any word that flatter you).
    This, combined with such a generous person who is willing to share his adventure so freely, detailed and unadorned.
    I learned a lot since I am a regular reader.Thank you so much!
    respects from Germany
    Marc

    ReplyDelete
    Replies
    1. Marc, i do your worlds also my too, fine speech indeed... What a great discovery is this blog. Thank you again Chris, for all the efforts to let us be part of it.

      About this specific day... Wow, flying gates, paparazzi searching for the best angle, and everything else...better than action movies! Nice to see the "M&M Best Boys" on the photos too! Send them congratulations too!

      Can´t wait! What happens next?!? Tell us, plx!!

      Delete
    2. Gentlemen,

      your words are entirely too flattering, and I'm sure undeserved. I am glad that you enjoy what you see here and you inspire me to continue in this vein.

      ~C

      Delete
  3. The Eagle has landed!

    This is so inspiring.
    Another thing to mention is that the "fancy" saw horse looks great. I hope that the photographers noticed that one too.

    Brgds
    Jonas

    ReplyDelete
    Replies
    1. Jonas,

      funny enough, on April 3rd an architect walked by the site. He didn't seem to notice the gate at all, but he was very interested in the sawhorses. And I was glad he was excited about them.

      Thanks for the comment.

      ~C

      Delete
  4. Epic is the right word! Wonderful to see all your work and planning coming to such a satisfying climax! Thanks for sharing the journey and looking forward to the final part.

    ReplyDelete
    Replies
    1. siavosh,

      thanks for your comment!

      ~C

      Delete
  5. I was wondering why the crane needed to be so big, I had't imagined lifting over the trees. It takes a lot of work to make something look that simple. Things that look simple are often accomplished by much planning and prep, that goes for the entire project not just the lifting and installing part.

    Was the granite cut entirely free hand? I couldn't see any sort of guide, even on the router.

    Great work,
    Harlan Barnhart

    ReplyDelete
    Replies
    1. Harlan,

      thanks for the comment and question. Yes, entirely cut freehand - workmanship of risk as 'David Pye' called it. The saw did not come with a guide though I suppose I could have rigged something up, and the router's edge guide would not have allowed the tool to drop low enough, so it was laid aside.

      ~C

      Delete
  6. Chris,

    Your blog justifies having internet access (from one who's never had a mobile phone). I know it must dramatically add to your effort to blog about your work after a long day. Please know that your work is appreciated!

    Dan

    ReplyDelete
    Replies
    1. Dan,

      very kind of you to say. I've gotten somewhat used to blogging so I don't find it all that onerous a task at the end of the day, and with these build threads, most of the content is photos anyhow. The videos take a bit of time, but mostly in the uploading to Youtube.

      ~C

      Delete
  7. Wow! Thanks so much for sharing your experience, and your craft.

    ReplyDelete
    Replies
    1. Michael,

      many thanks for your comment.

      ~C

      Delete
  8. What a harrowing install!....nice work!

    Mike

    ReplyDelete
    Replies
    1. Mike,

      it certainly had it's ups and downs - mostly ups though.

      ~C

      Delete
  9. I'm celebrating your success Chris. Congratulations, and many thanks for sharing it all.

    ReplyDelete
  10. Reading the story and seeing the culmination, the effort involved in getting the gate into position and assembled, our hearts are in our mouths.
    Knowing that something could go wrong at any minute!
    This is Real -Time and stories don't nessesarily have a succesfull conclusion, which makes it risky for you and tense for us to follow.
    It's like we don't want you to fail, because we want a Hero. If you do slip up, there can't possibly be any hope for the Thinking Craftsman.
    Many Thanks for taking the time to share.
    Big Smile from me.
    Gordon Millar

    ReplyDelete
    Replies
    1. Gordon,

      it felt in many respects as it must for someone going out onto a stage, not sure if they are remembering all their lines, worried perhaps that something unexpected will happen and wondering how they will deal with it. For those that do such things regularly, I'm sure they learn to cope with it but it was an unusual situation for a carpenter to find oneself in I think.

      ~C

      Delete
  11. I've been on several jobs where we had something very expensive moved into place by a crane operator. While it has been nerve wracking, they have (so far) been like surgeons with the way quickly and accurately placed the objects( like 50' trusses). Money well spent it would seem. Well done on setting the granite blocks. I have been very excited to watch the progress of this project.

    ReplyDelete
    Replies
    1. Paul,

      it sounds like you can relate to the situation- I also thought the crane operator highly skilled, and it was good to work with him.

      ~C

      Delete
  12. Chris,

    I've been following your blog for the last couple of months. You've done outstanding work here, although you hardly need me to tell you.

    Thanks for the blog.

    ReplyDelete
    Replies
    1. Nico,

      thanks for venturing a comment- greatly appreciated!

      ~C

      Delete
  13. I am not at all familiar with PoC but it seems to be a rather soft wood. Was there any denting when the assembly was hoisted in the slings? I have not seen whether you have placed a chamfer on all the edges.

    ReplyDelete
    Replies
    1. Mitchell,

      you're right, POC is a rather soft and easily dented material. Those pieces had chamfered arrises and lots of protection from the sling, and were unharmed by the lift. My main concern in regards to damage from the lifting was the stainless strips to secure the copper ridge piece, however that was also undamaged by the process.

      ~C

      Delete

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