sawing a mast for an old ship

artenvielfalt · July 29, 2008, 04:01:21 PM

hi guys,
no pictures of the job yet, and not sure i get the job either but i think my 10" Peterson can do the job.

I have a request from a marina to cut a 22m long ,mast for an old boat rebuild
(it is called Thor Heierdahl), the tree has 1m diameter at the bottom and is so perfect i have never seen before. i have my ideas of how it might be done, but maybe i can get some more information from you and maybe some new ideas too.
they have all the cranes and big equipment there so moving it is no problem.
i thought they will produce a long 25m long track from steel with the edge for the wheels on it and then we make a setting in the middle where the log is laying in and we lift it to the point they want it to be cut, then i will skim the edge off, turn it, do the same until we have a square and then make a groove bed for taking the edges of again, until we get a 8 edge, the rest must be done by chainsaw and handplainer, as the mast is big at the bottom, samller, bigger again for the cross mast (or however it is called) and smaller again and again bigger for the next crossmast and small again. so the smaller parts have to be done by chainsaw anyway. but i could do the main cutting.
what do you think about this idea of making the long tracks (levveling and so on with laser,..... all there.)
has any f you done a job like that before?
if so please tell me of your experience and the setup you used.
thanks and if done i will send pictures for sure to share all my troubles,.....
take care
Ulf from Germany

Tom · July 29, 2008, 04:19:48 PM

Is this a ship named for the Thor Heyrdahl of Kon Tiki fame? If so, what is the history of ship?

You may have gotten yourself into a front seat of historical involvement. Be sure to write down all of your experiences associated with it and take pictures as well. Take pictures of all the workers and people involved and anything that would be missed by a newspaper reporter. Be sure to get "everybody's name". It might even be worth trying to get releases from the people so that you can use the pictures in print later. I envy you the opportunity. :P 8)

timberfaller390 · July 29, 2008, 04:24:52 PM

sounds like quiet a project. Leveling everything with a laser is a good idea because with that length of material it would be easy to mess up if you were just a little out of level. how will you cut the taper or will you just be cutting it to one dimension and letting them handle it with saws and hand planes.

Radar67 · July 29, 2008, 06:16:00 PM

Didn't we have a couple of other members cut masts? One from New Zealand and the other....maybe England?

metalspinner · July 29, 2008, 06:28:15 PM

That sounds like a giant pencil post bed.

I visited member Teenswinger a while back, and he has some angle iron rails that extend his sawing to 30'. Longer would just require more angle iron. Maybe he will check in...

Jeff · July 29, 2008, 06:50:47 PM

She's beautiful!
http://www.tallshipstock.com/thor%20hey.htm

Ianab · July 29, 2008, 09:51:50 PM

Quote from: Radar67 on July 29, 2008, 06:16:00 PM
Didn't we have a couple of other members cut masts? One from New Zealand and the other....maybe England?

Yup.

https://forestryforum.com/board/index.php/topic,8172.msg110736.html#msg110736

Looking foward to seeing some pics of this job too.

Ian

bandmiller2 · July 30, 2008, 06:27:39 AM

ULF,your over my head ,but I would think of a piece of stock between centers on a wood lathe,adjustable at the small end with the track for your swing saw under/over it.Frank C.

thecfarm · July 30, 2008, 07:21:43 AM

That is a fine looking ship.Please post some pictures of the job you are about to under take.Sawing is alot harder than posting pictures. ;) We will help you on posting pictures.We all want to see the job being done.What kind of wood is being used?I bet thta is a fine looking log.
By the way,I took this back in the 8th grade,but have long forgotten it.How long is 22m and how big is 1m? I suppose someone can tell me how to convert this into somthing I can understand?
Maybe someone could put this into the Toolbox or Help.

metalspinner · July 30, 2008, 07:33:03 AM

Cfarm,
Multiply by 3' (+ or - a little bit, I believe).

Dan_Shade · July 30, 2008, 07:52:54 AM

22m is 71' 6"

I'm assuming it's a square mast (I hope so).

I'd use an alaskan mill to do that, you can create a "plane" by driving nails partway into the log using a taut string as a reference line and having all of the nail heads on one plane. then slide a board along on top of the nails to take the slab cut. I'd imagine you could be done in much less time than it takes to build a set of tracks, and most likely just as accurate.

another option would be to hand hew it, but that takes considerable skill.

zopi · July 30, 2008, 08:29:06 AM

Cross mast= Yardarm...

Is there a taper required in the overall length of the spar?

If so the small end of the log can be raised to achieve the taper.

BTW..the new spars for Old Ironsides were cut on a Woodmizer..

LeeB · July 30, 2008, 12:01:49 PM

1m = 3.281ft.

TexasTimbers · July 30, 2008, 02:47:49 PM

Turning the mast will not be as easy as you think, crane and all. I have worked around cranes quite a bit, and you need to plan this aspect of the operation more than what you have from reading what you have said about it. Having a crane on site that can lift the mast is one thing, having designed slings that allows you to gingerly rotate the mast accurately and safely is quite another. Don't neglect this phase of the operation. A little planning will save a really big mess.

I don't know the best type of saw to use for this but am waiting to see how y'all decide which one will be, but however you cut it, make sure you have a reference line the length of the tree that you can transfer to the next plane to be cut, so you can shim the sag out of the tree each time accurately or you will end up with a mess.

Can't wait to see this unfold. Great opportunity you have here make the most of it.

artenvielfalt · July 30, 2008, 03:40:43 PM

thanks for discussing my job that i don´t even have in the pocket yet, ,....... but really hope i will. i´m praying for it.
well all the concerns are true, crane and so on, but it is a big shipyard with U-form cranes on rails, so I thought of taking the tree out and then turn it with a forklift or something like that and then put it back in. the leveling will be done by them i think they are used to put whole tankers level and the bunk in the middle has to be designed especially for the use there, i will see to it when they call me for the job.
anyway even if i don´t get the job, i will go there to see the tree live and see how they do it.
Cheers guys
Ulf

smoothED · July 30, 2008, 09:02:00 PM

"urning the mast will not be as easy as you think, crane and all. I have worked around cranes quite a bit, and you need to plan this aspect of the operation more than what you have from reading what you have said about it. Having a crane on site that can lift the mast is one thing, having designed slings that allows you to gingerly rotate the mast accurately and safely is quite another. Don't neglect this phase of the operation. A little planning will save a really big mess."
Having a rolling block,useing the jib and main with a good operator,maybe 2 with that length,nylon slings would grip without doing damage,a basket with a wrap would turn it.

Dan_Shade · July 31, 2008, 07:00:19 AM

if I were trying to turn it, and it were "on the ground" so to speak, I'd drive several stakes/green fence posts in beside the log, and just get 5 guys with cant hooks to turn it against the posts, or wrap a strap around it to roll it against the stakes, then pull out the stakes afterwards.

A handy-man, or hi-lift jack will make it "easy" to lift up the center of the log to shim it up and get the sag out.

TexasTimbers · July 31, 2008, 08:57:22 AM

Cant hooks ??? I don't think so. Do you know how much that thing weighs?

Radar67 · July 31, 2008, 10:03:00 AM

I have to disagree TT. If I can turn a 22 inch square cant, 20 feet long, water oak with a cant hook, 5 guys could turn this log.

TexasTimbers · July 31, 2008, 12:13:19 PM

I think most of here can turn big logs. I am sure we have all felt that feeling "Wow. I can't believe I did that." after such a feat. But what i am saying is that turning a big log, and meticulously manipulating a log that heavy are two different things.

Probably 5 guys could get it rolling, but it has to be turned within the confines of the saw space - stationary. then, it has to be adjusted to the next saw plane. You guys might be right, but IMO it would not be the optimal way to do it when you have a million dollar crane sitting there, and rigging a couple of slings would take maybe an hour or two.

I figure it weighs roughly 15,000 - 20,000 lbs. that's not much weight for 5 guys to attempt to roll, but to "manuever accurately" and in place . . . . .