Replies

1. 
   Guest_ | May 31, 1999 08:45am | #1

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   Large diameter minus small diameter. This divided by length equals amount of taper per inch length. This divided by 12 equals taper per foot.

   For you, this is about 1 11/16" taper per foot.

1. 
   Guest_ | May 31, 1999 05:58pm | #2

   *fast3,

   Maybe you can post what you are building the tower from? Brick, block, stone, wood or steel? It would help in developing a plan of attack.

   Joseph FuscoView Image

1. 
   Guest_ | May 31, 1999 06:26pm | #3

   *fast3, If you are interested in light houses, did you know they are moving the Cape Hatteras Light house about a mile(in north Carolina)?I saw it jacked up this spring and ready to move...amazing. Huge masonry structure,something like 286 ft tall,and it sat for about 100 years on a wood foundation,untill the shore around it disappeared.Good luck,Stephen

1. 
   Guest_ | May 31, 1999 08:53pm | #4

   *Until we find out what you are building with, let me give you this simple list of tools you will need for your project.1. Three small to medium skyhooks.2. One 75' lenth of 3/4" nylon rope.3. a Hartford & Brahms secular extrusion kit (the one in the red package only).4. a portable stationary winch.After you let me know what materials you will be using, I will tell you how all this comes into play.Pete Draganic

1. 
   Guest_ | May 31, 1999 09:01pm | #5

   *Shouldn't that be large radius minus small radius? Seems like twice the taper that one wants according to Rich's math.

2. 
   Guest_ | May 31, 1999 09:47pm | #6

   *There is a 4' difference in diameter over a 14' rise. you need only calculate half of the 4' feet (2'on each side). A 2' difference over 14' is 1.71428 inches of loss per foot of rise. which is realatively near 1 23/32 inches. Of course this hardly helps our new friend here figure out how to acheive this loss. This would seem easy enough to construct out of wood or steel framing. But to lay simply out of block with no structural skeleton for reference would have me scratching my head too... at least at the current moment. I suppose you could elicit the use of a plumb bob and reference points on the inside floor of this structure. Pete Draganic

3. 
   Guest_ | Jun 01, 1999 01:13am | #7

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   What one would need here is a mason who's worked on brick smoke stacks to reveal his secrets.

   Joseph Fusco View Image

2. 
   fast3 | Jun 01, 1999 06:29am | #8

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   Pete, Joe, Rich, Stephen and anyone else that responded to my incomplete query

   Can I respond to every one with 1 message?
   Do you think that the Hartford & Brahms model 100 will work ? I sure asked for that. The material is a split face landscaping stone 4" high by 12" long with the corners relieved for doing curves. I was onsite this morning and still scratching my head when I figured what I needed was some kind of form to work to. I've been a mason for 25 years but never encountered anything like this. I had a sheet of 5' wide plywood left over from something else so I cut it to the inside diameter less 1 3/4" for 2 pcs. of hat channel. I cut another piece to the desired inside diameter at the top and connected them together with the 8-14' long hat channels. A plum bob hung from the center of the top piece lined up with the center mark on the bottom piece when every thing was braced and ready. It was a real comedy act trying to stand up but 2 of us easily put on 5' today and never tried to plum anything, just followed the hat channels. This is going to turn out to be quite a yard ornament for the plumber friend that I'm doing this for. I would still be interested in knowing how they built those smokestacks.
   Thanks fast3

3. 
   Guest_ | Jun 01, 1999 08:56am | #9

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   Just got back from a BBQ. My friend, Leon, was there; he's an excellant stone mason. I ran this by him; here is what he said.

   Either run a taut string veritical to the top--perhaps even extending past the top of the completed lighthouse, OR, build a "cage" of #9 wire and 3/8"--or pencil rod--and stack your rock to that. Just keep the taper constant and watch your radius. A third thing he suggested was to use a sono tube to the diameter(s) you need. They actually make them to this size.

   What do you think?

1. 
   Guest_ | Jun 01, 1999 06:12pm | #10

   *Fast3,I pray that you will be using mortar with those landscaping stones.

4. 
   fast3 | Jun 02, 1999 05:05am | #11

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   Hey guys,
   Making a cage or using sonotube as a base for a cage both sound like pretty reasonable alternatives to what we came up with. Yes we are using mortar, I believe the supplier says that the stone should only be stacked a maximum of 4' dry. thanks for the good advice.
   fast3

5. 
   Guest_ | Jun 02, 1999 03:25pm | #12

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   Just keep boogerin' till you're done, and then, you'll be done!

   blue

1. 
   Guest_ | Jun 02, 1999 03:41pm | #13

   *Saw them prepping the Nauset Light at the Cape Cod National Seashore for a move. It was not as challanging as C.H. Shorter, cast iron structure.Anyway, there's been a PBS series about lighthouses and they have mentioned some things about evolution of construction techniques. There may be an accompanying book.I'd also guess that a search on smokestack construction might reveal some techniques.

1. 
   Guest_ | Jun 02, 1999 08:56pm | #14

   *Have never tried anything like this, but for the reference angle, I would probably tape my electronic level to a straight 2x4 and tilt it until the read out said the correct number of degrees. Alternatively, I would cut a large plywood template so that one or both sides had the proper angle when the top of the template was level. I would then attach a torpedo or carpenter's level to the template and when the vial bubble indicated level, the side of the template would give you the proper tilt. This could be in addition to your guide strings or wires - particularly if they are inclined to get moved, stretched, broken, etc. I don't quite understand the comments about not having a central structure. It would seem that some type of central framework, sonotube, or at least a large post would be desirable if not essential for the integrety of this thing. Otherwise I sure wouldn't want to be standing too close in the next big shaker - and earthquakes don't happen only in California.

6. 
   Bill_Amaya | Jun 03, 1999 04:19am | #15

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   Fast3,

   I have actually built a structure very similar to what you are asking about. The tower we built was made of wood and supported a hot tub that was accessed from the 2nd floor master bedroom. Our tower also had 6 door openings in the bottom part of it. And it had two different pitches or tapers to it. So some of the things we did to figure this tower out were..... we layed out a cross section of the tower full size on the subfloor. That would be a vertical cross section. The cross section will look like an ice cream cone split down the middle. This will allow you to determine the radius of the tower for any given distance up from the bottom. You could than jig saw some circles out of plywood to the correct diameter for, say 4', 8', 12' etc. above the foundation. When you get to that height you can use the cooresponding circle to check your diameter. With a cross piece screwed to the circle template you could then drop a plumb bob down to your center point on the foundation to check for lean. Building it out of stone is a little different and I am not sure how accurate you need to be so one more thought. You could build a "mast" up the middle of your tower that is plumb. You could use the "mast" to afix a circle template to. Might look like a flat umbrella. With some strings attached to the "umbrella" and running to the foundation should give you a fair curve and something to eyeball to. Hope this helps! Good luck.

   Uncle Bill

7. 
   fast3 | Jun 03, 1999 04:19am | #16

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   I just registered here and am looking for any info or methods for keeping a consistant taper on a 20' tall circular tower. The base diameter is 6'4" and we will be shooting for approximatly 4'4" diameter at the top. Actually the first 6' is straight so the taper is only 14'
   Anyone have any simple tricks for achieving this ?