Tower down-- and I want it!

[N0BST]

An AM station in a neighboring town dropped their old tower a few weeks ago and I have the opportunity to get it but have never done anything of this scale.  I inspected it this afternoon and it looks like it had a fairly soft landing.  Tower is a 180' Utility with about a 14" face.  Damage appears confined to only to the top 60' leaving me a good 120' to work with.  The ground is somewhat soft though not swampy. 

I know I'll need an angle grinder to get rid of the tack welds on the flanges and some wrenches for the bolts, but what else would you want to have along with you if there were some bolts you couldn't budge?  What's the best way to get out the ones closest to the ground?  That thing uses some pretty good sized bolts, given the tower's size.

Lastly, what would be the best way to get the sections out of there?  I had thought of hauling my Allis Chalmers model C tractor out there and dragging them, but maybe renting something like an ASV with a bucket and rubber tracks would be better?  There's lots of brush in that field.  Anyone know how much this tower weighs per 20' section?

Thanks,

Scott Todd

[WQ9E]

Scott,

Are the tower components welded (cross bracing, etc.) or is this one of the style where everything bolts together?

If it does use welds to hold the structural components together and they just cut it off and let it fall it is certainly possible some of the welds could have been compromised with the defect not being easily visible because even if it hit soft ground the tower took quite a shock (and not of the type the manufacturer intended).  Think long and hard about the risk of climbing a tower of unknown condition and/or having the same tower near your home and family.

If it is bolted together (or you are willing to trust the welds) then I would suggest penetrating oil followed by an impact wrench to get the bolts loose.  If you can't get an air compressor to the tower site then a breaker bar would be my next choice and you should also be prepared for some which just will not come loose and may require cutting.  If you have a lot that won't come loose, look into acquiring a nut splitter.

Since you have an AC do you have a loader attached to it?  If you have (or can borrow) a hay rack or similar wagon load them on there and tow them away-I wouldn't drag them adding insult to the injury of already having the sections fall to the ground.  If you end up having to rent a lot of equipment and couple that with fixing and buying attachments for the tower your low cost tower is going to end up costing a lot and you should compare to what it would cost for some used standard tower like Rohn 45 or 55 for which accessories like rotor plates and torque bars are readily available.  If the tower is given to you the scrap material value could give you a start towards buying a used or new tower.

Sometimes free or cheap can really cost a lot of money:

Years ago in college I was the comptroller for my fraternity and one of the brothers arranged for a "free" pig for an upcoming Hawaii Luau style party.  When we went to pick up the free pig it was still running around the junk yard in which it was raised.  Some locals (extras left over from Deliverance) butchered the hog while playing catch with various pig organs.  It then turned out our free pig had consumed around $150 worth of food so that was check number 1 to release the remains to the frat boys.  Then one of the brothers who was majoring in hotel/restaurant purchased the necessary spices, butter, etc. for cooking the pig which was another 40 bucks or so and finally the pig is roasting on top of firewood that actually was free.  Overnight one of the brothers (henceforth known as brother Pyro) decided it wasn't cooking quickly enough so he really put the coal to the fire and when several of us wandered out about 10:00 the next morning all that was left was the equivalent of a 1 pound package of charred bacon that we could have gotten at the local A&P grocery for a couple of bucks. That was a really expensive free pig but one of the better lessons learned in college and it wasn't part of my B school curriculum.

At least the rum punch was good.  It was made by yours truly whose only mistake was sampling it several times while mixing it and then going to my 11:00 class; the prof (who later wrote one of my recommendation letters for Ph.D. programs) wasn't terribly impressed.

Rodger WQ9E

[WBear2GCR]

It's heavy. have at least a helper with a cell phone with you when working on it.

I'd suggest packing a "hot wrench" - Oxy/Acetylene torch set.
At minimum heating up rusted bolts with it will make 'em come off faster.

If you have compressed air, then an abrasive cutoff wheel tool is second best.

"Force 5 Persuader"  a 5lb hand sledge, appropriate punches, pry bars, at least one automotive floor jack, various large wood pieces (supports and to wack upon) 4x4's and 6x6's etc, penetranting stuff (mix 1:1 lacquer thinner and ATF into a squirt can - really works extremely well), automotive jack stands (hold the thing up as needed), chains/ropes, pulleys, come-along.

Definitely some bit of motorized thing with a bucket or blade

Even sitting on the GROUND, there will be significant force on the sections - so if you pull the bolts off the flanges, that thing will MOVE. You don't want to be in the way when that happens... you'll want to do something to keep the larger section stationary, and support the one being taken off...

If you can, go there after dark with two things: a cheap laser pointer and some means to hold it to the tower (some sort of visegrip or magnetic thing) and some white target material that you can also clip, tape or clamp to the tower. Now, you point the thing down the vertical legs, aim the thing to the target at the bottom of the tower which should be at the same height as the laser... now as you move the target UP to the laser you will see the difference in position, so if there is a serous bend as the result of the fall you can measure it. Do all three legs... of course there will be some bend just due to sitting on the ground... this is only if you want to measure it.

If you get a machine in there and "flip" the tower onto another face, and remeasure, you'll have a good idea if the bend is built in now or just because it is on the ground... but likely you can just look down the thing like a guitar neck and see it... 

Maybe post a jpeg of the tower and a closeup of the flange/section meeting points??

How long are the sections??


               _-_-bear

[KB5MD]

Better look that gift horse in the mouth real good; or should I say gift pig!

I couldn't resist that!

[wa6mtz]

One of the local auto clubs done some tests on penetrating fluids and found that a 50-50 mix of automatic transmission fluid and acetone worked better than Kroil and was much cheaper. I haven't tried it but am going to mix some up one day.

[ka3zlr]

Nutten betta than good old PBS Blaster....

73
Jack.

[K5UJ]

Did they trash the base insulator when they took it down?  If not, be sure to get it if you can!  Also the insulators and hardware attaching the guys to the tower if possible.  Even if you don't plan to use any or all of this other hams will fall all over themselves to get a decent tower insulator.

Rob K5UJ

[flintstone mop]

A tower that fell to Earth might have gone through a lot of stress.
There may have been hints earlier to let her lie in piece.
Free may be bad in this case

Fred

[W1ATR]

I sort of have to agree with the others on this one. I don't think I could trust my life to a salvaged tower that was dropped. With that in mind, your the only one here that has actually seen it, so the final call is up to you. Just think real hard about it. Even if you were to clean the paint off of each weld to inspect them, there could still be damage to the joint that you won't be able to see.

It's a pretty risky business climbing a slammed tower.

[KD6VXI]

At the very minimum, break each weld and redo it.  This will ensure you don't have any problems with welds breaking from the fall, and they did!, you can rest assured.  Also, just because you can't SEE the weld and a break, doesn't mean it isn't there.

It would be VERY expensive to magnaflux each and every weld on the thing, it's too much metal.

I'd say you have a great set of beam making material, but I wouldn't trust that thing in my backyard, I have kids, AND I enjoy living instead of picking through my house after my 180 foot tower falls on it and I have to see if any radio equip. made it.

Just think, you COULD make a KILLER 160 FULL SIZED yagi like those guys in (IIRC) .no did!


--Shane

[flintstone mop]

.

Just think, you COULD make a KILLER 160 FULL SIZED yagi like those guys in (IIRC) .no did!


--Shane

That was an awesome project. That musta been a million dollar project!!!

Fred

[k7yoo]

If you inspect the tower very closely you will find that it is made out of leaverite.
This means you should leaverite where she is.

Unless you have the heavy equipment, special gin pole, and properly trained crew to get this dog back vertical after having it professionally inspected I would forget it. I have personally passed up two similar towers for the above reasons. I have salvaged at least 5 smaller towers and nearly bought it on one "free" tower, even after re-guying it so it would not come down while I disassembled it with the correct gin pole. We don't want to hear another tower obituary!

Skip

[KD6VXI]

.

Just think, you COULD make a KILLER 160 FULL SIZED yagi like those guys in (IIRC) .no did!


--Shane

That was an awesome project. That musta been a million dollar project!!!

Fred

All I can say is

www.antennas.be
www.transmitters.be

THOSE guys be NUTS.  Even I will admit to their insanity... This from a guy with a 12A plate xformer.

--Shane

[WBear2GCR]

Now hang on a second... let's think about the physics of this tower's fall?

We can be pretty darn sure that the lowest portion of the tower when it hit the ground was not moving very fast and so would have sustained the least impact force. The higher up the tower, the greater the impact.

Now, we need to know more about how it was felled. IF the tower was dropped so that the base was elevated above ground, and the base did not contact ground until the last possible moment, or was in fact above ground when the top hit the ground, then we know something about what absorbed what energy.

It sounds from the description of the top 1/3 or so being bent that this is indeed how the tower fell - in which case most of the energy was absorbed by the bent upper section, and this de-accelerated the bottom 2/3 substantially before  it made contact/impact with the ground.

These days they use portable x-ray devices to look at structural elements, maybe you can hire someone for not that much $$ to come out and have a look at the key welds and a good spot check of some of the brace welds and get a "confidence factor" out of that...

Regardless, it would be really nice to see some jpegs of the beast as she sits??


             _-_-

I wonder what it would have taken to have had something like a 4ft high bed of something energy absorbing - maybe a bed of vermiculite? - spread out where the tower was going to be dropped?? Giant air pillows? Cheap, plentiful and fluffy is called for...

[flintstone mop]

.

Just think, you COULD make a KILLER 160 FULL SIZED yagi like those guys in (IIRC) .no did!


--Shane

[/qThat was an awesome project. That musta been a million dollar project!!!

Freduote]

All I can say is

www.antennas.be
www.transmitters.be

THOSE guys be NUTS.  Even I will admit to their insanity... This from a guy with a 12A plate xformer.

--Shane

The AMFONE is acting weird again with the bouncing up and down as I type.


Shane, the first link goes to a military site that makes small invisible antennas and the second link goes no where.

Frsed

[flintstone mop]

A very real and serious antenna.
Not for the faint-hearted or HHB budget

Fred


http://2.bp.blogspot.com/_Ot1q36B9jzs/SXNPATwjD5I/AAAAAAAAAW8/bP88tdlDLRM/s1600-h/M7.JPG

Sorry.....I can't get the image to display in this post. I can't follow instructions well.

[KD6VXI]

The AMFONE is acting weird again with the bouncing up and down as I type.

Shane, the first link goes to a military site that makes small invisible antennas and the second link goes no where.

Frsed

Sorry,

http://www.antenna.be
www.transmitter.be

Should have been singular, and not plural.

Up to a half megawatt sw transmitter, should tune NICELY at 40 meters.


--Shane

[W1RKW]

Think about the overall process or physics to drop the tower.  Someone had to cut one of the guy anchors. So if it was guyed by 3 guy supports now it only has 2 once one of them was cut. The tower now falls towards the 2 that are guyed. Factor in a slight breeze and one of the guys will pull more so than the other.  That means one of the towers  vertical members will more than likely hit the ground first. The ground is not going to be perfectly flat so when the tower lands on a vertical member is going to take the brunt of this fall and more than likely, if the tower was elevated by a tower insulator then the upper section of the tower will hit the ground first before the bottom section. The tower will suffer bending along it's length.  There will be a whip action at the end of the tower which will radiate down the entire length.  It's highly unlikely that the entire length will hit the ground equally so all sections will be stressed in various directions. I'd be very surprised if any salvaged sections will line up properly. And of course as others have mentioned the stress factor on the welds.  You may be wasting your time, energy and money.

[N0BST]

Thanks for the advice, everyone.  I'm only able to get on this list on weekends which is why it's taken me so long to respond.  To answer a few questions, my tractor doesn't have a loader on it so I'd have to rent something if I were to get it out that way.  The reason I have some hope for the rest of the tower is the bottom half of the beacon managed to survive the fall!  I'll see if I can get some pics and have them posted.

Scott Todd

[WQ9E]

Scott,

A good excuse to acquire a loader for your tractor 

Seriously, I was pleasantly surprised at how useful a loader is having grown up in the city with no exposure to tractors.  Shortly after I bought the place in the country I picked up a Deere 955 compact utility and the dealer convinced me that the loader would be a most useful implement.  I have used it on a couple of occasions to move radio gear and when we added a master suite to the house I used the loader to lower some of the heavies gear into the new basement during construction.  Of course most of the time it is used for less fun stuff like moving snow and firewood.

Rodger WQ9E

[Bill, KD0HG]

Scott,

A good excuse to acquire a loader for your tractor 


Rodger WQ9E

...And it certainly beats using a shovel to pile up a ton of horse droppings on the compost heap..And to yank out old fence posts...Move snow...Pull out small stumps..

I have the Yanmar version of that same Deere with the 3 popper diesel.

[K1JJ]

Here's a real-whirl data point:

Back in 1999 I had the opportunity to be on the crew that dropped a 300' Rohn 45 commericial tower. They were replacing it with a modern monopole tower. I was told I could have 1/2 of the good sections that survived in exchange for my help.

We systematically cut the guys on one side and let the tower fall. At first it just hesitated and started to sway. Then it jack-knifed at the 150' level and the top section broke off and plumeted to the ground. The bottom 150' fell relatively flat onto the ground.

About 80' were destroyed while the other 220' were in decent shape.  All that was required on a few of the sections was to slide a pipe onto one leg and straighten it slightly. This is the same and common procedure when a new section won't slide into another.

Anyway, I inspected all the welds and didn't find any obvious damage. I put up 100' of that tower and used 6 star guying with real man's HB torque arms. It held a pair of stacked 300 pound log periodics for a few years ( a BIG load) and is now my triple 10M Yagi tower.  Never had a problem with it and is as solid as a rock.  I've climbed it at least 100 times and always give it a good shake to check it out. I occasionally inspect the welds when I climb and have never found a bad one to date. I feel as good on that tower as the Rohn 45 150'er I bought new in 1986. 

I would NOT put up a SELF-Supporter tower that was dropped, but feel OK with a guyed tower. If you sight down each section and see that it is perfectly straight, chances are it didn't have any big stress.  The sections that WERE over-stressed looked like pretzels - it was very obvious.

So that's my opinion for what it's worth. I'm a scrounger and cheap bastard when it comes to parts and towers, but if I thought there was any real risk of using this tower I wouldn't. Again, if it's a guyed tower and if the section looks perfectly straight, I wud use it.

BTW, buy a gallon of that cold galavanizing zinc paint. The can weighs about 30 pounds from the heavy metal in it. Use a furry mitt from the paint store to apply it. The coating will last for at least 10-15 years and costs about $100, but well worth it. Forget painting it with regular paint if you value your time.

73,

Tom, K1JJ

[WQ9E]

...And it certainly beats using a shovel to pile up a ton of horse droppings on the compost heap..And to yank out old fence posts...Move snow...Pull out small stumps..

I have the Yanmar version of that same Deere with the 3 popper diesel.

Bill,

I bought mine in 1996 and I have only had two issues with it: one idler pulley on the 6 foot mower deck and a group of wasps who built their mud nest over the air vent on the fuel cap.  With the wasps, I had just started mowing and the engine suddenly started running rough-when I opened the hood the nest was obvious and it was creating a vacuum in the tank reducing the flow to the injection pump.  Apparently those wasps were addicted to the smell of diesel.

I wish my 2006 GMC Sierra diesel was as simple and easy to work on as these older "high emission" diesels.

Rodger WQ9E