Thanks for clearing that up. By the way, that is not old! I'm old!
(Ha Ha )
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of Bill Aycock
Sent: Thursday, March 11, 2010 9:50 PM
To: wisecrafter@suddenlink.net
Cc: Towertalk@contesting.com
Subject: Re: [TowerTalk] tower & antenna project questions
Thank you Jan--
I thought it was at least that old. That opinion has been disproved many
times, which is why the ARRL took the reference out.
I have seen concrete explode, and it took a LOT of local heat to do it. On
the occasion when I saw it, it was Rocket fuel. The ground system described
is, essentially, an "Ufer" ground, where there is connection between the
rebar cage and the ground system. The Army uses this system to protect
explosive storage facilities. Successfully. I worked in one, designing
Rockets, for 38 years. Go to the Wikipedia and look up Ufer.
The Lightning caused steam explosion is a myth. What IS bad, and can cause
concrete cracking, is having rebar in contact with both the ground and the
cement at a boundary. In this case, the steel rusts, admits water, and
cracks appear on freezing. They use Copper at the transition to stop that.
I have not seen a documented case of a Lightning-caused concrete explosion.
----- Original Message -----
From: "Jan Wise" <Wisecrafter@suddenlink.net>
To: "'Bill Aycock'" <billaycock@centurytel.net>
Sent: Thursday, March 11, 2010 7:31 PM
Subject: RE: [TowerTalk] tower & antenna project questions
> That came out of the ARRL Antenna Book 16th edition Copyright 1991.
> It is under bases for towers in the index. Pp 22-9 TOWER BASES
>
> -----Original Message-----
> From: Bill Aycock [mailto:billaycock@centurytel.net]
> Sent: Thursday, March 11, 2010 5:20 PM
> To: wisecrafter@suddenlink.net; Tower and HF antenna construction topics.
> Subject: Re: [TowerTalk] tower & antenna project questions
>
> That must be an OLD handbook. Can you give me the year, chapter and page
> where this old wives tale is? I'd like to find it in print, jut once.
> Bill--W4BSG
>
> ----- Original Message -----
> From: "Jan Wise" <Wisecrafter@suddenlink.net>
> To: "'Tower and HF antenna construction topics.'"
> <towertalk@contesting.com>
> Sent: Thursday, March 11, 2010 4:22 PM
> Subject: Re: [TowerTalk] tower & antenna project questions
>
>
>>I am not sure, but I think if you look at the Hand Book It will state that
>>you do not want the tower or anything else to be grounded that goes
>>through
>
>>concrete. The reason being that a hit from lightning
>> Will cause the concrete to explode. If I am wrong someone please let me
>> know !
>>
>
>
>
> __________ Information from ESET NOD32 Antivirus, version of virus
> signature
> database 4937 (20100311) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com
>
>
>
>
> __________ Information from ESET NOD32 Antivirus, version of virus
> signature
> database 4937 (20100311) __________
>
> The message was checked by ESET NOD32 Antivirus.
>
> http://www.eset.com
>
>
>
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4937 (20100311) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4937 (20100311) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
__________ Information from ESET NOD32 Antivirus, version of virus signature
database 4937 (20100311) __________
The message was checked by ESET NOD32 Antivirus.
http://www.eset.com
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|