[TowerTalk] Mast Wall Thickness

[Stan Stockton]

I have no idea what the strength is but I have a 2 inch (3/8 wall) x 24 foot mast with about 15 feet out of tower and 9 feet inside tower at a location that has been installed for 39 years.  It has had a 4 element 20 up 7.5 feet on the mast and a 4 element 15 at the top all that time.  For 35 of those years it also had a short 2 element 40 just above the tower. The mast is quite heavy with a 3/8" wall, but I'm convinced based on its longevity it is pretty strong. 

However, I have no idea how to equate 3/8 wall out of tower by 15 feet as compared to 1/4 inch wall out of tower by 10 feet nor do I know what you are planning to put on it.

73...Stan, K5GO

Sent from my iPad

On Feb 24, 2014, at 11:39 AM, Chris Pinholster <k4win at mac.com> wrote:

> I have been researching tower mast material. Both aluminum and steel.
> 
> If aluminum 60601 tubing with 2"OD and .125 wall fails at 35000 ps, what happens when you increase wall thickness?
> 
> If you increase the thickness of the mast wall, wouldn't that increase make a difference in the bend or failure rating? 
> The charts at the metal company I visited seemed to indicate that would be true. (I was looking at aluminum 2"OD and 1.5"ID)
> 
> Also I ran across a chart that showed that using a 14 ft mast, with 4 ft inside the tower and 10 ft above was stronger than an 11 ft mast with only 1ft inside the tower and 10 ft above. 
> 
> Any opinion or science from this learned group?
> 
> 
> 
> CHRIS PINHOLSTER
> k4win at mac.com
> 
> 
> 
> _______________________________________________
> 
> 
> 
> _______________________________________________
> TowerTalk mailing list
> TowerTalk at contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk