WBZ/Westinghouse/Springfield, MA

[Peter]

On Apr 3, 2008, at 8:28 AM, Dan.Strassberg wrote:

> WBZ's towers in Hull are 185.5 degrees tall. If my math is correct,
> that comes out to 492' or almost exactly 500m. I have no idea of the
> face dimension, but the towers appear to be triangular in cross
> section and quite slender relative to their height. From the photo, it
> appears that the towers are guyed at approximately 175' and 350' above
> ground. That leaves ~140' at the top unguyed. Is that approximately
> correct? And if so, isn't that a very great length of a slender
> uniform cross-section tower to be left to support itself--especially
> given the high wind loads one would expect in the unsheltered seaside
> location?

Two levels of guys is pretty much standard for old Class I-A and  
Class I-B verticals installed pre-War or, for a few of them installed  
just post-War.

The face is usually about 48", with 2" thick vertical members and an  
appropriate number of diagonal braces.

Recall that the 650 and 1210 Blaw-Knoxes (650 for pre- and post-War;  
1170 for pre-War, 1210 for post-War; both originally 225 degrees) are  
amongst the tallest verticals which have one level of guys, so it is  
not unreasonable that a constant cross section radiator of equal  
height, constructed conservatively, could make do with two levels of  
guys if a non-constant cross section could make do with only one level.

If my math works out correctly, WBZ on 990 would have had 192.2  
degree radiators ... very close to optimum for a Class I.