[Top] [All Lists]

[TowerTalk] Re: An Engineering Question

To: <>
Subject: [TowerTalk] Re: An Engineering Question
From: PEF@SNI.DK (Peter Frenning)
Date: Wed, 4 Jun 1997 10:44:59 +0200
>>I think sailboats lower their sails just as the curve starts
>>to get interesting for ham antennas!
>[Peter Frenning]  Even our biggest imaginable antennas wouldn't do much in
>moving a 40 foot sailboat! The forces involved in speeding thode things along
>at 6+ knots are incredible. In addition a boatmast has to withstand all kinds
>of forces, twisting, bending and compression. I've seen boat literally ripped
>apart before the mast failed (I've also seen inadequately adjusted masts fail
>for no apparent reason).
>Think about this: an average rcing cruiser at 40' sports something like 130
>sqm (that's about 1300 sq feet) of canvas WITHOUT the spinnaker! Hoist the
>balloon and you double the area, and it's by no means a steady force - quite
>the contrary.
>>Dave Hachadorian, K6LL
>Also, sailboats MOVE with the wind reducing the effective windspeed relative
>to the mast.  I hope your tower stays put . . .
>[Peter Frenning]  Have you ever been in a racing boat in gale force winds
>with the spinnaker up cutting into the wind?
>relative windspeeds are almost double the real thing! and THIS is what
>separates the men (and correctly rigged boats) from the boys.
>*********************************   OZ1PIF  *****************************
>Peter Frenning, UNIX Product Mgr., Siemens-Nixdorf DK, Ph.: +45 4477 4924
>Snailmail: Dybendalsvaenget 3, 2630 Taastrup, Denmark, Fax: +45 4477 4977
>                Email:, (NERV: pfrenning.cph)
>X400: C=DK; A=400NET; P=SCN; O=SNI; S=Frenning; G=Peter; OU1=CPH1; OU2=CC
***********  Come visit us on the web; URL
>FAQ on WWW:     
>Administrative requests:

FAQ on WWW:     
Administrative requests:

<Prev in Thread] Current Thread [Next in Thread>