[HamWAN PSDR] Capitol Peak cable system failure

[Bart Kus]

Hello,

I recently noticed we had multiple modems offline at Capitol Peak. Dale 
& I went to visit Capitol Peak a few days ago to inspect the situation.  
This is what we found:

https://photos.app.goo.gl/KXajGkDGLsW41dQz7

It's a little hard to see in the photos, but our cable bus has been 
ripped off the tower.  When examining the cabinet where the cables 
terminate, I found the cables to be wet, and we discovered water pooling 
in the bottom of the cabinet:

https://photos.app.goo.gl/kWwAWs2FvA6ghhC28

So not only are the cables dangling, they're also broken to the point 
where we lost communications and are now taking on water. This was 
likely caused by ice falling onto the cables, since that bottom bundle 
was mounted in such a way that it was protruding inside the tower, 
instead of being under the cover of angle iron like the rest of the 
horizontal coax nearby.  It's hard to pin down exactly when this 
happened, but the data I've seen points to Jan 23rd for S3 falling offline.

There is another cable of ours that had its support removed about 80ft 
up the tower.  It feeds the BawFaw link.  The damage was again along a 
horizontal run, from the cable ladder to the dish on the opposite side 
of the tower from the cable ladder.  We typically run these under the 
steel members, so I'm not sure what the failure there was.  I wasn't 
able to take good pictures of the dangling cable.

The whole bottom bundle is impacting on the edge of angle iron whenever 
the wind blows.  This has likely cut through the cables, although poor 
weather didn't allow close visual inspection.

I think this situation calls for some engineering changes in addressing 
this and other future deploys:

1) All horizontal runs must be protected from falling ice, by having 
steel members above them.
2) We should evaluate the use of tougher cable that is more resistant to 
physical damage.
3) We should evaluate the use of cable that is water-resistant when it 
does get breached.
4) We should evaluate the use of drip-loops (removing a section of 
jacket) before the cable reaches expensive equipment.
5) We should measure the forces required to remove beam clamps and 
establish minimum torque requirements.
6) A camera system may have spotted these cable failures before we 
experienced communication outages.  Deployment has been approved.

There is some good info on addressing (3) on this page, thanks to Dale's 
research:

https://www.truecable.com/blogs/cable-academy/into-the-great-outdoors-running-ethernet-cable-outside

To address (2) I think we can look at stepping up to CAT6, which is 
AWG23 instead of AWG24, and has a larger outer diameter.  The presence 
of a spline will also make the cable stronger.

This leaves us with a cushion problem, since our cushions are only 
designed for 1/4" cable and CAT6 is thicker than that.  It seems we have 
gotten exceedingly lucky here!  Valmont has just recently released a new 
cushion design that accepts 7 runs of 4mm-9mm cable! The part # is BCU158M7.



We also need to make sure these new cable selections will be compatible 
with our current-spec EZ-RJ45 ends.

I'm going to send a separate VOTE email to approve the purchasing of 
samples of this new hardware, so I can verify it will all work 
together.  Let's use this thread to discuss the problems, and if anyone 
has other/better solutions please share here.

--Bart

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