photos of tower 4 auxiliary main cable coming loose.

10aug20

Other Links:
auxmain4 damage main page
    On 10aug20 at 02:35:55 ast the auxmain cable from tower 4 (twr4 north aux main cable #301) came out of the socket at the tower and fell into the dish.
photos were taken of the damage using my iphone camera as well as the highres camera through the leica tm50 theodolite optics.

date/time
 		picts
 		camera/location
 		Description
10aug20 6am
 .jpeg1
.jpeg2
.jpeg3
 iphone
shot from base of tower 4
 first pictures of the damaged cable hanging from the platform.
  • the  auxmain is attached to the platform
  • It is laying over the auxmain cable from tower 12
  • it then goes down, leaning against the dome to the dish
  • you can see the two spots where the cable broke through the dome shell
10aug20 6:15am
 dish1
dish2
dishhr
 iphone
north edge of dish
looking south
(vip observing spot)
 holes in the dish caused by the falling cable.
  • The opening at the center of the dish (ao9) is east/west
  • It looks like none of the north south main cables (spaced every 25 ft) were broken
  • many of the east-west cables were broken.
  • In the east/west direction the damage spanned  5+ main cable sections or 125ft.
  • The cable sitting about 6 panel lengths( 36 feet) from the left edge of the ao9 opening.
  • the tangential dipole on the 5mhz hf tower has been bent.
  • the dishhr picture was my zooming in with the iphone..(not the most stable hand :).
10aug20 13:00
 twr4_1
twr4_2
 theodolite camera
from visitor center balcony
looking toward tower4
 Top of tower 4 from visitor center balcony        
  • the middle of the picture shows that socket that the cable pulled out of
  • the right side shows the auxmain4 on the south side that is still attached.
  • the black line down the middle of the tower is a dangling cable
10aug20 13:00
 plt1
plt2
plt3
plt4
 theodolite camera
from visitor center balcony
looking at aux4cable connection point on platform
 aux4main North cable connection point on platform
  • the cable connects about 60feet from the  north corner of the triangle.
  • the black rods are the ubolt that the cable connects to
  • plt1 is the rightmost portion of the ubolt
  • plt2,3 moves right to left to cover all of the ubolt
  • Some of the strands in the wire rope cable have popped.
  • plt4  shows the cable bending over the auxmain12 cable. The black plate is the rubbing plate that usually sit on top of the auxmain12 rubbing plate, so the cables don't wear where the overlap. The worry was    that the bolt in the rubbing plate might be scoring the aux12main cable (later pictures show that it is probably not doing that).
10aug20
13:00
 cbl1
cbl2
 theodolite camera
from visitor center balcony looking toward center of dish
 end of aux4min north  cable laying on the dish
  • this is the end of the cable that pulled out of the socket on tower 4.
  • You can still see zinc on the end of the cable.
  • each panel is 6 feet long so you can see about 18 feet of cable
  • the narrow wires are parts of the hf subreflector that came down.
11aug20
17:00
 cbl1
 iphone
from vertex shelter on platform looking at cable
 aux4main cable hanging over aux12main cable
  • This lets you exam the cable state down a ways from where it is hanging.
  • We had rotated the azimuth arm part way around in azimuth until the 2nd encoder came out of the encoder rack gear. We then had to go up an unplug the 2nd encoder to continue moving the  azimuth.
11aug20
17:00
 pic1
pic2
pic3
pic4
 iphone
from outside balcony on azimuth arm
 close ups of aux4main north rubbing plate on top of auxmain12 cable
  • pic1 shows the cable hanging over  aux12main cable
  • pic2 and 3 are closeups trying to see of the rubbing plate bolt is scoring the aux12main cable. In  these pictures you can not see any damage (but the bolt is awfully close).
  • These pictures were taken after we had finished rotating the azimuth to the hurricane stow position.
  • pic4 shows the end of the ubolt that the aux4main is connected to. tower 8 is in the background.
11aug20
17:00

 pic1

 iphone
from outside balcony on
azimuth arm
 looking down the aux4main cable from the azimuth arm balcony
  • this is after we had rotated the azimuth to the hurricane stow position,.
  • You can see the cable going to the ground and then back up snaking around the dish.
  • the black area below the opening is the road under the dish.
11aug20
17:00
 pic1
 iphone
stepping from the platform onto the cat walk.
 coming back from the platform stepping up from the platform unto the catwalk.
  • The shot is out of focus, but is shows that the platform is 12 to 18 inches below the catwalk step. This used to be pretty much level. (that's jaime in the background).


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