Albums: WA7DUH And WB7CNV Tower Construction

WA7DUH And WB7CNV Tower Construction

Photo essay of tower project at the station of Linda WB7CNV and Steve WA7DUH. They live just outside of the Richland and West Richland city limits in Benton County. Project is to initially erect a 65 ft guyed tower, but to design it for 75 ft or higher. Benton County has an ordinance controlling "communications facilities" (BCC 11.65) which includes "communication towers and antennas." Many of the requirements are exempted for amateur radio towers and antennas not exceeding 65 ft.
138 images Submitted by WA7DUH Steve St... on Sat, 08/04/2012 - 11:19am

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Prior to tower project, 44 ft fiberglass poles hold up a G5RV non-resonant dipole at the WB7CNV/WA7DUH residence.

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Uploaded on 08/04/2012 - 11:21am by WA7DUH Steve St... 946 visits

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Rebar grid construction for tower base.

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Uploaded on 08/04/2012 - 11:39am by WA7DUH Steve St... 859 visits

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Diagonal rebar wires are used to keep the grid square.

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Uploaded on 08/04/2012 - 11:39am by WA7DUH Steve St... 626 visits

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Linda WB7CNV cut about 450 tie wires for the tower base and 3 guy station rebar cages.

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Uploaded on 08/04/2012 - 11:39am by WA7DUH Steve St... 672 visits

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Tower base hole as specificed will be 4ft x 4ft x 5ft deep. 1st 6 inches is gravel and sand for moisture drainage, followed by 4 cement blocks that hold the bottom rebar grid up into the poured concrete. Tower base legs stick down into the gravel/sand (below the concrete so as to drain any water that may form in the tower legs. Another rebar grid will be embedded in the poured concrete 42 inches above the bottom grid seen in the picture.

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Uploaded on 08/04/2012 - 11:39am by WA7DUH Steve St... 593 visits

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The engineered specs call for #7 rebar (7/8"). Are we holding up a 2000 ft TV station antenna?

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Uploaded on 08/04/2012 - 11:39am by WA7DUH Steve St... 663 visits

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Benton County exemption from Benton County Code (BCC) 11.65 Communications Facilities that is really aimed at commercial installations such as TV/Radio stations or cell towers. However, this exemption did not remove the requirement for a building permit, structural analysis and original drawings with original (not copy) signature/stamp of Wash. State licensed Professional Engineer. Tower manufacturer's analysis and drawings were not acceptable (not original or Wash. licensed).

Also, county building dept. wanted to impose most of the requirements of BCC 11.65 anyway "for your and neighbor's protection". We battled several issues.

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Uploaded on 08/04/2012 - 6:16pm by WA7DUH Steve St... 697 visits

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One of three rebar cages for guy stations. Each guy station consists of a reinforced block of concrete 6ft x 4ft x 2ft high buried 4 ft below grade. That long 3/4 in rod is what the guy lines are tied to, and is buried in the concrete block. Each rod will sustain at least 8000 lbs of pull, which is about 4X overkill, since the worst case forces with an 88 mph wind is calculated to be 1000 lbs. Building code in Benton Co. requires survival of 88 mph winds.

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Uploaded on 08/04/2012 - 6:44pm by WA7DUH Steve St... 556 visits

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Uploaded on 08/04/2012 - 6:44pm by WA7DUH Steve St... 637 visits

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The guy rods have 6 x 6 x 1/2 in steel plates to keep them from pulling out of the concrete guy station blocks. Picture shows drilling the 3/4 in holes for the rods. I need a slower turning drill press.

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Uploaded on 08/04/2012 - 6:44pm by WA7DUH Steve St... 633 visits

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Holes for guy station anchors are 6ft long,4 ft wide and 4 ft deep. Concrete blocks are used to hold the rebar cage up off the bottom 6 inches so they are embedded in concrete when poured. Painted lines indicate the level of concrete when poured.

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Uploaded on 08/06/2012 - 8:49am by WA7DUH Steve St... 854 visits

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Lower painted line marks the height of the concrete.

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Uploaded on 08/06/2012 - 8:50am by WA7DUH Steve St... 609 visits

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Uploaded on 08/06/2012 - 8:50am by WA7DUH Steve St... 589 visits

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Yikes-- hit the sprinkler pipes. Anyone know a good way to find these sub-surface?

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Uploaded on 08/09/2012 - 7:59am by WA7DUH Steve St... 666 visits

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The break wasn't so bad. The mess was created when the sprinkler controller decided to turn the water on, washed out the far bank and filled the hole. Duhhhh.

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Uploaded on 08/09/2012 - 7:59am by WA7DUH Steve St... 694 visits

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Trying to fix a cave in. Sandy soil.

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Uploaded on 08/09/2012 - 7:59am by WA7DUH Steve St... 669 visits

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Uploaded on 08/09/2012 - 7:59am by WA7DUH Steve St... 581 visits

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Basic process when digging all the holes-- dirt goes in the cart, Linda (WB7CNV) hauls away.

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Uploaded on 08/09/2012 - 7:59am by WA7DUH Steve St... 588 visits

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This cart has a dump function, which really helps unloading!

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Uploaded on 08/09/2012 - 7:59am by WA7DUH Steve St... 796 visits

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Uploaded on 08/09/2012 - 8:00am by WA7DUH Steve St... 637 visits

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It's 104 today, so sweat band and wet neck towell in use!

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Uploaded on 08/09/2012 - 8:00am by WA7DUH Steve St... 969 visits

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Uploaded on 08/09/2012 - 8:00am by WA7DUH Steve St... 585 visits

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Uploaded on 08/09/2012 - 8:00am by WA7DUH Steve St... 634 visits

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Guy station base ready to be lowered into a guy station hole. Guy station blocks are buried about 4 feet down, so only half the dirt is hauled away. The pile in the background is what goes back in to cover it up.

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Uploaded on 08/09/2012 - 8:00am by WA7DUH Steve St... 608 visits

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Originally tried to lift rebar cage from a single point, but it caused the rebar cage to deform. A lifting frame was then built which pulled up vertical instead of an angle.

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Uploaded on 08/14/2012 - 5:23pm by WA7DUH Steve St... 595 visits