[TowerTalk] Tower Trailer Safety;maintainence

["Pat Barthelow" <aa6eg@hotmail.com>]

Folks:

I am refurbishing a State Highway Department (Caltrans) floodlight support 
trailer for re use as a ham radio tower trailer.  The trailer has a HD 
Tristao 60 ft tower, with two motorized pivot (to vertical) and telescoping 
(3 20 ft sections) cable drives.  The trailer is weathered, but inspection 
shows only localized surface rust of parts of the frame and erection 
fixtures.  I want to clean up and paint, possibly repair gavlanized 
surfaces, and replace lifting cables.  There will be a generator mounted 
aboard, and cabinets for equipment storage.  The tower is in excellent shape 
and has a HAM 4 rotator.  The trailer has two pivoting outriggers that are 
simple pipes, angled to the ground with footing plates, and a turnbuclke 
cable to bring the outrigger foot to bear  pressure on the ground. Pictures 
exist for anyone interested in discussing improvements, safety issues.  I 
see no locking features for each section, when extended.  How can this be 
made safe?  Is it safe to climb to each joint, and insert a block?

I am reading case histories of crane and tower accidents on the web, and 
have found a number of crane accidents (often fatal) that were caused by 
crane outriggers failing for a variety of reasons, often by putting more 
than allowable PSI on the ground, resulting in earth shifting, unbalancing 
the crane, and causing collapse.  Or outriggers that were not of sufficient 
radius to ensure stability.   Not wanting to experience this firsthand with 
the tower trailer, I want to learn more about outriggers, scrutinizing the 
adequacy of  the two existing ones at the rear of the trailer..  The trailer 
is only a single axle, is about 18 ft front to rear, approx 7 ft wide, and  
the tower is very close to the rear, when vertical, with the two outriggers, 
about 15 ft long, pivoted and producing a triangular footing comprising the 
outriggers, the road wheels, and the trailer tongue  screw jack.
Hopefully the ascii char drawing comes out OK below...
I am looking for feedback wrt safety issues, and surface rust refurbishment 
techniques..
Email me for pics if interested...
Tnx...de Pat AA6EG    aa6eg@hotmail.com
                             ____
                           /    0    \    Pintle ring for tow
                          /            \
                         /X     y      \  Vertical  Screw Jack at X to 
ground footing
                        /        y       \
                       /         y        \
                      /--------------------\    Cross member supporting 
horiz tower@ abt 6 ft fm gnd.
                      |          y         |    Y=Tristao 3 section 60 ft 
heavy duty tower
                      |          y         |         with motorized 
erection fixtures
                      |          y         |      Tower supported about 6ft 
high on trailer frame.
                      |          y         |
                      |          y         |
                   () |          y        | ()
                   () |          y        | ()  Road Wheels
                   () |          y        | ()
                      |          y        |
                      |       -------      |    Pivot axle for putting 
tower vertical @ about 5.5 ft fm gnd
                      |          y        |
                      |         / \       |
                      0-------/    \------0   Cradle for base of tower to 
be pinned vertical, abt 8" above gnd
                    X                        X
                  X                             X
                X                                 X
              X                                     X       Outriggers, 
Pivoting pipes from about 6' elevaiton
            X                                         X     Footing 
pressure through turnbucke-cable
          X                                             X
       [ X ]  foot pad                               [ X ]  foot pad


_______________________________________________

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