Rigging Errors

[RC0]

Here’s a couple of rigging mistakes while removing a Robinia this last Thursday. Nothing major but seems as I had the camera rolling I figured it might be worth posting.

 

The Hobbs ‘winch’ allows the ground-worker to reel-in unwanted rope slack which might occur as a branch/log begins to move after or while it’s being cut. The technique is especially useful where the pulley/block is set below branch/log i.e. blocking down a spar while implementing the notch-hinge technique.

 

While rigging a spar you wont notice the slack because it all happens so fast….but it happens i.e. when you cut a notch out of a log, what you’re doing is shortcutting its fall-path….kind of like having your feet kicked from underneath you and falling on your knees before folding over face first. So a deep, open-face notch induces more rope slack but is easy to tip, while a shallow notch falls further, minimises the slack but takes more effort to push/pull over.

 

In the first clip, the ground-worker (usually excellent) somehow manages to fall over while tending the slack but then instinctively grips the rope and causes the log to slam into limb that I’m attached to. Thankfully, it wasn’t my primary attachment point, so I was able to keep my footing easy enough….however, if not for that high tie-in point, I may have been found wanting….it wouldn’t be the first time either.

 

In the second clip the hobbs winch is utilized to pre-tension the line, so to aid a back-leaning-log, fall in the opposite direction. When pre-tensioning with either the Hobbs or GRCS-Harken (for those who don’t know), several wraps are required to gain the rope-traction needed around the spools to stop the rope from spinning as the winch is cranked….but once the lift/tension is achieved, the operator will more often than not have to remove a couple of wraps in order to then lower the log, unless it were extremely heavy of course. However, on this occasion the ground-worker forgot the second part but I should have really glanced down to make sure anyway.

 

The rotating log kinda looks like a big fish swimming around a very vulnerable prey….and don’t be fooled by its appearance on the clip, the wide-angled camera lens really squashes everything in so it all appears much smaller than in real life.

 

WARNING: The latter scene contains bad language so don’t watch if you're easily offended. Unfortunately, these things slip out in the heat of the moment. Thanks

 

[ame]http://uk.youtube.com/watch?v=KKVU6F3VU8Y[/ame]

Edited November 22, 2008 by RC0

[Nick Waring]

Wowzer, that 2nd clip was close. thanks for posting that reg, keep the vids coming, very insperitional.

Edited November 22, 2008 by Nick Waring

[Ian C]

Could of been nasty Reg, guess we all make mistakes but just goes to show how easy it is to get hurt in this job! keep the vids coming, love watching your work.

 

Oh and thanks for the warning of bad language, I HATE that word.......

 

 

 

 

 

Hell.........

[High Scale]

Nice post Reg.

[MattyF]

Does that guy use your hobbs a lot reg?..

[silky fox]

informative as usual reg

[Ian150482]

Crap, that second clip was close. Thanks for posting Reg.

[David Humphries]

Can't believe you grabbed the trunk @ 1.04 when it hit, what a big girls blouse

 

 

Never enough post error annalysis, nice one Mr Coates.

 

Great use of the site

 

 

 

 

 

 

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[scotspine1]

While rigging a spar you wont notice the slack because it all happens so fast….but it happens

 

It happens in this vid at 9.30, watch the rope belly down as the piece drops off the stem. Great footage -

 

[ame=http://uk.youtube.com/watch?v=tq1p4xc1GtM]http://uk.youtube.com/watch?v=tq1p4xc1GtM[/ame]

 

Rigging Errors vid - In the first clip of your vid why would you remove the slack from a piece so high up?

 

In the second clip, could those groundies milling around in the background have been put to good use by using a control/tag line to stop the piece swinging about wildly? Its very hard to judge the exact trajectory of a big piece your letting run, I've seen walls, fences and a greenhouse getting demolished when the guy running the ropes has misjudged the weight or wraps.

 

Nice vid again Reg, thanks for posting.

Edited November 22, 2008 by scotspine1

[Ben]

That second clip was hair raising, glad it didn't get you.