A tight squeeeeeze 'n' gargoyles

[Mark_B.]

A tight squeeeeeze \'n\' gargoyles

Yesterday we felled a Populus canadensis in a courtyard of the town hall in Basel. Dramatic tree in a extremely tight location. The tree was about 32 meters tall and well above the roof. It was a crying shame it was felled. The tree was sound and healthy, but I guess it's one of these psychological things where people feel a tree is too big for the location.

The council approached us about felling it a while back. Ethical qualms aside, it was a very interesting project to coordinate and set up.

It's been very cold here recently, so the wood becoming brittle was one consideration. Also, right in the decelearation zone, where you're slowing the bits that are rigged down were a pair of gargoyles and a stone table. All very historical. So: no uncoordinated dropping!

It was clearly time to haul out the GRCS! Using the visor attachment for the first time (check out Snarf's posts about this). Great piece of kit. What is does is fix the GRCS to the stem making any slippage impossible... it really makes me feel easier about dropping big wood in the GRCS!

Here's a view from the top of the tree into the drop zone and the working zone. As you can see it's not a ton of space and the pieces being rigged were sizeable.

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

GRCS attached with the visor, with Pascal - the star groundie of the day - in action...

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

Looking up the tree. We started a eight, by ten, when Lucas took this pic, most of the long limbs over the building had been removed.

It was a squeeze, with windows and old tiles all around. Combine this with brittle poplar limbs and you have a sure-fire receipe for a fiddly fell. Most of the time we were balancing limbs to avoid the load changing it's orientation and having branches snap and to avoid shocking the stem, or at least to reduce shock loads.

By the time we got this far it was pretty wibbly wobbly. Due to the removal of the side branches the structure of the tree looses it's natural shock absorbing system (i.e. the braches) and starts to move more - or differently. As a matter of course for this reason it can be a good idea to remove part or all of the top before removing the side braches.

In this case it wasn't possible due to lack of space. So we had to be pretty cautious rigging down the top. Nice, smooth and dynamic lowering. One of the moments you appreciate a good ground crew!

 

[pantheraba]

Re: A tight squeeeeeze \'n\' gargoyles

If I saw that job on my lunch break, I probably wouldn't go back to work, I'd stay for the show. Looks like an outstanding job...thanks for sharing.

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

View from the top...

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

Working the top. Bit tight for two. Up until then we had been using two lowering systems, lowering front and back. Just speeds things up a bit, and stops everyone getting cold.

After this Serge carried on and I went down.

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

Now you're probably wondering where the gargoyles come in.

Weeeell, usually, once the branches and width are down, the most difficult part is done. After that it's lowering the heavy wood. With the GRCS, no problem. Nice and smooth, dynamic lowering gradually braking the bits before they hit the ground.

Not here. I mentioned the gargoyles before? Here's a pic of one...

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

So, when I was lowering the top bits, I took a bit about body length, maybe 40cm dia. Poplar wood, I reckoned it'd weigh in at about 180kg. We had about 15 meters to drop it into. Pascal took one and a half wraps on the friction bollard.

The bit was a bit heavier than estimated, smacks the wall and just misses one of the gargoyles. Whew! That would have been our profit of the day down the drain. At first I couldn't figure out what was going on down below. As far as I was concerned the pieces had gone down nice and smooth. Yes, but...

I'm now officially gargoyle traumatized!/forum/images/graemlins/aaa.gif

After the job we discussed the situation. Pascal who was on the GRCS said it was his fault, not enough friction. I don't agree. As always, it's never one person in a team who goofs up, it's a chain of events. In this case, I was weighing up length of the piece vs. efficiency. Do you take one meter bits with low weight, but take into account the necessity to move the rigging system many times, this making it slow and more points for things to go wrong. Or do you choose larger pieces with more weight, but less change-overs and faster. There's a break-even point there. Make your plan and work it.
In this case I should maybe have taken into account more the fact that there was things in the lowering zone not to be damaged and made the pieces even smaller. But it was an unusual situation in that it wasn't the drop zone on the ground that was the problem but the deceleration zone three or four meters up that's usually clear to do dynamic thanggs in.

Anyway, to finish off with, this one made me laugh. It's a bit David Hamilton-ish. You know, the dirty old man who was alway photographing young boys and girls with a misty effect and turning the pixs into atrocious calendars...

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

What d'ya know, me again.

A very last one: This is how council boys and gals do their tidy-up. This baby cost them € 120'000. Wow. You'd want to have it running a lot with that kind of price tag.

Still, if someone offered me one for free, I might say "yes", so maybe I'm just jealous.

 

[Stumper]

Re: A tight squeeeeeze \'n\' gargoyles

It appears that Pascal was running the ropes in grippy gloves. That surprises me. I like those for climbing but find leathers to be superior for handling lowering lines.
Very interesting job Mark.

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

Good point, I asked him about the gloves, too.

Personally I prefer leather gloves for running lines, but having said that, in the end it didn't really matter anyway as there sure weren't no rubber left on the gloves in the end. /forum/images/graemlins/hot.gif

 

[Norm_Hall]

Re: A tight squeeeeeze \'n\' gargoyles

Nicely done Mark. Tite quarters all right. A good groundie can make you or break you. Did you switch out the winch for the drum when drop hitching? Thanks for sharing.

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

Norm, absolutely!

I think it's really important to change over. Not that I doubt the Harken's ability to bear extreme shock loading, but just from a systematic approach point of view, I think it ought to be clear that when there's no shock loading going on, use the Harken. If there's the possibility for a shock load, switch to the drum.

 

[120770]

Re: A tight squeeeeeze \'n\' gargoyles

Mark wicked and amazing pictures of the popular dismantle, would of been a nice job to be part off. Yeah I find these Showa rubber gloves a real pain for doing lowering also,they just burn up. Better using a good leather pair.

I guess you got snowed off work today also and yes has been real cold recently, seemed you had a good day in the office.

Scotty

 

[Mark Chisholm]

Re: A tight squeeeeeze \'n\' gargoyles

Nice work Mark, and thanks for documenting it. I love the view. I have one question, whenever I discuss removal of a tree by rigging it down with ropes and such I call it "removing a tree or roping it down or simply rigging". When I speak to my friends in Europe, they always say "we felled a tree" or a "tree felling job". This to me is a job where you simply cut it from the ground or "fell" it. No climbing involved. Why is it different in North America regarding this? Any idea?

 

[klimbinfool]

Re: A tight squeeeeeze \'n\' gargoyles

Very nice job Mark B.

Glad your asking that queston , MArk. I was was wondering the same thing myself.
I do have a question to . If you were worried about the tree being so brittle, why did you put two climbers in the top end of that tree? especially where it's most vulerable

Norm , that was a good question about switching over to the drum. Although , from what I have seen and done you cant hurt that Harken. You would have to be totally abusive and if you were, I wouldn't want to be in the tree. If a 5000lb Volvo cant be shock loaded into the HArken with out failing , I think it can withstand normal rigging.

The main reason I would switch over is the ability to let the pieces run more smoothly. The Harken has the abrasive surface for winching and sometimes makes it hard to to really let things move when you need them to .Thats my opinion though .

Greg

 

[Lumberjack]

Re: A tight squeeeeeze \'n\' gargoyles

For bigger rigging I use the drum, for stuff I can rig out on 1/2" or 9/16" I normally use the winch as I am lifting with it, then perhaps letting it run, depending on the job.

Here is one of the bigger pieces I have done (and have pictures to show it) using 3/4" stable braid and the drum, according to the chart it weighs around 2300lbs:

Loading on the trailer:

 

[Mark_B.]

Re: A tight squeeeeeze \'n\' gargoyles

Greg,

by the time we got to the top - as you point out, the most vulnerable part in terms of snapping - we felt the tree was not as brittle as we thought it might have been. On the contrary, the wood seemed quite heavy, as though water were allready being distributed through the tree before spring.

My main incentive for changing to the drum before bringing down the heavy stuf is if you're not winching, why bother with the Harken. It really hurts to smack the Harken with a large log. And that will damage it.

Mark,

I hear what you're saying. It's like with all these international things, we all share a common lannguage, apparently, but so often we mean different things. I think I sometimes get mixed up between german and english terms. But point taken, I'll try to be more precise in future.

 

[TreeCo]

Re: A tight squeeeeeze \'n\' gargoyles

[ QUOTE ]

It's like with all these international things, we all share a common lannguage, apparently, but so often we mean different things.

[/ QUOTE ]

Hey Mark B.

Thanks for the thread.

I threw a tree the other day./forum/images/graemlins/grin.gif

Not hurled....but threw.

Dan

 

[Colin]

Re: A tight squeeeeeze \'n\' gargoyles

Great job Mark, and well documented! Thanks!