Plunge cuts

[David Humphries]

Have been asked recently by a couple of members, if I could explain further what they are.

 

Not rocket science as you can see, & I'm sure plenty of eco-minded arbs have been doing this for a good while.

 

Here is a picture set of an Oak, that has had a dysfunctional lower branch reduced back by using fracture & coro cuts (due to target/open access directly below)

 

On the side of the limb, you can see three scored plunges.

 

This is predominantly created for the specific use of bats, though inverts will likely use aswell.

 

Probably not really needed on this specific tree, as there are plenty of potential habitat niches on it all over the canopy (cavities, delamination, loose bark etc......)

 

we just add a few when & where we can.

 

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[David Humphries]

The technique involves using the nose of the bar in an upward direction, & boring in to the wood.

 

Continuing this a number of times to expand the cavity inside, whilst keeping the entrance relatively narrow.

 

 

The main thing to be very concerned about is obviously kick back.

 

Only should be carried out by experienced & competant chainsaw users.

Not really one for the novice.

 

 

It's advisable to get in the most solid & safe work postion you can possibly acheive. (this sometimes for us, means using a mewp. If I/we deem that a suitable position can not be acheived via rope & harness)

 

 

 

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[Pat Ferrett]

Cheers for that

 

A couple of questions..

Do you aim to place the cuts from under the limb or in the side ?

Is it best for the cuts to be with the grain or accross ?

Do you aim for an avarage width and depth ?

[David Humphries]

Here's one from this morning.

 

This Oak monolith had been standing dead (monitored) for a number of years.

Decided to reduce it, back end of last year.

 

 

Assesed for bat potential prior to carrying out the reduction.

It hadn't been noted as any kind of roost, and had no known sitings or audio pick ups on evening bat walks.

 

But upon inspection during the ascent, we uncovered this little fury ball.

 

http://arbtalk.co.uk/forum/picture-forum/24495-anyone-home.html

 

 

 

So pulled off the job until further more indepth (endoscope) inspection.

 

Nothing found, so we went ahead & reduced to a more comfortable monolith height a few weeks back.

 

Partly in mitigation (now having evidence of it being used) I've decided to enhance it's potential for use, by installing a few plunges to go with the retained cavity & loose bark.

 

a few shots.........

 

 

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Edited February 18, 2011 by Monkey-D

[David Humphries]

Cheers for that

 

A couple of questions..

Do you aim to place the cuts from under the limb or in the side ?

Is it best for the cuts to be with the grain or accross ?

Do you aim for an avarage width and depth ?

 

 

You're welcome

 

Away from prevailing weather (wind/rain) is probably the best

 

Need to think about flight path in to the target aswell.

(not so important on the exposed Oak mono)

 

Variety of widths/depths & orientation would be ideal.

 

On the last set the length of the 12" bar on the topper dictated the dimensions.

 

Could feel I was cutting into fairly degraded brown rot decay.

Which would I'm sure, be easy enough to cavity into further, for what ever wee beastie chooses to sign the tenacy.

 

 

 

Hope that answers your queeries.

 

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Edited February 18, 2011 by Monkey-D

[Xerxses]

Nice one!

That will from now on be incorporated in my treemolestationpractices further on....

I havent decided what to do with a massive maple with heavy oxyporus decay where the tree is forking out all the limbs... might be a Monolith, but would quite like to do a phased reduction... safety issues....hm...

 

Thanks for the pics!

[Graham]

A couple here but hard to see in the pics. Hopefully the bats have taken residence now.

 

[David Humphries]

A couple here but hard to see in the pics. Hopefully the bats have taken residence now.]

 

 

Spot on sir !

 

 

 

Private or authority client Graham ?

 

 

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[Big J]

Fascinating stuff! Always interesting to see your work David.

[Graham]

Spot on sir !

 

 

 

Private or authority client Graham ?

 

 

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LA and in a town park. Only targets are ducks so not too many safety issues:001_smile: