lucky escape

[skyhuck]

the only reason you cut a gob is to create the direction of fell, I.E the front edge of the hinge.

 

a 20% gob will fell a tree just as good as a 50%, straight , leaning or what ever.

 

With assisted felling you only want the direction with the gob your rope will do the pulling. Far more important with assisted felling is a strong hinge and accurate felling cut.

 

Sounds like some need to go on a refresher course in felling:001_tt2:

 

Rubbish!!!

 

The hinge is a "fulcrum", if you move the hinge further back you are putting more of the weight of the tree in the direction you wish the tree to fall.

 

As you say you want a strong hinge, the nearer the middle of the tree you go the wider the hinge, the wider the hinge the more holding wood you have, it simple

[stoxs]

Rubbish!!!

 

The hinge is a "fulcrum", if you move the hinge further back you are putting more of the weight of the tree in the direction you wish the tree to fall.

 

As you say you want a strong hinge, the nearer the middle of the tree you go the wider the hinge, the wider the hinge the more holding wood you have, it simple

 

Why in all the NPTC courses i have been on you should never have a gob over 20% of the tree then?

 

So you are saying a 50% gob is better than a 20%

 

I would like to hear from an NPTC instructor on this cause you got me thinking

[skyhuck]

Why in all the NPTC courses i have been on you should never have a gob over 20% of the tree then?

 

So you are saying a 50% gob is better than a 20%

 

I would like to hear from an NPTC instructor on this cause you got me thinking

 

Gob size was set back when trees were being felled for timber, big gob = wasted wood.

 

I felled an Elm butt the other week with a gob of around 5%, I did not want to lose any timber and the stem was leaning where I wanted it to go.

[Rob D]

I'm sure there is other reasons for the gob/sink cut to be around the 20% to 25% mark other than to reduce timber wastage... As in reasons of forces, where the hinge is etc... but it'll take someone with more knowledge than me to say why a 20%-25% gob/sink is more effective than a 50% gob/sink.....

 

Why are we taught on all the NPTC courses it should be around 20% if it doesn't really matter?

[skyhuck]

I'm sure there is other reasons for the gob/sink cut to be around the 20% to 25% mark other than to reduce timber wastage... As in reasons of forces, where the hinge is etc... but it'll take someone with more knowledge than me to say why a 20%-25% gob/sink is more effective than a 50% gob/sink.....

 

Why are we taught on all the NPTC courses it should be around 20% if it doesn't really matter?

 

I have never done an NPTC training courses, I was only assessed to get my tickets.

 

But if I was on a course and some one told me something like that, I would want to know why.

 

I find I only learn things that I understand, I NEVER do any thing because I'm TOLD too.

 

This is not a criticism, I'm just saying thats how I am!!

 

I never understand how a any one can drive a car without knowing how it works, but my wife does just fine.

[combined tree services]

i use many many different cominations of Gob cut , back cut , eather to leave one side of the hinge thicker than the other etc etc , i have always felt that if a am not happy felling a tree whether it is 35 feet tall of 80 feet tall i will not fell it , but as i gained more experiance felling trees i began to feel more comfortable and able to fell more awkward trees . but never the less trying to fell a tree right beside an ABC cable that is in fact not classed as insulated and also within the live zone of the cable i would have either got the utility company to make the line dead or got the utility company in to take the down to beneath the wires .

[Rob D]

I have never done an NPTC training courses, I was only assessed to get my tickets.

 

But if I was on a course and some one told me something like that, I would want to know why.

 

I find I only learn things that I understand, I NEVER do any thing because I'm TOLD too.

 

This is not a criticism, I'm just saying thats how I am!!

 

I never understand how a any one can drive a car without knowing how it works, but my wife does just fine.

 

That's just it - they probably did tell us why but I'm going back 8 years or so now... I was younger then!

 

It feels right to me to do a sink/gob cut around the 20% to 25% region - i.e there is more control than if you do it at 50%... But in this case I feel ignorant in that I can't give any weight to my arguement because I don't know the theory behind it ...

[Marc]

Like the Huckster i've only ever done the assesment, and please don't start saying if the nptc instructor didn't teach it then its not the way to do it, there are many ways of tackling a job other than the nptc way. Nptc is just extrememly basic proof of competency and thats all, the real learning happens in the huge variety of situation we find ourselves in on a daily basis. Also in the limited time you have to do an nptc unit they can only teach you so much so they tend to show you the more ideal and reliable techniques, but there are many other ways.

 

As for the 20-25% my understanding and this is only really self taught info i've gained over the few years i've been doing this so i may be completly wrong, is that as the tree begins to go over the weight is being applied to the hinge at the optimum time for best control.

Like Huck said though sometimes though at 20-25% the hinge will not be wide enough, so you'll want to go deeper to use more of the trees diameter as a hinge for better control/hold.

 

If i've dismantled a tree and left with just a stick to fell I will nearly always do a gob cut of 50% or more this puts the hinge at or beyond the center of gravity making it easier to pull the stem over (particularly usefull on short fat stems where a rope assist is less usefull as you have less leverage, and wedging over a big stem with no crown in a direction it doesn't want to go can be hard work), a tree with a full crown though this is unwise as you want to overcome the cog of gravity through wedging, lever, rope or winch assist then once its past cog/going thats when you want the center of gravity to be on the hinge for greatest control.

 

 

 

O.k lesson over for tonight ha ha