Considering the addition of an arb digger

[Big J]

I was hoping to obtain some advice with regards to an arb digger. 

 

I've a large job coming up thinning a hardwood woodland. It's not fantastically accessible, and the extraction route is long. The limiting factor for productivity is the rate at which I can extract. I cannot do anything about the distance (measured at 680m to the centre of the first block to the middle of the extraction point) so the only way I can speed it up is to improve the presentation of the timber for me to collect. If it was in a neat pile next to ride, it would reduce loading time from 10 minutes to about 3 minutes or less. 

 

Due to the terrain, we're going to have to winch/grapple skid a lot of the timber to rides where the forwarder can operate. The side slopes are the issue in this woodland. So my train of thought is that if the trees are being skidded out to a ride, then the most efficient way to process them would be with a small excavator with a grapple saw. The trees are generally very straight and whilst you'd obviously not be able to do everything with the grapple saw, you'd be able to do much of it, and be able to stack the timber ready for the forwarder.

 

I'd thought that something like a Kubota U20 with a grapple saw (still to be determined which one) would be a valuable tool, and would speed up production in the woodland significantly. Additionally, the reduction in motor manual processing would result in less tired workers and better overall productivity on what'll be a long job.

 

Thoughts? 

[gdh]

We've done a bit of forestry (hardwood) work with our takeuchi 8tonner and it certainly speeds things up, especially felling into a field when you can scrape up brash quickly which you can't do with a forwarder/trailer.

 

Also have a tree shear which is brilliant for debranching and smaller trees.

[arboriculturist]

Same - with 7,5 tonne machine. A decent grapple saw on an Endcon tiltrotator and there would be no going back! that's a hefty investment though.Waste of time on anything less than 5 tonne machine. preferably 7.5.

[Big J]

So no point on a smaller machine? I actually don't have the space in this stand for a 7.5 tonner, such is the tightness of the access and the stand itself. 

 

[spuddog0507]

kubota u20 definatly a big no from me not big enough, we have had a kubota 5 tonner on a job this year and a hitatchi 2.9 tonne both with fixed geared rock grabs on, and as the hitatchie is ok and we have moved some biggish logs about with it, its no where near the machine as the 5 tonne kubota both machines have the same grab on and do make things easier like moving brash about and if there is a stump in the way just ripp it out, and when your loading timber you wont be loading it with crane on forwarder for long if you have digger and grab on site as with digger it takes a lot less time to load, and just to be curiouse how many lengths of timber you putting on forwarder if you can load in 3 mins or less it cant be many, first photo 5 tonne kuota 2nd 2.9 tonne hitatchie 3rd the grab and 4th 2.5 mtr O/S 740mm diameter moved with hitatchie but very carefully the amount of times i have had that on one track is unreal as compared to the bigger kubota, and a sound word of advise is if you can hire one in DO it as if it wont do your job you can all ways send it back just go as big as you can and steel tracks better than rubber in a forest enviroment. 

[LGP Eddie]

What max cut diameter are you realistically hoping for?

 

 

Eddie.

[Big J]

6 minutes ago, LGP Eddie said:

What max cut diameter are you realistically hoping for?

 

 

Eddie.

350mm I'd guess.

[LGP Eddie]

Firstly the U20 in Expanding undercarriage form is a straightforward No!

The reason for this is the horrendous lack of ground clearance due to the design of the box section slides.

The standard version is fine.

 

Grapple Saws I cannot recommend whatsoever on an Excavator with Fixed Mount, they are a complete bastard as soon as you take them away from straight cross cutting.

It’s a complete subject in itself and an expensive one!?

 

The tool you need and it will serve you well in all kinds of applications is a Mecanil SG160 with Radio Remote control.

 

Quite simply this Head dangle mounted with rotator to a suitable machine with two dual acting auxiliary circuits would be unreal.

350mm Cut, absolutely no hassle, just grab it and cut, you can angle it to suit the slope, limbs etc.

Load, stack, cross cut, fell, whatever.

 

Then there’s the fact you can mount it on larger carriers if required to do bigger jobs requiring more reach.

 

As for the carrier machine, it’s almost secondary in this situation.

I’d buy the Head and Hire the machine for the first job whilst I found my feet.

Hiring means you can get a new machine likely to have the necessary pipework, and if you need larger/smaller you can swap it.

You’ll learn an awful lot about what may be your ideal purchase.

 

This video shows a similar very simple head on a Kubota, the Mecanil has way more tricks up it’s sleeve than this.

 

 

 

See the U20’s Undercarriage design?

 

 

 

Eddie.

[Big J]

Thanks for all the info Eddie - loads of food for thought. Any idea on rough cost for a head like that?

[donnk]

350 a week for 7 tonners. no brainer. would maybe pay the 500 and get a 13 tonner