Jump to content
Big J

Low impact forestry services in Devon and the South West

Recommended Posts

Trouble is.......

 

What is classed as a thinning machine?  In Conor's example an Ergo isn't exactly a small machine, certainly not in first thinnings.  Put almost any off the shelf machine from any of the big manuracturers into first thinnings and it'll look HUGE.  What the manufacturers class as thinnings machines are, in my opinion, really more suited to later thinnings.  In order to do first thinnings properly you're looking as specialist small scale machinery (such as yours J) or going back to hand cutting - or a combination of both.  Problem then is a lack of funds to cover the costs.  Problem if you put machines that are too big in is you end up skinning trees and damaging the ground , you end up with butt rot and potentially unstable crops.  The result can be seen all over the place either non-thin regime or a delayed thin, more instability followed by premature clearfell.

 

There's still quite a bit of figuring out to be done in the thinning conundrum, small scale equipment seems to be getting better, but I thing there's still a bit to do to persuade people (owners / investors) that it's worthwhile doing properly.

 

 

I should add that I'm talking really about upland spruce (sitka) forests, those who are luckier to be lower down with better soils and more diverse crops may be able to make thinnings work easier.

  • Like 5

Share this post


Link to post
Share on other sites

Couple of points , 840 nice machine which I was very surprised at ( I'm used to 1510-1910 and 865) it carries well and with the right man at the helm can travel bad ground very well !

Conor, I'm guessing that wood was a private wood not state land ? I know if "we" had worked a wood like that for the three private companys we cut for we would have been looking for other work after that !! 

  • Like 1

Share this post


Link to post
Share on other sites

It comes back to cost every time doesn't it?

Unless a contractor is in small thinnings full time then its a case of making the best of what you have. Harvesters that will cut big will also cut small, but it doesn't work as well the other way round. Cutting two row racks in a lot of stands is the only option to facilitate machinery, but even a few degrees of side slope can bollocks things, forwarders tend to creep and standing trees get marked.

50-80 cu/m days are common in poor quality first thinnings and with a harvester/forwarder setup needing to earn £1500-1800 a day minimum  its not that attractive, taking downtime into consideration. The flip side of it is that timber stands don't have to achieve the quality of past generations,...most computerised mills are looking for 45cm max butt diameter which is easily achievable as a final crop.

In a perfect world perhaps things would be done differently, but since mechanised harvesting its been a case of go with it or get out, there could be ten + contractors look at harvesting sites and someone will always do it, normally highest bidder buys the wood, lowest bidder gets the harvesting. although marketing companies are specifying maximum size machinery in some areas it tends to get overlooked when theres a few quid at stake.

You only need to work crops that haven't been thinned to see the losses caused by suppression, this tends to get overlooked , yet damage in a thinned crop is the first thing that gets picked up on,..rock and a hard place.

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Elmsdown Forestry said:

Evening J

 

Have a  840tx myself, very capable machine and with the right operator very good over the ground. 

Just watch out for the pins/bolsters in the racks not Komatsu’s finest quality metal and bend really easily. Check the welds on the bunk extension and if it’s been extended to fit more than 2 bays of 2.7-2.8  stay away as will cause centre joint issues. 

Beware in stuff like Corsican 2 bays of 2.7 chip can easily be upto 15 ton. 

Good luck with it. 

 

 

Really appreciate the pointers. Many thanks for that. 

I don't think (though I may be wrong) that it's been used for double bays, as the capacities quoted to me by the owner were 12t of 4.9s, 10t of 3.7s and 8t of 3.1s, implying to me that that is all it's been used for. 

 

It's first job is a majority cedar thinning, with some douglas and spruce. Mostly just collecting from a track from winched material, with some tricky racks too.

Share this post


Link to post
Share on other sites
8 minutes ago, Big J said:

Really appreciate the pointers. Many thanks for that. 

I don't think (though I may be wrong) that it's been used for double bays, as the capacities quoted to me by the owner were 12t of 4.9s, 10t of 3.7s and 8t of 3.1s, implying to me that that is all it's been used for. 

 

It's first job is a majority cedar thinning, with some douglas and spruce. Mostly just collecting from a track from winched material, with some tricky racks too.

I did a stint on one last year , for short haul work they are handy machines.

Some were lengthened at the front and were ok,..its those that were lengthened behind the bogies that caused most problems as it puts too much leverage on centre joints.Its always worth bouncing the crane around on them to check for centre joint play ,bearings aren't cheap and if the casting is damaged you are looking at machining /line boring, which soon runs away with a few grand.

Sounds like yours is standard length.

  • Like 1

Share this post


Link to post
Share on other sites
28 minutes ago, ESS said:

It comes back to cost every time doesn't it?

Unless a contractor is in small thinnings full time then its a case of making the best of what you have. Harvesters that will cut big will also cut small, but it doesn't work as well the other way round. Cutting two row racks in a lot of stands is the only option to facilitate machinery, but even a few degrees of side slope can bollocks things, forwarders tend to creep and standing trees get marked.

50-80 cu/m days are common in poor quality first thinnings and with a harvester/forwarder setup needing to earn £1500-1800 a day minimum  its not that attractive, taking downtime into consideration. The flip side of it is that timber stands don't have to achieve the quality of past generations,...most computerised mills are looking for 45cm max butt diameter which is easily achievable as a final crop.

In a perfect world perhaps things would be done differently, but since mechanised harvesting its been a case of go with it or get out, there could be ten + contractors look at harvesting sites and someone will always do it, normally highest bidder buys the wood, lowest bidder gets the harvesting. although marketing companies are specifying maximum size machinery in some areas it tends to get overlooked when theres a few quid at stake.

You only need to work crops that haven't been thinned to see the losses caused by suppression, this tends to get overlooked , yet damage in a thinned crop is the first thing that gets picked up on,..rock and a hard place.

 

1 hour ago, Spruce Pirate said:

Trouble is.......

 

What is classed as a thinning machine?  In Conor's example an Ergo isn't exactly a small machine, certainly not in first thinnings.  Put almost any off the shelf machine from any of the big manuracturers into first thinnings and it'll look HUGE.  What the manufacturers class as thinnings machines are, in my opinion, really more suited to later thinnings.  In order to do first thinnings properly you're looking as specialist small scale machinery (such as yours J) or going back to hand cutting - or a combination of both.  Problem then is a lack of funds to cover the costs.  Problem if you put machines that are too big in is you end up skinning trees and damaging the ground , you end up with butt rot and potentially unstable crops.  The result can be seen all over the place either non-thin regime or a delayed thin, more instability followed by premature clearfell.

 

There's still quite a bit of figuring out to be done in the thinning conundrum, small scale equipment seems to be getting better, but I thing there's still a bit to do to persuade people (owners / investors) that it's worthwhile doing properly.

 

 

I should add that I'm talking really about upland spruce (sitka) forests, those who are luckier to be lower down with better soils and more diverse crops may be able to make thinnings work easier.

 

I'd like to get your opinions on a thinning approach I'd like to undertake on our next job. 


We've about 10 acres of spruce to thin. It's had racks in 4 years ago, and the trees adjacent to the racks are noticeably much larger than the internal trees. 1 in 7 so far. 

 

I'd suggested some further thinning as not much was taken out of the matrix at all. In in the interests of keeping it fairly simple, and in order to maximise the growth of the remaining crop, I was proposing a sort of hit and miss line thin between the racks. So, presently, there are 6 lines between each rack. Starting with line 3, you remove one tree. You then take the next tree from line 4, and then back to line 3, then back to 4 and so on. My theory is that having seen the hugely increased growth in the lines adjacent to the rack, conventional rack thinning results in improved growth and form in only two lines (those adjacent to the rack) whereas this hit and miss method results in additional space for all trees in all racks between the main racks (with extra space in lines 2, 3, 4 and 5, with additional space already present in lines 1 and 6 from the previous rack thinning). 

 

My thoughts regarding the advantages are as follows:

 

  • It's very simple for the cutters to grasp. No need for them to selectively thin, as they'll have a rigid structure to work to
  • It creates a slightly more organic feel to the thinning than putting in another rack, as the hit and miss approach means you won't see a straight rack
  • It creates extra space and light for every tree between the existing racks
  • It suits my winch processor setup as it's super easy for me to do but you be a complete PITA for a harvester.

 

My justification for going in relatively soon after the last thinning is that it's a sitka stand of not especially good form or YC. The ground is generally too dry and the trees at a little over 20 years old are only averaging 40-45ft, and I reckon are around 0.17-0.2 cube per tree. In performing a 15% thin, I think we can increase the growth rate of what remains, and we're offering £6/t for it standing, which I don't think is too bad for a low impact approach on a sensitive site.

 

My hope is that if this method proves successful on this site, it could be used on other first thinnings. I'd then propose putting racks in at 1 in 14 intervals, with hit and miss thinning inbetween. Fewer racks is something I can get away with wiht the winch processor and it leaves a less mechanised finish for the landowner. 

 

If you disagree with the approach, please say. I have a lot of time in machines to think about these things and I'm happy to be told when something is a shit idea!

  • Thanks 1

Share this post


Link to post
Share on other sites
Just now, ESS said:

I did a stint on one last year , for short haul work they are handy machines.

Some were lengthened at the front and were ok,..its those that were lengthened behind the bogies that caused most problems as it puts too much leverage on centre joints.Its always worth bouncing the crane around on them to check for centre joint play ,bearings aren't cheap and if the casting is damaged you are looking at machining /line boring, which soon runs away with a few grand.

Sounds like yours is standard length.

I have that experience with the dinky forwarder. It has a bed extension that I can put in, but I never do as it completely buggers the balance of the machine, and as you say, you can feel the stress on the centre joint. It's best suited to 3m lengths, but 3.7s are OK

Share this post


Link to post
Share on other sites

 

2 minutes ago, Big J said:

 

 

I'd like to get your opinions on a thinning approach I'd like to undertake on our next job. 


We've about 10 acres of spruce to thin. It's had racks in 4 years ago, and the trees adjacent to the racks are noticeably much larger than the internal trees. 1 in 7 so far. 

 

I'd suggested some further thinning as not much was taken out of the matrix at all. In in the interests of keeping it fairly simple, and in order to maximise the growth of the remaining crop, I was proposing a sort of hit and miss line thin between the racks. So, presently, there are 6 lines between each rack. Starting with line 3, you remove one tree. You then take the next tree from line 4, and then back to line 3, then back to 4 and so on. My theory is that having seen the hugely increased growth in the lines adjacent to the rack, conventional rack thinning results in improved growth and form in only two lines (those adjacent to the rack) whereas this hit and miss method results in additional space for all trees in all racks between the main racks (with extra space in lines 2, 3, 4 and 5, with additional space already present in lines 1 and 6 from the previous rack thinning). 

 

My thoughts regarding the advantages are as follows:

 

  • It's very simple for the cutters to grasp. No need for them to selectively thin, as they'll have a rigid structure to work to
  • It creates a slightly more organic feel to the thinning than putting in another rack, as the hit and miss approach means you won't see a straight rack
  • It creates extra space and light for every tree between the existing racks
  • It suits my winch processor setup as it's super easy for me to do but you be a complete PITA for a harvester.

 

My justification for going in relatively soon after the last thinning is that it's a sitka stand of not especially good form or YC. The ground is generally too dry and the trees at a little over 20 years old are only averaging 40-45ft, and I reckon are around 0.17-0.2 cube per tree. In performing a 15% thin, I think we can increase the growth rate of what remains, and we're offering £6/t for it standing, which I don't think is too bad for a low impact approach on a sensitive site.

 

My hope is that if this method proves successful on this site, it could be used on other first thinnings. I'd then propose putting racks in at 1 in 14 intervals, with hit and miss thinning inbetween. Fewer racks is something I can get away with wiht the winch processor and it leaves a less mechanised finish for the landowner. 

 

If you disagree with the approach, please say. I have a lot of time in machines to think about these things and I'm happy to be told when something is a shit idea!

 

It's the last day of my easter "holiday" and I need to be up early tomorrow so I'll re-read your post tomorrow when my brain is working properly.  All I can remember right now is that the yield models show as little as 3 years between thinnings for sitka so you're not totally out with going in so soon.

  • Like 1

Share this post


Link to post
Share on other sites
 
I'd like to get your opinions on a thinning approach I'd like to undertake on our next job. 

We've about 10 acres of spruce to thin. It's had racks in 4 years ago, and the trees adjacent to the racks are noticeably much larger than the internal trees. 1 in 7 so far. 
 
I'd suggested some further thinning as not much was taken out of the matrix at all. In in the interests of keeping it fairly simple, and in order to maximise the growth of the remaining crop, I was proposing a sort of hit and miss line thin between the racks. So, presently, there are 6 lines between each rack. Starting with line 3, you remove one tree. You then take the next tree from line 4, and then back to line 3, then back to 4 and so on. My theory is that having seen the hugely increased growth in the lines adjacent to the rack, conventional rack thinning results in improved growth and form in only two lines (those adjacent to the rack) whereas this hit and miss method results in additional space for all trees in all racks between the main racks (with extra space in lines 2, 3, 4 and 5, with additional space already present in lines 1 and 6 from the previous rack thinning). 
 
My thoughts regarding the advantages are as follows:
 
  • It's very simple for the cutters to grasp. No need for them to selectively thin, as they'll have a rigid structure to work to
  • It creates a slightly more organic feel to the thinning than putting in another rack, as the hit and miss approach means you won't see a straight rack
  • It creates extra space and light for every tree between the existing racks
  • It suits my winch processor setup as it's super easy for me to do but you be a complete PITA for a harvester.
 
My justification for going in relatively soon after the last thinning is that it's a sitka stand of not especially good form or YC. The ground is generally too dry and the trees at a little over 20 years old are only averaging 40-45ft, and I reckon are around 0.17-0.2 cube per tree. In performing a 15% thin, I think we can increase the growth rate of what remains, and we're offering £6/t for it standing, which I don't think is too bad for a low impact approach on a sensitive site.
 
My hope is that if this method proves successful on this site, it could be used on other first thinnings. I'd then propose putting racks in at 1 in 14 intervals, with hit and miss thinning inbetween. Fewer racks is something I can get away with wiht the winch processor and it leaves a less mechanised finish for the landowner. 
 
If you disagree with the approach, please say. I have a lot of time in machines to think about these things and I'm happy to be told when something is a shit idea!
The only thing that may cause problems is sitkas ability to remain resolutely stuck to their surrounding trees, and not fall over.

Share this post


Link to post
Share on other sites
10 minutes ago, slack ma girdle said:
On 22/04/2019 at 23:26, Big J said:
 
I'd like to get your opinions on a thinning approach I'd like to undertake on our next job. 

We've about 10 acres of spruce to thin. It's had racks in 4 years ago, and the trees adjacent to the racks are noticeably much larger than the internal trees. 1 in 7 so far. 
 
I'd suggested some further thinning as not much was taken out of the matrix at all. In in the interests of keeping it fairly simple, and in order to maximise the growth of the remaining crop, I was proposing a sort of hit and miss line thin between the racks. So, presently, there are 6 lines between each rack. Starting with line 3, you remove one tree. You then take the next tree from line 4, and then back to line 3, then back to 4 and so on. My theory is that having seen the hugely increased growth in the lines adjacent to the rack, conventional rack thinning results in improved growth and form in only two lines (those adjacent to the rack) whereas this hit and miss method results in additional space for all trees in all racks between the main racks (with extra space in lines 2, 3, 4 and 5, with additional space already present in lines 1 and 6 from the previous rack thinning). 
 
My thoughts regarding the advantages are as follows:
 
  • It's very simple for the cutters to grasp. No need for them to selectively thin, as they'll have a rigid structure to work to
  • It creates a slightly more organic feel to the thinning than putting in another rack, as the hit and miss approach means you won't see a straight rack
  • It creates extra space and light for every tree between the existing racks
  • It suits my winch processor setup as it's super easy for me to do but you be a complete PITA for a harvester.
 
My justification for going in relatively soon after the last thinning is that it's a sitka stand of not especially good form or YC. The ground is generally too dry and the trees at a little over 20 years old are only averaging 40-45ft, and I reckon are around 0.17-0.2 cube per tree. In performing a 15% thin, I think we can increase the growth rate of what remains, and we're offering £6/t for it standing, which I don't think is too bad for a low impact approach on a sensitive site.
 
My hope is that if this method proves successful on this site, it could be used on other first thinnings. I'd then propose putting racks in at 1 in 14 intervals, with hit and miss thinning inbetween. Fewer racks is something I can get away with wiht the winch processor and it leaves a less mechanised finish for the landowner. 
 
If you disagree with the approach, please say. I have a lot of time in machines to think about these things and I'm happy to be told when something is a shit idea!

Read more  

The only thing that may cause problems is sitkas ability to remain resolutely stuck to their surrounding trees, and not fall over.

Luckily, we don't need it to fall. Severed from stump is fine as the winch will pull it out to the processor, dropping it as it goes. 

 

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Featured Adverts

About

Arbtalk.co.uk is a hub for the arboriculture industry in the UK.  
If you're just starting out and you need business, equipment, tech or training support you're in the right place.  If you've done it, made it, got a van load of oily t-shirts and have decided to give something back by sharing your knowledge or wisdom,  then you're welcome too.
If you would like to contribute to making this industry more effective and safe then welcome.
Just like a living tree, it'll always be a work in progress.
Please have a look around, sign up, share and contribute the best you have.

See you inside.

The Arbtalk Team

Follow us

×

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.