Mechanised delimber

[donnk]

i have dread visions of that flying off the top of the tree and chasing a screaming logger down the hill madly stabbing his remote control until it runs out of hose.

 

On the flip side, could have some fun with BT poles if they dont sort out my internet speed .....

[Big J]

Coming from a sawmilling point of view, the benefits are very substantial. With species such as larch, douglas and western red cedar, it would be extremely beneficial to high prune the branches at an early stage to improve the quality of the final crop. Dead knots highly devalue the final product, and as a sawmill, being able to offer clean, knot free timber products means you can charge a premium. That grade of timber is largely covered by imported stock presently. If I (as a sawmill) can charge more for the end product, I can pay more for the raw material too. 

 

For pristine douglas, I'd expect to pay at least 25% more than for standard grade, if not more than that. Particularly for douglas, as it's widely used structurally and knots (whether live or dead) will devalue the beam.

 

The cost implications aren't high. Say for instance it's DF, you high prune only your final crop and possibly the final thinning stock. You do this after the second thin, at say 25 years. The trees are 60-70ft and you prune 35-45ft of the stem. After a second thin, you might have 1000 stems per hectare. You only prune 400 of them. That's a cost of about £400. You final crop will usually attain 500t/ha, of which 50% would be premium sawlog material. So 250t at 25% more than the average (which for long length DF is presently about £75-80/t) gives you a return on your £400 investment of £4600-5000 per hectare. Seems pretty sensible to me.

[openspaceman]

8 hours ago, Big J said:

Coming from a sawmilling point of view, the benefits are very substantial. With species such as larch, douglas and western red cedar, it would be extremely beneficial to high prune the branches at an early stage to improve the quality of the final crop. Dead knots highly devalue the final product, and as a sawmill, being able to offer clean, knot free timber products means you can charge a premium.

Yes but traditionally we have not grown high quality softwoods, largely because the premium wasn't offered for clean stems, John McHardy at Longleat did instigate high pruning but I don't know whether it is paying back.

 

It's a chicken and egg situation, similar to when corsican pine was introduced. At first sawmills milling pine only wanted scots pine and wouldn't accept the corsican pine as it came on stream from later thinnings. Once the supply of corsican  increased as Theford's plantings came of age in the 80s  mills converted to it and it became more difficult to find mills taking scots pine. With red band needle blight I wonder what will be done.

8 hours ago, Big J said:

 

 

That grade of timber is largely covered by imported stock presently. If I (as a sawmill) can charge more for the end product, I can pay more for the raw material too. 

There's a good reason for that; it often comes from places with harsher climates than ours and the growth rates are lower, as lower branches get shaded out they are snapped off by clumps of snow falling from the crown.

8 hours ago, Big J said:

 

 

 

The cost implications aren't high. Say for instance it's DF, you high prune only your final crop and possibly the final thinning stock. You do this after the second thin, at say 25 years. The trees are 60-70ft and you prune 35-45ft of the stem. After a second thin, you might have 1000 stems per hectare. You only prune 400 of them. That's a cost of about £400. You final crop will usually attain 500t/ha, of which 50% would be premium sawlog material. So 250t at 25% more than the average (which for long length DF is presently about £75-80/t) gives you a return on your £400 investment of £4600-5000 per hectare. Seems pretty sensible to me.

I had a boss that liked to do spreadsheets like that, he lost millions on one project despite us telling him his figures were overly optimistic.

 

Just think how the shape of a conifer is as it grows, basically a stem tapering evenly as it rises to the active crown and then tapering faster, like a bullet. You can only prune the steady taper without compromising growth but you want clean timber up to that point, so if you start pruning when the tree is say10cms at 5 metres it will be 15cms at the bottom, hence the clear timber will only be outside that 15cms core. Then you have to repeat the exercise at 10 metres and so the knotty core is never more than 15cms diameter uns so weiter. Given that many mills only take 45cm logs now the clear timber is only the bit from 45 down to 15.

 

In sylviculture the concept of net discounted revenue is important to a grower, especially one that is not likely to be around when the tree is felled, basically it tries to calculate what the money today is worth to the grower compared with what he expects it might be worth at end of rotation if he invests it in the crop now. Most of the time after planting and establishment this means  spending money after you have closed the gate on a plantation is resisted.

 

When I realised how badly the sylvicultural needs were being compromised by establishment in Tuley tubes I  took to trying to persuade owners to undertake  formative pruning and did some on some oak trees I established, my intention was to have a 6metre clear butt but I seldom got up to more than about 4 metres. It was why I invested in a telescopic silky early on.

[Honda]

That looks like a useful machine but it should only need one man to operate it. The second man is doing nothing except helping to move it from tree to tree. Another wheel on the base would do that. 

[wills-mill]

They're properly keen on high pruning in NZ. A lot of their Radiata is ending up here (and elsewhere) as Accoya branded timber for window frames and external joinery, it's absolutely immaculate in terms of knot content.

I'd love to see this level of knowledge, passion and commitment from UK landowners...
 

 

[Stere]

I got some loppers made in nz  they are used to pruning foresty  conifers.

 

 

 

Best loppers ever heavy though ?

 

Here on radiata

 

Infos:

 

https://safetree.nz/wp-content/uploads/2015/03/Silvicultural-Pruning.pdf

 

Edited January 16, 2020 by Stere

[drinksloe]

Is the UK timber industry not going the other way thou.

 

Smaller dia stems and shorter crop rotations, are some of the new SS hybrids not meant knock 5+ years of rotations.

Surely shorter faster growing will not benefit  quality timber.

 

Mibbee different in other parts of country where u tend to grow better quality timber, in this area tend to have lots of quick but poor quality timber.