Several trees come down every year at Lisnavagh
(let alone around the rest of the country), and from these trees
we can select the timber that is suitable to bring into the Lisnavagh
Timber Project for further processing. Trees come down for a number
of reasons.
They get blown over in high winds (called
"windblow").
They are felled because they are dead,
dangerous or diseased/rotting.
They are felled when woods are being thinned.
(Thinning is the removal of selected trees which are competing
or interfering with other trees. This is done in order to allow
better trees to grow on.)
They are felled when a wood is clear felled
(i.e. all of the trees in a wood are felled at once, usually when
the trees are mature, or over-mature). Clear felling of hardwood/broadleaved
woods is fairly rare now.
We
do not fell trees just because the Timber Project needs the
wood from them! If we fell a tree, it is for reasons of good forestry
practice or safety.
When a tree comes to our attention, we go
out to see it. If it seems suitable, we take a record, including
photographs, notes on the species, condition, dimensions of commercial
timber, the date and reason it came down, etc. The tree is given
a unique reference number. These details are then listed on our
database.
At this point, the tree may also be marked
up to give guidance to the chainsaw operator as to where to joint
the tree into logs.
After a while, a good number of trees and
logs are ready for felling and/or jointing and collection and the
next stage of the process begins.
Felling and jointing
To
fell a tree requires the right skill and experience, as well as
chainsaws, wire ropes, winches and safety equipment.
Occasionally, as in the (enlargeable) picture
to the left, a tree surgeon is necessary. In this case, the branches
of a dead sessile oak tree were being cut back to reduce the damage
that might be caused to adjacent trees, a fence and a gateway...
The idea was to fell the main part of the very large tree between
the gateposts of the 8 ft gateway 30 feet away from the trunk
- that's quite a challenge! But it was the only way to minimise
the damage caused when the tree came down. The photo shows the tree
surgeon up in the tree (about 30 feet up or more) having just cut
back a branch (which is pictured in mid-air). When he later felled
the tree it caused very little damage the nearby oak... and landed
between the gateposts. Perfect!
Even
in more conventional felling, care is taken to ensure the tree falls
in a sensible direction to cause minimum damage to other trees or
property, and also so that the tree lands as "softly"
as possible, thus minimising the risk of "shake" (cracks)
in the timber of the tree.
Not all trees need felling though, as much
of the timber taken into the Lisnavagh Timber Project is the result
of storm damage and they are already down - hopefully without too
much damage to themselves or anything else.
The
next stage is to joint the trees. The timber that is deemed suitable
for sawmilling is jointed (cut) out of the tree in suitable lengths.
Ideally, the logs that result from the jointing are straight, free
of big knots and at least 18" in diameter. The rest of the
tree is perhaps used for firewood, or left in the wood to rot back
into the soil (as a valuable contribution to a woodland's extremely
diverse ecosystem).
Forwarding or Extraction
of timber
This is the removal of the logs of timber,
after felling and/or jointing, from a wood to a point where they
can be collected by a lorry or tractor & trailer for delivery
to the sawmill.
Extraction
of logs can be carried out by using a number of alternative methods,
including a forwarder (pictured left), winches, ponies or a standard
JCB type digger. At Lisnavagh we have used all of these methods,
and the choice depends upon the circumstances, but we frequently
use our own (quite old!) Massey Ferguson 50B digger with a grab
fork.
A
forwarder (such as the ones pictured above and right) is probably
the fastest and most efficient way there is to remove timber from
a wood, but especially in quantity. These amazing tracked or rubber
wheeled machines can roll over pretty much anything in a woodland
and pick up logs well over a tonne in weight. The logs go into the
"basket" on the back. The machine can travel quite quickly
though woodland or on the road.
Our
Massey Ferguson 50B, which we bought 2nd hand in 1979, is a bit
of an old faithful! This workhorse is still going after many years
of constant service. To date, this machine has removed most of the
timber used in the Lisnavagh Timber Project.
The method that may cause least damage in
woodland is towing logs out of a wood with horses or ponies. It
is a wonderful sight and we hope to be able to show you some pictures
shortly, as we are expecting a pony team here next week. The usefulness
of ponies is limited by the size of the logs being extracted.
Transport to sawmill
Once
the logs are extracted from the wood (i.e. "at roadside")
they are collected and brought to a sawmilling yard.
Most timber travelling any distance will
be collected by a lorry & trailer, such as the one in the (enlargeable)
picture to the right. Typically, at least 20 tonnes of timber can
be loaded onto these lorries (using their own crane and grab).
If the timber is very local to the sawmill,
or in our case on our own land, it works out far cheaper to use
a digger and a tractor & trailer to collect and deliver the
timber as it is jointed & extracted from the woods. This usually
involves up to perhaps four or five tonnes of timber per load.
Page Updated:
Friday, 14 December, 2007
