Planning and implementing forest operations to achieve ... - Woodweb

• where stability is not a question, and Silvaculture treatments
• when the road surface is not being reclaimed
as a planting area.
In the planning process, before a road is permanently
deactivated, it must be considered if the cut-block
When a road is at a grade or slope, rain water builds up ground requires mechanical treatment with equipment
and travels down the road surface. This concentration
before planting? Potential treatments include brush
of flow (usually in the wheel tracks) as it builds up can piling, ground scarification, or tilling.
now have the capacity to transport sediment which in
this case is the road surfacing material. The immediate Back spar trail rehabilitation
eye attention is drawn to the rough eroded road surface.
It is unacceptable to allow deposition of eroded
Older pre-eode backspar trails can have many of the
sediments and road frees into an adjacent watercourse, same concerns as a road.
The waterbar is used to control water on the road . Alteration of drainage.
surface. It commonly directs built-up surface flow
either into the ditchline or out onto the outside slope. • Unstable side cast material.
Use the same caution as you would when considering
to install a crossditch and discharge concentrated water • Sidecast material perched on steep gully
onto an outside fill slope. (See Fill and mid-slope sidewalls.
failures section below.)
• In-filled watercourses and gullies (dammed
As for a cross ditch, the waterbar must be skewed
up).
(placed at an angle) across the road. They should be
constructed wide and shallow. They should be • Compacted ground
adequately armored on the bottom, sides, berm, and
outflow area. They should no bet constructed with
Excavator size
oversteep sides and an uneompacted bottom, berm and
discharge apron that will erode with time and
Deactivating present and older unstable roads calls for
contribute to the siltation process that we are trying to some thought and care when selecting machine size.
prevent.
• A large 50 metric tonne (100,000+ lbs)
Fill and mid-slope failures
machine will give you reach and large bucket
capacity but is hampered by restricted swing
When we discharge concentrated water onto fill or a and its sheer mass (weight) The reason the
rounded outside slope, we must always ask, is it safe to
road edge has been called to be pulled back
place concentrated water at this location? We are now is that the road edge is failing. For safety the
placing a concentrated amount of water onto an outside
operator is forced to place his machine as far
slope that has never historically felt a concentration of to the inside of the cut bank as possible -
water,
nowhisswingisrestrictedbythebankina
large machine!
• Will the concentrated water erode a channel
and transport sediment? * A mid-size 30 metric tonne (60,000+lbs)
machine is the popular size for deactivation.
• Will it over-saturate the ground and in turn Large enough to have reach and bucket
cause slope instability?
capacity, yet light enough to address the
safety factor.
• Will it fail to dissipate into the ground and
continue to travel on the surface? (Water has * A 20 metric tonne (40,000 lbs) machine is
been known to travel downslope 2 to 300 also extensively used in deactivation. Its
meters and finally find a piece of ground to advantage is its extremely quick cycle time,
oversaturate with a resulting midslope smaller size, and comparatively light weight.
failure).
• Smaller 12 metric tonne (24,000+ lbs)
machines have a place in deactivation where
the value desired is a nimble machine with
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