Salvage Logging of Storm Damaged Timber
Operational safety through use of machinery
- Human health is the most important
consideration. Safety is more important than costs and loss of timber.
- Don't attempt to bring down lodged
trees without direct access to a machine.
- On site trees should only be cut at
the stump. All further work can then be done on a conversion site, where the
stems can be processed safely.
- For operational safety reasons, a
sufficiently powerful crawler excavator with a clamshell is to be used to
untangle trees on large windthrow areas. Clamping the tree also avoids
splitting of the stem. Cable skidders are less appropriate. Grapple skidders
should only be used on site if more suitable machinery is not available.
- Cable skidders, preferably with a
grapple, can be used for minor volumes, more or less uniformly in the direction
of windthrow and on slopes.
- On steep slopes, cable cranes are
used to untangle trees. Stems can be trimmed and crosscut on the roadside.
- Operational safety is enhanced when
the woodcutter and machine operator communicate via walkie-talkies. Forest workers have to wear clearly visible reflective
- With particularly dangerous trees,
it is advisable to leave a safety lug, preferably in a desired length. This can
be cut off and skidded later.
- Where roots are particularly
dangerous, they can be secured by the cable skidder or the crawler excavator.
- Grapple skidders can be used to
manipulate timber accurately and to remove brushwood.
Tips for the
use of crawler excavators for untangling windthrown trees
- Crawler excavators should have a
capacity of at least 100 KW to ensure enough reserves, especially for grappling
and lifting. Its not only the range but the combination of range and lifting
power which is crucial. The weight of the excavator ought to be at least 25
tons. This increases operational safety and productivity. Basic principle:
Rather an over-dimensioned machine than an under-dimensioned one.
- Crawler excavators with a range
below 10 metres are not appropriate. The higher the range the better (distance
between skid roads!).
- Distances between skid roads do not
automatically equal twice the range of the machine. All procedural actions to
maximise the distance should be taken. The skid roads have to be marked out
before the operation begins. This enables the woodcutter to identify the crane
range and can therefore influence accessibility of the tree through
crosscutting. Basic principle: It’s better to keep different qualities together
and crosscut them later on the conversion site.
- Straight skid roads facilitate
- Using a big, solid grapple (with
rotator) is advantageous for handling remaining logs. Excavators with a griper
for demolition works proved to be convenient.
- Ordinary crawler excavators (without
tiltable cab) may only be used on gradients less than 15% inclination, even in
the fall line. Do not use on steep slopes!
- The crawler excavator has to prepare
the skid road in a way that the skidder can use it at any time. Logs have to be
left on the skid road or removed.
- Crawler excavators are often
operated by employees of the building industry without any experience and
training in the forestry sector. Therefore, an intensive instruction is
necessary, especially in teamworking with the chainsaw operator.
- The chainsaw operator has to keep a minimum safety
distance from the excavator and must wear reflective clothing. The excavator is
used to help the chainsaw operator by untangling logs. Walkie-talkies are
necessary for communication.
after Storm "Lothar"
2000, contractors worked on a large scale for all types of forests owners in
salvage logging. Due to the limited extent of the damage in Baden-Wuerttemberg (and small parts in Bavaria) as well as pan-Europe in France and Switzerland, it was quickly
apparent that there would be no lack of logging and skidding contractors. The
more serious problem turned out to be the selection of trustworthy and
top-quality forest contractors, who could maintain the established quality
standards (e.g. careful logging and compliance of the accident prevention
regulation). The cooperation of long-time business partners has in most cases
proved the best solution due to familiarity with the sites and the requirements
of the forest office.
- External contractors
- Communication problems
with foreign workers
- Insufficient technical
equipment, under-dimensioned/old machines, resulting in driving across the
- Rare compliance with
accident prevention regulations
- Rare compliance with
- State forester's area to
control was too large, "overworked and no time to maintain quality-standards"
- Disregarding of quality standards
in general, especially in favor of quick logging
- The engagement of known
contractors is best. There is often a long-standing, trusted cooperative relationship. The reduced need for control and instruction
should not be underestimated in times of coping with storm damages.
- The contractor market is
large. Even in the event of enormous storm occurrences it’s not necessary to
accept the first tender (especially if an unknown and/or external contractor).
There is enough time to select by attributes.
- The cheapest contractor
is not necessary the best contractor. The offers need to be assessed in terms
of additional costs (e.g. need of later clearing and slash disposal as a result
of different working techniques or more time and effort for supervision of
- References of unknown
contractors need to be provided and (if possible) checked.
- With unknown
contractors, contracts should be made on a quantity basis (up to 5000 m³).
Further contracts should be entered into if the operation meets expectation.
This isn’t always easy to achieve, but experience has shown that it is
worthwhile to choose the “right” contractor to relieve the forest ranger’s
- Before contract signing,
a detailed instruction of working techniques and quality-standards is
necessary. Especially important is the definition of settlement and method of
log measurement. In particular the prohibition of driving areas and compliance
with skid roads must be pointed out. The contractor must commit him/herself to
using the machinery named in the offer or similar.
- Before contract
commencement the general terms and conditions and requirements regarding
forestry work as well as differing forest district specific requirements need
to be talked through and put down on paper.
- Logging and skidding
should as far as possible be assigned to one contractor. This also applies to
- Especially contractors
who are not familiar with the site require more supervision. A detailed
instruction of local circumstances and requirements of the forest office/
forestry enterprise is essential. Work instructions have to be written down.
Even during the term of contract extensive supervision and control is
- The selected working
technique has to be in line with the stand, the direction of wind throw and the
roading infrastructure. The contractor does not define the roading
infrastructure concept, the forestry enterprise does. Requests from the
contractor can not be fulfilled.
- If job performance is
unsatisfactory, problems need to be immediately talked through with the
contractor. The contractor should be reminded of his/her obligation to remedy
deficiencies. The forestry enterprise should stipulate the option to cancel the
contract with the contractor. This possibility should be used in authorised
- The skid road system has
to be permanently marked in the stand as well as on a map (if possible
calibrated), so that after windthrow external persons (supporting personnel,
contractor) can re-establish the skid roads.
- Additional contractors
could be recruited from well known forest ranger colleagues in non-affected
areas. Unproblematic implementation of the contact and good work are not
guaranteed, but the chances of finding a good and trustworthy contractor will
- It may be possible to
recruit additional contractors via permanent contractors.
- Not every machine is
appropriate to every operation. Do not use under-dimensioned equipment! Before
work begins it must be established which machinery is to be used. To avoid
excessive driving, certain machine efficiencies (kW) and machine equipment
should be fixed in the contract (e.g. crawler excavators with minimum 100 kW,
crane extension ≥ 10 m)!
- A central
contractor-database could lead to more transparency in the contractor market.
- The work quality of
external contractors should be measured against local contractors. Often
external contractors were excused from meeting expected standards; however
permanent contractors have been required to fulfil these same quality standards
- Reduce the forest
rangers control span down to no more than 3 logging groups (forest workers/
contractors). A thorough preparation, organisation and supervision of the
logging operations, as well as monitoring the timer inventory of several crews
or contractors is impossible. If continuous logging is necessary or desired and
the number of crews/contractors increases, additional support personnel should
be assigned to the forest ranger.
from salvage logging in 1990 and 1999
- The contractor's prices
should not be inflated by competition from the lower forest administration/
- In recent cases of
regional storm damaged timber logging (up to three federal states affected) the
nationwide available cutting capacity has proven to be adequate. The first
offers received might not be the best. Keeping calm and waiting for better
offers as well as collecting information and references saves money and eases
future working conditions.
- Experience showed that
the logging process was faster than estimated. Keeping calm and planning
logging calmly relaxes personnel and reduces cutting prices.
- The cutting process and
timber removal need to be co-ordinated. If removal is delayed, timber quality
suffers and forest protection problems occur. If in doubt, cutting should be
stopped until the timber removal is organised.
- Working in windthrown
timber requires a high mental and physical effort from forest workers. A
rotation of crews after 6 to 8 weeks with reassignment to less exhausting tasks
reduces the risk of an accident.
- Shortage of timber
inventory and operation control of forest worker crews may be reduced by the
complete transfer of workers from one district to another (forest ranger,
forest workers and tractor).
- Standard lengths of long
timber ease timber transportation and stack construction at wet storages. With
lengths of 18 m all kinds of haulage can be used (depending on the length of
the wagon!). If it is clear at the time of logging that the timber will not be
transported by railway, it should be cut at the top.
- Mechanical bark peeling
should be carried out in areas where irrigation capacity is limited or valuable
stem timber is present.
- Discussion and
cooperation with colleagues avoids "district blindness" and helps increase
- At contract commencement,
a detailed instruction of working techniques and quality-standards must be
given to contractors. Especially important is agreement regarding settlement
and method of log measurement.
- The forest enterprise is
responsible for maintaining quality standards. The contractor does not define
the working technique or the technology to be used. This is determined by the
forest ranger on site.
windthrow no area driving! The skid roads at windthrow area can be clearly seen
through the snow cover.
- Soil preservation
through concentration of operation: prohibit driving across the area during
logging and following slash removal.
- Utilization of existing
skid road system. Strict compliance with skid roads. Therefore it’s necessary
to designate skid roads continuously, right from the roadway.
- Compliance of skid road
distance of 40 m over sensitive soils. The higher costs and associated lower
returns are justified by the need for soil protection.
- Skid roads shouldn’t be
narrower than 20 m on the flat and slightly sloping terrain and narrower than
30 m on slopes.
- No new construction of
skid roads, even if trees lie in positions difficult to access from the
existing skid road system. The higher costs and lower returns from “forced
assortments” are justified by of the need for soil protection.
- The skid road width has
to be as small as possible and should not exceed 5 metres.
- Take note of the Soil
Protection Act (Bodenschutzgesetz). The forest office is the responsible
authority for soil protection under the Soil Protection Act. Take note of the
principles of forest road construction for the construction of forest roads and
give special consideration to forest biotopes and waterways.
- Road maintenance: repair
road damage immediately to avoid high future costs.
- Conserve driveability of
skid roads through the use of high flotation tyres. Before constructing a new
skid road, a partial repair of the existing skid road with suitable material
should be carried out.
- Minimise skidding
damages through the selection of approved working techniques, suitable forest
technology and appropriate bucking.
- Driving on skid roads is
only permitted during suitable, dry weather conditions to maintain its
driveability. This principle especially applies if there is no brushwood
material available to armour the skid road (e.g. at motor-manual logging, in
- Intensive familiarisation
with the skid road system is necessary before logging begins. It is best to
adopt the old skid road system.
- When clearing the roads
(think of the assortment creation!) it might be appropriate to cut a strip at
the right and left side of the stand. This marks the old skid road system,
which can be used again.
- Useable skid roads and
log trails should be clearly marked. “Wild driving” through the stand must be
- The skid road distance
has to be at least 20 m.
- In the state forest of Baden-Wuerttemberg only chain- and
hydraulic oils indicated with a "Blue Angel" environment label are allowed.
- When refuelling chain
saws, a fill-in system should be used.
- The special protection
status of the area must be known (to meet water and soil protection
- Discharge of oil or fuel
is to avoid in every circumstance.
- Oil binding and
absorbing material has to be available.
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