Technodiversity Glossary

When the tree is felled (lays on ground) the limbs are cut from bottom to top. Three methods: 2 whorls at a time, whorl by whorl, and in the crown from top to the side. When finished turn the log and work the other side

Functiogram

• High efficiency
• High work quality (No risk for roller damage, flush cut of branches, better measuring under difficult stem conditions etc.)
• Low investment
• Low relocation cost

• Open space for standpoint of the worker needed
• Danger to hit legs and shoes with chainsaw
• Danger to injure the legs and feet
• Static strain on backbone
• Heavy effort/cardio workload
• Low productivity

• Delimbing broad-leaved trees
• Delimbing conifer trees where no processor/harvester is able to do a good job

Economic suitability

Example:

• machine costs without personal costs: 4,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 1
• in total: 39,00 Euro/h
• regression line minutes per tree
  • b₀ = 2
  • b₁ (tree volume) = 10

Ecological suitability

Ecogram

Social suitability

• S-class: 
  • in the stand or on the trail no contact with the forest road -> S5
  • processing on the forest road -> S2 
• E-class: motor-manual work, very heavy and dangerous -> E2

After measuring and decision where the optimal cuts have to be set, the trunk is cut into 2 or more pieces, (nearly) each of them marketable assortment.

Functiogram

• To separate assortments, lend them to different customers
• Enable collecting machines (like forwarder) to collect , lower damage in stand and on soil

• Costs
• Therefore only available after pre-skidding

• Separating logs to different assortments
• On skid road = separate forwarding
• On forest road=separate storage
• Poplar plantations in Italy (buyer-marked)
• High-value assortment production, customer-driven grading (veneer)

Economic suitability

Example:

• machine costs without personal costs: 4,00 Euro/h
• personal costs per person: 35,00 Euro/h
• number of persons: 1
• in total: 39,00 Euro/h
• regression line minutes per tree
  • b₀ = 5,0
  • b₁ (tree volume) = 3,5

Ecological suitability

• Ecogram 

Social suitability

• S-class:
• • in the stand or on the trail no contact with the forest road -> S5
  • processing on the forest road -> S2
• E-class: motor-manual work, very heavy and dangerous -> E2
  

If a working method is recognized to be a good solution for a certain task, it can be upraised as standard. For a standard method, the tools, machines, working steps, inputs and outputs are described in detail as well as the operational method of the worker. So, by naming the standard all persons have a common view of the process that should be performed. This is also the basis for education: since everything is standardized, the standard method can be explained and trained very well.

In former times we called it “best practice” – but this word puts into mind that it should never be modified. Standard, in contrast, has the implication that it defines the direction and the goal, but can be adapted to the acute situation if needed.

(See more under TDiv PR1-E03)

under certain conditions.

T-classes 1-3, P-classes 1 and 2: At stands with temporary trails or permanent trials with 20 m spacing, the fully mechanized ctl-method is best for coniferous trees and for young broadleaf trees, too.

T-classes 1-3, P-class 3: Where the 40 m trail spacing is adopted, the almost fully mechanized ctl-method with auxiliary felling by chainsaw sets the standard.

T-classes 1-3, P-class 4: At wider trail spacing, which happens mainly in valuable broadleaf stands, partly mechanized tree length methods are preferred.

T-classes 4 and 5, all P-classes or all T-classes, but P-class 5: Outside trafficable areas, methods that use the yarder for extraction set the standard.

(See more at TDiv PR1-D05)

Ergonomics follows a very simple basic model that derives from physics: When you impact any body with a certain stress, the body will react with a corresponding strain. For example, when you push a wooden stick that is fixed at one end from the side (= stress), it will get bowed (= strain). When we release the stress, the stick will become straight again. This means that the strain will release, too.

But if the stress exceeds a certain threshold, the strain can overcome the resistance of the stick, so that it will break. This limit to damage defines the maximum stress that the wooden stick can bear.

When we transfer this simple model to working conditions, it must be modified in a couple of points.

On the stress side, standard methods have a typical stress. But on the strain side, people are individuals:

They have different attributes like gender, age, height, weight, power… In practical life, these attributes are regarded to be invariable.

Everybody has his individual abilities and strengths. The same job that is easy for somebody can be difficult for another person; we say that the first person is more talented for this job than the other one.

Most jobs require a certain technique. Skilled persons can reach results that will never be possible for unskilled persons.

These three factors together – attributes, abilities and skills -form the capability of the person. If their capability fits the demands of the standard method, the strain is low. If not, strain will keep accumulating…

But due to organic reasons like health, conditioning, tiredness, hunger and time of the day, the strength can vary. We call that: disposition. On the other side, motivation also has an important influence on. Both together are called: readiness for work.

While capability is the potential of any given person, readiness is the percentage of that potential actually activated.

When the worker can manage his workload independently, he can find the right pace to keep strain at an acceptable level.But sometimes the strain exceeds that level. For example, when the worker is pushed to reach a certain performance that is beyond his long-term capacity or when he is so motivated that he does not realize that he is overreaching.

Then the strain will accumulate.

To remain with our simple model above, we look for a permanent work loadthat can be coped with on a day-by-day basis until the worker retires. If the actual strain momentarily exceeds this permanent load, it will not be a problem. In real life, this happens very often. It can even improve the training and exercise (conditioning). But at the end of the day there should be a balance between periods of excessive strain and periods of lower strain (recovery). Otherwise, overload will accumulate and result in damage.

Based on this model, there are various possibilities to lower the strain. It is up to the manager to combine them in the best possible way, by:

-       providing enough time for breaks adequate to the type and quantity of strain (recovery);

-       encouraging physical and psychological fitness through proper exercise and diet (conditioning);

-       creating ideal working conditions to increase readiness

-       adapting work assignments to the physical and psychological capacity of each worker;

-       the ultimate measure is to assign tasks and to adjust the workloads according to each worker’s individual capacity.

But when we have different technical options for performing a certain job, we should prefer the option that fits best the capacity of the available workers.

(See more under TDiv PR1-E04)

Originally the term "strategy" has been used in military and means leading a large army. Today the term is adapted to civil needs and means decisions that create potential for action in the future. 

In our context of forest operations, the person, who is responsible for strategical decisions (a forest district officer, e.g.), decides about investments in tools, machines and workforce. His job is to develop the resources that are necessary to solve any future problems.

(see more in TDiv PR1-A05)

Ergonomics follows a very simple basic model that derives from physics: When you impact any body with a certain stress, the body will react with a corresponding strain. For example, when you push a wooden stick that is fixed at one end from the side (= stress), it will get bowed (= strain). When we release the stress, the stick will become straight again. This means that the strain will release, too.

But if the stress exceeds a certain threshold, the strain can overcome the resistance of the stick, so that it will break. This limit to damage defines the maximum stress that the wooden stick can bear.

When we transfer this simple model to working conditions, it must be modified in a couple of points.

On the stress side, the working method is connected with typical stresses. For example at motor-manual processing: The chainsaw produces noise and vibration, has toxic emissions and is very dangerous. The natural working site can be heavy and dangerous, and the social relations with colleagues and superiors may cause stress, too. This stress seems very complex.

But social stress from group dynamics normally has nothing to do with the standard work method and pertains to social science, not ergonomics... And stress coming from the natural environment causes a percentual scaling of the stress that is connected with the working method as such. So, the composition of stress is very typical for this specific working method. Thus: Without knowing how the stressing factors are combined and how they work together, the complex stress is typical for this standard method and can be assessed by expert opinion.  

The simple model that we had above feigns that the stress of a standard method will permanently cause the same strain for the worker. But here the reality is much more complex, too, because all workers are different concerning attributes, health, conditions etc.  

(See more under TDiv PR1-E03)

Suitability, ecological see ecological suitability

Suitability, economic see economic suitability

Suitability, social see social suitability