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Regardless of the type of construction and logging equipment used in a particular project, harvesting operations themselves remain difficult, often hazardous operations that can cause substantial damage to the forest ecosystem unless environmentally sound practices are followed. In particular, road construction in mountainous terrain can inflict scars on the landscape which can seldom be remedied at a later stage and only at much higher costs.

Therefore, the selection of construction machinery as well as all other harvesting equipment should not only be guided by short-term economic benefits but should take account of environmental considerations.

7.1. Description of the road construction equipment

The road construction equipment described below was used at the studied construction sites.

Table 12. Construction equipment used in the road projects under review

 Kharungla roadKorila extension 
Equipment featuresCaterpillar
320B L
Dresser TD 12Unit
Type of tracked equipmentExcavatorBulldozer 
flywheel power95.582.0  (kW)
Operating weight20 700   13 172(kg)
Overall width3.183.83(m)
Overall track length4.46n.a.(m)
Overall length with bladen.a.4.89(m)
Ground pressure4567    (kPa)
Fuel tank refill capacity290246(l)
Maximum travel speed3.4–5.510.0–11.7      (km/h)
Gradability7070   (%)
Pry-out force120n.a.    (kN)
Penetration force104n.a.     (kN)
Bucket capacity (heaped)1.10n.a.    (m3)
Maximum reach at ground level9.31n.a.   (m)
Maximum digging depth6.290.49   (m)

Note: n.a. = not applicable

It should be noted that although road construction is machine-intensive, labour remains the most critical element for achieving the goals of environmentally friendly engineering practice. Only if operators are competent in their skills, and motivated to work properly and efficiently can they be expected to contribute effectively to these goals (FAO, 1996).

7.2. Description of the logging equipment

The following sledge winch was used on both logging sites, the Korila and the Helela site, where work and time studies on long-distance cable logging were carried out.

Table 13. Cable crane unit used at study sites

Kharungla/Helela logging site
Equipment featuresGantner USW 60D 1000Unit
Type of winchsingle drum sledge winch 
Operating weight1 500(kg)  
Payload2 500(kg)  
Mainline - diameter12(mm) 
Skyline - diameter24(mm)

Since diesel engines lose considerable power with increasing altitude (about 30 percent at 3 000 m above sea level), this more powerful 60 kW winch, as used at the study sites, should be used at high altitudes (2 000–4 000 m above sea level). The much cheaper 45 kW winch should be adequate in the lower areas like in the Geruwa-Demula FMU and most of Lingmethang FMU of TFDP (Roetzer, 1996).

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