Necessity of using aerostats and balloons for logging

Presently Russias timber industry, particularly in its Far Eastern region and Siberia, is faced with a number of problems connected to the following factors:

 Timber felling site remoteness from populated areas causes supplementary expenditures for building and maintenancing wood-roads and bridges. It also influences hauling unit deterioration and log removal productivity, so the net cost of the wood is high.

 The main resources of high-grade timber are located in regions difficult to access or in prohibited areas where conventional mechanisms cannot be used for logging.

 The big problem is that in Summer, Spring, and Autumn periods volumes of forest harvesting operations are reduced because some wood-cutting areas become inaccessible for land transport.

 Environmental deterioration is another problem. Clean wood dragging and machinery movement on the slope can lead to excessive damage to the top-soil, and cause an additional expenditures for soil control and forest recreation. These expenditures may become very sizable since the mountain environment is particularly sensitive. Besides, about 80% of streams spring from woodland, and being damaged and polluted may become dried up and influence another global ecological problems. For example, according to ecological statistics the extermination of a forest based ant hill leads to the damage inflicted by insects to growing trees over 1 hectare area during the next two years. One may surmise how many ant hills are destroyed while ground machines are used for wood harvesting.

 In the Far Eastern region of Russia, specifically in the Khabarovsk territory, old machines, chiefly caterpillar TT-4, are used. This technology is based on the method of wood skidding that has bad effect on undergrowth and soil conditions. For the past five years the majority of local fellers did not make re-equipment of their wood harvesting machinery. This is primarily due to the following reasons:

 Rise in the cost of machinery and their component parts;

 Inability of conventional machinery to satisfy modern rules of forest harvesting;

 Extensive competition from foreign technology, such as Timbco, Timberjack which are more productive and reliable, but are of a very high price and have a number of shortcomings:

 - they need additional wood roads to the wood-cutting area;

 - despite modern technology of felling and logging they do not exclude the underbrush damage as well as causing considerable soil disturbance, particularly during warm seasons;

 - inability to log over very steep slopes (more then 30 ), and in prohibited areas;

 - inability to make partial cuts.

At present in the Khabarovsk territory some companies have tested helicopter logging. This technology reduces to zero a lot of the above mentioned disadvantages. However, one of the most essential disadvantages is the high cost and insecurity of working.

It may be very interesting to have a technology that has all of the advantages of air logging but has none of the negative features peculiar to helicopter logging. Such a technology exists. This is aerostatic airborne vehicles.

At present, when the ecological demands in forests are becoming acute and the timber industry demands immediate productivity, the aerostat technology may play a rather important and favorable role in the forest industry of the Far Eastern region and possibly the whole of Russia.

Some logging systems used on a difficult of access terrain

Different systems for wood harvesting in mountains

Helicopter Mi-8MTV

Balloon logging system Q=3,5 tons

Skidding caterpillar

-4

Cable system

ML-43

Cable system

ML-59

Timberjack

Harvester1270 + Forwarder 1110

Scheduled payload, m3

2 - 3

2 - 3

8 - 14

2 - 4

5 - 8

8 - 10

Shift output, m3

100-150

100-120

60-80

30-50

80-100

200-250

Operating personnel

6

8

7

8

8

3

Equipment coast, $

3.500.000 +800-1000 $/

200.000

25.000

45.000

120.000

700.000

Necessity to build wood roads, runs

-

-

+

+

+

+

Devastation of undergrowth during logging, %

0

0

80

75

60

60

Soil deterioration, %

0

0

100

80

60

100

Noise affecting on live organisms, %

100

0

100

50

50

100

Safety of work, %

0

80

50

80

80

50

Maximal logging distance, km

3 - 5

1,5 - 2

0,3 - 0,5

0,3 - 0,5

0,5 - 0,7

0,3 -0,5

  

AMERICAN SCIENTISTS ESTIMATIONS

Timber Harvesting Alternatives, Washington State University Cooperative Extension, 1985, p. 21:

Balloons used for logging are a lift-augmented skyline system most suitable for downhill yarding. The balloons used to lift the logs free of the ground, while the cable system restrains and transports the turn. Logs can be flown completely clear of the ground. This enables balloon systems to be used to log some extremely difficult terrain with a minimum of site disturbance.

Balloon logging systems have a maximum yarding distance of about 5,000 feet depending on the situation. This feature lessens the road requirements considerably over highlead and many skyline systems. Long, unbroken slopes that would be difficult to log and would require expensive and environmentally questionable mid-slope roads for conventional skyline logging are suitable for balloons. Logging with balloons is feasible only in clearcuts, although balloon logging has been tried experimentally in partial cuts.

Weather condition play a critical role in balloon logging. During operations, winds cannot exceed 25 to 30 mph or the balloon will have to be tied down until the wind subside. Rain or snow on a balloon will reduce its lifting capacity. Temperature and elevation can have an effect on the balloons performance, as well.

 

AMERICAN CABLE LOGGING SYSTEMS (Click it!)

Timber Harvesting Alternatives, Washington State University Cooperative Extension, 1985

 

Substantiation of the chosen system

From all evidence one can maintain that balloon cable system has considerable advantages over other wood harvesting equipment. The system occupies a certain position between helicopter and ground machines combining in itself the best features of ground and air logging. Besides, it has attractive prospects for development that may be proved by the following supplementary conveniences:

 Possibility to use chain balloon logging system containing two or more units working in one line in to extend yarding distance up to 7-10 km.

 Possibility of using large payload balloons or aerostats (5, 7, 10 tons).

 Logs can be yarded both downhill and uphill. With all this going on, the steepness of a slope does not matter. Wood can be logged from a hollow and from behind a hill as well. All this demonstrates mobility and up-to-dateness of the system. See schemes of the logging.

 Lighting mounted on the towing implements allows working even in dark time.

 Undergrowth and soil are not subjected to deterioration as balloon or aerostat is settled directly over the bunch during lifting.

 With the help of aerostats (balloons) clearcuts as well as partial cuts are feasible.

 Winch machine can be placed both on the ground and on water vessels (ship, raft, barge), for instance while logging on a steep slope along a stream or a bay.

 Balloon logging secures safe working conditions, since unlike helicopter yarding it is operated from the ground by an operator.

 As distinct from conventional cable logging systems, balloon systems needs no hacking routes for main and haulback lines beforehand.

Balloon yarding outturn computation, Q (balloon payload) = 3500 kg

Computation bases on the following :

 actual load - 2000 kg or 2.5 m3

 deadhead balloon moving speed - 2 m / sec

 loaded balloon moving speed - 5 m / sec

 logs hooking time - 2 min

 logs releasing time - 1 min

 one working shift time - 8 hours

L (logging distance), m

200

500

700

1000

1200

1500

Hourly outturn, Ph

Shift outturn, Psh

(m3)

_27,5_

220

_17,5_

140

_15_

120

_12,5_

100

_10_

80

_8_

64

Round turn (min)

5,3

7

8,2

11,6

14

17,5

 

Description of balloon cable logging system

The main part of the system is a balloon or aerostat whose payload depends primarily on the logged stand. Circled cables-and-blocks system driven by two single-drum winches enables the balloon to change its position over terrain at an altitude of about 500 meters and at a distance up to 2 km. Some variants of use of the balloon logging system are shown in pics 1-9.

Cable unreeling over a piece of woodland is made with the help of an auxiliary cable (5-6 mm) by an auxiliary winch. Before logging, the wood is felled and limbed (in compliance with rules of the Regulation on safe wood harvesting in the mountains). The work of fellers, chokermen, and machine-operators is coordinated by a foreman through wireless radio. During moving the balloon in a certain direction one winch reels in while the other reels out the cable. When the set-point is reached by the balloon both winches reel in the cable pulling the balloon towards the ground lowering it 50-70 meters. After choking is completed the winch brakes are released and the balloon lifts the wood bunch up to 100-150 meters. Afterwards, the balloon with the load is moved to the landing. After finishing work at one location, the system with the help of a winch moves to another.

Notice:

Balloon (aerostat) may work in a wind blowing at speeds up to 15 m/sec, while parking near the ground permissible wind cannot exceed 25 m/sec.