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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A study on reducing primary transport costs in the South African timber industry.

Lusso, Cary D. January 2005 (has links)
Harvesting and transport accounts for up to 70% of the total production cost of roundwood in South Africa. This invokes an interest to improve harvesting systems through the introduction of improved equipment, road networks and more refined operating techniques. A literature review was conducted which investigated the various harvesting systems and equipment with a focus on ground based extraction, as it accounts for 96% of the timber being extracted annually in South Africa. A review of forest roads in South Africa was also conducted and it was concluded that at present there has been little focus on the upgrading and maintenance of forest road networks. It was concluded that the most significant reduction in transport costs would be achieved by reducing the distances travelled by expensive extended pnmary transport (R5.83 t-1.km-1) and by allowing less expensive secondary terminal transport (R0.4 t-1.km-1) to move further into the plantations. This could only be achieved by investing large amounts of capital into the upgrading of forest roads to a standard suitable to service secondary transport vehicles. A model was developed which was able to determine the tonnage of timber needed to flow over a particular road that will warrant the upgrading cost. The model was applied to two study areas, the first study yielded no results due to the already dense network of B- class roads, possibly excessive. The second study area identified three possible road upgrades to improve the existing transport system. A full costing of the existing and modified transport system was completed and a significant cost saving was shown, not accounting for the road upgrading cost. Capital budgets were used to account for more complex parameters, such as tax and discount rates, previously excluded from the simple model. These were used to determine the economic viability of the upgrades and to evaluate the suitability of the model. The model proved to be successful and confirmed that forest roads can be optimised accompanied by significant cost savings. The model is generic and simple allowing for easy application to a variety of situations and is also flexible to modifications. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2005.
2

An investigation into the shorthaul transport of pulpwood in South Africa

Ackerman, Pierre Alexander 12 1900 (has links)
Thesis (MScFor)--Stellenbosch University 2001. / ENGLISH ABSTRACT: Ackerman PA. 2001. An Investigation into the Shorthaul Transport of Pulpwood in South Africa. M.Sc. in Forestry thesis. University of Stellenbosch. 178 pp Shorthaul transport also known as secondary intermediate transport (SIT), a unique feature of pulpwood transport in South Africa, is an additional transport phase within traditional secondary transport. SIT originates at a roadside landing or depot and terminates at another depot, rail siding or merchandising area (not the final destination). The reason for the addition of SIT into the transport chain is identified as the steady decline of forest road conditions to the extent that highway vehicles are unable to reach roadside landings, necessitating the use of intermediate storage sites, from where the timber is once again loaded and transported to final destination. An industry survey established that the decline of forest road conditions are related to excessively high road densities, insufficient funding for road maintenance/upgrading and the lack of understanding by landowners of the importance of maintaining forest road infrastructure. Total funding, by pulpwood companies on roads have shown an increase of R18.55 million from 1997 to 2000, however, subsequent surveys have indicated, that despite this increase in funding, the forest road conditions continue deteriorating. Of the total annual pulpwood intake of 9.39 million tonnes for 1998, 3.7 million tonnes are subject to SIT. Of this 3.7 million tonnes, 2.5 million tonnes are transported from stump to depot and 1.2 million tonnes are transported from landing to depot. The survey identified the agricultural tractor and semi-trailer as the most favoured transport system between stump or landing and depot, responsible for transporting 2.22 million tonnes annually. For 1998, manual loading and three wheel log loaders accounted for the loading of 0.6 and 2.1 million tonnes respectively of the 3.7 million tonnes subject to SIT. This survey information, assisted by newly developed terminology, was used to develop transport scenarios for the economic analysis of total cost of the different transport phases. A network analysis model and pixel-based geographic information system (GIS) were combined to analyse the various transport scenarios within three study areas in the KwaZulu/Natal Midlands, employing SIT on poor, high-density road networks. The simple pixel-based GIS contained information on the forest road network, surface cover and slopes. The results of the economic analysis highlighted the need for the reduction of road network density and for the improvement of the remaining network. This would eliminate the need for extended primary transport and allow the use of highway vehicles transporting from the compartment roadside to and past plantation exits. Results show an average annual cost penalty to the industry, by maintaining SIT, to be R43.25 million or R8.24/m3 . By not employing SIT the industry will potentially save R4.60 for every tonne of the 9.4 million tonnes consumed by the pulpwood processing plants during 1998. Key words: Network analysis. Pixel-based GIS. Timber transport. Secondary transport. Secondary intermediate transport. Secondary terminal transport. Extended primary transport. Primary transport. Dirichlet tessellations. Shorthaul. Note: Throughout this document a full stop (.) is used as a decimal separator. / AFRIKAANSE OPSOMMING: Ackerman PA. 2001.'n Ondersoek na die kortafstand vervoer van pulphout in Suid- Afrika. MSc in Bosbou tesis. Universiteit van Stellenbosch. 178 pp. sekondere intermediere vervoer (SIV), 'n addisionele vervoer-fase binne tradisionele sekondere houtvervoer, is 'n unieke kenmerk van pulphout vervoer in Suid-Afrika. SIV begin op pad, by 'n spesifieke vak of depot en eindig by 'n ander depot, syspoor of verwerkingsgebied (nie die finale bestemming nie). Aangesien die toestand van bospaaie toenemend verswak en omdat swaarpadvervoer nie langer vakke kan bereik nie, word vervoerkontrakteurs al hoe meer gedwing om van depots gebruik te maak waarheen hout deur middel van SIV vervoer moet word. Die hout word dan weer daar gelaai en na 'n verwerkingsfabriek vervoer deur middel van swaarpadvervoer. 'n Landwye opname het getoon dat die swak toestand van bospaaie toegeskryf kan word aan oormatige paddigthede, onvoldoende befondsing vir die instandhouding/ opgradering van paaie en 'n gebrek aan begrip vir die belangrikheid van die onderhoud van pad infrastruktuu r. Die totale kostes aan padverbeterings en opgraderings in die pulphout bedryf, het van 1997 tot 2000 met R18.55 miljoen toegeneem. Verdere opnames toon egter dat ten spyte van hierdie verhoging in befondsing, die toestand van bospaaie steeds onbevredigend is. Van die totale jaarlikse pulphout inname van 9.39 miljoen ton gedurende 1998, word 3.7 miljoen ton aan SIV blootgestel. Van die volume word 2.5 en 1.2 miljoen ton onderskeidelik vanaf die stomp en pad na depots vervoer. Die opname het ook landboutrekkers met leunwaens ge·identifiseer as die gewildste houtvervoer middel tussen die stomp/pad en depots. Hande-arbeid en driewielbloklaaiers is op hulle beurt verantwoordelik vir die laai van onderskeidelik 0.6 en 2.1 miljoen ton pulphout wat deur middel van SIV vervoer word. Inligting uit die opname ondersteun deur nuutgeskepte vakterminologie, is gebruik om verskillende vervoersisteme vir die ekonomiese analise van totale koste van die verskillende vervoerfases te bereken. 'n Netwerk analise model en pixel gebaseerde GIS is in kombinasie gebruik om verskillende vervoer scenarios in drie areas in Kwa-Zulu Natal te ontleed, wat gebruik maak van SIV op swak bospaaie met hoenetwerkdigthede. Die eenvoudige pixel-gebaseerde GIS het inligting weergegee oor bospadnetwerke, oppervlakbedekking en hellings. Die behoefte aan die vermindering van paddigtheid en die verbetering van bospaaie as sulks, is deur die resultate van die ekonomiese ontleding na vore gebring. Dit sal die behoefte vir uitgebreide primers vervoer uitskakel en die gebruik van tradisionele swaar padvoertuie moontlik maak. Die resultate van hierdie opname toon dat die bedryf addisioneel gemiddeld R43.25 miljoen/jaar of R8.24/m3 betaal vir die 3.7 miljoen ton wat onderhewig is aan SIV. Vir die totale 9.4 miljoen m3 het SIV die maatskappye gedurende 1998 R4.60 meer gekos vir elke m3 wat vervoer was. Sleutelwoorde: Netwerkanalise. Houtvervoer. Sekondere vervoer. sekondere intermediere verveer. Sekondere terminale vervoer. VerJengde prirnere vervoer. Kortafstand vervoer. Pixel-gebaseerde GIS Nota: In hierdie document word deurgans 'n punt (.) gebruik om desimale van heelgetalle te skei.
3

The effect of South African provincial road condition on the efficiency of forest product transport

Nicholls, Stephen John 03 1900 (has links)
Thesis (MScFor)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The context of the study is concern over declining provincial road condition due to insufficient government funding of road maintenance. These roads are by their public nature used by a wide variety of commercial and private interests contributing a variety of axle loads. There was no information available on the use of these roads by forest companies and the road conditions. Consequently a survey was conducted to determine condition and length of each segment of provincial road in use by forestry companies and the volume of wood transported over them. In addition data was gathered on other users and their contribution to the volume transported over each section. The questionnaire indicated that the provincial roads are in a poor state. The literature review suggested a significant reduction in total cost of transport can be achieved by maintaining or rebuilding these roads. South African forest companies provide the majority of the heaviest axle loading to these roads and must theretore take responsibility tor damage caused to them. Also a variety of forest companies use the same roads and consequently collaborative studies between companies are needed. A modified Dijkstra's algorithm was used to quantify the effect of the condition of South African provincial roads on the efficiency of the transport ottorest products. The model requires digitised raster road and forest map layers combined with transport vehicle specification as input. The products of the model are optimum routes from all source points to a single exit point or sink, the total volume transported across all road nodes and the total cost to extract all wood from a map section. This output allows managers to identify critical roads tor management attention and make tentative estimates of possible reductions to total cost by altering the road condition. The manager is able to test the sensitivity of the solution to changes in variables and gain a better overall picture of the interactions within the system. The model results, and improved understanding, will provide input to more specific and collaborative studies. South African forest managers can respond to the poor provincial road network by conducting ad hue maintenance to these roads to prevent them becoming completely impassable or to rebuild them to their design state and maintain them at that state. The cost of taking no actions is that these roads would eventually become impassable. The road network model determined that, for the study area, a unilateral decision to rebuild and maintain all roads would result in a net increase in transport costs ofR 2 million/year. When compared to the cost of ad hue road improvements for the same area of R 8 million it is obvious that proper road management is a better option. It was shown that 75% of the reduction in total cost is generated by improving only 31 % of the provincial road surface. Consequently, by improving selected roads (20% of the total provincial road network for the area) it was possible to generate a net cost R 2.9 million lower than if the roads were left as they are. If reductions in operating costs are included the net cost to the forest industry is R 3.1 million/year lower than leaving the roads as they are. In addition to the cost being lower, an improved road network would be in place and the current ad hue spending would be unnecessary. On a larger scale it was estimated that poor provincial road management costs the industry as a whole R 26 million or R 1.52/m3/year. This money can be used to offset the costs of maintaining and upgrading roads. It is therefore concluded that the South African forest industry needs to assess its policy on provincial road management and become more active in the managing of these roads. The tool developed and presented is intended as a prototype decision support tool in developing future policies. / AFRIKAANSE OPSOMMING: Die inhoud van hierdie studie handelaar die verval van provinsiale paaie as gevolg van die regering se onvoldoende fondse vir die instandhouding van die paaie. Hierdie paaie word as gevolg van hulle publieke aard deur 'n wye verskeidenheid kommersiële en private belange gebruik, wat bydra tot 'n verskeidenheid van asladings. Daar was geen inligting oor die bosbou maatskappye se gebruik van paaie of die toestand van die paaie beskikbaar nie. Gevolglik is 'n opname gemaak 0111 die kondisie en lengte van elke segment van die paaie wat deur die bosbou maatskappye gebruik word, vas te stel, asook die volume hout wat oor die paaie vervoer word. Data oor ander verbruikers van die paaie is verder ingesamel, asook hul bydrae tot die volume wat oor die paaie vervoer word. Die vraelys het aangedui dat die provinsiale paaie in 'n baie swak toestand is. 'n Literatuurstudie het getoon dat 'n beduidende daling in die totale vervoerkoste moontlik is deur hierdie paaie te onderhou afoor te bou. Die Suid-Afrikaanse bosbou maatskappye voorsien die meerderheid van die swaarste asladings op hierdie paaie en moet dus verantwoordelikheid neem vir beskadigde paaie, 'n Verskeidenheid bosbou maatskappye gebruik die paaie; gevolglik is gesamentlike studies tussen die maatskappye ook nodig. 'n Aangepaste Dijkstra algoritme is gebruik om die effek van die toestand van Suid- Afrikaanse provinsiale paaie op die effektiwiteit van die vervoer van bosbou produkte, vas te stel. Hierdie model benodig digitale inligting oor die hoofen bosbou paaie, asook die spesifikasies van die voertuie wat gebruik word. Die resultaat van die model is die optimale roetes vanaf alle bronpunt oorspronge tot by 'n enkele bestemming, die totale volume vervoer oor al die padnodusse en die totale koste verbonde aan die verwydering van alle hout uit 'n afgemerkte seksie op die kaart. Hierdie produk of result ate stel bestuurders in staat 0111 kritieke paaie vir aandag te identitiseer en om tentatiewe voorspellings van moontlike afname in die totale kostes te maak indien die toestande van paaie verbeter sou word. Die bestuurder kan die sensitiwiteit van die oplossing vir variasie in die veranderlikes toets en sodoende 'n beter geheelbeeld kry van die interaksie binne die sisteem. Die resultate van die model en n beter begrip daarvan, kan insterte lewer in meer spesitieke studies en gesamentlike studies tussen maatskappye. Suid Afrikaanse bosbou bestuurders kan teen die swak provinsiale padnetwerk optree deur ad hoc instandhouding toe te pas op hierdie paaie om te voorkom dat hulle totaal en alonbegaanbaar word. Ofhulle kan die paaie restoureer tot hul oorspronklike toestand en hulle dan in stand hou. Die kostes daaraan verbonde om nie op te tree nie, is dat hierdie paaie uiteindelik on-gaanbaar sal word. Die padnetwerkmodel het gewys dat vir die spesitieke studie area, 'n eenparige besluit 0111 alle paaie te herbou en onderhou, 'n algehele toename in vervoerkostes van R2 miljoen/jaar tot gevolg sal hê. Wanneer dit vergelyk word met die R8 miljoen wat die ad hoc padverbeterings kos, is dit duidelik dat geskikte padbestuur 'n beter opsie is. Daar is bewys dat 75% van die daling in totale kostes genereer kan word deur verbeteringe aan die oppervlaktes van slegs 31% van die provinsiale paaie te maak. Gevolglik was dit moontlik om netto kostes van R2,9 miljoen ruinder te genereer as vanneer geen instandhouding gedoen is nie. Dit is bewerkstellig deur verbeteringe aan geselekteerde paaie aante bring (20% van die totale provinsiale padnetwerk vir die area.) As die daling in bedryfskoste ingesluit is, sal die netto koste vir die bedryf R3.1 millioen/jaar ruinder wees as om die paaie so te los sonder enige aandag. Verder, tot laer koste sal daar 'n verbeterde pad netwerk in plek wees en die huidige ad hoc spandeering aan die paaie nie meer nodig wees nie. Op groot skaal, is die benaderd voorspelling dat 'n swak provinsialepadbestuurstelsel die bosbou bedryf R26 millioen of R 1.52/m3 uit die sakjaag. Hiedie misbruikde geld kan eerder teruggeploeg word in pad onderhoud en opgradeerings werksaamhede. Dit is dus nodig dat die bosbou bedryf sy beleid weer in oonskou moet neem in verband met die bestuur van provinsiale paaie en ook meer aktief die voortou sal moet neem in die instandhoudind van provinsiale paaie. Die metodiek hier ontwikkel kan 'n inleidende doel dien in die ontwikkeling van toekoemstige besluit neeming rakend die bestuur van provinsiale paaie.

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