Browsing by Author "Pienaar, Wessel J."
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- ItemBedryfs- en tegnologiese vereistes vir die winsgewende lewering van spoorgoederevervoer(AOSIS, 2017-11-17) Pienaar, Wessel J.In hierdie oorsigartikel word verslag gedoen oor die vernaamste bedryfs- en tegnologiese vereistes waaraan kommersieel lewensvatbare spoorvervoerstelsels in ’n ekonomies ongereguleerde goederevervoermark moet voldoen. Die volgende aspekte word bespreek: (1) Die marksegmente wat oor die algemeen winsgewend deur spoorvervoer in nywerheidslande bedien word; (2) vergelykende koste van spoorvervoer en die bedryfsmetodes wat gebruik word om spoorvervoer kostevoordeliger te maak; en (3) die vernaamste tegnologiese vereistes waaraan kommersieel lewensvatbare spoorvervoerstelsels moet voldoen. Wat tegnologiese vereistes betref, word in besonder gelet op die volgende: (1) die soorte treine en doelgeboude spoortrokke wat gepaste marksegmente ten beste bedien; (2) die eienskappe van spoorvervoereindpunte wat doeltreffende spoorvervoerbedryf onderskraag; en (3) die hanteringstoerusting wat benodig word om die spoorbedryf te laat vlot. Die doelgeboude trokmodelle en die soort treine waarin die trokke saamgestel word om ten beste aan spoorvervoeroperateurs se besondere bedryfsbehoeftes te voldoen, asook die belangrikste faktore wat spoortrokke se ontwerp onderlê, word bespreek. Voorts word die eienskappe van die vernaamste soorte eindpunte waar goedertreine aandoen, bespreek. Laastens word die hanteringstoerusting beskryf waarmee die spektrum van karweibare goedere vinnig, veilig en teen laagste eenheidskoste in en uit trokke gelaai, of na ander vervoermodusse oorgelaai word.
- ItemDetermination of the cost component in the social cost-benefit analysis of road projects in South Africa(Southern African Institute for Industrial Engineering, 2021-05) Pienaar, Wessel J.ENGLISH ABSTRACT: The article deals with the preferred approach to determine the cost component in the social cost-benefit analysis (SCBA) of road projects in South Africa. The article is in four parts. The first part, the introduction, provides the reasons why investment cost should be identified as a single cost entity in the SCBA of a road project, regardless of the criteria according to which a project is adjudicated. The second part discusses the principles that guide the determination of the social opportunity costs (SOC) of road projects. The third part identifies the two items that form the cost component of the SCBA of road projects; the SOC of (i) the land required to accommodate the road reserve, and (ii) the construction of the road. The cost component of the latter is sub-divided into labour, plant, equipment, fuel, materials, and normal profit. The section also details a recommended procedure to convert the financial budget of a road construction project to an estimate of its SOC. The fourth section draws some conclusions from the study.
- ItemEkonomiese aspekte van pypleidingvervoer : 'n Suid-Afrikaanse perspektief(AOSIS, 2009) Pienaar, Wessel J.Economic aspects of pipeline transport: a South African perspective Pipeline transport is unique among modes of transport in that the pipe, which facilitates freight movement, is both the way and the vehicle, and it is permanently connected to terminals, which facilitate freight storage. This feature makes it the only mode of transport that does not require any materials or goods handling. In view of the facts that pipeline infrastructure is extremely capital intensive and that it has an unprecedented longevity, pipeline transport enjoys the highest level of economies of scale of all modes of transport. This economy is subject to steady and enduring high levels of demand. It is also the only mode of freight transport of which the operations do not require a return journey, whereby joint cost due to empty running is avoided. The commercial transport of crude oil and petroleum products by pipeline and the envisaged new investment in this mode of transport are receiving increased attention in South Africa. Transnet Pipelines recently obtained permission from the National Energy Regulator of South Africa (Nersa) to construct and operate a new 60-cm petroleum products pipeline 704 kilometres in length from Durban to Gauteng. In addition, the newly-formed Petroline consortium recently obtained permission to construct and operate a 30 cm petroleum products pipeline 199 kilometres in length from Maputo to Nelspruit, with an extension of 249 kilometres in length eventually to Kendal, where it can be linked up with the present Transnet pipeline network. The disadvantages of pipeline transport lie mainly in its extreme functional speciali sation and dependence upon sustained high-volume traffic. The initial cost of installation is high and justified only when both the demand and supply are guaranteed to continue for an indefi nite period. Despite the fact that tank ships run empty during return trips, pipeline transport can only compete with sea transport between the same origin and destination if the pipeline route is considerably shorter than the sea route, or where sea transport is subject to exceptional charges, such as heavy canal dues. The economic assessment of a pipeline necessitates the investigation of several alternatives in order to determine whether the project is justifiable in terms of the economic resources its commercial existence will require. Firstly, alternative locations of the pipeline may have to be compared. A second consideration is the size of the pipeline, since one with a larger diameter, and capable of handling a greater traffic volume, involves higher initial investment cost but lower costs for pumps and energy to propel the pumps. A third decision concerns the choice of pump technology. Most pumps are driven by electric motors, although diesel engines or gas turbines can also be used. A fourth important consideration is whether the refinery should be located at the beginning of the line (upstream, close to the oil field or the port of entry) or at the end of the line (downstream, close to the market). The fifth step in the economic evaluation is to compare the pipeline cost with the cost of the next best transport alternative, which is usually rail transport. If these investigations indicate that a pipeline promises to be technically feasible, financially viable and economically justified, detailed design of the pipeline may commence. In terms of market participants the supply of pipeline transport is the most highly concentrated of all freight transport modes. With a few exceptions, there is but one crude oil, one products and one natural gas pipeline connecting producing areas or refineries and areas of consumption. This high degree of monopoly results from declining unit costs with increases in capacity, so that the lowest costs are achieved by a concentration of output in a single pipeline. Therefore, pipeline operations that can fulfil entire market demands are pure natural monopolies. Where the distance between supply points (such as geographically separated oil fields or ports of entry) is far in relation to the delivery distance to the market area, such an area’s fuel demand can often be most efficiently fulfilled by two or more different pipeline operations. The clients of a common carrier are direct competitors in the wholesale fuel market, therefore they should bear full cost responsibility for the service rendered by the pipeline. Service below total cost to a client implies that it is subsidized by its competitors. The only instance when delivery can take place below total cost is when:the necessary spare capacity exists to accommodate the consignment (i.e. that the opportunity for another consignment to be delivered at full cost is not jeopardized);all the avoidable (i.e. short-run) costs are covered and some contribution to unavoidable (i.e. fi xed or long-run) costs is made; and the consignment delivery would not have taken place at a price covering full costs.
- ItemFunksionele aspekte van spoorvervoereindpunte wat die suksesvolle vervoer van goedere per spoor ondersteun(Suid-Afrikaanse Akademie vir Wetenskap en Kuns, 2020-04-03) Pienaar, Wessel J.Hierdie artikel bied ’n oorsig van die funksionele aspekte van spoorvervoereindpunte wat die suksesvolle lewering van goederespoordienste kan ondersteun. Ten aanvang word die primêre en sekondêre funksies van goederevervoereindpunte in die algemeen bespreek, waarna spoorvervoereindpunte in die besonder bespreek word. Spoorvervoereindpunte bestaan uit verskeie werftipes wat elkeen ingerig is om sekere funksies te verrig of werksaamhede te hanteer. Die primêre en sekondêre funksies van al die werftipes word vermeld. Daarna word die funksies bespreek van die vier breë klasse goederespoorvervoereindpunte wat vandag aangetref word, naamlik (1) losmaat-, (2) grootmaat-, (3) opry-afry- en (4) intermodale eindpunte. Grootmaateindpunte word verder verdeel in ertseindpunte, eindpunte by die tenkwerwe van olieraffi naderye en chemiese aanlegte, en eindpunte by graansuiers. Die soorte treine, spoortrokke en hanteringstoerusting wat by elke eindpuntklas aangewend word en die goederesoorte wat by elkeen hanteer word, word vermeld.
- ItemGoederevervoermodusse wat in internasionale handel gebruik word(AOSIS, 2018) Pienaar, Wessel J.Sedert die ekonomiese deregulering van goederevervoerbedrywighede in nywerheidslande oor die wêreld heen en die vrymaking van internasionale handelspraktyke het dit nodig geword om ’n praktiese kennis van die tipe goederevervoertegnologie te hê wat kan help om die doelmatige en doeltreffende deelname in internasionale handel te ondersteun. In dié oorsigartikel word verslag gedoen oor die vernaamste bedryfs- en tegnologiese eienskappe van die goederevervoermodusse wat in internasionale handel gebruik word. Die fokus is in besonder op daardie aspekte wat die bedryf van internasionale goederevervoer onderskei van dié van plaaslike goederevervoer. Al vyf goederevervoermodusse word bespreek, te wete lug-, pad-, spoor-, pypleiding- en skeepsvervoer. Voortspruitend uit die navorsing word aanbevelings gemaak om die doelmatigheid en doeltreffendheid van goederevervoer tussen Suid-Afrika en ander lande te help verbeter.
- ItemLiggingsaspekte van spoorvervoereindpunte wat die winsgewendheid van goederespoordienste ondersteun(Suid-Afrikaanse Akademie vir Wetenskap en Kuns, 2020-04) Pienaar, Wessel J.Hierdie artikel bied ’n oorsig van liggingsaspekte van spoorvervoereindpunte wat die lewering van winsgewende goederespoordienste kan ondersteun. Aangesien spoorvervoer tot vaste roetes beperk is en ’n stasie-tot-stasie-diens eerder as ’n diens van perseel tot perseel lewer, is die plasing van spoorvervoereindpunte en die uitleg van die spoornetwerk van deurslaggewende belang vir die suksesvolle bedryf van goederespoorvervoerdienste. Liggingsaspekte van losmaat-, grootmaat-, opry-afry- en intermodale eindpunte word bespreek. Die artikel beskou die invloed wat die veranderde rol van spoorvervoer sedert die ekonomiese deregulering van goederevervoer op die ligging van spoorvervoereindpunte het, aan die hand van die drie mees bepalende faktore daarvan. Hierdie faktore is: (1) die verkeer se oorsprong- en bestemmingsplekke, (2) die verkeersomvang en (3) die aard van die eindpuntaktiwiteite. Ten slotte word die uitwerking van die uitleg van die spoornetwerk op die toeganklikheid van spoorvervoereindpunte oorsigtelik bespreek.
- ItemLogistiek : die oorsprong, konseptuele ontwikkeling en betekenis daarvan in hedendaagse gebruik(Bureau of the WAT, 2002) Pienaar, Wessel J.Hierdie artikel beskryf die oorsprong van die woord logistiek, stip die ontwikkeling daarvan uit en verklaar die hedendaagse betekenis daarvan. Die ontwikkelingsgang van die begrip word aangedui vanaf die oorsprong daarvan in Grieks, met inagneming van die opeenvolgende opname daarvan in Laat-Latyn, Frans en Nederlands, tot by die huidige gebruik daarvan in Afrikaans. Die vestiging van die Franse logistique as milit?re konsep gedurende die Napoleontiese oorlog, en die uitbreiding daarvan tot 'n bedryfsbegrip ná afloop van die Tweede Wêreldoorlog word verduidelik. Die ontwikkelingsgang sedertdien van die betekenis van die konsep in bedryfsverband word bespreek. Eietydse omskrywings van logistiek, betreffende die gebruik daarvan in die bedryfslewe en in die omgangstaal, word verskaf. Vervolgens bied die artikel 'n eietydse definisie van logistiek in bedryfsverband. Ten slotte word aangetoon hoe doeltreffende bedryfslogistiek waarde toevoeg.
- ItemLogistieke aspekte van pypleidingvervoer in die voorsiening van petroleumprodukte(AOSIS, 2008) Pienaar, Wessel J.The commercial transportation of crude oil and petroleum products by pipeline is receiving increased attention in South Africa. Transnet Pipeline Transport has recently obtained permission from the National Energy Regulator of South Africa (Nersa) to construct and operate a new petroleum products pipeline of 60 cm diameter from Durban to Gauteng. At an operating speed of 10 km/h the proposed 60 cm Transnet pipeline would be able to deliver 3,54 million litres of petroleum product per hour. This is equivalent to 89 deliveries per hour using road tank vehicles with an average carrying capacity of 40 000 litres of fuel per vehicle. This pipeline throughput is also equivalent to two trains departing per hour, each consisting of 42 petroleum tank wagons with an average carrying capacity of 42 500 litres of fuel per wagon. Considering that such road trucks and rail wagons return empty to the upstream refineries in Durban, it is clear that there is no tenable long-term alternative to pipeline transport: pipeline transport is substantially cheaper than road and rail transport; pipeline transport is much safer than rail and especially road transport; and pipeline transport frees up alternative road and rail transport capacity. Pipeline transport is a non-containerised bulk mode of transport for the carriage of suitable liquids (for example, petroleum commodities, which include crude oil, refined fuel products and liquid petro-chemicals), gas, slurrified coal and certain water-suspended ores and minerals. In South Africa, petroleum products account for the majority of commercial pipeline traffic, followed by crude oil and natural gas. There are three basic types of petroleum pipeline transport systems: Gathering pipeline systems Crude oil trunk pipeline systems Refined products pipeline systems collectively, these systems provide a continuous link between extraction, processing, distribution, and wholesalers’ depots in areas of consumption. The following activities are involved in the flow of goods between place of origin and place of consumption or application: Demand forecasting, Facility site selection, Procurement, Materials handling, Packaging, Warehouse management, Inventory management,Order processing, Logistics communications, Transport, Reverse logistics. Because cost is incurred without adding value each time goods are handled (activity 4) at a terminal or storage facility, a primary logistics objective is to eliminate handling wherever possible. With the carriage of crude oil and petroleum products by pipeline this objective is fully met. Commodity intake, haulage, and discharge are combined in one process, usually a remote-controlled operation. Pipeline transport is a non-containerised bulk mode of transport thereby obviating the need for packaging (activity 5) and returning empty containers. Pipelines provide a direct and long-term link between these origins and destinations. If necessary a continuous service can be provided with no need for a return trip or a reverse pumping process (activity 11). The elimination of handling, packaging and reverse logistics activities contribute substantially to the high measure of economies of scale that pipeline transport enjoys. The article provides a description of each of the eleven logistics activities in the context of pipeline transport. Effective logistics service is a prerequisite to help ensure that customers receive the required products at the desired quality and quantity, where and when needed. The most pertinent determinants of logistics service performance are suitability, accessibility, goods security, transit time, reliability and flexibility. The article offers a discussion of the extent to which pipeline transport conforms to each of these measures of effectiveness.
- ItemMathematical principles of road congestion pricing(Operations Research Society of South Africa, 2009) Pienaar, Wessel J.; Nel, J. HannelieThis paper briefly considers the objectives of road congestion pricing and identifies prerequisites to the successful application of such a pricing scheme. The paper is divided into two sections. In the first section, a mathematical analysis of the constituents of an optimal road congestion price is offered. The eliminated inefficiency loss achieved by the introduction of a congestion levy is usually evaluated by means of an integral involving marginal trip cost, travel demand and average trip cost in two-dimensional (travel time, traffic flow)-space. In this section we show that this loss may, in fact, be evaluated more easily for a general marginal trip cost function and a linear demand function as the difference between the areas of a rectangle (representing the part of road agency revenue that lies below the original trip cost) and a triangle (representing the loss of consumer surplus of the reduced traffic) in (travel time, traffic flow)-space, eliminating the need to use integration. The next section deals with the application of the illustrated mathematical principles and proofs to a hypothetical case study relating to road congestion pricing in Cape Town.
- ItemMobiele toerusting wat die suksesvolle vervoer van intermodale standaardhouers per spoor ondersteun(Suid-Afrikaanse Akademie vir Wetenskap en Kuns, 2021) Pienaar, Wessel J.Hierdie artikel bied ’n oorsig van die tegniese en funksionele eienskappe van mobiele toerusting wat die suksesvolle vervoer van intermodale standaardhouers per spoor ondersteun. Die toerusting ter sprake is goederetreine, houerspoortrokke, intermodale standaardhouers en mobiele houerhanteringstoerusting. Goederetreine word verdeel in trokvragtreine en eenheidstreine, en die gepastheid van elke treinsoort vir die grootskaalse vervoer van intermodale standaardhouers word aangetoon. Daarna word die twee soorte doelgeboude houerspoortrokke toegelig. Die tien soorte intermodale standaardhouers wat beskikbaar is om goedere in te vervoer, word vervolgens behandel. Ten slotte word die funksies en eienskappe bespreek van hedendaagse mobiele hanteringstoerusting wat doeltreffend aan die houerhanteringsvereistes van moderne intermodale vervoerbedrywighede voldoen.
- ItemRiglyne by die keuse van padprojekte deur die owerheid(Suid-Afrikaanse Akademie vir Wetenskap en Kuns, 2019) Pienaar, Wessel J.AFRIKAANSE OPSOMMING: Dié artikel verduidelik waarom die voorsiening van openbare paaie aan markmislukking onderhewig is, en verduidelik die redes waarom openbare paaie deur die staat voorsien word. Dié oorwegings is hoofsaaklik ekonomies van aard en word uit 'n sektorale, mikro- en makroëkonomiese oogpunt toegelig. Die bedryfseienskappe van padvervoer, teenoor dié van spoorvervoer, wat vir die stimulering van ekonomiese lewenskragtigheid bevorderlik is, word oorsigtelik verduidelik. Die staat se plig om padinfrastruktuur te voorsien bring mee dat daarvoor begroot moet word. Die artikel beskryf die situasie wanneer padowerhede reaktief die voordele van padvoorsiening moet probeer maksimeer onder die beperking van fiskale rantsoenering en 'n vaste begroting. Ten slotte word voorgestel dat padowerhede, met oordeelkundige benutting ook van leningsfondse, proaktief optree om die voordele van padvoorsiening te maksimeer deur hulle padboubegrotings as veranderlik te benader, maar onderworpe aan 'n prestasiereël.
- ItemVoorgestelde metodes om die voordele van padprojekte te maksimeer(Suid-Afrikaanse Akademie vir Wetenskap en Kuns, 2019) Pienaar, Wessel J.AFRIKAANS OPSOMMING: Hierdie artikel stel metodes voor wat 'n vervoerowerheid kan volg om die voordele van padvoorsiening te maksimeer. Ná die inleiding word 'n metode voorgestel waarvolgens openbare padprojekte gekies kan word wanneer 'n vaste begroting vir padbouprojekte geld. Hierdie metode bestaan uit vyf stappe en is gegrond op die inkrementele-voordeel-koste-beginsel. 'n Prestasiegeoriënteerde metode word voorgestel vir die proaktiewe keuse van padprojekte om ekonomiese groei en ontwikkeling teweeg te bring wanneer 'n veranderlike begroting moontlik is. Die metode bestaan uit drie stappe en is, soos die keuringsproses wat bespreek is, gegrond op die inkrementele-voordeel-koste-beginsel. Hierdie twee metodes word met behulp van voorbeelde toegelig. Die gevolgtrekkings wat uit die studie vloei, word dan aangebied.
- Item'n Voorgestelde reguleringsraamwerk vir pad- en spoorvragvervoer in Suid-Afrika(AOSIS, 2007) Pienaar, Wessel J.The increase in the number of freight vehicles on South Africa’s rural road network has received substantial attention. Insinuations persist that long-distance road freight haulage is of a somewhat unsavoury economic nature, and that strict economic re-regulation of the land freight transport is necessary. During the 1970s road transport replaced rail carriage as the dominant form of long-distance freight transport (excluding minerals and ore) in South Africa. On long hauls road freight carriers transport certain primary products of an organic nature (such as timber, fish and agricultural produce), some semi-finished goods, many finished goods and most consumer goods. Road freight carriers are continuously gaining market share on long-distance links where rail transport is the more cost efficient mode. The greater value added by road freight carriers in comparison with rail transport through service effectiveness is often more than the cost premium paid for utilising their service rather than making use of rail transport. Throughout history, governments have involved themselves in transport. A diverse range of arguments have been advanced for this involvement in transport, including the following: Control of excessive competition, co-ordination of transport, integration of transport with economic policy, maintenance of safety, security, and order, provision of costly infrastructure, provision of public goods, recovery of the true resource cost of transport inputs, regulation of harmful conduct and externalities, restraint of monopoly power, and social support. A set of nine instruments can be identified that governments apply to influence the performance of the freight transport industry: Legislation, direct supply, fiscal measures, monetary measures, moral appeal and persuasion, policies relating to strategic commodities, procurement policy, provision of information, and research and development. The best prospects for a sound development of land freight transport activity in South Africa will be offered within the framework of a free-functioning freight transport market.
- ItemDie wiskundige grondslag van die bedryfslogistiek as studiegebied(AOSIS, 2006) Pienaar, Wessel J.This article describes the meaning of the word logistics, outlines its mathematical basis and explains the meaning thereof as a contemporary field of study. The concept of logistics management is described in a business context and the strategic, tactical and operational tiers thereof are identified. The relationship that exists between systems analysis and logistics management is indicated. The role and essence of operations research in logistics decision- making are described. The most pertinent operations research topics in the field of logistics as well as the mathematical competencies a logistician should possess, are identified.