Extra capacity to Richards Bay at lower cost

INTRO: Spoornet's coal exports are set to grow - if costs are cut to beat competition. While extra substations are going in, the target of 65 million tonnes a year will mainly be achieved through more efficient operations

BYLINE: Philip van Heerden

Senior Manager (Planning)

Spoornet

BYLINE: Dave Budler

Senior Manager (Strategic Planning)

Excoal, Spoornet

SOUTH AFRICA'S premier coal export line serving the purpose built deep water port at Richards Bay was inaugurated on April 1 1976. At the time construction of the line was authorised in 1971, it formed part of a plan to ship 109 million tonnes of coal from the Witbank mines over a 12 year period.

Design capacity at opening was 21million tonnes a year. Diesel operation had been envisaged for the first few years, but electrification was brought forward as a result of the 1973 oil crisis and completed soon after the line opened. Over the intervening period, successive stages of upgrading have taken place to increase capacity, and 58·3 million tonnes was hauled in 1995. In 1996 the tonnage of coal moved fell slightly to 58·1million. The current target for 1997 is 62 million tonnes.

Heavy haul on narrow gauge

The Richards Bay line forms part of Spoornet's 1065mm gauge national network, but qualifies as a heavy haul line in its own right. It is the increased worldwide demand for steam coal that has driven up throughput, requiring continual increases in capacity.

The challenge facing Spoornet's planners is to anticipate how the demand for capacity is going to change in future, so that management can implement timely adjustments while taking into account the long life of capital assets.

In a highly competitive market for coal, high tonnages will only be sustained if transport costs are reduced, so any further increase in capacity has to minimise investment in new infrastructure and rolling stock. The answer lies in tightening up operations.

Richards Bay Coal Terminal (RBCT) is the company which owns and operates the coal terminal at the port; its shareholders are the coal mining groups. RBCT co-ordinates the tonnage exported through the terminal from the various mines in the group in accordance with the particular RBCT shareholder's entitlement.

The mines load the trains, generally by means of rapid loaders, although low volume mines use front-end loaders and similar equipment. RBCT is responsible for unloading the trains at the port using rotary dumpers, with the wagons still coupled.

The present understanding is that Spoornet should be capable of handling a maximum of 65million tonnes a year, but the actual annual capacity which RBCT requires is negotiated a year in advance. This arrangement, though necessary for practical reasons, causes some difficulties for both parties.

The RBCT shareholders need to conclude their contracts in advance and to anticipate market opportunities. Ideally, they want to ship coal to the port at short notice according to demand. On the other hand, Spoornet requires a regular flow of traffic for maximum utilisation of its capital-intensive assets. To acquire additional rolling stock or change the railway infrastructure requires long lead times.

RBCT shareholders suffer financially if they do not fulfil their contractual supply obligations, or lose opportunities because they cannot respond quickly to new market demands. Spoornet faces additional costs if it over-capitalises, and cannot generate adequate returns over the long investment life of its assets, typically 30 years.

Because of the long lead time to increase railway capacity (both in terms of infrastructure and rolling stock), Spoornet's planners must look beyond the current understanding with the mine owners, and need a long-term perspective. This means understanding the long-term world demand for coal, and its price; the extent of economically mineable South African reserves; and the role of rail transport in the supply chain.

Present capacity

The coal line runs from Blackhill (the furthest mine) to the coal terminal in Richards Bay, a distance of 580 km. The sections from Vryheid to Richards Bay (212 km) and Ermelo to Broodsnyersplaas (93 km) were newly constructed in 1971-76, with heavy upgrading to ease gradients and curvature between Ermelo and Vryheid.

Because there was already 3 kV DC electrification in the area, the Blackhill - Ermelo section is at this voltage. From Ermelo to Richards Bay 25 kV 50Hz AC is used. This was the first application of 25 kV AC electrification in South Africa, although the new Sishen to Saldahna Bay iron ore line was being electrified at 50 kV at about the same time.

Initially, coal was transported in wagons with a payload of 58 tonnes and an axleload of 20 tonnes. As the line was upgraded, wagons with an axleload of 26 tonnes and a payload of 84 tonnes were introduced to reduce unit costs.

Over the DC section between Blackhill and Ermelo, trains are run in lengths of 100 wagons, but over the AC section from Ermelo to Richards Bay they are combined into 200 wagon lengths.

Between Ermelo and Richards Bay, the minimum headway is 30min which equates to a theoretical maximum of 48 trains per day in each direction. Presently, some 11 to 12 loaded coal trains of 200 wagons are run daily, together with a further 12 trains of general traffic - half the theoretical maximum. Allowing for paths lost due to track maintenance, malfunctions and operating delays, sufficient reserve capacity remains to meet anticipated increases in coal export tonnage.

Between Blackhill and Ermelo a similar situation exists in that there is no immediate requirement for an increase in line capacity.

Extra power

Four new AC substations are being installed which will increase overhead line capacity on the Ermelo - Richards Bay section to about 72million tonnes a year during the course of 1997. The sites for the substations, with a combined rating of 80 MW, were selected after careful analysis in order to limit investment to essential requirements only.

Because of the large incremental increases which new substations provide, the target of 65million tonnes a year required in terms of Spoornet's obligation was unavoidably exceeded. Additional DC substations were installed on the Blackhill - Ermelo section during 1996, giving a capacity slightly in excess of 65million tonnes a year.

Locos and wagons

The locomotive fleet comprises AC units from Class 11E (3900 kW), Class 7E-1 (3000 kW) and Class 7E-3 (3000 kW). Class 10E-1 locos of 3090 kW are used on the DC section. The capacity of the combined fleet meets the 65million tonnes a year requirement.

CCL and CCR wagons are used for coal exports; CCR denotes a braking system upgrade. The earlier CCL-1 and CCL-3 types were designed for 20 tonne axleloads and are known collectively as 'smalls'; they are now used at mines with axleload limitations, and can be redeployed for domestic coal traffic as the Richards Bay fleet is augmented with newer rolling stock.

Later designs (CCL/CCR-5 to CCL/CCR-9) with an increased payload and a 26 tonne axleload are known collectively as 'jumbos'. New coal wagons are exclusively of this type to reduce unit transportation costs. The capacity of the current export fleet is 61 to 62million tonnes a year, which can accommodate peaks in the presently-agreed export tempo. Further capacity increases can be provided either by building more wagons, or decreasing the current average turnaround time of the fleet.

Predicting future capacity

Investments in railway infrastructure and rolling stock need to be governed by two primary considerations:

Â? What future capacity should be provided?

Â? Can the replacement cost of an ageing fleet and worn infrastructure be recovered during the remainder of the export life cycle?

Spoornet needs to be flexible to handle sudden surges in coal exports to the greatest possible extent within reasonable risk/return limits. It also needs to look further into the future in order to make prudent anticipatory decisions, given the long lead time for investment and the much longer period over which it is amortised.

The prognosis is for increased world demand for steam coal, but in the light of competition South Africa's share of the market must be assessed in terms of its ability to supply at economic rates. A key demand imposed by this market in future is expected to be a reduction in real terms in the cost of hauling coal from mine to port.

Spoornet has therefore reviewed options available to reduce unit costs. These include longer trains, faster trains, bigger wagons and improved turnaroud times.

Longer trains were initially rejected because current lengths of 200 wagon trains are already at the limits imposed by coupler stresses, the length of brake pipes from locomotives to the rear of the train, and the forces transferred from locomotives to the track.

However, in-train motive power using Locotrol has recently been tested on electric locomotives with encouraging results. This will permit additional locomotives to be placed in the middle of a train, controlled by radio from the leading locomotive.

The expectation is that mid-train power will eliminate the present technical constraints, and permit trains much longer than 200 wagons. However, trains longer than 200 wagons will require the rebuilding of yards and other infrastructure and are not considered an attractive option.

As regards speed, the current limit for 200 wagon trains in the loaded direction is 60 km/h. With the total mass of the train exceeding 21000 tonnes, only modest gains in time are expected due to the short periods that line constraints would permit speeds in excess of 60 km/h.

The international trend is to increase the axleload of heavy haul wagons to 30 tonnes and more. The current limit of 26 tonnes on the coal line is imposed principally by the wheel bearings and track formation. It is expected that the track could carry 30 tonne axleloads, allowing payload per wagon to be increased from 84 to 96 tonnes.

Practical considerations resulting from the introduction of larger wagons have sidelined this option. Wagon unloading tipplers in the port would need to be replaced at high capital cost; rapid loading installations at the mines would require upgrading, also at high cost; and logistic problems would result from introducing a third super-jumbo size of wagon.

Turnaround time

A more promising avenue is reducing average wagon turnaround time. For jumbos, which serve the larger mines having rapid loaders, turnaround is 60hours. Smalls are diverted, as required, to the smaller mines served by lighter lines and generally filled by slower front-end loaders, resulting in an average turnaround time of 66hours.

The theoretical round-trip running time, adding loaded and empty trips, is 25hours. The balance is taken up by loading and unloading operations, train checks, locomotive changes, joining/splitting 200 wagon consists at Ermelo and operating delays.

A detailed analysis has been undertaken to quantify times taken in the total turnaround cycle. A total of 18 processes were identified, and for each a skewed distribution time curve was obtained based on actual process time records.

The results were fed into a computer model which revealed what the effect of improvements would be. These effects were then prioritised to determine where effort should be concentrated to achieve maximum benefit.

A strategic approach

This analysis has formed the basis of a new strategic approach to the operation of the coal line. Faced with difficult decisions which could lead to possible over-investment, Spoornet has begun to focus on how to squeeze more out of the existing assets. Analysis has indicated that the greatest yields will come from a reduction in rolling stock turnaround time.

A prime requirement is greater availability (and reliability) of rolling stock. This has far-reaching implications for:

Â? the optimum location of maintenance and repair facilities;

Â? maintenance and repair procedures in accordance with planned operational duty cycles;

Â? inventory levels and maintenance skills availability to promote minimum out-of-service time;

Â? rapid and effective response to in-service failures;

Â? methods to eliminate operational failures.

Further turnaround time reductions lie in the train operating field, requiring attention to:

Â? procedures and regulations;

Â? staffing, morale and reward;

Â? information flow;

Â? focused management on all operating aspects, including clear and constantly updated directives to staff.

Infrastructure maintenance needs to be planned in such a manner that the least number of train paths are closed by track occupations. Co-ordination between civil, electrical and signalling engineering staff must be improved to the point that all work necessitating service disruptions is planned for the same area of track occupation.

Overall, maintenance efforts must aim at eliminating failures affecting the running of trains, rather than merely effecting repairs.

Implementation

As loading times affect total turnaround time, an incentive bonus for the mines has been introduced for speedier release of wagons once they have been presented for loading.

Serious consideration is being given to the introduction of automatic vehicle identification (AVI) on the coal line. At present, lists of wagon numbers in train consists are compiled by staff and are prone to error. The numbers of defective wagons removed during transit are not always deleted due to oversight, which leads to further error in the wagon lists. Other potential benefits are:

Â? accurate information on the position of any particular wagon in a train;

Â? constantly-updated information on the position of a wagon;

Â? accurate identification of overloaded wagons passing over in-motion weigh bridges;

Â? accurate identification of hot boxes or bogies running skew.

AVI would also form the basis for input data into a computerised expert system designed to optimise train movements, and log rolling stock in-service periods for planned maintenance purposes.

The coal line has recently been ring-fenced with its own management structure. This will result in increased focus on world best practice operations, process-oriented technological innovations, daily operational and management control, cost curtailment, implementation of measures to reduce turnaround time, risk management, and the development of further strategies to attune the line further to the needs of the coal export industry.

Reduction in turnaround time will automatically lead to greater rolling stock capacity without the need to increase the fleet size.

As there is already adequate line capacity for increases in throughput, attention to reducing costs has shifted away from massive rolling stock capital investment to focused management attention on greater operational efficiency. o

In a highly competitive market for coal, high tonnages will only be sustained if transport costs are reduced, so any further increase in capacity has to minimise investment in new infrastructure and rolling stock

CAPTION: Class 10E-1 locos working off 3 kV DC power supply haul coal traffic on the northern section of the Richards Bay coal line; they will hand over to 25 kV Types 11E and 7E at Ermelo

CAPTION: Below: Most Richards Bay coal train loading is the responsibility of the mine operators; larger mines use rapid loaders for short turnaround times

CAPTION: Above: Derived from earlier CCL1 and CCL3 designs (smalls), Spoornet's CCL8 Jumbo wagon is one of several types with an increased payload and 26 tonne axleload dedicated to Richards Bay traffic

CAPTION: Power supplies on both the AC and DC sections of route have been boosted by adding substation capacity. This DC installation was one of several added on the Blackhill - Ermelo part of the route during 1996

Une capacité supplémentaire vers Richards Bay à moindre coût

Il est prévu que le tonnage de charbon exporté de Spoornet augmente, mais uniquement si le coût est réduit pour combattre la concurrence sur le marché mondial. Alors que des stations électriques supplémentaires vont être installées cette année sur la ligne de transport lourd de charbon de 580 km à destination de Richards Bay, la capacité de 65 millions de tonnes spécifiée par les producteurs sera essentiellement réalisée grâce à des changements opérationnels de faible coût destinés à augmenter l'utilisation du matériel roulant

Kostengünstigere Zusatzkapazität auf der Strecke nach Richards Bay

Spoornets Güteraufkommen an Exportkohle wird voraussichtlich steigen, allerdings nur unter der Voraussetzung, daß die Kosten im Hinblick auf die internationale Wettbewerbsfähigkeit gesenkt werden. Zwar wird in diesem Jahr zusätzliche Unterwerkskapazität auf der 580 km langen Schwergutkohlenstrecke nach Richards Bay installiert, doch wird die von den Produzenten angegebene Kapazität von 65 Millionen Tonnen in erster Linie durch kostengünstige Betriebsänderungen erzielt werden, die auf eine verstärkte Nutzung von Schienenfahrzeugen abgezielt sind

Mayor capacidad en Richards Bay con un menor coste

El tonelaje de carbón exportado de Spoornet espera recibir un empuje, pero únicamente si se reducen los costes para conseguir vencer a la competencia en los mercados mundiales. Mientras que se est procediendo a la instalación de una mayor capacidad de substantación este año en la línea de gran tr fico de 580 km a Richards Bay, se lograr la capacidad de 65 millones de toneladas especificada por los productores mediante unos cambios operaciones bajos diseñados para elevar la utilización de los trenes