THE rock dumps at the Sishen iron-ore mine tower over the table-top-flat Northern Cape landscape. The massive pit, swept by a bitingly cold June wind that stirs up rust-red dust, makes trucks so large that a grown man barely reaches halfway up their wheels look like toys.

Sishen's owner, Kumba Iron Ore, is Africa's largest iron-ore producer and the world's fourth biggest, needing the world's longest trains to haul ore to the port of Saldanha on the Atlantic seaboard. Once its Kolomela mine is in full production, Kumba will have an output of 44-million tons of ore a year, and it wants to add another 15-million tons to its Northern Cape production.

The trains that haul 34000 tons of the iron ore, which consists of surprisingly heavy stones the size of a thumb, are the longest in the world. At 4km, they become a study in a vanishing point of perspective. A car will wait for up to 15 minutes at a level crossing for the train to pass.

It takes two hours to load a set of 114 wagons and there are three of these sets per train bound for Saldanha, 861km away. The thundering sound of the automated loading stations dropping 100 precisely measured tons of ore into each wagon is deafening.

It is eerie watching a train creeping steadily forward, the only sound being the regular crash of ore into steel wagons bracketed by hissing hydraulics. There is not a single person in sight.

A joke on the mine is that you can spot a new building because it does not yet have a coat of red dust, which is pervasive despite water bowsers regularly spraying the wide roads out of the pit.

The mine stretches 13km north to south and measures 2,5km at its widest point and will eventually be 5km across as hundreds of millions of tons of waste rock are moved to expose the deeper parts of the mine to reach the ore.

Not all the dumps are waste rock. The mine stockpiles ore yielding an iron content of less than 45% until new technology can economically upgrade the material in an expensive electricity environment, making it saleable. The mine sells ore with iron content greater than 60%.

Kumba Iron Ore owns 74% of the mine, with Exxaro Resources, workers and a community trust holding the balance. Anglo American holds 65% of Kumba.

Kumba Resources was formed when Iscor, a state-owned iron and steel company set up in 1928, was broken up into its mining and steel businesses in 2001 and each was separately listed. Kumba Resources was then split into Kumba Iron Ore and a new company, Exxaro Resources, which housed the nonferrous assets.

Kumba is one of Anglo American's star performers, benefiting from strong demand from China for the steel-making ingredient.

The Sishen mine's employee share scheme payout in December of R500000 each was one that miners on other operations can only dream about. It has resulted in instant wealth for thousands of workers who live in nearby towns, giving the local economy a boost.

Kumba feared its workers would take the money and leave, but it ran extensive "financial fitness training schemes" after people initially said they would use their payouts to start their own businesses. "We spent a lot of time making sure we didn't end up with half our workforce. We're putting big disincentives into the second scheme to ensure we cut down on absenteeism and people leaving," says Kumba CEO Chris Griffith.

"It took a while for us to get going this year and it did have something to do with people with money in their pockets," he says.

The iron-ore line is one of the most successful in the Transnet Freight Rail stable and there are plans to grow its capacity to 83-million tons from 60-million tons as part of the rail utility's R300bn, seven-year expansion programme to boost total rail volumes to 350-million tons from 200-million tons, creating thousands of jobs in the process.

The investment in new rolling stock and the improvements to the Saldanha line have led to disagreement between Transnet and mining companies about who is and who is not pulling their weight. Mining companies producing bulk commodities have long complained that among the biggest constraints to their ability to grow is a lack of rail capacity and an inferior service.

Transnet says it is tackling these issues.

In February, there was a remarkable dressing-down of coal mining companies by Transnet GM Divyesh Kalan, who said they were not keeping pace with the upgraded rail capacity. Now tales are told on the Sishen-Saldanha line of trains waiting at sidings for the mines to fill them.

Iron-ore miners Assmang, which operates the Khumani mine to the north of Sishen, and Kumba hotly deny they are struggling to keep up, explaining they have expansion projects under way that are ramping up and once these are on stream the pressure will switch back to Transnet.

"This is the first time ever that we've not been ahead of Transnet. There's only one reason for that. Our new Kolomela mine is in ramp-up mode," Mr Griffith says. "Transnet is making a big song and dance about this, but I'll keep quiet because it will change. Next year, the shoe will be back on the other foot. They will be under serious pressure. I've got no objection to them making a song and dance because they're thinking about productivity," he says.

Assmang management says they use every spare train they can and have put systems in place to make sure Transnet does not wait for them.

For a developing country such as South Africa, having key industries bickering about competitiveness is a healthy sign and should be a model in other sectors.