During a three-month period, which ran from mid-June to mid-September this year, INFRASET Railway Products supplied 48,000 precast concrete sleepers to Transnet Freight Rail (TFR). Weighing a cumulative 12,400t, the sleepers were used in a routine maintenance programme on the 860km Saldanha / Sishen ore export line.
Comprising 31,000 PY pressed-steel shoulder and 17,000 PY galvanised-steel shoulder units, each sleeper weighs ±300kg. Rated at 60MPa, this latest batch was used to replace sleepers where the line forges inland for some 33km off the Cape’s west coast near Strandfontein. The galavnised units were installed on the 12km portion nearest the coast where sea spray can cause rusting.
The sleepers were manufactured at two of INFRASET’s factories, 30,000 units in Brakpan, Gauteng, and 18,000 units in De Aar, Northern Cape. The De Aar factory is jointly owned by INFRASET and Empowa Investments through BEE joint venture company, Empowa Grinaker-LTA.
Although it took three months to manufacture and deliver the sleepers to site, the actual process of removing the old sleepers and installing new ones took only ten days, a period during the second half of September when the line was shut down completely. Two heavy-on-track sleeper replacement machines, a P190 and a P811, both purpose-built for mechanical sleeper installation were used on the project. The P190 is owned by Lennings Rail Services, an Aveng Group company like INFRASET.
INFRASET Railway Products product manager, Sizwe Mkhize, says the sleepers will have to perform consistently well over the next 50 years and handle the anticipated increases in iron ore exports.
Delivery of 12,400t of product, over great distances to site presented its own set of challenges.
Rail was deemed the most effective transport method and flat-bed NZ wagons were used to carry the sleepers. This called for integrated scheduling between the manufacturing and delivery processes and INFRASET worked closely with Terence Appies, an infrastructure resource manager at TFR, to meet the delivery schedule.
Appies commented that there were several factors, which complicated the delivery process.
“Unlike in previous years when Transnet averaged three shutdowns annually, this year we had to contend with seven, and this placed our resource scheduling under considerable additional pressure.
“This meant that NZ wagons weren’t always readily available. Moreover, the lines were often being used for the delivery of revenue generating goods, which were obviously given precedence over goods for in-house maintenance, as important as that was.
“Good logistical planning and of course timing were crucial to the success of the delivery programme. Once loaded, at either Brakpan or De Aar, the sleeper wagons had to be integrated with Transnet’s goods schedule. Ideally we aimed to deliver sleepers in discrete sleeper-wagon blocks of between 30 and 40 NZ wagons. For quantities lower than 30, the wagons were mixed with other goods wagons, either at the Sentrarand Marshalling yard near Babsfontein or at Beaconsfield near Kimberley.
“Our scheduling had to allow for delays of up to three days before dispatch from the marshalling yards took place. Besides the availability of NZ wagons, other factors such as the availability of locomotives, line space and crews to man the trains, all had to be coordinated. The last load delivered to site coincided with the shutdown period and this enabled these sleepers to be off-loaded and installed in a single operation,” concluded Appies.
TFR currently deploys 207 NZ wagons. An order has been placed for further 100, which should be met during the next 6-8 months.