A 13-kilometre belt change inside a 30-day shutdown
ContiTech has completed the first replacement of the ST10000 steel-cord belt on the CP01 and CP02 incline conveyors at Codelco's Chuquicamata Underground mine in Chile, and Codelco closed the shutdown that consumed the work - its Mantenimiento Mayor 2026, or MM26 - on 1 June 2026, after more than 30 days of execution and a mobilisation of close to 6,000 people. The parameters sit at the edge of what belt conveyors do anywhere: more than 13,000 metres of belt at about 161 kilograms per metre, running up an 8.5-degree incline, built from 42 rolls joined with splices 11,450 millimetres long, on a circuit Codelco describes as carrying the highest-tension conveyor belts in the mining industry. International Mining reported the new belt pulled onto the system on 7 May 2026, ahead of the shutdown's formal close-out; the same intervention also replaced the overland conveyor's belt and its drive pulley and overhauled three primary crushers. This was not a repair. It was the scheduled first change-out of the strongest conveyor belt in service, treated as a capital project in its own right.
The splice, not the belt, is the specification
The editorial judgement belongs up front: at this tension class, the procurement object is the splice system, not the belt's headline rating. The ST10000 designation - a nominal breaking strength of 10,000 N/mm - is the number that gets quoted, but the original system design, as TAKRAF outlined in a Beltcon presentation reported by International Mining, ran the belt at an operating safety factor of S=5.0 and therefore required belt connections with a reference fatigue strength of at least 50% of nominal breaking force; the splice technology developed for the system proved 60% on a belt test rig at the University of Hanover. A buyer comparing offers on ST rating alone is comparing the wrong number: two belts of identical rating with splice fatigue efficiencies of 50% and 60% are not the same product at S=5.0. Sequencing is the second lesson. Bret Hall, Head of Services - ContiTech Industrial Solutions Americas, said when the belt was pulled on: "The ST10000 conveyor belt has been successfully pulled onto the conveyor system, marking a huge achievement for the entire team. While important work still remains – including permanent closing splices – this milestone demonstrates exceptional planning, coordination, and execution under challenging conditions." Belt-on and splices-closed are separate milestones on separate critical paths, and a replacement plan that conflates them misprices the shutdown.
42 rolls, two conveyors, one underground transfer
The system being re-belted explains the logistics. CP01 and CP02, commissioned in 2019, haul crushed copper ore from underground storage bins through a tunnel of nearly 7 kilometres that climbs almost 1 kilometre vertically; on surface, an overland conveyor carries the ore a further 6 kilometres to the distribution silo. The design deliberately minimises transfer points - just one underground, in ABB's account of the original commissioning - which concentrates the duty onto two principal conveyors rated at 11,000 t/h each and driven by gearless drives: 11 synchronous motors of 5 MW, within 58 MW of total installed drive power including feeder conveyors. ABB's framing of the truckless design - eliminating the need for 120 large haul trucks - is a manufacturer's claim from commissioning, but the structural point stands without it: when a two-conveyor system has no parallel route, its belt is a single point of failure for the whole mine, and the spare-belt question stops being a stores decision. Forty-two rolls and more than 13 kilometres of 161 kg/m belt is a manufacturing slot, a shipping programme and a laydown area, all of which have to exist before the shutdown window opens.
Ten years of preparation is the headline number
Codelco's own account of MM26, carried by Portal Minero and Guia Minera on 1 June 2026, stresses preparation over spectacle: the intervention renewed the C01 and C02 belts, the overland conveyor belt and its drive pulley, and overhauled three primary crushers, under the division's SOMA maintenance operating system. Rodrigo Madrid, the underground mine's maintenance manager, said in the statement (translated): "We are talking about an intervention that is unique in the world, not only because of the characteristics of the belts and the complexity of the system, but also because of the level of preparation it required, where professional teams worked for more than 10 years on its planning, preparation and development." Victor Yanez, the ore transport maintenance superintendent, added that the work was completed without incidents and that the management area passed nine million accident-free hours. For buyers of high-tension belting, the transferable fact is the horizon: belt manufacture, splice validation and shutdown engineering for this change-out were running a decade before the purchase became visible. At ST10000, the purchase order is the last document in the programme, not the first.
What this case does not settle
Three boundaries keep this case honest. First, it is not evidence in the new-build choice between steel-cord and fabric construction: the question here was replacement evidence on an installed ST10000 circuit - tested splice fatigue, roll logistics, shutdown scope - not first-time belt selection. Second, it is not a story about splicing equipment: vulcanising presses are tools, whereas these 11,450 mm joints are validated structures carrying a fatigue number, and it is the number, not the tool, that a specification can hold a supplier to. Third, the public record has gaps that no amount of inference should fill. Neither Codelco nor ContiTech has disclosed the belt's price or the change-out contract value; Codelco did not name the supplier of the overland conveyor's replacement belt; and while Continental told International Mining in February 2026 that its expanded Ponta Grossa plant in Brazil can now make ultra-heavy mining belts in the Americas, the origin of this specific belt has not been stated. One context note for contract holders: the ContiTech services organisation that executed the pull-on is the same business whose sale by Continental to Lone Star had not closed at the last verified check, so service-continuity questions belong in current framework reviews.
Five checks for the next high-tension belt replacement
First, specify splice fatigue efficiency as a tested percentage of nominal breaking force, and name the test rig and the reference method in the document; an ST rating by itself does not describe the joint that actually carries the load. Second, fix the joint geometry and the roll plan - splice length, roll count, roll mass - in the replacement specification, because at 161 kg per metre these numbers determine the shutdown method statement, the winding equipment and the laydown area. Third, schedule belt-on and closing-splice completion as separate milestones with separate acceptance evidence; the May 2026 sequence at Chuquicamata shows they can sit weeks apart inside one intervention. Fourth, start the replacement programme years, not months, ahead: belt manufacturing slots for ultra-heavy steel-cord product are scarce, splice validation takes rig time, and the shutdown window is fixed by the mine plan, not by procurement. Finally, ask where the replacement belt will be manufactured and who will execute and warranty the splices - regional heavy-belt capacity and the service organisation behind it have both moved in the last two years, and the answer on a 2026 quotation may not match the answer filed from the original 2019 installation.
Manufacturer announcements and our analysis are distinguished. Product claims require verification for the specific application.
Sources
International Mining - ContiTech completes first ever replacement of a ST10000 conveyor belt at Chuquicamata (7 May 2026) ↗Trade-press report of the belt pull-on milestone: 161 kg/m, 8.5-degree incline, 42 rolls, 11,450 mm joints, Bret Hall (ContiTech) quoted verbatim. System background is attributed inside the report to TAKRAF's Beltcon presentation (S=5.0, splice fatigue 50% required / 60% proven at University of Hanover) and to ABB's commissioning statement (11,000 t/h, 11 x 5 MW gearless drives, 58 MW total). Belt price and contract value not disclosed.
Portal Minero - Chuquicamata Subterranea culmino su Mantenimiento Mayor 2026 (1 June 2026) ↗Chilean mining press carrying Codelco's MM26 completion statement: 30+ days, about 6,000 people, C01/C02 and overland belts replaced, overland drive pulley changed, three primary crushers overhauled. Rodrigo Madrid quoted on the 10-plus years of preparation; Victor Yanez on zero incidents and nine million accident-free hours. Madrid's quote is translated in the English text.
Guia Minera de Chile - Chuquicamata Subterranea culmino su Mantenimiento Mayor 2026 (June 2026) ↗Second Chilean outlet carrying the same Codelco statement, used to cross-check the MM26 scope (belt changes, drive pulley, crusher overhauls) and the named-manager quotes. The belt supplier for the overland conveyor's replacement belt is not named in either Codelco text.
