The Estrada de Ferro Carajás opened on 28 February 1985, laid on broad 1,600-millimeter gauge and running 892 kilometers from Parauapebas, in the state of Pará, northeast to São Luís. Its freight is overwhelmingly one substance. The Carajás mine at the far end is the largest iron ore mine in the world, and the rock is exceptionally rich - the concession's known reserves average 65.4 percent iron, high enough that the ore needs comparatively little beneficiation before it goes to sea. Ponta da Madeira is the terminus, owned and run by Vale, and it sits immediately alongside the public wharves of Porto do Itaqui. From the air the two blur into one continuous industrial coastline. On the ground they are separate operations with separate logic: Itaqui takes the state's grain, fuel and general cargo, while Ponta da Madeira takes the train.

The site was chosen for its water. São Marcos Bay offers a natural draft of 26 meters at low tide, which is deep enough that the largest bulk carriers afloat can come alongside without a dredger working around the clock. What the bay gave in depth, though, it took back in movement. The tidal range here is large and the currents it generates were strong enough to make berthing genuinely difficult, a problem the engineers eventually answered underwater rather than above it, placing concrete breakers on the bottom to take the energy out of the flow. It is the sort of fix that leaves no visible trace. Stand on the pier and you see only ships, conveyors and stockpiles; the hardest engineering problem the terminal ever solved is invisible beneath the surface.

Ponta da Madeira is one of the few Brazilian terminals equipped for the Valemax class - very large ore carriers of 380,000 to 400,000 deadweight tons, around 360 to 362 meters long, 65 meters in the beam, drawing 22 to 23 meters when laden. Vale ordered them to make the long haul to Asia competitive with Australian ore, and by 2020 some sixty-eight of them existed. Their reception was not universally warm. In January 2012, China banned dry bulk carriers over 300,000 tons from its ports on safety grounds, weeks after the Vale Beijing suffered structural damage; the embargo held until July 2015, when Dalian, Qingdao and Lianyungang opened to them. In the interim the ships kept loading here and unloading elsewhere - Rotterdam, Sohar, Ōita, Dangjin - which is one way to read a shipping map as a political document.

An ore railway is easy to imagine as a closed loop of rock and money, sealed off from the country it crosses. The Carajás line is not that. It makes twenty-five stops between Parauapebas and São Luís, through Marabá, Açailândia and Santa Inês, and it runs a passenger service - about 350,000 riders a year, in economy, executive and accessible carriages, on a journey of some fourteen hours that is frequently longer. For many towns along the corridor, this is not a scenic railway or a novelty. It is the affordable way to reach a hospital, a university, a job or a funeral. The ore trains have priority. The people wait, and then they board, and the same rails that carry Brazil's largest export also carry its passengers at a walking pace across two states.

In 2020 Ponta da Madeira handled 190.1 million tons, the highest figure of any port in Brazil. The railway feeding it moved 179.5 million tons in 2024, of which roughly 177 million was iron ore, the remainder fuel, copper, pig iron, coal and manganese. Those numbers are still climbing, driven by the S11D deposit near Carajás, for which the terminal has been progressively expanded. Meanwhile a quieter shift is underway on the same waterfront: bulk agricultural cargo, soy and grain out of Brazil's expanding northern export corridor, now moves in volumes that would have seemed fanciful when the piers were built. The container yard remains almost an afterthought, dwarfed by the ore stockpiles. For now, the arithmetic of this coast is still written in iron.