There’s something inherently captivating about a train stretching seemingly endlessly across the horizon. A hypnotic ribbon of steel, a massive steel serpent winding through the landscape, the sight of an exceptionally long train is a testament to the power of engineering, logistics, and raw industrial might. While passenger trains are typically limited in length for practical reasons like station platforms and tight curves, it’s in the realm of freight – particularly bulk commodities – where trains truly achieve epic proportions.

So, what constitutes “the most long train,” and where do these behemoths roam?

The Ultimate Record Holder: BHP Iron Ore, Australia

The undisputed champion of train length belongs to BHP Billiton’s iron ore trains in Western Australia. These incredible formations transport iron ore from inland mines to port facilities. While they regularly run trains over 2.5 kilometers (1.5 miles) long, the record-breaking journey occurred on June 21, 2001.

This particular train consisted of:

• 682 loaded iron ore wagons
• 8 powerful General Electric AC6000CW locomotives
• A staggering total length of 7.353 kilometers (4.568 miles)

This single train moved 82,262 tonnes (over 90,000 short tons) of iron ore, making it the heaviest and longest train ever recorded. It operated with a single driver, a remarkable feat of automation and distributed power.

Other Notable Giants:

While BHP holds the top spot, several other railways around the world regularly operate trains of impressive length:

• Mauritania Iron Ore Train: This train is legendary not just for its length (up to 3 kilometers or 1.8 miles), but also for its unique role. It transports iron ore from Zouérat to the port of Nouadhibou. What makes it truly remarkable is that it often carries passengers on top of the ore wagons or in dedicated carriages attached to the end, offering a rugged, unforgettable journey through the desert. It’s one of the longest and heaviest regularly scheduled trains in the world.
• North American Freight Trains: The vast distances and efficient rail networks of the United States and Canada are ideal for long trains. It’s common to see freight trains exceeding 3 kilometers (2 miles) in length, particularly on routes carrying bulk commodities like coal, grain, and general merchandise. Innovations like Distributed Power Units (DPUs) – locomotives placed in the middle or at the end of the train, controlled remotely from the lead engine – have made these extremely long formations feasible by distributing the pulling and braking forces.
• South African Iron Ore Trains: Transnet Freight Rail operates long heavy-haul trains, especially on its Sishen-Saldanha line, moving iron ore. These can also stretch over 2 kilometers (1.2 miles) with multiple locomotives.
• Chinese Heavy Haul Railways: With its massive industrial output, China has also invested heavily in long-distance heavy-haul rail, operating significant length trains for coal and other resources.

Why Go Long? The Benefits of Scale

The rationale behind operating such gargantuan trains is simple: efficiency and economy of scale.

• Reduced Costs: Fewer locomotives per ton of freight, fewer drivers, and less track congestion mean lower operating costs.
• Environmental Impact: Moving more goods in fewer, longer trains generally results in lower fuel consumption and greenhouse gas emissions per ton-mile compared to trucking or even shorter trains.
• Capacity: Long trains maximize the capacity of a given rail line.

The Engineering Challenges

Operating trains of such immense length is no small feat. It requires overcoming significant engineering challenges:

• Braking: Applying brakes evenly across several kilometers of train is complex. “Slack action” – the compression and expansion of couplings – can cause immense forces and even derailments if not managed precisely. DPUs are crucial here, allowing for synchronized braking across the entire length.
• Coupling Strength: The couplers between wagons must withstand enormous pulling and pushing forces, especially on grades and during braking.
• Track Infrastructure: Curves must be gentle, and grades carefully managed. Signalling systems need to be adapted for the immense length.
• Derailment Risk: The longer the train, the more points there are for potential issues like wheel defects or track irregularities to cause a derailment.

The Future of Long Trains

As technology advances, particularly in automation and intelligent rail systems, the possibility of even longer trains continues to be explored. While the record set by BHP’s iron ore train remains an almost unreachable benchmark, the regular operation of multi-kilometer trains is a testament to the ingenuity of railway engineers and the enduring power of the steel wheel on the steel rail. These “giants of the rails” continue to be a vital, impressive, and often awe-inspiring component of global logistics and industry.