Whether rail is a greener mode of transport compared to putting your project cargo on a ship is a debate to be had. Some say it is, and others say that it can’t compare to shipping when it comes to ton-mile. Moving project cargo on rail does have its limitations.

This overview provided by DB Cargo’s André van Dam, a veteran expert on exceptional transports and customized rail projects, gives an insight into the dimensions and weights of cargo that can be moved by rail. The overview also looks into the industry-specific jargon.

Gauge

Railway lines in Europe are classified based on their strength and dimensions, van Dam says. The available space above the track, in terms of height and width, is referred to as the gauge. The gauge always starts from the ‘head of the rail’ and is measured at the centre between both rails. In most countries, gauges are defined with a maximum height of 4650mm, including the cargo. However, in France and Italy, the gauges are lower, typically up to 4280mm.

Unlike roadways, railway gauges are not rectangular; they are designed to fit tunnels and pass signals. To accommodate higher cargoes within the maximum height limit, cargo can be turned or wagons with lower beds or girders can be used. Exceptions to the height limit are rarely possible due to the presence of power lines above, says van Dam.

The longer the cargo, the slimmer the waggon

The gauge on all lines has a total width of 3150 mm, says van Dam. It decreases in the higher part, fitting to the tunnel shape. This means that the allowed width of a cargo is 3150 mm. “It is there where the difficulties ‘kick in’: the longer the waggon or the cargo, the more it tends to the inside when running curved tracks,” says van Dam.

Compared to transporting oversized cargo on the road, trucks can make wider turns and choose their path around a corner. “We cannot, we just have to stay on track,” van Dam adds. Compensation needs to be applied when considering bends, meaning the allowed width of the cargo is decreased.

“The longer the wagon or cargo, the greater the adjustment required. Therefore, wagons are constructed to fit the width allowed by their length at all times. A 15-metre wagon can be up to 3.10 metres wide, while a 25-metre wagon can be up to 2.70 metres wide. The same procedure must be followed for the loaded cargo, taking into account the gauge at higher points,” van Dam says.

Exceeding the limit

In certain instances, the cargo can exceed the gauge, up to certain dimensions. Moving wider cargo on regular trains is possible with the width reaching up to 3200 millimetres, with an eye on the length of the cargo due to tending.

“Even loads of up to 3500 mm could be possible in some cases, but then we have to adapt routing or schedule of the train,” van Dam said, adding that for each cargo wider than the gauge a transport permit is needed.

Determining factors

Two main elements determine the weight which can be moved by rail, the construction of the waggon itself, and the capability of the stretch it has to run. Similar to the dimensions, all railway lines are categorized, from A to E, indicating the maximum axle load of waggons to run that line.

“Of course, the strength of bridges to cross is part of this, as well as the construction of the track and the density of the ground below. Most lines are at level C (20t/axle) or D (22,5t/axle). This standard is far over the regular road allowance of 10t/axle,” van Dam said.

Regular 4-axled waggons built to category C can carry up to about 56 tons of cargo and waggons built to category D can carry up to about 62 tons of cargo. Regular 6-axled waggons can carry up to 65 tons in C and up to 74 tons in D, noted van Dam.

On certain lines and under special conditions, the 6-axled waggons can carry weights even up to 100 tons. Waggons with more axles (8,10,12 or 16) can load even heavier cargo, up to 200 tons, granted the dimensions of the cargo fit within the gauge parameters.

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This article was originally published in our sister publication ProjectCargoJournal.com