Brazil's busiest railway is set to get even busier; Brazil's 905km metre-gauge Vitoria a Minas Railway handles a staggering 32% of all Brazilian railfreight, measured in tonne-km, on just 3% of the national rail network. Its main traffic, iron-ore, is set to grow

International Railway Journal, May, 2005 by Theodor Gevert

EFVM was originally built to reach the diamond reserves northwest of Vitoria. Discovery of iron-ore at Itabira changed this. Today EFVM is owned by the private mining giant Companhia Vale do Rio Doce (CVRD) and is one of the world's busiest railways. More than 120 million net tonnes of freight, mainly iron-ore, are transported annually over its single main line.

By the 1970s, 160-wagon iron-ore trains had become standard. Growing traffic has since forced the railway to operate longer trains which gave rise to a lot of technical challenges. The first problem stems from the sheer size of the trains. Trains of more than 160 wagons, headed by two General Electric (GE) Dash 9 locomotives, begin to lose braking efficiency because of the time it takes for air pressure to run through the air pipes. To this must be added increases in the risk of broken couplings due to internal shocks and compression. The solution was the use of distributed traction. This was tested on the standard 160-wagon formation and also on larger trains up to 240 wagons.

Besides the field tests, computerised simulations were made using specific software programs. After much simulation and on-line testing, a new standard train formation was designed: 1 Dash 9 + 160 wagons + 1 Dash 9 + 80 wagons + 1 Dash 9 + 80 wagons, with only one driver in the lead locomotive. All locomotives are controlled from the lead unit using GE-Harris Locotrol remote control equipment. Signals between the locomotives are transmitted by radio. The decision to have 80-wagon rakes is based on a classification yard that receives wagons from different mines along the line in 80-wagon cuts.

Advantages of using distributed power on 320-wagon trains include reduced coupler wear, reduced coupler breakage, increased life span for rails and wheels, reduced brake shoe wear, increased traction capacity, and increased train control. The result is less tractive effort in any one spot along the train, less track wear, and expected fuel savings of about 5%. These trains average 31,000 tonnes with a total locomotive output of 8.95MW. A manually-controlled banking locomotive is added at the rear of the train to cope with long inclines.

An important factor is the line's profile; it is built in a mountainous region, resulting in short but fairly steep gradients and some sharp curves that cause involuntary shocks amongst the wagons in a train. Tunnels cause a further problem, as the radio signal between the main and remotely-controlled locomotives is temporarily lost. Some tunnels are over 1km long and have gradients and curves. In some cases, there are inclines, descents, and curves all in the same tunnel.

The solution was to feed the line profile into each lead locomotive's computer; GPS not only informs the Central Control Post (CCP) where the train is, it also informs each Locotrol-controlled locomotive allowing it to perform when in the second or third position on long trains.

Trains with three locomotives and 320 wagons (100 tonnes/wagon), were operated regularly between 2001 and 2003. Last year, trains of 240 loaded wagons became standard, as in most yards, except Desembargador Drummond, trains have to make extra manoeuvres to handle more than 240 wagons. This problem will be solved as yards are lengthened. The railway is also simulating and testing other arrangements to see if 320 wagons is the best standard for its iron-ore trains, but trains with 320 empty wagons are still operated regularly. Until more yards are lengthened, the time lost in shunting trains of 80 loaded wagons into trains of 320 wagons is considered excessive, the 240-wagon train providing better turnaround.

A major advantage of operating such large trains is an increase in transport capacity, which avoids having to add a third track to the double-track main line. Other advantages are small savings in fuel and staff. But it presents problems such as the need for longer sidings and lead tracks in yards and the effects of hunting in longer trains.

Strong Growth

Over the coming five years EFVM should see a traffic growth of 58 million tonnes/year in iron-ore production coming from four mines along its lines. Railway and port capacity will grow accordingly, but how best to handle this technically and economically is the big question.

The amount of hunting grows almost geometrically with the increase in the size of the train, and increases the danger of derailment on perfectly maintained track, due solely to the increase in the length of the train. Although derailments due to hunting have not occurred, the danger is so real that EFVM's long iron-ore trains must come to a full stop when meeting the daily passenger train even though the main line is largely double track.

EFVM's busiest section sees an average of 63 trains/day, 73% of which are iron-ore trains. Traffic is expected to grow by 50%, from 119 million net tonnes in 2004 to 130 million this year, and 177 million in 2009.

EFVM's five-year investment plans include the purchase of additional locomotives and wagons, and infrastructure improvements such as: