IWT4 - Commercial Application

Vale is the second largest mining company in the world and a world leader in the iron ore market segment. The EFC is a mine to port iron ore transportation operation in an extreme environment, with the mine close to the Amazon and the port near Sao Luis in the north of Brazil. This 1600mm gauge railroad spans almost 900km of harsh terrain, and boasts the longest trains in the world, more than three kilometers in length.

With the current world demand for iron ore Vale has planned a massive increase in capacity of the EFC railway. The current capacity of 120 Million tons of ore is expected to be increased to 230 Million by 2014/2015. Achieving this increase is a massive undertaking and includes activities such as doubling the track, increasing the number and capacity of the rotary unloaders, right through to drastically increasing the capacity of their wheel lathes. As part of this Vale aims to increase the capacity of each ore wagon by 20 tonnes, resulting in an axle load of over 37.5 metric tons. An essential part of implementing this upgrade is to understand the implication on vehicle and track and a cornerstone in achieving this is the measurement of wheel rail forces.

While it is easy to calculate the forces arising from the static axle load, the forces resulting from the dynamics are more difficult to determine. By using an instrumented wheelset the dynamic forces can be measured directly, enabling the load on the vehicle and the infrastructure to be determined.

Interfleet’s latest Instrumented Wheelset Technology (IWT4) was chosen as it is able to directly measure vertical, lateral, and longitudinal forces, while using the ore wagon’s standard wheelset.

Two IWT4 wheelsets were manufactured at Interfleet’s laboratory in Sweden and shipped to Sao Luis together with a state of the art data acquisition and evaluation system. A customised evaluation and reporting system was developed for Vale. This system provides exception reporting linked to positions on the network, and allows the operator to analyse and display data via a user friendly interface.

In February 2010 Interfleet engineers travelled to Sao Luis to commission the system and train Vale staff in its operation. A test train was composed consisting of Vale’s test coach, a new type wagon (called GDU) fitted with the two IWT4 wheelsets, four of Vale’s standard Iron Ore wagons (GDT), and a locomotive. During the first half of 2010 Vale staff used the system to evaluate the performance of a number of bogies to determine the best configuration for their 37.5T wagon fleet.

The measurement of wheel rail forces has been and will continue to be an important part of implementing a drastic increase in capacity of Vale’s EFC system. By measuring wheel rail forces Vale are moving towards an optimized configuration for their 37,5 tonne ore cars.