Change of bogies

The bogie, a group of two or three pairs of wheels on close axles, supportive with each other, can be the driver or can be towed. The difference between the both of them is that the first one has drive and the second one does not.
The bogies have a frame, two or three axles and wheels.
All those pieces might need maintenance, but it is usually changed for a new unit or a preserved one.
The weight of a bogie goes between 15 t and 35 t, depending on whether it is driving or it is being towed.
Eyher designs and manufactures bogie drops, which are adapted to each need and tipe of workshop, using hydraulic or electromechanics according to the weight of the bogie and the size of the pit.