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Automatic gauge changing for freight. The OGI project

The third rail (c) implies solutions of great technical and operational complexity, that affect
the existent services in the modified line and requires a complete upgrade of signalling, cate-
nary and operational systems.
The last solution (d) is very extended in passenger trains and services but it still has not been
successfully developed in freight trains. One of the main reasons why it has not already been
implemented in freight trains deals with the axle load and, more accurately, with the total
weigh of the train.

2.2 The axle load and the weight of the train - different automatic variable
gauge systems for passenger trains and freight trains

The existent technology of automatic gauge changing mechanism for passenger trains entails
to release the weight of the wheels to allow them to adapt the new position. That means that
the weight of the train is not supported by the wheels during the change operation and it is the
changeover platform that support the weight of the train while it passes through the changeo-
ver facility.
The axle load of most passenger automatic variable gauge trains in Spain is about 17-18 t/axle
(e.g.Talgo 250 is 18 t/axle ). Consequently, the total weigh of a passenger train that passes
2
through a variable gauge facility is about 250-280 tonnes for a simple train and no more of 500-
600 tonnes for a multiple-unit train. These variable gauge passenger train weigh is much lower
than the axle load of a freight train.
Nowadays freight rolling stock is designed for the standard 22,5 t/axle. This means, in the end,
25-32% increase compared with the previous passenger example of 17-18 t/axle. This variation
and the fact that a 700m freight train could carry 1500-2000 tonnes or even more, depending
on the track conditions, make it difficult to extend the current variable gauge technology to
the freight trains.
To develop a variable gauge technology to higher axle load and heavier trains, the first objec-
tive is to be able to adapt the wheels to the new position without releasing the weight of the
train from wheels. This entails a significant difference between the actual automatic variable
gauge technology - valid for passenger trains - and the automatic variable gauge technology
valid for freight trains.

2.3 The OGI project

The OGI project that is being developed by the consortium TRIA-AZVI will mean an important
step in terms of a new concept for the freight operation rail services and also in the construc-
tion and gauge adaptation of new rail lines in Spain.

This project consists on the development of two new automatic variable gauge systems for frei-
ght trains and its certification according to the European standards. Both solutions are based on
the OGI technology developed in the 70's for which has been necessary an important labour of
re-engineering to adapt it to the current time.
The two new variable gauge wheelsets are being certified for two different types of freight wa-
gons and wheel diameters: 920 mm and 760 mm. The 920 mm wheel diameter is the one that
mounts the standard bogie Y21 (valid for 1435-1668 mm gauge tracks) which is similar to the
European standard bogie Y25 (just valid for 1435 mm gauge tracks). This type of bogie is the
most extended all around Europe. The 760 mm wheel diameter is used in wagons for transport
of cars.

2 Corporate catalogue - TALGO

International Congress on High-speed Rail: Technologies and Long Term Impacts - Ciudad Real (Spain) - 25th anniversary Madrid-Sevilla corridor 73