3.8 Performance
The IEP Trains must have a maximum service speed of at least 125mph and shall be able to achieve that speed on the whole of the IEP Network. The requirement to be able to operate at 125mph applies during operation in Standard Mode and Locomotive Hauled Mode.
It is accepted that 125mph may not be achieved under the following circumstances:
- on adverse gradients;
- in excessive headwinds;
- in the case of an IEP Train containing Bi-mode IEP Units operating in Self Power Mode;
- in the case where more than 312m of the IEP Train length comprises of Electric IEP Units;
• where any hauling Locomotive has insufficient tractive effort or maximum speed to allow 125mph to be achieved;
• in the event that the braking performance of an IEP Train is incompatible with the the infrastructure at 125mph due to the braking performance of a hauling locomotive;
- under Adverse Infrastructure Conditions;
- where, in the event of failure of the IEP Train, it is not possible to raise two pantographs at the maximum pantograph spacing permitted by the train formation. In this event, subject to the other provisos of this provision, at least 100mph must be achieved if the pantograph spacing is 75m or greater and no less than 80mph shall be achieved for lesser spacings; and
- in the event that it is not possible to show compatibility between the pantograph and the infrastructure, when an IEP Train is operating with two pantographs raised, on any portion of the Great Western Main Line between Paddington and Airport Junction where the line speed is greater than 100mph. In this event, the IEP Train shall be capable of 100mph or the speed at which operation is shown to be compatible with the overhead line, whichever is greater.
The IEP Trains operating under electric power shall through modification be capable ofhigher speeds than 125mph to allow for possible line speed upgrades or new lines with higher speed limits being available. The capability of the IEP Train in this regard, together with a summary of the modifications required shall be detailed through the Design Process.