Page 100 - 6748

Andrej: The record speed exceeded the standard operating speed by a huge margin. It was 80%
faster at its peak. So you would imagine that the TCV used for the record run was heavily
modified. In fact, that wasn’t really the case.
The train was modified to a certain extent but, with a few exceptions, it was essentially just an
ordinary TCV. As you can see from this slide, one of the biggest differences was that the
modified train was significantly shorter, in order to make it lighter. There was a 50% reduction
in length, down to 100 metres, compared with a 200-metre standard length. The coaches being
pulled were perfectly standard - the only differences were that some of the seats had been
removed to make way for all of the monitoring equipment that was carried on board. And some
changes were made to the bodywork, to make it slightly more aerodynamic, which meant the
drag coefficient was reduced by 15%. The wheels on the modified train were marginally bigger
than the standard size. The diameter was increased by 19%, in order to reduce the speed of
revolution, to limit friction and centrifugal force. And the power of the electric motors was
substantially higher than the standard units - boosted by 68%. But none of the changes was
fundamental. So my point is, standard high-speed trains can be made to go faster by a
considerable amount.

d ► 10.3 Listen again and complete the following table about the modified TGV using the
figures in the box.
+ 68% + 19% - 15% - 50% + 80%
Technical criteria Modified TGV: % difference from standard model
Maximum speed
Train length (with coaches)
Aerodynamic drag
Diameter of wheels
Motor power output

e Complete the following sentences from the talk by underlining the correct words.
1 The record speed exceeded the standard operating speed by a tiny/huge margin.
2 The train was modified to a certain/considerable extent...
3 ...the modified train was significantly/slightly shorter, ...
4 ... changes were made to the bodywork, to make it slightly/much more aerodynamic...
5 The wheels on the modified train were marginally/substantially bigger ...
6 ...the power of the electric motors was marginally/substantially higher than the standard
units ...
7 ... standard high-speed trains can be made to go faster by a slight/ considerable amount.

f Rewrite the following sentences to describe the modifications that were made to the TGV
for the record attempt. Use the phrases in Exercise 6e to replace the words in bold.
1 The supply voltage in the catenary cables had to be increased from 25,000 to 31,000
volts.
2 To limit oscillation, the tension of the catenary cables had to be increased by 60%.
3 On some curves, the camber of the track had to be increased by a few centimetres.
4 The 574.8km/h record beat the previous record, set in 1990, by 59.5 km/h.
5 In perfect conditions the TGV could probably have gone faster by 5 to 10 km/h.

7 In pairs, choose a product or type of technology you know well and compare its
performance and quality with an earlier model, describing the extent of the differences.

IV Describing capabilities and limitations

98