The German-built Siemens Desiro trains, which began running in the seaside town on Sunday, represent the biggest order for any new rolling stock in the country.

Of the 174 ordered costing �1bn, 120 have already been completed fully equipped with electric doors and air conditioning.

But only 45 will be in use in the South because the region's tracks do not have enough power supply to run all of them.

The rest of the new fleet, introduced a year later than planned, will remain in Germany until the tracks are upgraded.