Siemens says the test programme is designed to ensure that the fleet of 60 eight-car and 55 12-car trains will be able to operate reliably at the planned frequency of 24 trains/hour in central London when the £6.5bn upgrading project has been completed in 2018. In order to achieve this frequency, the core section will be equipped with ETCS and automatic train operation.

The current Thameslink operator, First Capital Connect, has been managing the contract for new fleet, but the franchise was recently awarded to Govia, a joint venture of Go-Ahead and Keolis, which will take over in September. The first train is due to arrive in Britain in August.