The Amsterdam public transport company GVB has said its new train security system will be launched next July on the long-awaited new north/south metro line.

The system will later be expanded so that it covers all Amsterdam metro lines, Amsterdam alderman for public transport Pieter Litjens said in a letter to the city council.

Originally the GVB planned to install the new system in the existing metro system first, then in the new Noord/Zuidlijn. But a letter from the security system’s producer Alstom outlining serious delays in getting the system on stream forced the GVB to decide the north/south link will be served first.

The GVB still plans on opening the new metro line on 22 July 2018. But Noord/Zuidlijn director Hoite Detmar was quoted in the NRC as saying it carried a ‘big risk’.

Litjen’s letter said the problems with the security system will ‘almost certainly’ be resolved before the planned opening. ‘Together with Alstom we are examining whether the present version of the train security system is adequate for the operation of the new line’

But Litjens warns ‘given this development, there is a chance that not everything will be ready on time.’

Although the original budget for the new metro line was €1.4bn, the final cost is likely to be well over €3bn. Work started in 2002, and was due to end in 2011 but ran into massive buildings subsidence problems and technical issues along the way.