The work to be done on the Slovenian side of the railway tunnel is estimated at EUR 33.7 million, the Slovenian Infrastructure Agency said in a press release on Tuesday.

Electricity-powered railway runs through what is an almost 8-kilometre tunnel which was inaugurated in 1906.

Construction work is due to be launched on 10 August, but the majority of the works should be carried out between October 2020 and July 2021 when the rail line will be completely closed.

The railway tunnel is scheduled to reopen in September 2021 when speeds will be increased as a result of the upgrade from the current 50km/h to 120km/h.

Two bids were made in response to the tender for the upgrade in April, apart from Strabag also a group of companies which offered the price of slightly over EUR 73 million.

To produce project and investment documents for the tunnel upgrade, Slovenia and Austria have received almost EUR 3 million in EU funds.

The entire upgrade on the Slovenian side is valued at almost EUR 79 million, VAT included, with EUR 47.6 million expected to come from EU cohesion funds.

Given the current transport trends, the Infrastructure Agency expects the upgrade to suffice at least until 2040, after which a second railway tunnel will be needed.

Slovenia and Austria are currently engaged in another major infrastructure project as they are expanding the Karavanke motorway tunnel with a second tube.