The expansion of the Swiss Gotthard road tunnel will be more difficult and more expensive, resulting in extra costs of between CHF15-20 million. +Get the most important news from Switzerland in your inbox On the south side of the tunnel, explosives will have to be used instead of a mechanical tunnel boring machine. The Federal Roads Office (FEDRO) said the extra costs were caused by geological reasons. + Read more: why is the Gotthard Base Tunnel so important? Excavation of the second corridor has been ongoing since February this year. While the tunnel boring on the north side is proceeding according to plan, the one on the south side had to be stopped on June 23 after about 190 metres. A partially unstable rock mass, characterised by fractures and cavities, made mechanical drilling 'very difficult and challenging' for the next 500 metres or so. According to FEDRO, the excavation work with blasting will take about six to eight months. All other work on the north and south sides is ...
