Rock removal must precede Mitholz ammunition clearance

Unstable rock above buried ammunition in Mitholz must be secured before the explosives can be cleared, SRF reports. Under the Swiss defence department’s schedule, the main clearance is due to begin in 2037 and is expected to be completed by 2044.

The Zweispitz, the Dreispitz and parts of the Fluh rock face must be removed in layers from top to bottom. The Fluh and the highly unstable Dreispitz lie directly above the ammunition. The former railway tunnel is also a significant safety risk.

Work in the tunnel was completed in September 2026. It will remain filled until the ammunition is recovered, and the fill will be removed before clearance begins. Securing underground cavities and other protective measures have reduced the risk of an explosion and made it possible to prepare for the next stages.

Preparatory and protective work is expected to continue until 2037. Once clearance is complete, the land will be restored and Mitholz is due to be resettled, though whether that can happen as planned remains uncertain. So far, 56 people living within the security perimeter have had to leave their homes.

The preparatory and protective measures are the largest identified cost item in the defence department’s plan, with 1.09 billion Swiss francs budgeted. That is nearly half of the approved total credit of 2.59 billion francs. The project is funded by the defence department and the regular federal budget. About 147 million francs have been spent so far, but the final cost is unknown.

The schedule could also change depending on how much ammunition is recovered and whether further finds are made. The whereabouts of about 2,400 missing aerial bombs are also unclear; it has not been established how many exploded in the 1947 blasts and how many may still be inside the mountain.