Increasingly, locomotive-drawn trains are being replaced by multiple unit and articulated trains. To service these new train compositions a section of the train service depot Tannwald in Olten has to be renovated by 2018. Not only does the building have to be extended in length, but the roof has to be raised to accommodate the necessary crane installations.

We were commissioned to review the decision criteria for the roof scenarios and prepare a second opinion of the preliminary and construction projects. The focus of our reviews was on the plausibility of the decisions, the content of the phase documentations, the measures taken for construction under operation and the feasibility of the construction costs.