TUNNEL CONSTRUCTION Tunnelbau Niobium Silver Bimetallic Coin 25€ Euro Austria 2013

Opened in 1848, the vertex tunnel of the Semmering railway was the world's first alpine tunnel. The ‘New Austrian Tunnelling Method', which uses the geographical stress of surrounding rock to strengthen a tunnel, was developed from 1957 to 1965 and has since done a great deal to revolutionise tunnel construction around the world. A present-day tunnel boring machine features in the niobium pill of the coin's obverse, its rotating motion symbolised by three arrows. The obverse's outer silver ring shows the mountains through which the machine pierces. The coins reverse makes excellent use of the niobium pill to show one of the many road tunnels that pepper Austria's alpine landscape today, while a tunnel worker uses a pneumatic drill to loosen rock in the silver ring alongside the word "Tunnelbau" (tunnel construction). Minted to a maximum of 65,000 pieces in Special Uncirculated quality only, the coin contains 9 grammes of 900 Fine Silver in its outer ring and 6.5 grammes of 998 pure niobium. Each piece is encapsulated, boxed and comes complete with a numbered certificate guaranteeing its authenticity.