At 7,845 m (25,738 ft), the bridge covers half the distance between Sweden and the Danish island of Amager, the border between the two countries being 5.3 km (3.3 mi) from the Swedish end. The structure has a mass of 82,000 tonnes and supports two railway tracks beneath four road lanes in a horizontal girder extending along the entire length of the bridge. On both approaches to the three cable-stayed bridge sections, the girder is supported every 140 m (459 ft) by concrete piers. The two pairs of free-standing cable-supporting towers are 204 m (669 ft) high allowing shipping 57 m (187 ft) of head room under the main span, but most ships' captains prefer to pass through the unobstructed Drogden Strait above the Drogden Tunnel. The cable-stayed main span is 491 m (1,611 ft) long. A girder and cable-stayed design was chosen to provide the specific rigidity necessary to carry heavy rail traffic, and also to resist large accumulations of ice.[citation needed ] The bridge experiences occasional brief closures during very severe weather, such as the St. Jude storm of October 2013.[18]