Three Bridges in Trøndelag

Bridges have always been important elements of transportation and communication infrastructures in Norway. At least since medieval times, bridges have been commonly used to help travellers pass difficult patches of terrain like marshes, rivers or ravines. Few examples of these old bridges are known today, and even fewer have been archaeologically investigated. This paper presents three bridges from different time periods, all located in the Trøndelag counties in central Norway. In Trondheim several foundation elements of the old medieval bridge across the Nidelven River have been investigated and recorded. The bridge is known from written sources, and could be as old as the city itself. Samples have been dendro-chronologically dated to the thirteenth century. Steinvikholm castle in North Trøndelag County was the last stand of the Catholic archbishop ruling Norway in the turbulent years before the reformation in 1537. The last pieces of evidence of the original sixteenth century bridge connecting the castle island and the mainland are still visible in the intertidal zone. The remains of the bridge have been described and partially recorded two or three times during the nineteenth and twentieth centuries. Using modern digital measuring equipment, all visible remains have now been recorded, and a current assessment of the construction, as well as its condition, complements the older descriptions. In the banks of the river Driva at Oppdal in South Trøndelag County, a bridge foundation was washed out under a two meter thick layer of gravel. The position of the foundation indicated that the course of the river had changed since it was constructed. The preserved part of the foundation consisted of a triangular timber frame covered with a floor of small lumber. The construction has been dated using dendrochronology to AD 1639, which fits well with a royal initiative on remediation of infrastructure. The three bridges are different in construction and function, but can all be linked to political power in their respective time periods.