Rehabilitation of the Highest Wooden Telecommunication Tower

The unique telecommunication tower, over 110 m high, was built in 1933 as a spatial truss completely from larch wood. All connections were made with brass bolts. During 65 years of continuous service the tower was examined and protected several times but there were also long periods without proper maintenance. In 1998 the structure was carefully inspected, measured and checked by calculations. Imperfections in geometry of truss joints as well as damages in wooden members have been recorded. On the basis of tests of material specimens and Computer analyses the ränge of necessary strengthening has been assumed. The tower was old enough to be treated as a monument of technology, so, the methods of repair, strengthening and protection were limited. The specific method of strengthening by means of carbon fibre polymer Strips was introduced in the most endangered members ofthe structure. General protection works have been used for the entire tower.