NON DESTRUCTIVE DYNAMIC TESTING OF STONE PINNACLES ON THE PALACE-OF-WESTMINSTER

This paper describes some non-destructive tests which were used to eva luate the integrity of 534 stone pinnacles on the Palace of Westminste r. The objective of the tests was to measure the fundamental natural f requency of the individual pinnacles so that the frequency of each pin nacle could be compared with the frequencies of similar pinnacles, the reby identifying any pinnacle which was significantly different from t he norm. Initial tests were undertaken to establish the viability of t he test method, and these are described. Eventually, two types of test were established: an impact test for the smaller pinnacles, which inv olved attaching a transducer to a pinnacle and monitoring the pinnacle response to a gentle impact load; and a laser test for the larger pin nacles, which involved monitoring their ambient (wind) response. Both types of test are described and examples of test data are given, The u se and limitations of the test methods are discussed.