Huntly Power station, which was commssioned in 1982, consists of four 250 MW, single reheat steam turbo-alternators. New Zealand, being an active earthquake region, caused the designers to come up with a unique way of protecting the machines from these possible earthquakes; they mounted all the main machinery on low tuned, all steel foundation structures, (as opposed to the normal stiff concrete foundations).  The effect of these foundations was to introduced a raft of resonance problems which included lowering the generator 2nd critical into the running range, bearing resonances on the generator and major resonances in the steam turbine driven main boiler feed pump. This paper looks at how these resonances were analysed and the temporary work around to allow the machines to be commissioned until permanent solutions could be engineered.  The paper also looks at the long term consequence of these resonances and how they have been allowed for by alarm profiling the vibration during the machine run up.

Simon Hurricks was born in the UK and Immigrated to New Zealand in 1957. Simon gained a NZ Certificate in mechanical engineering in 1974 and has been employed by Genesis Energy Ltd and its predecessors for 46 years and has been stationed at Huntly power station for 37 years as Predictive Maintenance engineer. Simon has specialised in vibration analysis and balancing for 40 years and has extensive experience in solving resonance issues and modal balancing of flexible shafts. Simon was treasurer and past president of the Vibrations Association of NZ and has presented papers at all of their 28 annual conferences. Simon has had articles published by both Bently Nevada and BK Vibro.