Colin, thanks for taking the time to reply.
I tried some more imaging sessions last night and had no obvious vibration effects on images. I not sure if there was less traffic passing – I had also tightened up the RA and Dec axis slackness a little, there has to be a little on the ME otherwise it jams when slewing. I’ve read a lot about adding sand, but no reports actual improvement of before and after sand. Have you actually tried this method. The pier does not sound a ringing tone when struck . I shall try out your suggestions.