Thanks Jack, i will reach out to him for sure. i will let you know. by the way, i did track down a RPM tool for my TT. a simple laser reader, i forget the brand name as i am at work right now.
Try and contact Joe Lavrencik of Critical Mass Systems. Your table is a heavy one and the weight distribution is uneven. Bladder type isolation will not work and neither will sprung suspensions. That leaves CMS and as mentioned HRS. Joe is from Chicago so is no stranger to mass transit noise. He's also a very honest guy and will tell you if his products will work in your situation or not. I once asked him to make speaker mounts for me and he said no because he said he didn't know how to make proper ones yet. I'm guessing his rack system will work for you for as long as the vibrations are not heavy laterally or on the horizontal plain. If this is the case then I fear, there is no solution except to get that pipe fixed by the City.
Joseph Lavrencik <firstname.lastname@example.org>
You can also ask Joe Kubala as a character reference. They've been doing shows together for as long as I can remember.