Chris Gannon and John Meyer from Robinson Seismic explain how the Ro-Glider works. Lead rubber bearings aren’t suitable for light structures, so Robinson Seismic has developed the Ro-Glider to handle these lighter structures.
The lead rubber bearing is used for heavy structures because it can take a very large vertical load on it.
And so if you use this wooden block as a light building if my hand is the ground and it moves then the building just moves the same as the ground, the rubber bearing is not doing anything for us. The Ro-glider is a sliding device and if I now put our building on something where it can slide and move the ground round, the ground moves more than the building does, so the building doesn't take anywhere near the forces or the movement that the ground does. And that’s why we have developed the ro-glider. So anything that has a weight of perhaps less than 100 tonnes on each pile or each column the Ro-glider becomes a viable option.
We have two sliding surfaces on it, so the device doesn't have to be as high as a rubber bearing because since both surfaces slide we get twice the displacement out of the diameter of the device. Whereas if the lead rubber bearing, if the device isn't big enough in diameter, and the building moves too far it falls off the bearing. How the Ro-glider works is you have a puck on both sides of the device, so when the device displaces itself, both sides slide to double the distance that you get out of it, where as if you had only one sliding surface you’d only have half the displacement.
We have only just recently invented the ro-glider and so the first building in the world to get to ro-glider is two buildings in fact, in Wanganui Hospital, and so that is quite exciting for us.