Oviform pipe was used back in the hay day of early settlement Australia. It was laid by hand by the convicts and usually made from cobblestones or occasionally clay bricks or blocks. They are predominantly throughout Sydney in the older sections and still in use today. There may be a few in Melbourne and Brisbane, but not many. As I understand it, 80% of the remaining pipes are heritage listed, and therefore the councils have some constraints on the methods used to reline them. I would have thought that the pipes would go the other way, but apparently not. Check out the photo to the left… Obviously a sample is out of the question… but there is a manufacturer in Germany of a HDPE version of the pipe. I have made contact with them to see if we can get some samples so we can do some tests with relining that shape.