When did PVC sewer pipe and fernco fittings come in to widespread use?

[RDWRER]

Found some questionable joins of pvc to clay in the sewer around my 1970s built extension. The 6 inch clay pipes are just broken out (quite neatly) at the side with the 4 inch pvc inserted in. Seems to have worked for 50 odd years.

This got me wondering, did the pvc to clay adaptors (Fernco etc) we use today come along at the same time as the adoption of pvc pipe?

Lots of other things point to some cheapest quote cowboys being responsible for my old extension but I wonder if that was the way it was done in the 70s until fernco fittings came along?

 

[Hugh Jaleak]

Plastic pipes have been around since the 70's, and suitable fittings to join to Clayware were available from around the same time. I suspect the clay junctions were expensive so the Builder improvised a connection to save money.