This was fitted into a 1960/70s council house.
Sorry the photos are poor, too many cobwebs etc.
Vertical pipe on left with 4" emerging to right http://i66.tinypic.com/2iv01u1.jpg
Shows another 2" pipe emerging and heading off in the same direction as other horiz 4" pipe. http://i66.tinypic.com/34t48bt.jpg