This is probably the most unusual new coaster type I was working on. A lot of progress was made and I even had a preview image but like most of my stuff it was never finished.
Yes, the pipeline coaster was a ride that Arrow was working on in the early 90s. Only a short prototype layout was built. One was considered for Alton Towers, but John Wardley did not like the ride and decided to go with a B&M invert instead.
Of all the rides I did not finish, this one has had the most development, but it would still take substantial effort to finish especially since it would now need the diagonal sloped turns as well.