Not exactly a pre-oiler, but I once worked a shipboard application of a gas turbine where it was used for "dash" propulsion (a small % of time) - and diesels drove the ship most of the time. During diesel ops, a clutch was supposed to disengage the turbine.
But the clutch was usually dragging, so the turbine would slowly turn for days on end. To protect its bearings, a small electric oil pump was added to keep a small flow going.
