Did you talk to the guards guarding stormfist castle? Normally they tell you were captain Ralf is, and then they mark it on your map...so it should be easy to find that way.
Just go straight south from the castle,without following the road. It's between the castle and the kazerne (sowwy,don't remember the English word for kazerne, I hope it's similar)
about Tingalf: try going down the sewers again, wasn't there a scroll you needed to take or something? A scroll that would prove the goods were stolen by Tingalf? I'm not sure anymore...
