Sorry Mutt, I didn't word it very well. To the best of my knowledge my company operates to JAR regulations (B747 400 series), my understanding is that your TODR commences at the start of your t/o roll and finishes when you are 35ft above the rwy (or clearway should your company choose to utilize it) following failure of the critical engine at V1. This is valid for a dry rwy, however on a wet rwy the a/c only has to achieve 15ft. I'm wondering if on a contaminated rwy (as distinct to a wet rwy) if it's 15ft as well? We carry RTOW charts on board (dry/wet/contaminated) however it's not stipulated.