Gargleblaster. I believe the accident you refer to was caused by aquaplaning. The weather was atrocious at the time, seem to remember that it was either the tail end of a typhoon, or rain squalls that preceeded one. Certaily a number of aircraft had decided to give Kai Tak a miss at the time. The tail was indeed removed by explosives, this was carried out by the bomb disposal unit of the Royal Hong Kong Police, and it needed several attempts, says something for structural integrity. You are right about the tug, it was nearby at the time of the incident, and the Captain used his initiative by nudging the aircraft towards the end of the runway, all exited without getting their feet wet!