This is a classic case of the dance of death.
Two ships on complementary courses, displaced to starboard.
One ship opts for port to port,
the other ship decides to pass starboard to starboard.
Neither ship talks to the other,
which is the only solution in this situation.
Picture of Horta in Durban on way to Hamburg for repairs,
shows nearly symmetric bow damage back to hawsepipe, low.
Collision bulkhead probably OK.
Depth of penetration was at least 10 m.
Would be nice to know if these ships were inerted.
In 1972, almost certainly were not..
Could have made a difference.
CEDRE lists this spill at 115,000 tons.