What was the name of contraction second watch?

There's no established concept or term called "contraction second watch." This phrase doesn't appear in any common nautical, military, or medical contexts.

Possible Misunderstandings:

* "Second Watch" in Maritime: This refers to a specific period of duty on a ship, typically from midnight to 4 AM.

* "Contraction" in Medical: This usually refers to the tightening of the uterus during childbirth.

It's possible you're thinking of a different phrase or concept. Could you provide more context or information about where you encountered this term?