共通 きょうつう せん信号 しんごう もうではありませんでした
kyōtsūsenshin gōmo udewa arimasendeshita

Noun
Desu Copula

The polite, past negative form of 共通線信号網

1. Was not a common line signaling system.; Was not a shared line signal network.

Past/Perfective
Negative
Polite
Formal Register
Computing