All of the pintype insulators seen in use along this service road were glass. Boston Edison always used them; most were CD 164s, 165.1s and 167s. That all-in-one three phase transformer is pretty beefy! Its customer secondaries are the four heavier cables beneath. There still are some scenes like this one in Boston Edison territory (now Eversource) with plenty of variety and differing types of line construction representing the last 90 years where there is 4kv primary (there is plenty of that within their overhead in-service functioning "museum") LOL.