Pintype insulators are not visible upon these crossarms. I suspect some type of ramshorn hook insulators were employed on the underside of these arms since some stretches of these insulators were used in the 1860s along the main RR line along the coast from points north to New York City, especially in southeastern CT.

Added note: John R. from CT made the suggestion that perhaps this was a new replacement pole not yet outfitted with pintype insulators. That could be since we see a pole with sidepins down behind it.