Rosh yeshiva of Torah Vodaath and leading posek
Rabbi Yaakov Kamenetsky and the Rabbinic Rulings on Large-City Eruvin
Rabbi Yaakov Kamenetsky's name appears in the public rabbinic record opposing reliance on the Manhattan eruv and later large-city proposals.
The Manhattan ruling
Rabbi Yaakov Kamenetsky was one of the five leading Rabbonim named on the Agudath HaRabbonim ruling of 18 Sivan 5722. The ruling prohibited reliance on the Manhattan eruv and warned the public not to carry on its strength.
The question involved more than whether a wire could be stretched around a route. Manhattan's streets, population, bridges, openings, and possible status as a reshus harabim had to be considered together. The Rabbonim concluded that the proposed arrangement did not provide a basis for public carrying.
New York and other large cities
Rabbi Kamenetsky is also named in the later large-city proclamation that restated the Manhattan prohibition and extended its warning to other major cities. That later notice rejected the idea that Manhattan stood alone and that an eruv elsewhere in New York could be accepted without confronting the same large-city problems.
His role in these collective rulings places him among the central American poskim whose public position shaped the practical discussion for decades.
The Brooklyn setting
Brooklyn proposals arose within the same continuous city and raised the same underlying questions of reshus harabim and public reliance. Rav Moshe later applied his own analysis directly to Flatbush and Boro Park.
For Crown Heights, the local Beis Din gives the direct instruction. Rabbi Kamenetsky's large-city ruling remains part of the earlier rabbinic foundation cited in that local psak.