There are people who attempt to rationalize why Rav Moshe allowed an eruv to be erected in Queens. For example, some claim that Kew Gardens Hills is considered a suburb of Queens while others allege that Queens was not incorporated into the city as a whole unit, but rather as a set of disparate neighborhoods. Therefore, they argue, the population of Queens is considered divided and each neighborhood is independent of the other, which is why Rav Moshe allowed an eruv to be erected there. This assumption is incorrect; Rav Moshe never claimed that Kew Gardens was a separate entity, only that it was a small neighborhood in Queens (Igros Moshe, O.C. 4:86 and Addendum to O.C. 4:89). Additionally, Kew Gardens Hills is part of Queens just as Boro Park and Flatbush are part of Brooklyn, as can be seen on any map of the area. Every neighborhood in Queens is built up to the adjoining neighborhood and forms one contiguous borough just as all neighborhoods do in Brooklyn. Why then did Rav Moshe allow an eruv in Queens and oppose one in Brooklyn? Even more so, since both Brooklyn and Queens have similar populations of over 2,000,000, why did Rav Moshe not apply the same gezeirah that he implemented regarding Brooklyn and Detriot to negate an eruv in Kew Gardens Hills, Queens as well (see previous post Three Million: More or Less?)?
Additionally, in a speech given a while ago about the eruv in Flatbush, there was a claim made that the reason Rav Moshe allowed an eruv in Kew Gardens Hills, Queens was that the area is encircled with mechitzos. This is a fabrication, as Rav Moshe never refers to mechitzos in any teshuvah concerning Kew Gardens Hills (ibid., 4:86 and Addendum to O.C. 4:89). Nor does anyone else mention mechitzos regarding Kew Gardens Hills (See Minchas Chein, siman 24 and Minchas Asher, 1:51-52, 2:56-57, 2:59). More so, since Brooklyn is encircled with mechitzos as well, why should it be any different than Kew Gardens Hills? If Brooklyn would require dalsos at it’s pirtzos, Kew Gardens Hills would require dalsos as well (Igros Moshe, O.C. 1:139:3).
The underlying principle must be that Rav Moshe allowed an eruv in Kew Gardens Hills because the tzuras hapesach there separated the neighborhood just as he stated the eruvin in Europe demarcated the Jewish quarters from their cities (ibid., 5:28:5). Rav Moshe considered the eruv, in and of itself, a separation of the shishim ribo and allowed the eruv there. Consequentially, Rav Moshe was not concerned about the possibility that a twelve mil by twelve mil section of Queens which includes Kew Gardens Hills might be classified as a reshus harabbim, even though Queens ― like Brooklyn ― had a population well over 2,000,000. The important issue was that in Kew Gardens Hills, a neighborhood in Queens, they were dividing only a part of Queens, which contained less than shishim ribo with a tzuras hapesach in contrast to Brooklyn where Rav Moshe was under the impression that the tzuras hapesach encircled more than shishim ribo (Igros Moshe, O.C. 5:28:5 and Addendum to O.C. 4:89).
These are the facts: