iacisrmma:
“youdontsay: Yes I understand R’ Moshe’s psak regarding 3 million people in a 12 mil by 12 mil area. That is why the question was asked in 1979 as to why should Queens and Brooklyn be treated differently. Brooklyn has approximately 69.5 mi of land area and Queens has 108.2 mi. Total population in Queens was slightly less than Brooklyn. So why was the entire Brooklyn used cover a 12 mil by 12 mil area but Queens not? I heard from Rav Hillel David the response I gave above as he conferred numerous times with R’ Moshe as he is now and was then one of the noted poskim in Flatbush during the eruv controversy in the late seventies. You don’t want to believe it, fine. I know what I heard from him.”
Brooklyn is smaller than twelve mil by twelve mil, and Rav Moshe stated this clearly in his teshuvos:
(Igros Moshe, 4:87).
ולכן בברוקלין שהוא עיר אחת מלאה אוכלוסין אבל אפשר שהיא יותר מי”ב מיל על י”ב מיל
And then Rav Moshe’s final teshuvah on the matter (ibid., 4:88):
ונמצא שכל ברוקלין הוא רק י”ב מיל על י”ב וקצת יותר
Brooklyn is over sixty-nine square miles (without its inland water, which I think should also be included in the tally and would make it even larger). Twelve mil by twelve mil is sixty-four square miles (according to Rav Moshe’s shiur amah in regards to hilchos Shabbos). However, after Rav Moshe was informed that the area that Brooklyn encompasses is greater than twelve mil by twelve mil, he argued that an eruv should not be established, because some may think that since it was a heavily populated area it was a reshus harabbim (in essence a gezeirah, — shema yitu; see ibid., 4:88, and see also 5:29 where he argues that even Detroit could be problematic because of this gezeirah).
However, the end of the story was, that Rav Moshe was led to believe that besides for a population of close to three million, over a million people come into the borough to work (ibid., the end of 4:88). Therefore, he argued that Brooklyn is osser l’dinah. (These facts were made up out of whole cloth by people who simply did not want an eruv and were willing to tell tale tales to Rav Moshe in order to achieve their goals.)
Consequentially, the issue with the Queens eruv is, why didn’t Rav Moshe object at least because of his gezeirah. Queens is also a heavily populated area (no less than Detroit).
The only answer that follows all of Rav Moshe’s teshuvos is:
While Rav Moshe maintained that if an area of twelve mil by twelve mil is classified [or thought of] as a reshus harabbim, an eruv cannot be erected in any part of that area; nevertheless, we see that he allowed eruvin for Kew Garden Hills, Queens (ibid., 4:86); Oak Park and Southfield, Detroit (ibid., 5:29); and the Jewish quarters in Europe (ibid., 5:28:5) which he would have otherwise objected to. The reason Rav Moshe allowed for a neighborhood of these large cities to be demarcated with an eruv was because they contained less than shishim ribo. However, regarding Boro Park and Flatbush Rav Moshe was led to believe that independently they contained populations greater than shishim ribo; therefore, an eruv could not demarcate these Brooklyn neighborhoods (ibid., 5:28:5 and Addendum to O.C. 4:89). There is no other rational reason why Rav Moshe argued that both Boro Park and Flatbush contain more than shishim ribo if not that this was the defining motive to allow a city to be divided with a tzuras hapesach.
As to why some argue excuses in the name of Rav Moshe that don’t follow his teshvos, I would say they don’t know his teshuvos that well. However, to claim that these arguments are Rav Moshe’s is simply not true, and definitely not possible, since Rav Moshe wrote otherwise.