Common Problems in the Construction of Eruvin in Urban Areas part 1

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    A certain Posek once took my chavrusa and me on a field trip around the eruv of an urban community. He brought us to a specific street marked on the eruv map as the border of the eruv. He offered us $10.00 if we were successful at identifying the lines of the eruv. Of course, we did not earn those $10.00! It might come as a shock to anyone who has built a private backyard eruv to realize that building a communal eruv usually entails little installation of wire. For the most part, resourceful eruv committees spend weeks and months identifying pre- existing structures to serve as part of the communal enclosure. Such structures often are actual walls: fences, embankments, riverbanks, sides of buildings, etc., but overwhelmingly consist of overhead cable belonging to the electric or telephone utility companies. Concern over funds or municipal regulations often make it expedient to use such pre-existing structures. Urban eruvin, therefore, often follow what seem to be illogical patterns, separating sidewalks from streets, cutting through alleys, or encompassing broad areas with few Jews. The use of wall-like structures, as long as they are man-made, poses few problems (with the emphasis on "few" - we will return later to explore some possible problems). It is the use of overhead cable that causes most of the problems encountered in contemporary urban eruvin.

    The most basic halacha of tzuras hapesach (literally: the form of a door way), the door frame effect that Halacha L'Moshe Me'Sinai recognizes as a wall, is that the wire which crosses over the poles (the "lechayayim") must pass over the top of the poles, not on or over the sides of the poles. Crossing over the side of the poles constitutes the problem of tzuras hapesach min hatzad, explicitly invalidated by the Gemara in Messeches Eruvin1 (fig. 1).

    This halacha poses a formidable problem when using overhead cable in the construction of an eruv. Occasionally the cable does in fact go from the top of one pole to the top of the next. More often, however, the cable is attached to the side of the pole. Frequently, the same cable will weave back and forth, going from the top of the pole to the side of the next one, out on a crossbar and back again in quick succession2!

    In Israel, where the municipal authorities are cooperative, the problem of tzuras hapesach min hatzad is easily rectified. Wide barrels that are at least ten tefachim high are placed underneath the overhead cable. The halachic principle of gud asek mechitzta3 (literally: extend the walls up) then creates an imaginary line directly up from the top of the barrel to the cable. We then view the barrel, not the utility pole, as the lechi for the tzuras hapesach (fig. 2).

    In Chutz La'Aretz, however, the authorities are not as cooperative, and will usually not allow such obtrusive tikkunim. The usual approach here, therefore, is to bolt a plank, a rod, or tubing4 to the utility pole to serve as the lechi wherever one is necessary.


    The problem most frequently encountered in the use of a narrow object as lechi is in the application of gud asek. The Chazon Ish5 rules that the imaginary line is always drawn straight up, no matter the angle of the lechi. Many utility poles are warped or bent at an angle. This may occur either because of carelessness in the original construction, weather conditions over time, or blows by cars or trucks. The lechayayim attached to such poles bend with them at the same angle. Gud asek, however, still draws the imaginary line straight up from the top of the lechi (fig. 3)6! In this situation the gud asek is meaningless, as the line drawn from the top of the lechi will not hit the overhead cable. Some Rabbanim will, nonetheless, allow the use of gud asek lechayayim in the construction of an eruv based on utility poles. To prevent the bent pole problem they use a surveyor's tool or a plumb line to determine whether the lechi is directly underneath the overhead cable. At best, however, this is a hazardous approach. A single pasul lechi can invalidate an entire eruv. An average sized urban eruv may contain hundreds of lechayayim attached to telephone poles. The surveyor (usually a utility company employee or a hastily trained member of the local eruv committee) must meticulously check every pole. This can be a time consuming, tedious, and sometimes expensive task. Unless one's yir'as shomayim is very strong, diligence tends to erode over time. Any pole may bend over time, requiring constant surveillance7.

    Another problem may arise when gud asek lechayayim are used. Often a utility company box may be attached to the utility pole between the lechi and the overhead cable. If the lechi is built all the way up to the box, or to within three tefachim of it, then the box may be considered part of the lechi. The halachic device of "lavud" connects them (see Section 3 below). If, however, the lechi ends more than three tefachim beneath the box, then the box is a hefsek that interrupts the gud asek8.

    Due to all these considerations, "state of the art" eruvin do not utilize gud asek lechayayim, but build the lechi all the way up to the overhead cable. No imaginary lines need then be drawn, as an actual line goes all the way to the wire. Actual lines may bend at an angle and remain halachically valid9.


    The Mishna Berura10 cites a disagreement as to whether the cable must be absolutely taut or may sag and/or sway in the wind between the lechayayim (fig. 5). The trend, based on the Aruch HaShulchan and others11, is to be lenient. As long as when there is no wind the cable at rest runs due straight from lechi to lechi the eruv is considered valid. As we have noted, overhead cables often weave back and forth. A typical question that arises concerns the following case (fig. 6): Three utility poles, each consisting of an upright pole and a crossbar across the top, stand in a row. The overhead cable runs directly across the first and third pole in the row, but is connected to the crossbar of the middle pole. Here, even when at rest, the cable does not run directly from lechi to lechi.

    Rabbi Meir Arik12 discusses the possibility of ruling l'kulla where the cable is within three tefachim of the hypothetical straight line. He explores whether it is possible to make use here ofthe halachic device of lavud (literally: connected). Halachically, two objects within three tefachim of each other are considered connected. Here we would view the cable as "connected," i.e., repositioned, to its proper hypothetical straight line. Questions, however, may be raised concerning this approach. Rabbi Aryeh Pomeranchek13 identifies only two types of lavud, neither of which are applicable to our case. One type of lavud allows us to regard any object within three tefachim of another object as if it is connected to that other object; the other type of lavud allows us to regard the space between two objects as closed and/or blocked. Lavud does not allow us to reposition an object to a place within three tefachim of its actual location, which would be necessary to correct this problem.

    Often the upright pole will extend above the crossbar. In such circumstances, even the use of lavud would only halachically "reposition" the cable to the side of the pole. We are still not left with a straight line, and may have brought upon ourselves the problem of tzuras hapesach min hatzad.

    Rabbi Ben Zion Sternfeld of Bilsk14 argues that even a cable veering more than three tefachim off the imaginary straight line may be acceptable. Based on this premise it should theoretically be possible to construct an eruv around a city with just two lechayayim. The cables could encompass the entire city and return to the same lechayayim (fig. 7)! Extending this approach to such an absurd conclusion might by itself be sufficient reason to reject such a kulla. One may also, however, take issue with the Bilsker Rav's extrapolation from the Gemara in Eruvin (ibid.). The Gemara there discusses the halacha of "pischei shima'ei", door frames whose posts are not straight but consist of stones jutting in and out (fig. 8). The Gemara rules that such posts are not true door posts and are therefore not valid lechayayim. A tzuras hapesach with such lechayayim is therefore invalid. The Bilsker Rav posits that, since the Gemara only discussed and invalidated crooked doorposts, one may deduce that a crooked lintel (in our case, the cable) does not pose a problem. This premise is easily refuted. The Gemara often discusses the most prevalent scenario and leaves us to draw conclusions as to other possible ramifications. The Chazon Ish15 explicitly invalidates such a tzuras hapesach. It is worthwhile emphasizing again that any problem can invalidate an entire eruv.


    Several problems arise concerning the position of the utility pole and/or the lechi attached to the pole. Occasionally the path of the utility cables requires the placement of poles on private property. By itself such positioning is not a problem. Often, however, such property is surrounded by fences that the eruv is thus forced to cross (fig. 9). The Mishna Berura16 and others rule that such a situation invalidates an eruv. Several reasons are given for this ruling. The three most significant are: a) The lechi must be recognizable outside the enclosure. The fact that the enclosure is a chain link fence through which one can see does not rectify the problem. Halachically such a fence is regarded - because of lavud - as a solid wall; b) The halachicprinciple of "beisa kman d'malia dami" (literally: a house - or any other ten tefachim high enclosure - is regarded as a solid block)17 requires us to view the entire enclosed area as one solid block. Since the maximum measurement of a lechi is four amos18, if the enclosed area is more than four amos on any side, we have a problem; c) The principle of gud asek requires us to regard the surrounding fence as if it disrupted the tzuras hapesach. A similar problem applies in a case where a hedge that is larger than the allowed measurements has grown to surround the lechi (fig. 10)19.

    The Avnei Nezer20 refutes the first two problems we have raised. As to the first problem, the Avnei Nezer holds that a tzuras hapesach need not be recognizable. He proves this from the fact that there is no maximum height above which a tzuras hapesach is invalid21, although the Gemara at the beginning of Messeches Eruvin states that the eye does not discern that which is above twenty amos. Concerning the second problem he says that beisa kman d'malia dami only applies to a covered reshus hayachid such as a house. This approach seems borne out by Rashi's commentary (ibid.) on this principle. The Avnei Nezer does take the third reason into consideration. He therefore rules that in such cases the height of the lechi (not the height of the utility pole to which it is attached) must exceed the height of the surrounding fence or hedge by at least ten tefachim. It is then regarded as a distinct wall above and beyond the surrounding fence whose significance cannot be nullified by an imaginary gud asek. Other Poskim advance more lenient positions, but even the position of the Avnei Nezer is cited as a heter b'she'as hadechak22. It therefore seems difficult to rely on their opinions.

    (I once heard in the name of a respected Posek that in the final analysis every contemporary eruv must rely on some variation of the Avnei Nezer's ruling. He noted that every tzuras hapesach invariably crosses over parked cars. The cars' dimensions are sufficient to form an interrupting fence. The validity of the eruv, therefore, is contingent on our regarding the eruv overhead as a distinct wall above and beyond the interrupting fence. A wall's significance cannot be nullified by an imaginary gud asek.)


    Due to the many problems involved in the use of overhead cable, it is obviously preferable to use fences and other wall-like structures wherever possible. Usually, however, it is difficult to rely on fences alone. For example, inevitably fences must be interrupted to allow streets to pass through. To insure that the continuous line of the eruv encompasses the city, the enclosure must travel across the street. This may be achieved either by way of building a tzuras hapesach across the street or by jumping to an overhead cable that crosses the street23. A problem frequently arises in this situation. Even in the best of circumstances, i.e., where the overhead cables are directly over the utility pole, the poles are usually behind and not within three tefachim of the fence (fig. 11). The fact that the poles are behind the fence returns us to the previous problem of lechayayim enclosed by fences. The fact that the poles are more than threetefachim away from the fence raises an additional problem: what connects the fence to the overhead cable? The fence is usually larger than the allowable measurements for a lechi, so drawing the gud asek line up from the fence does not help. If the poles were within three tefachim of the fence we could probably use lavud to validate the eruv24. In the case we have presented here, however, we probably have to look for guidance to the Chazon Ish25.

    The Chazon Ish discusses a case where structures used in constructing an enclosure connect or overlap, but do not meet (fig. 12). In the Chazon Ish's case, a north-south wall or tzuras hapesach bisects an east-west tzuras hapesach26, or connects with it at points between the east-west's tzuras hapesach's lechayayim. The north-south wall or tzuras hapesach halachically eliminates the lechayayim of the east-west tzuras hapesach. Since they are beyond the area of the enclosure, they are halachically insignificant. The same ruling may be applied to our case. To validate this enclosure a lechi would have to be placed on the fence directly underneath the overhead cable (thus creating a gud asek).


    Let us now discuss problems that arise when pre-existing wall-like structures are used in constructing an eruv. It is important to stress the necessity to ascertain that such structures are man-made. Natural walls, such as cliffs and riverbanks, are considered halachically valid. Most Poskim27, however, hold that such walls are "einam mukafim l'dira" (literally: not surrounding for dwelling)28. They were not made with the intent to sustain habitation, and they therefore cannot enclose an area that is larger than five thousand square amos (a "beis se'asayim"). If, therefore, a section of the communal eruv wider than ten amos in length (the maximum break allowed in the line of an eruv) consisted of a natural structure, an additional tikkun would be required there.

    Another issue that often arises in the area of wall-like structures is perhaps best explored through the history of eruvin in New York City. The chronicles of this history are replete with controversy and intrigue. Volumes upon volumes have been written concerning the many issues involved in the construction of various eruvin in the boroughs of Manhattan, Brooklyn, and Queens. Most of the issues involved are beyond the scope of this kuntres. Some are uniquely relevant to the peculiar situation of New York. Let us therefore focus on one specific issue that has widespread ramifications.

    Rabbi Yehoshua Siegel, commonly known as the Sherpser Rav, first arrived in New York in 1884 and settled on the Lower East Side. The Sherpser Rav was the foremost rabbi of Polish-Chassidic origin in America at the time and, in fact, was a rival of Rabbi Jacob Joseph, the Chief Rabbi of New York, who was of Lithuanian extraction. In 1907 the Sherpser Rav published a pamphlet, "Eruv V'Hotza'a," which allowed the residents of the Lower East Side to carry in the streets on Shabbos. Jews of Lithuanian descent generally did not rely on theSherpser Rav's heter. Indeed, a founder of Yeshivas Rabbeinu Yitzchok Elchonon, Rabbi Yehuda David Bernstein, wrote a pamphlet, "Hilchasa Rabasa L'Shabasa," disputing the heter. Nevertheless, people were still carrying on the Lower East Side as late as 1947, when Rabbi Yosef Eliyahu Henkin29 wrote that the rationale for the heter no longer applied.

    What walls did the Sherpser Rav use in formulating his heter? The Lower East Side was surrounded on three sides by the walls that front on the East River, and on the fourth side by the Third Avenue elevated train line. An elevated train line looks just like a classic tzuras hapesach: the support beams may be seen as lechayayim and the overhead train tracks may be seen as the lintel. Such an approach is quoted by the She'arim Mitzuyanim B'Halacha30 in the name of the She'eilos U'Teshuvos Even Yekara. The She'arim Mitzuyanim B'Halacha, however, based on a Magen Avraham31, takes issue with the Even Yekara. A door frame is distinct from the walls and ceiling of the room to which it is affixed. The door frame effect which forms a tzuras hapesach therefore also requires that the lechayayim and lintel be distinct from the walls of the structure to which they are affixed. The She'arim Mitzuyanim B'Halacha therefore rules that a bridge or overpass may only be regarded as a tzuras hapesach if it has features that may be regarded as distinct from its wall. The Chazon Ish holds this way as well32.

    It is possible that another principle may prevent us from viewing an elevated train line, bridge, highway overpass, or toll booth as a tzuras hapesach. In 1952, Rabbi Refael Ber Weissmandel proposed a heter to carry on Shabbos in Brooklyn based on the elevated train lines. His logic, however, was not based on the principle of tzuras hapesach, but on that of "pi tikra yored v'sosem" (literally: the lip of a roof comes down and closes)33 (fig. 13). This principle, as defined in the Shulchan Aruch34, is that, when a roof is at least four tefachim by four tefachim and set atop two whole walls, we view the thickness of the roof as an imaginary wall on the remaining two sides. Rabbi Moshe Feinstein35 disagreed with Rabbi Weissmandel's application of this principle to elevated train lines. Among his reasons was his observation that several Rishonim do not view the principle of pi tikra as creating walls, but as creating a defined area in which one is allowed to carry.

    It seems significant that neither Rabbi Weissmandel nor Reb Moshe discuss the possibility of viewing the elevated train line as a tzuras hapesach. We may assume that the reason for this omission is related to the logic we developed above, that a tzuras hapesach must resemble a traditional door frame. By definition, a tzuras hapesach whose lintel is more than four tefachim wide is a roof. It therefore can no longer be viewed as a door frame36.

Converted by Andrew Scriven

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