What's an Eruv? -- Or... "You want to do WHAT?!"
In order to answer a Jewish question, you first have to explain why anyone would be talking about the question you are answering. G-d says we aren’t supposed to work on the Shabbes. But Jews ask questions. We may be a nation of priests, but we are also a nation of lawyers.
What do you mean work? Well, among other things, we mean carrying stuff around.
Carrying what? Anything, keys, books, kids, you name it; we can’t carry it.
Carrying where? Outside the house. (We get a break here because when Solomon invented the eruv, homes included fenced back yards.)
Since in traditional Judaism, men are obligated to go to synagogue to pray four times on Shabbes, someone has to stay with the kids. Now a pious man can pray 6 or 7 hours on Shabbes. So guess who is stuck in the house all Shabbes. Jewish men are commanded to keep their wives happy. Solomon had 1,000 wives. So, he said: “All cities have walls. Instead of using the back yard fence as the boundary; we will use the wall around the city as the boundary. We’ll be one big family for Shabbes, we can visit each other and share meals.”
This was nice. And it worked real well up until we were kicked out of Israel. Now if we try to put a stone wall up across Broadway or Main Street, people are inexplicably unsympathetic.
So, operating on the well-known fact that walls have doorways, we just put up string of doorways around the area where Jews live. The telephone pole becomes a doorpost; the wire running over the top of the pole becomes the “lintel” (i.e. the top of the doorframe). In fact, using telephone poles, buildings, string, light poles, embankments and a variety of other things, most of which are already in place, we create a continuous wall around the neighborhoods where Jews live. The wall is mostly invisible to people who don’t know what to look for.
Life being what it is, we don’t want to make what we put up too obvious. There are several reasons. Firstly, it’s chutzpahdic to make it glaringly obvious. Our neighbors have spent hundreds of millions of dollars making these neighborhoods beautiful and we are prepared to do something ugly? Secondly, we don’t want to invite vandalism, either by anti-Semites or by bored children. Thirdly, doing it unobtrusively is frequently cheaper. Lastly, doing it unobtrusively creates shalom with the goyim around us.
Now, of course, we need permission from everyone whose property we touch. The utilities, which own the poles, the property owners that our lines cross, the government, which owns the streets that we cross, and sometimes neighborhood associations, all must give us permission or else we can’t do it. We need to follow the building code from Jewish law and the building code from where ever we are living now. (They usually don’t contradict each other.) For centuries now, we have been able to put up these “walls” at the boundary, the eruv, of the Jewish neighborhoods.
Since the purpose of the eruv is to carry food to where it is needed, we keep food, for any Jew who wants to get it on Shabbes, in a specific location inside the eruv. The proper blessing is made, and then we have an eruv. Usually, we use Passover matza. (Frequently the matza is kept at a synagogue. If the men run out of food for shalosh seudas, they might dip into the “eruv” (the matza upon which the blessing is made), and the Rabbi has to replenish the supply before the next Shabbes.
Every week the wall should be checked to make sure it is kosher. Frequently there is a break of some sort. So the checkers call out a repair crew and fix it if possible. Then they notify the community whether the eruv is “up” or “down.” If it is down, then people who have made plans to eat with friends may have to quickly prepare a meal at home.
Hundreds of cities in the US and around the world have eruvs. There is a separate eruv directory on this website. Many cities have more than one because there is more than one Jewish neighborhood.
The average eruv costs $40,000 to erect. Like any modern building project, it can cost more to deal with permits than it costs for construction. Cities have legitimate questions regarding eruvs that they need to ask before one is erected. Pole owners want to make sure that nothing is done in an unsafe manner on their poles.
One note about eruv kashrus: There are two halachic issues which the general public should be aware of about eruvim.
The first question is whether someone “holds” by an eruv. This can be a complex question. See the Eruv FAQs.
The second question is whether the eruv is kosher. There are legitimate disagreements about every aspect of Jewish law. A practical issue happens when someone carries wine in an eruv to someone’s house for Shabbes lunch. If the host believes the eruv is kosher, he can drink the wine on Shabbes (even if he usually does not avail himself of the eruv). If he believes the eruv is not kosher, he should not drink the wine on Shabbes.On this, as on other aspects of Jewish law, consult your local orthodox rabbi. For many Orthodox Jews, an eruv has become as necessary as the second car or a second bathroom. We could get along without it, but life is just so much nicer with it.