Building MoCo eruvim: Architecture and material culture (updated)

This is the second post in the series, Courtyards of Convenience: Montgomery County’s Eruvim


The Capital Beltway carries I-495 through Washington, D.C.’s Maryland and Virginia suburbs. The iconic 64-mile highway completed in 1964 is a symbolic barrier between Washington and the rest of the nation. The dichotomy, inside versus outside the Beltway, has permeated popular culture.

National Capital Beltway showing portions adjacent to Montgomery County eruvim. Adapted from Bing Maps. Click on the image to see a full-size version.

A four-mile segment of the Beltway in Montgomery County, Maryland, acts as another symbolic boundary. Areas within this segment have been incorporated into the perimeters of two Orthodox Jewish eruvim that wrap around parts of Silver Spring and Wheaton creating symbolically enclosed spaces that allow Jews to move within them on the Sabbath.

Walking to synagogue on the Sabbath inside the eruv. Photograph by David Rotenstein, October 2010.

Carrying inside the eruv on the way to synagogue on the Sabbath. Photograph by David Rotenstein, October 2010.

This idea for the research that is being presented in these posts was planted in 1999 while I was working as a museum curator in South Carolina. The museum was putting the final touches on an exhibition documenting Jewish life in the Palmetto State and I first read about eruvim in the research prepared for the exhibit. Because I was raised in a Reform Jewish home in a southern community with a small Jewish population, eruvim were completely off my radar screen up to that point.

Most Saturdays,  my wife and I shop at Magruders supermarket in Kemp Mill and we pass by the Orthodox Jews walking to synagogue. They are carrying bags, pushing strollers, and using medical devices normally prohibited by Jewish law. I figured that there must be an eruv encircling the area and I began looking where all 21st century research starts: a Google search.

I found the Young Israel Shomrai  Emunah Website with its eruv map and information and I found Websites for another five Montgomery County eruvim. After downloading a few maps and driving around to see the ways in which the eruvim were demarcated, I began contacting the Orthodox congregations to speak with the members who are responsible for inspecting and maintaining the eruvim. And, after releasing an earlier version of this post, I learned of a seventh Montgomery County eruv.

Kosher Pastry Oven cafe, Kemp Mill. Photograph by David Rotenstein, October 2010.

I interviewed volunteers from two congregations — Woodside and Potomac — by telephone and I met one eruv overseer for coffee one morning in Kemp Mill’s Kosher Pastry Oven café.

After transcribing the recorded interviews and doing additional documentary research into the history and material culture of eruvim, I set out to document Montgomery County’s eruvim for a paper I hope to write. I visited each of the county’s eruvim with a digital camera and video camera to capture the built and borrowed elements that comprise each boundary.

This series of blog posts is a way for me to work through my understanding of the eruvim in a dynamic and urbanizing area just outside the nation’s capital. Concerns over security, privacy, and safety were never far from my mind as I began the research.

Montgomery County’s eruvim are well documented in maps published on the Internet. The maps vary in detail from general outlines overlaid onto street maps to polygon layers created in Google Maps that show precise perimeter locations. The people responsible for each eruv expressed concerns to me that by revealing specific locational information I may be endangering the integrity of vulnerable eruv structures.

I also faced the paradox of photographing people walking to temple to document the behavior facilitated by the eruvim without violating their privacy and desires to not be photographed on the Sabbath. In this series I attempt to accommodate the concerns expressed by not providing specific geographic locations for vulnerable eruv structures and my photos of people walking to synagogue on the Sabbath do not show faces.

About the Eruvim

Eruvim are spaces constructed by Orthodox Jews that mix public and private spaces into a single symbolic sacred area — a domain — that allows Jews to carry and push things normally prohibited during the 25-hour Jewish Sabbath. There are many complex descriptions and definitions of eruvim as cultural institutions and as artifacts. So far, I have found Oliver Valins’ explanation of the objectives eruv builders try to achieve highly accessible:  Eruvim are built to create a single public domain: “to encircle an area with suitable partitions” and “to unify residents contained within the enclosure.”[1]

Montgomery County’s eruvim are multi-layered cultural landscapes. I introduced the six seven eruvim and their spatial limits in the first post in this series. This post looks at the material culture — the physical and architectural attributes — of Montgomery County’s eruvim.

Eruv string juxtaposed against the sky. Photograph by David Rotenstein, October 2010.

As I wrote last week, Montgomery County’s eruvim are one of three particular eruvim types: eruv hatserot or “courtyarderuvim. Eruv hatserot may be as small as a yard or contain several square miles. Before the expansive Silver Spring eruv was built, a small eruv had been built around apartment buildings in White Oak, according to the late Young Israel Shomrai rabbi Gedalia Anemer.[2]

Jews who build eruvim are bound by a complex and weighty body of rabbinic law  — Halakhah — that dictates how and where the structures may be built. American, Canadian, and European Eruvim have been documented by architectural historians, anthropologists, folklorists, and cultural geographers.[3]

Legal scholars have written about the questions — in the United States, the Constitutional issues — raised by allowing Jewish congregations to symbolically and physically appropriate secular public space for sacred purposes.[4] Eruvim proposed in Tenafly, New Jersey, and Northwest London’s Barnet Borough sparked heated legal and community battles. Many of the most vocal opponents to eruvim have turned out to be Reform Jews who oppose being “ghettoized” by the enclosure.[5]

The most comprehensive source documenting eruvim in modern society is Rabbi Yosef Gavriel Bechhofer’s book, The Contemprary Eruv: Eruvin in Modern Metropolitan Areas. Bechhofer, like many Orthodox Jews writing on the eruv use the Aramaic plural, eruvin rather than the modern Hebrew plural, eruvim. The book, which was first published in 1998, includes guidance for adapting existing utility and transportation infrastructure to eruvim and he discusses the challenges congregations face when proposing eruvim.

Eruvim as Institutions

Eruvim are inherently institutional. They include formal and informal constraints and there are enforcement mechanisms in place in Jewish faith for those who violate rabbinic laws.[6] All eruvim are part of a larger Orthodox Jewish institution and each eruv has its own institutional characteristics, including local rules for its construction and maintenance, and an organizational structure that includes the individuals who manage the eruv, the congregations that worship and live within its boundaries, and the non-observant population at large who live, work, worship, and travel through the eruv.

All of the congregations rely on volunteers to manage their eruvim and to ensure that the eruv is intact for each week’s Sabbath. Only one of Montgomery County’s eruvim appears to have a complex organizational structure that goes beyond the volunteer committees found in the other congregations.

The Silver Spring Eruv Association handles fundraising for its eruv in addition to overseeing the weekly inspections and updates to the congregations it serves. Silver Spring’s eruv, which covers more than 13 square miles, is inspected weekly by a paid contractor from Baltimore who travels the entire perimeter ensuring the structure is intact for the Sabbath.

Silver Spring Eruv Association inspector making his rounds before the Sabbath. Photograph by David Rotenstein, October 2010.

Laying Out and Building the Eruvim

Orthodox congregations work with their local rabbis and experts in eruv construction. The Silver Spring Eruv Association sought advice from rabbis at Baltimore’s Ner Israel Rabbinical College. Before an eruv is constructed, its boundaries must be established.

One of the Jewish legal principles attached to eruvim is the requirement that official permission must be obtained and rent paid for the privilege. In Montgomery County, eruvim have been authorized by formal proclamations issued by county executives.

A key consideration in determining the eruv’s limits is identifying areas in proximity to the synagogue which have Orthodox Jewish families in them. Sometimes eruv boundaries are adjusted because families move and the eruv is either enlarged or reduced.

One Silver Spring resident who is responsible for his congregation’s eruv’s status recalled how his family’s home came to be included in the Silver Spring eruv in the late 1970s. “I was a teenager, but we were already living in the house where my parents now live,” he said.

I remember this quite clearly, actually. We were just outside in front of our house and we saw two — we must have been relatively new in the neighborhood because we didn’t know these people but we saw a bunch of guys with yarmulkes and surveying equipment in front of our house and we went out and my father said, “What are you doing?” and they said, “We’re laying out the eruv.”

Eruv perimeters are erected from “partially borrowed and partially constructed” elements.[7] The Silver Spring eruv overseer explained there are the halakhic considerations for siting the eruv boundaries and there are the practical reasons.  Oftentimes the practical reasons come down to finding the path of least resistance.

“A boundary can be a physical boundary, like a wall or a fence or a slope of a certain slope — it has to meet certain requirements,” he said. He described the eruv’s boundaries in strict architectural terms:

It’s in effect a doorway, two vertical posts and a horizontal connector on top of them.

So you can put that up anywhere, but when the eruv was being constructed, what they looked for was how to put it up with the least work. And if you go outside and you look at the telephone — the utility poles, what we call telephone poles — you’ll see that the electrical lines, the lowest on a typical pole, the lowest line is cable, the next one is telephone, and above that is electricity.

Eruv inspector repairs a lechi attached to a utility pole. Photograph by David Rotenstein, October 2010.

After the repair, the inspector ensures that the lechi is correctly aligned beneath the wire by sighting along his hammer handle. Photograph by David Rotenstein, October 2010.

Structures and Buildings

At the heart of each Montgomery County eruv is a synagogue. Most eruvim, like Woodside’s, have one congregation. The Silver Spring Eruv Association covers multiple Young Israel Shomrai buildings and it includes the Young Israel White Oak congregation and the Shaare Tefila and Southeast Hebrew congregations.

Young Israel Shomrai Emunah Synagogue, Silver Spring. Photograph by David Rotenstein, October 2010.

Woodside Synagogue, Silver Spring. Photograph by David Rotenstein, October 2010.

Synagogues within eruvim — although located well within the boundaries and not attached to the perimeter — sometimes have exterior alterations that visually broadcast the eruv’s status, supplementing telephone hotlines, Website status updates, and email lists. Each synagogue is vested with the authority to determine how its eruv is managed and inspected and how — or if— congregants should be notified if the eruv is not intact. A break in the eruv renders it possul or invalid. One English congregation suggested raising a flag to notify members while a Silver Spring synagogue uses a light attached to its roof.[8] One eruv manager explained how this works:

Some, not all, some of the synagogues have on the roof a green light and a red light so as you are walking to synagogue on a Friday afternoon you can see if the green light or the red light is on. Green means good, it’s up. Red means it’s down.

Light atop synagogue signalling that the eruv us intact. Photograph by David Rotenstein, October 2010.

Each eruv’s space encloses the single-family homes of Jews and non-Jews, apartment buildings, businesses, and a wide array of non-Jewish — and non-Orthodox-Jewish — places of worship. Among the places within Montgomery County’s eruvim are Downtown Silver Spring and Wheaton’s central business district; busy road corridors like Georgia Avenue; and quiet residential streets in twentieth century suburbs like Northwood Park (platted in 1936), where I live. In neighboring Washington, the Obama family lives within the Georgetown eruv’s boundaries and the headquarters of the other two government branches, the U.S. Capitol and the U.S. Supreme Court, also are located within the large Washington eruv.

Inside eruvim: The Capitol and U.S. Supreme Court in Washington; Silver Spring's 1939 World's Fair Home, Northwood Park.

Borrowed Structures

Through the contracts they execute with local and state governments, public utilities, and private property owners, the Jewish congregations who build and maintain eruvim appropriate elements within the built landscape that meet the rabbinic requirements and which are the most cost effective.

Because none of Montgomery County’s neighborhoods is a walled medieval town, eruv builders use the widespread electricity and telecommunications infrastructure dissecting the county. Light and telephone poles linked by wires and cables create an almost unbroken network that winds its way throughout the entire county.

The vertical poles serve as vertical door posts and existing utility lines are the lintels. To satisfy rabbinic law requiring alignment of the lechi with the lintels, some poles are modified with thin plastic strips attached to them or with furring strips or two-by-fours attached to poles.

Eruv boundary: borrowed pole and wires. Photograph by David Rotenstein, October 2010.

Eruv boundary: borrowed pole and wires. The vertical black strips are the attached lechi. Photograph by David Rotenstein, October 2010.

Eruv boundary: borrowed pole and wires. The vertical black strips are the attached lechi. Photograph by David Rotenstein, October 2010.

The eruv’s walls are mostly transparent, formed by the open vertical spaces beneath the overhead wires or kaneh. In parts of the boundaries that lack a suitable utility infrastructure, existing fences and walls that meet the Halakhic criteria are appropriated by the eruv and, as architectural historian Jenifer Cousineau, wrote, “conceptually transformed.”[9] In Montgomery County, this includes large portions of the concrete sound wall that separates suburban neighborhoods from the Capital Beltway (I-495).

This fence serves as part of one eruv. Photograph by David Rotenstein, October 2010.

Built Structures

Montgomery County’s eruvim require built structures — tsuras ha’pesach — to rectify gaps created by highways and streets where existing elements do not meet rabbinic standards. These built structures often are  simple wood posts sunk into the ground onto which string has been attached to the top in accordance with rabbinic standards closing small gaps.

An eruv overseer explained to me how the built portions of the Silver Spring eruv were constructed:

The lechi is the vertical post either fastened — it’s fastened to the wall. Well here, it’s actually a chain link fence, not a wall, actually at both sides. Because there’s a chain link fence here and then the wall picks up and then the wall ends and there’s a chain link fence there. So in these two cases, the lechi is attached to the chain link fence, if I remember correctly. In these two cases, there’s a rule that if any space of  less than three hand breadths — a hand breadth is called a tefach — so we say nine inches to be cautious, a space of less than nine inches is viewed as being filled. So over here, we just have a lechi that’s within nine inches of the wall and here too.

A fence and the Beltway sound wall are connected by string attached to the tops of wood poles (lechi) tall enough to meet the requirements:

Lechi rectifying gap adjacent to the Beltway sound wall. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Eruv along the Capital Beltway. Lechi and Beltway sound wall. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Highway overpasses are rectified by lechi and a monofilament — fishing line — attached to their tops:

Tzuras Ha’Pesach (doorway) created at a highway overpass. If you look closely, you'll see the fishing line in the center of the frame juxtaposed against the highway sign. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Another highway overpass Tzuras Ha’Pesach. Note the attachment of the fishing line to the lechi. If you look closely you can see the line extending along the length of the barrier fence. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Where the eruv boundary crosses a more formidable obstacle, more creative approaches are required like this Tzuras Ha’Pesach that parallels a stream bridge:

Tzuras Ha’Pesach constructed parallel to a highway bridge. Note the lechis in the foreground and the string carried across the stream. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

It is important that the kaneh, or string, be attached to or pass directly over the top of the lechi. To secure the string to the lechi, builders are allowed to drill holes into the lechi to anchor the string once it passes over the top.

Closeup showing a lechi near a Beltway sound wall. This image illustrates how the string is secured to the lechi through a drilled hole after passing over the top. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Closeup showing another lechi near a Beltway sound wall. This image illustrates how the string is secured to the lechi through a drilled hole after passing over the top. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Lechi and string (fishing line) at a highway overpass. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Dr. Robert Kreitman, a National Institutes of Health oncologist, has inspected and maintained the Potomac eruv for the past 15 years. Although he wasn’t involved with its initial construction in the 1980s, he did participate in enlarging its area.

“Many years ago, for about a year or two, we enlarged the eruv because other people were south of the border of the eruv, south of Bells Mill,” Kreitman explained in a telephone interview. “We probably used up a hundred or two hundred — between a hundred and two hundred lechis and I just bought those myself.” He added,

It was a lot of fun, actually, and it wasn’t very expensive. You know, for a furring strip that’s eight-foot long, it was like 86 cents and so we only need that to be half that size and 40 inches is really the legal size of the lechi and so you can do the math. It’s not very expensive to use lechi.

One of the Woodside Synagogue’s eruv volunteers explained that their congregation’s eruv was built by a contractor who also worked on the Aspen Hill and Silver Spring eruvim. The similarities in the materials — plastic cable molding for lechi — and design are evident.

Most eruv boundaries may be built by appropriating existing landscape and architectural elements or by adding the simple strips to poles to create valid lechi. Other areas require more robust structures. To rectify a portion at the terminus of a suburban street near the Capital Beltway, one eruv includes a small vertical plank wall.

Constructed portion attaching a utility pole to the Beltway at the terminus of a suburban street. Note the lechis (plastic) vertically placed along the pole beneath the wires. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Another eruv uses a non-conducting cable strung between two existing utility poles to connect the Beltway sound wall to utility poles along a busy street before entering another quiet subdivision near the Beltway.

Eruv and the Capital Beltway. The string is visible as a diagonal element in the middle of the frame. Photograph by David Rotenstein, October 2010. Click on the image to see a full-size version.

Next in Courtyards of Convenience: Life inside the eruvim.

  1. Mapping Montgomery County’s Eruvim
  2. Making the symbolic real: Building and maintaining the eruvim (this post)
  3. Life inside the Eruvim
  4. Eruvim in the Information Age

An Eruv Glossary

There are several sources available to decode the Hebrew and Yiddish terms attached to eruvim. The Boston Eruv Corporation has a useful glossary as does the Rockland (New York) Eruv.

Eruv: Symbolic enclosure created to enable Jews to carry and push things on the Sabbath.

Eruv Hatserot: A courtyard eruv.

Halakhah: Rabbinic law

Kaneh (or Korah): Lintels in a doorway.

Lechi: A vertical element that symbolically  represents a doorpost.

Possul (Pasul): Invalid, not kosher.

reshus ha’yachid: Private domain.

reshus ha’rabbim: Public domain.

Tefach: A biblical Hebrew unit of measurement, about 3.2 inches.

Tzuras Ha’Pesach: A doorway comprised of vertical posts (lechi) and horizontal lintels (kaneh).

© 2010 David S. Rotenstein


[1] O. Valins, “Institutionalised religion: sacred texts and Jewish spatial practice,” Geoforum 31 (2000): 581.

[2] Felicity Barringer, “An Imaginary Wall Encloses Community of Orthodox Jews,” The Washington Post, January 14, 1980.

[3] Davina Cooper, “Talmudic Territory? Space, Law, and Modernist Discourse,” Journal of Law and Society 23, no. 4 (1996): 529-548; Jennifer Cousineau, “Rabbinic Urbanism in London: Rituals and the Material Culture of the Sabbath,” Jewish Social Studies 11, no. 3, New Series (Spring – Summer 2005): 36-57; Jennifer Cousineau, “Making the northwest London eruv, 1988–2003: The construction, representation and experience of a Sabbath space” (University of California, Berkeley, 2006); Jennifer Cousineau, “The Domestication of Urban Jewish Space and the North-West London Eruv,” in Jews at home : the domestication of identity, vol. 2, Jewish Cultural Studies (Oxford [England]: Littman Library of Jewish Civilization, 2010), 43-74; Charlotte Elisheva Fonrobert, “From Separatism to Urbanism: The Dead Sea Scrolls and the Origins of the Rabbinic Eruv,” Dead Sea Discoveries 11, no. 1 (2004): 43-71; Charlotte Elisheva Fonrobert, “The Political Symbolism of the Eruv,” Jewish Social Studies 11, no. 3 (2005): 9-35; A. Gilbreath, “Corporation of London: eruv is threat to heath,” Ham and High (June 26, 1998): 5; Valins, “Institutionalised religion: sacred texts and Jewish spatial practice”; Peter Vincent and Peter Warft, “Eruvim: Talmudic Places in a Postmodern World,” Transactions of the Institute of British Geographers 27, no. 1 (2002): 30-51.

[4] Alexandra Lang Susman, “Strings Attached: An Analysis Of The Eruv Under The Religion Clauses Of The First Amendment And The Religious Land Use And Institutionalized Persons Act” (2009); Valerie Stoker, “Drawing the Line: Hasidic Jews, Eruvim, and the Public Space of Outremont, Quebec,” History of Religions 43, no. 1 (2003): 18-49; Susan H. Lees, “Jewish space in Suburbia: Interpreting the eruv conflict in Tenafly, New Jersey,” Contemporary Jewery 27, no. 1 (2007): 42-79; Sophie Watson, “Symbolic Spaces of Difference: Contesting the Eruv in Barnet, London and Tenafly, New Jersey,” Environment and Planning D: Society and Space 23 (2005): 597-613.

[5] Cousineau, “Rabbinic Urbanism in London,” 51; Watson, “Symbolic Spaces of Difference: Contesting the Eruv in Barnet, London and Tenafly, New Jersey,” 603; Cooper, “Talmudic Territory? Space, Law, and Modernist Discourse,” 538; Vincent and Warft, “Eruvim: Talmudic Places in a Postmodern World.”

[6] Yosef Gavriel Bechhofer, The Contemporary Eruv: Eruvin in Modern Metropolitan Areas, Second Edition. (Jerusalem: Feldheim, 2002), 100-102.

[7] Cousineau, “Rabbinic Urbanism in London,” 48.

[8] Valins, “Institutionalised religion: sacred texts and Jewish spatial practice,” 583.

[9] Cousineau, “Rabbinic Urbanism in London,” 48.

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