LONDON — A rather proper, restrained, British — but clearly audible — gasp of delight went up from the standing-room-only crowd at London's Finchley United Synagogue when the announcement was made:
London's eruv, or Sabbath boundary, would finally be operating as of last Friday.
"It is hard to believe it is about to become a reality," said Peter Sheldon, the president of Britain's mainstream Orthodox movement, the United Synagogue.
Another case of classic British understatement — since the United Synagogue organization had worked for 13 years to get the eruv up.
The eruv, a boundary that allows Orthodox Jews to carry some items and push carriages and wheelchairs on the Sabbath.
The 11-mile enclosure in northwest London covers some of the city's most Jewish neighborhoods, including Golders Green and Hendon, plus much of Hampstead Garden Suburb and some of Finchley.
Addressing an audience estimated at more than 1,200 on the Monday night before the eruv "went live," Sheldon described the campaign to erect it as "the stuff of which TV sitcoms are made."
On the face of it, creating an eruv appears to be a simple task.
The idea is to symbolically enclose a public space, making it into "private" space — like one's home — where prohibitions against carrying on the Sabbath do not apply.
Dozens of cities across the United States have them, as do communities in Israel, Europe and as far away as Sydney and Melbourne, Australia.
So what took so long in London?
Eruv campaigners faced difficulties from all sides, observers say: from property owners and town planning authorities, from less observant Jews who said the eruv would attract fervently religious Jews to their neighborhood and from fervently religous Jews who said it did not meet the standards of halachah, or Jewish law.
Rudi Vis, a local member of Parliament campaigning for re-election in 2001, criticized it as a form of social engineering.
"Nobody ever thought, including ourselves, that this would be up and running," said Rabbi Jeremy Conway, who supervises inspections of the eruv.
Actually drawing the boundaries of the eruv proved surprisingly easy, however, he said while on an inspection two days before the eruv went live.
Two long artificial boundaries, the M1 highway and London Underground's Northern Line, already border the area with the highest concentration of Jews in north London.
The fences along the two transport corridors make up the eastern and western boundaries of the eruv, he said.
"Joining the two sides was the trick," he said.
Shimon Eider, a New Jersey-based rabbi who is one of the world's foremost experts on eruvim, helped design London's, Conway said.
Jewish law requires that eruv boundaries be unbroken, at least symbolically, and that is where the eruv plan ran into serious difficulties.
There are 34 gaps in the 11-mile boundary, mostly due to roads crossing it.
The normal solution is to build a symbolic door across the gaps so that it is theoretically possible to close them.
Such doors, known as tzures hapesach, generally consist of poles with a wire strung between them.
The London eruv design required the erection of 82 poles — which in turn required planning permission from local councils and residents.
Many people with philosophical objections to the eruv used planning regulations to try to stop it, said Oliver Valins of the Institute for Jewish Policy Research, a London think tank.
But patience and perseverance — and a measure of flexibility — won out, Conway said.
"The placement of the poles had to be agreed with householders and councils. We tried to accommodate everyone," he said.
Dayan Chanoch Ehrentreu, the head of the London Beit Din, or rabbinic court, expl