
An eruv is a fence inside which Orthodox Jews can carry on certain activities during Shabbat. That “fence” can be a simple, continuous wire which marks out an area. Shabbat or Sabbath is the seventh day of the week, a day when Orthodox Jews refrain from work and often spend time visiting their Synagogue.
Under Jewish religious law, people are prohibited from any form of Melakhah on the Sabbath. Often translated as “work”, Melakhah more closely means “deliberate activity” or “skill and craftsmanship”. Within that definition there are 39 prohibited activities including things like baking, tanning and dyeing wool.
The prohibited activities are not directly quoted in the Torah but are derived from its teachings. That extension or interpretation of the Torah’s teachings has been extended and therefore there are many more prohibited activities than the original 39.
Some Jewish Observers extend the prohibited activities to include driving a motor car, using electrical devices and even carrying articles outside their house and that’s where an Eruv becomes important.
Within the boundaries of an Eruv an Orthodox Jew can carry items that they might not otherwise be allowed under their faith. Those items might be a simple as a bunch of keys.
What does an Eruv do?
An Eruv lays out an area that extends and integrates a number of private and public properties in to a singular domain which is enclosed by the fence. To many non-Jewish people, they imagine a “gated community” or high-walled area but that is not necessarily the case. An Eruv can be constructed by a simple, continuous wire held high. That can simply be achieved by stringing that wire between telegraph poles or electrical poles.
Who cares?
Obviously, many people within the Jewish Community around St Ives care very greatly and that has been highlighted in The Australian Jewish News and also a blog about the Northern Eruv.

But construction is not without its opposition and in particular The St Ives Progress Association has been quite vocal. They have worked in concert with Ku-ring-gai Council to oppose the construction of the Eruv via the Land and Environment Council.
The case between the Northern Eruv and Ku-ring-gai council does not appear to have gone away entirely, with the addition of a number of grey pipes to the side of electrical power poles in the area. Those pipes are the source of ongoing questions to council who have referred the investigation to Ausgrid as the poles are their property.
Other Eruv’s in Sydney
There is another major in Eruv in Sydney around the Bondi area which most non-Jewish people would not have seen and are probably not aware that it exists. It is detailed here.
So next time you are wondering around St Ives and you see the grey conduit running up the side of the electrical poles, they have been put there to construct the Northern Eruv.