We are fortunate to have an Eruv in our neighborhood including most of Cote St. Luc / Hampstead / Snowdon, under the direction of (Rabbi Joshua Schmidman - of blessed memory, and assisted by) Rabbi Michael Whitman. An Eruv (Hebrew for "union" or "joining") is a symbolic boundary around an area that permits Jews to carry, push, or throw objects outside on Shabbos, actions that are otherwise prohibited by Jewish law. By symbolically enclosing this area, the boundary converts the outside public space into a private domain, as if all the inhabitants were members of one family.
Having an Eruv only relates to the halachos of carrying. All other halachos of Shabbos still apply. It must be emphasized that muktzah items remain muktzah and may not be moved or used even with an Eruv; such items include umbrellas, wallets, and purses. Also, any action done on Shabbos to prepare for after Shabbos is prohibited. For example, you may not walk to synagogue on Shabbos afternoon carrying your car keys so that you can drive home after Shabbos. This is because the keys are being carried on Shabbos only for use after Shabbos. Furthermore, some pastimes may still be prohibited such as ball playing, bicycle riding, etc. Concerning these issues, please consult your rabbi.
There is another vital, though subtle, aspect of Shabbos observance that must be remembered - maintaining the atmosphere of Shabbos. Shabbos is a day of sanctity - a day of spiritual transcendence. With an Eruv there are many activities that may not fall into any specific prohibition other than destroying the holiness of Shabbos. The purpose of an Eruv is not to make Shabbos more mundane, but to make Shabbos more sanctified.
Using the Eruv involves the halachos regarding assumptions. Because many things can happen to invalidate the Eruv and thus, frequent repairs are necessary, we must determine when the Eruv can be assumed to be in operation. For this reason the Eruv is checked every Friday morning. Once that inspection has been successfully completed, the web site and answering machine tape is set for that Shabbos. To ascertain that the Eruv is in operation on a given Shabbos, you must either check the website, www.eruvmontreal.org, or call the Eruv hotline, 514-418-6892, on Friday. Sometimes repairs are being made until close to Shabbos. Sometimes there is no answer at the hotline number; this happens when many people call at once. Please wait a few moments and call again. You cannot rely on the Eruv each week just because it was up the previous week. It is best to get in the habit of calling the hotline just before each Shabbos.
Once you hear that the Eruv is up for a given Shabbos, you may assume that the Eruv will remain intact all Shabbos long. Our experience has been that the Eruv is quite durable - even medium strength windstorms, snowstorms, or thunderstorms rarely cause damage to the Eruv. But, in the event of unusual conditions where tree limbs are felled, the assumption that the Eruv is intact may be void. Nonetheless, you should be very hesitant to conclude that the Eruv has gone down. Even if you see something that appears to call the Eruv into question, it may not necessarily be a problem since many places along the Eruv perimeter have backups built into the system. In such a case, you should contact your rabbi.
Inevitably, from time to time the Eruv will be down. Although all possible attempts will be made to have the Eruv functional every week, you should always make contingency arrangements when planning anything on Shabbos that relies on the Eruv.
Our Jewish community is fortunate to have an Eruv. May it be the will of the Almighty that our Eruv fulfill its deepest meaning; that we are joined, united - that we are truly one family.
Rabbi Michael Whitman