1. Reshus Harabim and Highway 401
One of the most difficult issues relating to the eruv are the problems associated with building an eruv around a reshus harabim. According to many poskim, the streets of Toronto would not be considered a reshus harabim. Even according to those poskim who would consider Toronto to be a reshus harabim, the eruv which is Oymed Meruba Al Haparetz on at least three of its sides render it a reshus hayachid.
It is nearly impossible though to overcome the problems associated with incorporating the 401 into the eruv. The previous method to resolve this issue was to take the position that the 401, as it crosses Toronto, is not a reshus harabim even though there are, without a doubt, more than 600,000 people who travel on it every day. This was based on a position that people travelling in cars, although moving, are considered in their own reshus.
In order to avoid this issue, the area of the 401 was in effect stripped out of the eruv using the walls running along the highway and a series of tzuros hapesach at the ramps. The 401 is thus not within the geographical boundaries of the eruv. Special crossings were put in place beneath the 401 at the two points where it crosses Bathurst Street and Wilson Avenue.
A practical result is that the 401 technically renders the areas to the north and south of it as two independent eruvim with the advantage that one area is not dependent on the other in case of a break.
2. Three seperate Eruvim
Aside from the separate divisions north and south of the 401, the Eruv is further divided along the CN tracks which runs just north of Steeles Avenue so that the areas north and south of these tracks are also two technically separate eruvim.
3. Construction Techniques
The Committee had to use a degree of ingunuity to create mechitzos which would both withstand the Canadian environment in terms of durability and win approval from railway and municipal authorities for safety. Many spots in the eruv required precise determinations to ensure that in cases of a tzuras hapesach, the wire was on top of the pole and methods needed to be devised to ensure that these determinations were done accurately.
In many cases, plastic tubing was installed all the way up along telephone poles to ensure that the lechis were directly beneath the wire. In some instances, cooperation was obtained from Ontario Hydro to install barrels or extra wide posts as lechis alongside hydro poles and to strap them securely to the poles.
4. Karfef
There is a rule that an area in excess of 5000 square amos which is not intended for human habitation or purpose (karfif yoser mibeis sosayim shelo hukaf ledira) within an eruv would invalidate the eruv. This is a manifestation of the rule that one cannot carry, even in an area with a proper eruv, if it is open to an area where one may not carry. An example of this would be a field which is cropped. It should be mentioned that one should not carry within a fenced off cemetery, construction site or other area not intended for human habitation. Parks and bodies of water are used directly for human purpose and thus do not pose problems.
Another interesting result of this issue is the area between Highway 7 and the 407. The eruv committee is currently trying to complete the enclosure of this area with actual walls. As this area has pockets of undeveloped land which is still being farmed, the issue of karfef is a serious obstacle.
5. Municipal Licenses
In order to make a proper eruv chatzeiros, licenses from municipal authorities were required. The eruv Committee needed to explain the concept of the eruv to municipal officials in both the City of Toronto and the City of Vaughan and lobby for municipal resolutions to be passed by both councils. Of course, the committee spent countless hours with officials of the railways, the police and municipal building authorities on safety issues.
6. Other Issues
In a number of other areas, the committee improved the eruv in order to accommodate the more stringent view on an issue. For example, although the edges of the railway and highway 401 overpasses may halachically create a mechitza using the principle of pi tikrah, the committee, in order to follow the more stringent views in this case, constructed regular tzuros hapesach at the underpasses.
Furthermore, it was stated above that a gap in a mechitza of up to 10 amos is acceptable in an area which is deemed to be a chatzer. However, the enclosures of a movui may be invalidated by gaps over four tefachim. In order to ensure that the Toronto eruv would satisfy the stringencies associated with a movui, the committee closed all gaps of over four tefachim which were necessary to be closed with tzuros hapesach.