Walls, Gaps, and Omed Merube

A wall must have halachic form

A fence or retaining wall generally needs the required height and must not be interrupted below that height. An embankment may be judged by its rise over its horizontal run; a slope that is too gradual is not a wall merely because it separates two elevations.

Building facades can sometimes form standing wall, but driveways, entrances, vacant lots, setbacks, side yards, and streets break the line. The calculation begins only after the actual wall line has been located.

The calculation belongs to a defined side

Omed and parutz are compared on the relevant side or segment of an enclosure. Before adding lengths, one must show that the structures belong to one boundary and meet at halachically effective corners.

A total drawn from scattered buildings, rail embankments, and retaining walls across a wide area does not state which open spaces belong in the denominator or how the separate structures connect. A percentage without its measured line cannot be checked.

When the standing portions exceed the openings

Omed merube al haparutz can preserve a side when its standing portions are greater than its breaches. The rule does not erase the breaches; it allows the standing wall to govern the side under the conditions set by halacha.

The measurements must use the same line and the same standard throughout. If the claimed wall changes direction, jumps across an opening, or relies on a different feature, the transition itself needs an accepted closure.

A public street is not an ordinary gap

Openings wider than ten amos normally require tzuras hapesach or another proper closure. Public roads wider than sixteen amos raise the further question of a breach used as reshus harabim.

The analysis presented by Rabbi Levin, drawing on Shulchan Aruch HaRav and the Tzemach Tzedek, does not allow attached buildings or a larger omed-merube calculation to neutralize such public openings. If the road is a genuine reshus harabim, doors are required under that approach.

Bridges and openings through a claimed natural wall

A river or shoreline wall is interrupted where a wide bridge carries the public through it. The physical wall below the bridge may be out of sight or directly traversed by the public way, and the bridge approaches can contain several separate lanes and sidewalks.

Rabbi Levin applies this problem to Brooklyn's water boundaries: a bridge wider than sixteen amos cannot be treated as though the riverbank continued untouched beneath it. The bridge opening and its connection to the surrounding roads require their own enclosure.