Practically speaking, how long would it have taken to build the Israeli zombie-defense wall in World War Z?

Question

My impression was that the wall protected the borders of the entire country of Israel. This would have taken a long time especially if you wanted to buttress the wall properly. At least a few years? I'm not an engineer, but I would be interested to get a civil engineer's perspective on this.

Another thing I was wondering about was if there were multiple walls for defense which may have been mentioned in Max Brooks's book -- not including more minor defensive addenda like the metal fences that covered the roofs of some pathways -- or if it was a single continuous wall like the Maginot Line, seemingly protective in terms of size and scale but actually quite weak as an actual defense against zombies.

Overall, it seems impractical that Israel could have built the wall quickly enough to protect all its borders prior to the rapid onslaught of the global zombie infection. Still it was an interesting plot device with great and impressive visual effect as seen in the movie.

Answer 1

Israel's borders, not including coastline, are approximately 767km in length. If the zombies can swim across the Dead Sea or Red Sea, add about another 90km to cover those coastlines.

The closest comparison for large scale walls would be the 4th generation Berlin Wall, which was a pair of concrete walls 3.6m high, 1.2m thick, and 106km long, separated by a 100m "death strip". Construction of this wall was started in 1975 and completed sometime in 1980.

Assuming similar construction rates, an Israel-surrounding wall would take 35-40 years to build.

If you went and threw every available resource at the construction, you could probably cut that down to a few years, but not likely much less than that.

One plausible explanation for how they put up such a wall so quickly would be that the in-universe Israel had a large part of such a wall already built or in the late stages of construction, basically an expanded version of the existing West Bank Barrier.

Answer 2

Haven't seen the movie yet, but I am currently reading the e-book, and searched through it for occurences of "Israel" and "wall"...

The book only refers to a single wall, and it is vaguely implied that construction started some time before or just around the time of the outbreak of the zombie plague. It might have originally been intended to defend against Israel's neighbors or to keep out illegal immigrants, it doesn't mention its height. The following quote is from the recollection of Saladin Kader, a Palestinian entering Israel at the time the disease was just starting to spread, but still in relatively small numbers and most of the public not aware of its severity:

As we approached the border, I saw the Wall for the first time. It was still unfinished, naked steel beams rising above the concrete foundation. I'd known about the infamous "security fence"- what citizen of the Arab world didn't - but I'd always been led to believe that it only surrounded the West Bank and Gaza Strip. Out here, in the middle of this barren desert, it only confirmed my theory that the Israelis were expecting an attack along their entire border.

Note that Kader is portrayed as being strongly anti-Israel at the time, and he wasn't aware of the existence of the zombies yet - or at least he didn't believe the rumors.

The same person about the location of the wall (emphasis and [editing] mine):

In your opinion, what do you believe was the cause of that war?
I think there were many causes. I know the repatriation of Palestinians was unpopular, so was the general pullout from the West Bank [...] Al Quds [Arabic for Jerusalem], I believe ... that was the final straw. The Coalition Government decided that it was the one major weak point, too large to control and a hole that led right into the heart of Israel. They not only evacuated the city, but the entire Nablus to Hebron corridor as well. They believed that rebuilding a shorter wall along the 1967 demarcation line was the only way to ensure physical security, no matter what backlash might occur from their own religious right

This is a confusing statement, as the border in 1967 (after the Six-Day War) was not shorter than it is at present at all, but included all of the Sinai, Gaza, the West Bank and the Golan Heights. So my interpretation of "1967 demarcation line" is the border before that war, more commonly known as the 1949 demarcation line or Green Line.

How long it would take to build such a wall is difficult to tell; I don't agree with Compro01's assumption that this wall would have a construction rate similar to that of the Berlin wall. The longer a planned wall is, the easier it becomes to assign more workers and to complete longer stretches of wall per day. Still, months to several years seems a reasonable guess.

However, in the book, it does take a while for the disease to become a global catastrophe. Early outbreaks were small and could be contained most of the time. With Israel imposing an early "voluntary quarantine", and having dogs at the border that could sniff out the contaminated so nobody would turn zombie once inside, it seems fairly plausible to me that they could buy enough time to complete the wall.