Thread by @erlichya

On rockets in Tel-Aviv🚀, measures, and statistics
[with some comparisons to covid19]
A thread without politics.
Hint: I use cute emojis but it is anything but cute.
🧵🧵🧵
👇👇👇

In the past four days, Hamas and other Islamic extremists have launched over 3000 rockets on Israeli cities, a country that has one of the highest population density in the world (rank #17, 20x the US). Yet, less than 10 civilians were killed.

How can it be?

First, let's get familiarized ourself with the Hamas rockets. Their rockets can target nearly every population center in Israel with a warhead of 10kg-250kg explosives. But they have one main drawbacks: low accuracy

This photo shows a launch of rockets from Gaza from last night. It clearly shows high spread from the launching point. Instead of getting one (or two) beams, there is a remarkable deviation. The rockets fly in a ballistic path and cannot correct. So they aim to civilian clusters.

But here is where things start to fail for them. Approximately, 20% of the Hamas launches fail and instead of reaching Israel they actually hit Gaza strip instead.
Source: maariv.co.il/news/military/…

Next, Israel tries to intercept the rockets with a magical system called Iron Dome. The system detects the rockets as they are launched and fires anti-rocket missiles that can rapidly reach the anticipated crossing point.

The system efficacy is around 85% to 90%. This is our active immunity against these rockets. However, it can only reach this efficacy with a normal "rocket load". So Hamas tries to launch many rockets at the same time to reach a breakthrough. The Iron Dome fights that by...

estimating which rockets are likely to hit populous places vs. empty places (e.g. the sea) and to save the missiles to the most dangerous rockets. That already means that a considerable fraction (~90%) of the *dangerous* rockets do not reach their destination.

If the rocket was not intercepted, the worst place to be is the middle of the street. You can either get hit by a shrapnel from the rocket but also from debris of Iron Dome.

So the next layer consists of early warning sirens. In my town (and TLV area) you have 90sec hide. Me:

Sirens, like many inventions, are not side effect free. Two women were killed in past two days in separate incidents as they ran to the shelter. Also it has deep psychological effects. Thus, Israel operates them in small geographical segments.
Source: israelhayom.co.il/news/local/art…

The last layer of defense consists of home shelters, which about third of Israeli houses have. These are regular rooms that were built from enforced concrete and have a heavy metal door and one window with a movable metal plate. In peace days, it is my home office 🤷‍♂️.

These rooms provide very good protection. The image below is (or was) the house of the father of our friends. It was *directly* hit by a rocket on Wed night.

Luckily, they stayed at the home shelter and did not even get a scratch! The house is basically totaled.

But even home shelters can fail from time to time. Two days ago, this cute boy, 5yo, was killed by a Hamas rocket, as the metal plate in the window (click to enlarge) of the home shelter failed to contain a very high impact shrapnel.

So we basically have a funnel. Hamas launches thousands of rockets. 20% fail to reach Israel. A good amount (85%-90%) of those that go to civilian clusters are intercepted. Most of the rest fall in the middle of the street. But sirens alert people to hide.

Those that directly hit buildings, sometimes fail to penetrate, and when they do, ~third of the houses have highly effective home shelter.

Due to this highly effective multi later system, "only" six civilians were killed directly due to rocket attacks so far.

Their names:
Ido Aviga'il, 5yo.
Khalil Awad, 52yo.
Nadin Awad, 16yo.
Sumia Santos, 32yo.
Nela Gurevitch, 52yo.
Lea Yom-Tov, 63yo.

Update: since I wrote this tweet another citizen was killed due to a rocket from Gaza. I will write his name once it will be announced.

His name is Gershon Franco 55. He had severe disabilities that prevented him from finding a proper shelter. This is a good reminder that the weakest and poorest pay first the price of wars. RIP.