engineering

Jaffa Gate

Jaffa Gate is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jaffa Gate rather than just read about it. In short: Jaffa Gate (Hebrew: שער יפו, romanized: Sha'ar Yafo; Arabic: باب الخليل, romanized: Bāb al-Khalīl, "Hebron Gate") is one of the seven main open gates of the Old City of Jerusalem. The name Jaffa Gate is currently used for both the historical Ottoman gate from 1538, and for the wide gap in the city wall adjacent to it to the south.

Key takeaways

Jaffa Gate belongs to engineering; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Jaffa Gate to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Jaffa Gate from memory before moving on to harder problems.

Reference excerpt

Jaffa Gate (Hebrew: שער יפו, romanized: Sha'ar Yafo; Arabic: باب الخليل, romanized: Bāb al-Khalīl, "Hebron Gate") is one of the seven main open gates of the Old City of Jerusalem. The name Jaffa Gate is currently used for both the historical Ottoman gate from 1538, and for the wide gap in the city wall adjacent to it to the south. The old gate has the layout of a medieval gate tower with an L-shaped entryway, which was secured at both ends (north and east) with heavy doors. The breach in the wall was created in 1898 by the Ottoman authorities in order to allow German emperor Wilhelm II to enter the city triumphally. The breach and the ramp leading to it now allow cars to access the Old City from the west. The L-shape of the historical gateway was a classical defensive measure designed to slow oncoming attackers, with its outer gate oriented in the direction of Jaffa Road, from which travellers including pilgrims arrived at the end of their journey from the port of Jaffa.

Names

Both the Jaffa Gate and Jaffa Road are named after the port of Jaffa, from which the Prophet Jonah embarked on his sea journey and pilgrims debarked on their trip to the Holy City. Now the name Jaffa Road is only used for the city street going through the city of Jerusalem outside the historical Old City, while the multi-lane modern road further connecting it westwards with Tel Aviv-Yafo is part of Israel Highway 1. The Arabic name for the gate, Bab el-Khalil, literally "Gate of the Friend", refers to Abraham, "the beloved of God". Since by tradition the burial site of Ibrahim/Abraham is in Hebron, whose Arabic name is el-Khalil, so the Arabic name for the Jaffa Gate translates as "Hebron Gate". The Hebrew name Hebron derives from the term חבר haver, "friend". In medieval times the Arabs called this gate Bab Mihrab Dawud, or "Gate of David's Chamber or Sanctuary", on the belief that the room atop the Herodian tower stump represented the "private chamber" or "prayer room" of Prophet Dawud, which is specifically mentioned in the Quran (Surah 38. Sad, Ayah 21). In Islam, King David is known as the Prophet Dawud. The Crusaders, who rebuilt the citadel to the south of Jaffa Gate, also built a gate behind the present location of Jaffa Gate, calling it "David's Gate".

Architecture

1538 gate tower

Like the stones used for the rest of the Old City walls, the stones of Jaffa Gate are large, hewn, sand-colored blocks. The entryway stands about 20 feet (6.1 meters) high, and the wall rises another 20 feet above that.

1898 breach in the wall Adjacent to the old gate tower (the 1538 Jaffa Gate proper, which is used only by pedestrians), is a wide breach in the wall, through which the roadway passes. This breach is located between the gate tower and the citadel/Tower of David. Photographs from circa 1870 to 1890 show that originally the city wall was continuous at that point, although the wall segment between the citadel and the gate tower was much lower, because a moat ran around the citadel, and the city wall at that point was constructed from the bottom of the moat up. Therefore, even though the overall height of that wall segment was presumably the same as the rest of the city wall's, therefore providing a similar level of protection from invaders, the top of the wall segment only reached about two metres above the moat, a much lower elevation than both the adjacent city wall and citadel. The breach was made by the Ottoman authorities ahead of Emperor Wilhelm II of Germany's visit to the city and allowed him and his retinue to comfortably enter Jerusalem riding on horses and in carriages. Part of the moat also had to be filled in for the purpose.

Associated structures

The Citadel, aka the "Tower of David"

The Tower of David is an ancient citadel located near the Jaffa Gate entrance to the Old City of Jerusalem. Built to strengthen a strategically weak point in the Old City's defenses, the citadel that stands today was constructed during the 2nd century BCE and subsequently destroyed and rebuilt by, in succession, the Christian, Muslim, Mamluk, and Ottoman conquerors of Jerusalem. The strong bulwarks still seen today surrounding the base of the tower are believed to have been built by king Herod, in memorial of his brother, and was formerly named the Tower of Phasael (Hebrew: מגדל פצאל). During the Jewish war with Rome, Simon bar Giora made the tower his place of residence. Of the original tower itself, some sixteen courses of the original stone ashlars can still be seen rising from ground level, upon which were added smaller stones in a later period, which added significantly to its height. The site contains important archaeological finds dating back 2,700 years, and is a venue for benefit events, craft shows, concerts, and sound-and-light performances.

Ottoman clock tower

… excerpt ends here. Continue reading the full article.

Illustrations

Jaffa Gate: Old City Gates — Old City Gates

Jaffa Gate: Jaffa Gate from northwest (1891) — Jaffa Gate from northwest (1891)

Worked examples

Example 1 — a first encounter with Jaffa Gate

Start with the simplest possible case. Write down what Jaffa Gate claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jaffa Gate before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jaffa Gate ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jaffa Gate

In research: Jaffa Gate appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Jaffa Gate in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Jaffa Gate is common in secondary-school and first-year university syllabi. It links to neighbouring topics Buildings and structures completed in 1898, Gates in Jerusalem's Old City Walls, Historic sites in Jerusalem, so understanding it makes those chapters shorter.
In everyday life: Look for Jaffa Gate outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Jaffa Gate in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Jaffa Gate means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Jaffa Gate out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Jaffa Gate in simple terms?

Why does Jaffa Gate matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jaffa Gate?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jaffa Gate.