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Ruby Tower

Ruby Tower 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 Ruby Tower rather than just read about it. In short: The Ruby Tower was a six-story building in Manila, Philippines, completed c. 1965 that collapsed on August 2, 1968, during the Casiguran earthquake killing over 250 people. Background The building, constructed at a cost of $250,000, was located on the corner of Doroteo Jose and Teodora Alonso Streets in Santa Cruz, a district in the northern part of Manila.

Ruby Tower — main illustration
Ruby Tower — illustration

Key takeaways

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

Reference excerpt

The Ruby Tower was a six-story building in Manila, Philippines, completed c. 1965 that collapsed on August 2, 1968, during the Casiguran earthquake killing over 250 people.

Background The building, constructed at a cost of $250,000, was located on the corner of Doroteo Jose and Teodora Alonso Streets in Santa Cruz, a district in the northern part of Manila. The reinforced-concrete building measured 45.5 m × 30 m (149 ft × 98 ft), with a height of 20.5 m (67 ft). It was of a slab-and-beam design supported by columns, the rear wall with the primary resistance to shear or torsional forces. The mixed commercial and residential building contained 38 commercial spaces on the lower two floors and 76 residential units on the upper four floors. It housed 600 to 1,000 people.

Collapse and rescue effort The 7.3-magnitude 1968 Casiguran earthquake, centered more than 200 km (120 mi) away, hit at 4:19 am and caused the building to collapse in a pancake fashion burying over 500 people. A volunteer force of over 6,000 mobilized to free the victims trapped in the rubble, as there was no government disaster plan in place at the time. Many people were rescued alive, including about 30 who later died from their injuries. At least 260 people were injured. The rescue effort turned to recovery and lasted over a week. Not all of the bodies were identified. A part of the northern end of the floors one and two remained standing. The lower levels collapsed straight downward, while the upper floors shifted south as they collapsed, with the roof shifting 30 feet (9.1 m) south and 10 feet (3.0 m) east of its original location. Its long columns buckled in the earthquake. By August 4, Philippine soldiers and heavy construction equipment were in use. They were assisted for 10 days by personnel of the United States military. In 80% of the building, the collapsed floors were separated by debris (portions of columns and walls) leaving spaces of 3 feet (0.91 m) or less, with very limited lateral movement. As a result, many holes had to be cut through the concrete with jackhammers and oxygen-acetylene torches to reach the pockets. Philippine and US military, and civilian contractors all participated in this work. Around 3,000 rescuers, including soldiers and civilians, worked daily, all coordinated by Brigadier General Gaudencio Tobias of the Philippine Army. The nearby Cayetano Arellano High School (formerly Manila North High School) was used as a command center, canteen and rest area, medical clinic and morgue. The US effort was directed by Rear Admiral Draper Kauffman and included US Navy and US Marine Corps personnel from Subic Bay Naval Complex and US Army and US Air Force personnel from Clark Air Force Base. The Boy Scouts of the Philippines managed the collection and identification of items of value as they were retrieved. The last of the 268 survivors pulled from the building were two girls, aged 9 and 12, who were found on August 9, having survived in the wreckage for 125 hours. Another 260 bodies were retrieved. The deaths in the collapse accounted for the majority of all deaths in the earthquake, causing the Casiguran earthquake to be alternatively called the Ruby Tower earthquake.

Analysis and legacy The collapse was attributed to the design, poor workmanship and concrete quality. Court cases were brought alleging both civil and criminal liability. A case against the construction company was brought before the Supreme Court, where the company was found liable for poor construction including insufficient reinforcement in columns, and joints not built to specifications. After the collapse of Ruby Tower, the Philippines created the National Committee on Disaster Operation (NCDO), predecessor of the National Disaster Risk Reduction and Management Council (NDRRMC), setting minimum standards for building construction. The first national building code was established in 1972 by the Republic Act 6541, An Act to Ordain and Institute a National Building Code of the Philippines. Five years later, it became the National Building Code of the Philippines by order of then President Ferdinand Marcos Sr.

Memorial The Ruby Tower Memorial Hall is a two-story structure on the site, made from the portion of the building that remained standing, where the victims are remembered. Built in 1974, the shrine includes 100 black and white photographs of people killed in the collapse.

See also Ruby Tower Memorial, a memorial in Manila Chinese Cemetery

Notes

References

Media related to Ruby Tower at Wikimedia Commons

Illustrations

Ruby Tower illustration
Ruby Tower: Ruby Tower Hall
Ruby Tower Hall

Worked examples

Example 1 — a first encounter with Ruby Tower

Start with the simplest possible case. Write down what Ruby Tower 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 Ruby Tower 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 Ruby Tower 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 Ruby Tower

In research
Ruby Tower 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 Ruby Tower 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
Ruby Tower is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1968 in the Philippines, Building and structure collapses in Asia, Buildings and structures completed in 1967, so understanding it makes those chapters shorter.
In everyday life
Look for Ruby Tower 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 Ruby Tower in 20 minutes

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

Frequently asked questions

What is Ruby Tower in simple terms?

The Ruby Tower was a six-story building in Manila, Philippines, completed c. 1965 that collapsed on August 2, 1968, during the Casiguran earthquake killing over 250 people. Background The building, constructed at a cost of $250,000, was located on the corner of Doroteo Jose and Teodora Alonso Stree…

Why does Ruby Tower 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 Ruby Tower?

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 Ruby Tower.

Tags

  • 1968 in the Philippines
  • Building and structure collapses in Asia
  • Buildings and structures completed in 1967
  • Buildings and structures demolished in 1968
  • Buildings and structures in Santa Cruz, Manila
  • History of Manila

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