science

Scharfenberg coupler

Scharfenberg coupler is a science 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 Scharfenberg coupler rather than just read about it. In short: The Scharfenberg coupler (German: Scharfenbergkupplung, abbreviated Schaku) is a commonly used type of fully automatic railway coupling. Designed in 1903 by Karl Scharfenberg in Königsberg, Germany (today Kaliningrad, Russia), the coupler has gradually spread from transit trains to regular passenger service trains, although outside Europe its use is generally restricted to mass transit systems.

Key takeaways

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

Reference excerpt

The Scharfenberg coupler (German: Scharfenbergkupplung, abbreviated Schaku) is a commonly used type of fully automatic railway coupling. Designed in 1903 by Karl Scharfenberg in Königsberg, Germany (today Kaliningrad, Russia), the coupler has gradually spread from transit trains to regular passenger service trains, although outside Europe its use is generally restricted to mass transit systems. The Schaku is superior in many ways to the AAR (Janney/knuckle) coupler because it also automates electrical and pneumatic connections and disconnections. However, there is no standard for the placement of these electro-pneumatic connections. Some rail operators have placed them on the sides while others have placed them either below or above the mechanical portion of the coupler.

Scharfenberg as a technical design principle and brand name Scharfenberg and the abbreviation Schaku are registered trademarks of Voith Patent GmbH. For this reason, only couplings from Voith can use this name. The associated coupling principle is also referred to as latch type design. It is not protected by a patent and is used with fully compatible couplers from manufacturers such as Dellner or Wabtec.

Working principles The face of the Scharfenberg coupler has a protruding cone and a matching cup. Inside the cone there is a rigid metal hoop connected to a revolving, spring-loaded metal disk with a notch on the opposite side. When ready to couple, the spring turns the disk so the hoop is extended from the cone. As the cars meet, the hoop enters the cup on the other coupler, stopping against the disk. The hoops are then pressed back into their own coupler, causing the disks to rotate until the notches align with the hoops. After the hoops have entered, the notches on the disks spring back into the hoop extended position, locking the coupling. In the coupled position, forces on the hoops and disk will balance out, which means that the Scharfenberg, unlike many other couplers, is not dependent on heavy latches to stay locked. Small air cylinders, acting on the rotating heads of the coupler, ensure the engagement of the components, making it unnecessary to use force to get a good coupling. Joining portions of a passenger train can be done at very low speed (less than 3 km/h or 2 mph in the final approach), so that the passengers are not jolted. One problem with the coupler is that it is often hard to connect it in a curve. Planned coupling is normally done on a straight flat track, while there has been trouble coupling a broken down train at an unplanned place.

Uses

Rail equipment manufacturers such as Alstom offer the Schaku as an option on their mass transit passenger cars and locomotives. Presently, Scharfenberg couplers are in use on the following passenger transit systems:

Australia Victoria - V/Line (VLocity 160, Sprinter), Metro Trains Melbourne (Comeng, Siemens Nexas, X'Trapolis 100 [also used in Chile]) New South Wales - Sydney Trains (T, M, A & B sets), NSW TrainLink (Endeavour railcar and Xplorer) Western Australia - Transperth (A-series, B-series train) South Australia - Adelaide Metro (3000 class railcar) Queensland - Queensland Rail (EMU, ICE, SMU, IMU, NGR)

Brazil São Paulo - Companhia Paulista de Trens Metropolitanos (All vehicles, except 1700 and 5400 series) São Paulo - Companhia do Metropolitano de São Paulo (Type F, M and P vehicles) Salvador - CCR Metrô Bahia

Canada Montreal - Metro Montreal - REM Vancouver - SkyTrain Toronto - Scarborough RT

Europe Thalys TGV – All French high-speed trains are equipped with Scharfenberg type 10 couplers. ICE – All German high-speed trains are equipped with Scharfenberg type 10 couplers. Many regional train EMUs and DMUs in Europe Rhine-Ruhr Stadtbahn - Almost all German light-rail and streetcar systems use Scharfenberg couplers. SBB Cargo – In 2019, the Swiss freight operator introduced cargo wagons with Voith CargoFlex, an extension of Scharfenberg type 10 couplers. Channel Tunnel - Eurotunnel Le Shuttle Narrow-gauge railways in Saxony, Germany

Spain Renfe commuter, regional and high speed trainsets and multiple units Talgo III trainsets (now retired) Euskotren EMUs FGV trainsets Madrid, Barcelona and Bilbao metros (some are used only if a train needs to be towed) CAF Urbos trams (towing only, some adapted with electric connections) Iryo and Ouigo high speed trainsets Renfe metre-gauge electric and diesel multiple units

United Kingdom

Class 175 Alstom "Coradia" Class 180 Alstom "Adelante", used on Grand Central Class 185 Siemens "Desiro", operated by TransPennine Express. Class 332 Class 333 Class 458 Alstom "Coradia Jun" Hitachi A-train Bombardier M5000 London Underground 2009 Stock Glasgow Subway 3rd Generation Rolling Stock

Indonesia Soekarno–Hatta Airport Skytrain Whoosh Jabodebek LRT

New Zealand Auckland - AM class Wellington - FP/FT class

Philippines Metro Manila MRT Line 3 Class 3000 and Class 3100

Saudi Arabia Haramain High Speed Train - Talgo 350 train

Singapore Mass Rapid Transit

Taiwan Taipei - Taipei Metro (Matra VAL 256 and Bombardier Innovia APM 256) New Taipei City - New Taipei Metro (Hitachi Rail Italy Driverless Metro (4-car and 2-car)) Taoyuan - Taoyuan Airport MRT (Commuter and Express) Taichung - Taichung MRT (Kawasaki/TRSC EMU) Kaohsiung - Kaohsiung Metro (Siemens Modular Metro)

Thailand Bangkok - BTS Skytrain, MRT, Airport Rail Link and SRT Red Lines

United States Austin - CapMetro Redline (Stadler GTW) Baltimore - Baltimore Light RailLink (New light rail vehicles) Buffalo - Buffalo Metro Rail California - Caltrans Division of Rail (Stadler FLIRT H2 State Owned Fleet) Denver - RTD Bus & Rail (New light rail vehicles) Dallas - DART Silverline (Stadler FLIRT DMU) Denton County - DCTA A-Train (Stadler GTW DMU) Fort Worth - Trinity Metro TEXRail (Stadler FLIRT DMU) Minneapolis - METRO (Light rail vehicles) New Jersey - New Jersey Transit (New light rail vehicles & Stadler GTW DMU) Norfolk, Virginia - HRT (Light rail vehicles) Northeast Corridor - Amtrak (Avelia Liberty) Portland, Oregon - Trimet (Light rail vehicles) San Bernardino - Metrolink Arrow Service (Stadler FLIRT DMU & FLIRT H2) San Francisco Bay Area - BART (New Type D and E vehicles and Stadler FLIRT GTW) San Francisco Bay Area - Muni Metro (New Type 4 vehicles) San Francisco Bay Area - Caltrain (Stadler KISS) San Diego County, California (NCTD Sprinter hybrid rail) Seattle - Sound Transit Link (Light Rail Vehicles)

Types

… excerpt ends here. Continue reading the full article.

Illustrations

Scharfenberg coupler on a DUEWAG GT6-70D/N low floor tram. Note the partially worn off Schaku logo on the right.

Worked examples

Example 1 — a first encounter with Scharfenberg coupler

Start with the simplest possible case. Write down what Scharfenberg coupler claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Scharfenberg coupler 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 Scharfenberg coupler 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 Scharfenberg coupler

In research: Scharfenberg coupler appears in science 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 Scharfenberg coupler 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: Scharfenberg coupler is common in secondary-school and first-year university syllabi. It links to neighbouring topics Couplers, so understanding it makes those chapters shorter.
In everyday life: Look for Scharfenberg coupler 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 Scharfenberg coupler in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Scharfenberg coupler 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 Scharfenberg coupler out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Scharfenberg coupler in simple terms?

Why does Scharfenberg coupler matter?

Because it connects several science 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 Scharfenberg coupler?

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 Scharfenberg coupler.