sentence-transformers/squad huggingface dataset:
Passage: When power is lost in a traction elevator system, all elevators will initially come to a halt. One by one, each car in the group will return to the lobby floor, open its doors and shut down. People in the remaining elevators may see an indicator light or hear a voice announcement informing them that the elevator will return to the lobby shortly. Once all cars have successfully returned, the system will then automatically select one or more cars to be used for normal operations and these cars will return to service. The car(s) selected to run under emergency power can be manually overridden by a key or strip switch in the lobby. In order to help prevent entrapment, when the system detects that it is running low on power, it will bring the running cars to the lobby or nearest floor, open the doors and shut down.

Question: What sequence of events happens when the power shuts off in a traction elevator and the elevators all stop?

Question: What do any passengers experience at this point?

Question: After all cars go to the lobby, what is the next step?

Question: How are the selected cars then readied for passengers?

Question: What is a safety feature to prevent entrapment?
Passage: In hydraulic elevator systems, emergency power will lower the elevators to the lowest landing and open the doors to allow passengers to exit. The doors then close after an adjustable time period and the car remains unusable until reset, usually by cycling the elevator main power switch. Typically, due to the high current draw when starting the pump motor, hydraulic elevators are not run using standard emergency power systems. Buildings like hospitals and nursing homes usually size their emergency generators to accommodate this draw. However, the increasing use of current-limiting motor starters, commonly known as "soft-start" contactors, avoid much of this problem, and the current draw of the pump motor is less of a limiting concern.

Question: How do hydraulic elevators work in emergencies?

Question: Once the passengers have exited, what happens?

Question: For what reason are hydraulic elevators not powered by the standard emergency system?

Question: What are current-limiting motor starters referred to as?
Passage: Past problems with hydraulic elevators include underground electrolytic destruction of the cylinder and bulkhead, pipe failures, and control failures. Single bulkhead cylinders, typically built prior to a 1972 ASME A17.1 Elevator Safety Code change requiring a second dished bulkhead, were subject to possible catastrophic failure. The code previously permitted only single-bottom hydraulic cylinders. In the event of a cylinder breach, the fluid loss results in uncontrolled down movement of the elevator. This creates two significant hazards: being subject to an impact at the bottom when the elevator stops suddenly and being in the entrance for a potential shear if the rider is partly in the elevator. Because it is impossible to verify the system at all times, the code requires periodic testing of the pressure capability. Another solution to protect against a cylinder blowout is to install a plunger gripping device. One commercially available is known by the marketing name "LifeJacket". This is a device which, in the event of an uncontrolled downward acceleration, nondestructively grips the plunger and stops the car. A device known as an overspeed or rupture valve is attached to the hydraulic inlet/outlet of the cylinder and is adjusted for a maximum flow rate. If a pipe or hose were to break (rupture), the flow rate of the rupture valve will surpass a set limit and mechanically stop the outlet flow of hydraulic fluid, thus stopping the plunger and the car in the down direction.

Question: Underground electrolytic malfunctions in hydraulic elevators can result in the destruction of what?

Question: What Elevator Safety Code change required a second dished bulkhead?

Question: Before the code change was enacted what was the only permitted hydraulic cylinder type?

Question: Once the cylinder is breached, what calamity does the loss of fluid cause?

Question: What testing does the code require?
Passage: Safety testing of mine shaft elevator rails is routinely undertaken. The method involves destructive testing of a segment of the cable. The ends of the segment are frayed, then set in conical zinc molds. Each end of the segment is then secured in a large, hydraulic stretching machine. The segment is then placed under increasing load to the point of failure. Data about elasticity, load, and other factors is compiled and a report is produced. The report is then analyzed to determine whether or not the entire rail is safe to use.

Question: What part of the mine shaft requires routine testing?

Question: What is the first step in destructive testing?

Question: Afterwards, what type of machine is the segment secured in?

Question: What type of testing is done to the an area of the cable?

Question: What types of information are collected in the process?
Passage: Passenger elevators capacity is related to the available floor space. Generally passenger elevators are available in capacities from 500 to 2,700 kg (1,000–6,000 lb) in 230 kg (500 lb) increments.[citation needed] Generally passenger elevators in buildings of eight floors or fewer are hydraulic or electric, which can reach speeds up to 1 m/s (200 ft/min) hydraulic and up to 152 m/min (500 ft/min) electric. In buildings up to ten floors, electric and gearless elevators are likely to have speeds up to 3 m/s (500 ft/min), and above ten floors speeds range 3 to 10 m/s (500–2,000 ft/min).[citation needed]

Question: What dictates passenger elevator capacities?

Question: What capacities are passenger elevators availablee in?

Question: What types of passenger elevators are installed in structures of up to eight floors?

Question: Hydraulic elevators can reach speeds up to 1m/s or how many feet per minute?

Question: Electric elevators can reach speeds up to 3 m/s or how many feet per minute?
Passage: Sometimes passenger elevators are used as a city transport along with funiculars. For example, there is a 3-station underground public elevator in Yalta, Ukraine, which takes passengers from the top of a hill above the Black Sea on which hotels are perched, to a tunnel located on the beach below. At Casco Viejo station in the Bilbao Metro, the elevator that provides access to the station from a hilltop neighborhood doubles as city transportation: the station's ticket barriers are set up in such a way that passengers can pay to reach the elevator from the entrance in the lower city, or vice versa. See also the Elevators for urban transport section.

Question: Passenger elevators, used in city transport share similarities to what other ascending and descending vehicles counterbalancing each other?

Question: What type of public elevator in Yalta, Ukraine, transport passengers from a hill above the Black Sea to a tunnel down on the beach?

Question: The elevator located at the Casco Viejo station in the Bilbao Metro is also used for what?

Question: How is that set up?
Passage: A freight elevator, or goods lift, is an elevator designed to carry goods, rather than passengers. Freight elevators are generally required to display a written notice in the car that the use by passengers is prohibited (though not necessarily illegal), though certain freight elevators allow dual use through the use of an inconspicuous riser. In order for an elevator to be legal to carry passengers in some jurisdictions it must have a solid inner door. Freight elevators are typically larger and capable of carrying heavier loads than a passenger elevator, generally from 2,300 to 4,500 kg. Freight elevators may have manually operated doors, and often have rugged interior finishes to prevent damage while loading and unloading. Although hydraulic freight elevators exist, electric elevators are more energy efficient for the work of freight lifting.[citation needed]

Question: What is another name for a freight elevator?

Question: What type of notice is required to be visible in most freight elevators?

Question: Some freight elevators allow transport of both freight and passengers by using what?

Question: How do freight elevators differ from passenger elevators?

Question: What type of elevator is better suited for carrying freight?
Passage: Stage lifts and orchestra lifts are specialized elevators, typically powered by hydraulics, that are used to raise and lower entire sections of a theater stage. For example, Radio City Music Hall has four such elevators: an orchestra lift that covers a large area of the stage, and three smaller lifts near the rear of the stage. In this case, the orchestra lift is powerful enough to raise an entire orchestra, or an entire cast of performers (including live elephants) up to stage level from below. There's a barrel on the background of the image of the left which can be used as a scale to represent the size of the mechanism

Question: How are stage lifts powered?

Question: How many hydraulic elevators are there at Radio City Music Hall?

Question: What is an orchestra lift used for?

Question: What is on the background of the image which can be used as a scale to represent the size of the mechanism?
Passage: A residential elevator is often permitted to be of lower cost and complexity than full commercial elevators. They may have unique design characteristics suited for home furnishings, such as hinged wooden shaft-access doors rather than the typical metal sliding doors of commercial elevators. Construction may be less robust than in commercial designs with shorter maintenance periods, but safety systems such as locks on shaft access doors, fall arrestors, and emergency phones must still be present in the event of malfunction.

Question: What type of elevators are generally less costly than full commercial elevators?

Question: What type of doors do commercial elevators use?

Question: What safety mechanisms are still required, despite lower design costs?

Question: What type of elevator has a hinged wooden shaft-access door?
Passage: Some types of residential elevators do not use a traditional elevator shaft, machine room, and elevator hoistway. This allows an elevator to be installed where a traditional elevator may not fit, and simplifies installation. The ASME board first approved machine-room-less systems in a revision of the ASME A17.1 in 2007. Machine-room-less elevators have been available commercially since the mid 1990s, however cost and overall size prevented their adoption to the residential elevator market until around 2010.

Question: What types of elevators occassionaly do not use a traditional elevator shaft, machine room or hoistway?

Question: In what year were Machine-room-less elevators first allowed?

Question: This decision reflected a revision of what?

Question: What benefits does this serve?
Passage: Dumbwaiters are small freight elevators that are intended to carry food, books or other small freight loads rather than passengers. They often connect kitchens to rooms on other floors. they usually do not have the same safety features found in passenger elevators, like various ropes for redundancy. they have a lower capacity, and they can be up to 1 meter (3 ft.) tall. there's a control panel at every stop, that mimics the ones found in passenger elevators, like calling, door control, floor selection.

Question: What are small freight elevators used for things such as food, called?

Question: What rooms are dumbwaiters frequently used in?

Question: What is a safety feature found in passenger elevators they generally do not have?

Question: What is the height restriction on dumbwaiters?

Question: What features do they have that mimic passenger elevators?
Passage: Material transport elevators generally consist of an inclined plane on which a conveyor belt runs. The conveyor often includes partitions to ensure that the material moves forward. These elevators are often used in industrial and agricultural applications. When such mechanisms (or spiral screws or pneumatic transport) are used to elevate grain for storage in large vertical silos, the entire structure is called a grain elevator. Belt elevators are often used in docks for loading loose materials such as coal, iron ore and grain into the holds of bulk carriers

Question: What do the partians do on the conveyor?

Question: An inclined plane with a conveyor belt describes what type of elevator?

Question: What industries are these types of elevators generally used in?

Question: What are spiral screws used for?

Question: What type of elevators are used for loading loose materials into bulk carriers?
Passage: Elevators necessitated new social protocols. When Nicholas II of Russia visited the Hotel Adlon in Berlin, his courtiers panicked about who would enter the elevator first, and who would press the buttons. In Lifted: A Cultural History of the Elevator, author Andreas Bernard documents other social impacts caused by the modern elevator, including thriller movies about stuck elevators, casual encounters and sexual tension on elevators, the reduction of personal space, and concerns about personal hygiene.

Question: The invention of elevators brought with it questions of social etiquette and formalities, generally referred to as what?

Question: The last tsar of Russia, Nicholas ll encountered his first elevator at the Hotel Adloin in what city?

Question: This caused a stir in deciding who should enter first and who should do what?

Question: Andreas Bernard wrote about the social aspects of the new elevators in what book?
Passage: In addition to the call buttons, elevators usually have floor indicators (often illuminated by LED) and direction lanterns. The former are almost universal in cab interiors with more than two stops and may be found outside the elevators as well on one or more of the floors. Floor indicators can consist of a dial with a rotating needle, but the most common types are those with successively illuminated floor indications or LCDs. Likewise, a change of floors or an arrival at a floor is indicated by a sound, depending on the elevator.

Question: Modern elevator position or floor indicaters often use what type of bulbs?

Question: What type of lanterns are used outside elevators as well as inside most cabs?

Question: What do floor indicaters often consist of?

Question: What generally indicates the arrival of the elevator at a new floor?
Passage: Direction lanterns are also found both inside and outside elevator cars, but they should always be visible from outside because their primary purpose is to help people decide whether or not to get on the elevator. If somebody waiting for the elevator wants to go up, but a car comes first that indicates that it is going down, then the person may decide not to get on the elevator. If the person waits, then one will still stop going up. Direction indicators are sometimes etched with arrows or shaped like arrows and/or use the convention that one that lights up red means "down" and green means "up". Since the color convention is often undermined or overridden by systems that do not invoke it, it is usually used only in conjunction with other differentiating factors. An example of a place whose elevators use only the color convention to differentiate between directions is the Museum of Contemporary Art in Chicago, where a single circle can be made to light up green for "up" and red for "down". Sometimes directions must be inferred by the position of the indicators relative to one another.

Question: What is the main function of direction lanterns?

Question: What might change your mind about whether or not to enter an elevator?

Question: What type of etching might you see on a direction indicator?

Question: Some elevators may use the color convention for only what purpose?
Passage: There are several technologies aimed to provide better experience to passengers suffering from claustrophobia, anthropophobia or social anxiety. Israeli startup DigiGage uses motion sensors to scroll the pre-rendered images, building and floor-specific content on a screen embedded into the wall as the cab moves up and down. British company LiftEye provides a virtual window technology to turn common elevator into panoramic. It creates 3d video panorama using live feed from cameras placed vertically along the facade and synchronizes it with cab movement. The video is projected on a wall-sized screens making it look like the walls are made of glass.

Question: New technologies aim to provide a better elevator experience to passengers who suffer from what?

Question: What Israeli company uses motion sensors to display information on a screen embedded in the wall of the cabs?

Question: LiftEye uses virtual window technology for what?

Question: How does it produce the panoramic effects?

Question: Where is the video projected?
Passage: In most US and Canadian jurisdictions, passenger elevators are required to conform to the American Society of Mechanical Engineers' Standard A17.1, Safety Code for Elevators and Escalators. As of 2006, all states except Kansas, Mississippi, North Dakota, and South Dakota have adopted some version of ASME codes, though not necessarily the most recent. In Canada the document is the CAN/CSA B44 Safety Standard, which was harmonized with the US version in the 2000 edition.[citation needed] In addition, passenger elevators may be required to conform to the requirements of A17.3 for existing elevators where referenced by the local jurisdiction. Passenger elevators are tested using the ASME A17.2 Standard. The frequency of these tests is mandated by the local jurisdiction, which may be a town, city, state or provincial standard.

Question: In what neighboring countries are passenger elevators required to adhere to Standard A17.1?

Question: What is the equivilent to the US Standard A17.1 called in Canada?

Question: What is Standard A17.1?

Question: What are passenger elevators tested with?
Passage: Most elevators have a location in which the permit for the building owner to operate the elevator is displayed. While some jurisdictions require the permit to be displayed in the elevator cab, other jurisdictions allow for the operating permit to be kept on file elsewhere – such as the maintenance office – and to be made available for inspection on demand. In such cases instead of the permit being displayed in the elevator cab, often a notice is posted in its place informing riders of where the actual permits are kept.

Question: Whose name is on the permit required for operation of an elevator?

Question: Do all jurisdictions require the permit to be displayed in the elevator?

Question: Aside from the elevator, where else might a permit be displayed?

Question: What type of notice can be displayed in the elevator in lieu of the permit?
Passage: As of January 2008, Spain is the nation with the most elevators installed in the world, with 950,000 elevators installed that run more than one hundred million lifts every day, followed by United States with 700,000 elevators installed and China with 610,000 elevators installed since 1949. In Brazil, it is estimated that there are approximately 300,000 elevators currently in operation. The world's largest market for elevators is Italy, with more than 1,629 million euros of sales and 1,224 million euros of internal market.

Question: What country had the second most elevators installed?

Question: In 2008, what country had the largest number of elevators?

Question: How many elevators had China installed since 1949?

Question: What country boasts the worlds largest market for elevators?

Question: How many elevators are in Brazil?
Passage: Double deck elevators are used in the Taipei 101 office tower. Tenants of even-numbered floors first take an escalator (or an elevator from the parking garage) to the 2nd level, where they will enter the upper deck and arrive at their floors. The lower deck is turned off during low-volume hours, and the upper deck can act as a single-level elevator stopping at all adjacent floors. For example, the 85th floor restaurants can be accessed from the 60th floor sky-lobby. Restaurant customers must clear their reservations at the reception counter on the 2nd floor. A bank of express elevators stop only on the sky lobby levels (36 and 60, upper-deck car), where tenants can transfer to "local" elevators.

Question: What type of elevators are used in the Taipei 101 office tower?

Question: During what hours is the lower deck turned off?

Question: During the low volume hours, what can the upper deck function as?

Question: On what floor must restaurant customers clear their reservations?

Question: What levels make up the "sky lobby"?
Passage: The high-speed observation deck elevators accelerate to a world-record certified speed of 1,010 metres per minute (61 km/h) in 16 seconds, and then it slows down for arrival with subtle air pressure sensations. The door opens after 37 seconds from the 5th floor. Special features include aerodynamic car and counterweights, and cabin pressure control to help passengers adapt smoothly to pressure changes. The downwards journey is completed at a reduced speed of 600 meters per minute, with the doors opening at the 52nd second.

Question: How fast do the observation deck elevators travel?

Question: This speed holds what record?

Question: What does cabin pressure control do?

Question: How fast does the elevator drop down?

Question: At what floor do the doors open on the way down?
Passage: The Twilight Zone Tower of Terror is the common name for a series of elevator attractions at the Disney's Hollywood Studios park in Orlando, the Disney California Adventure Park park in Anaheim, the Walt Disney Studios Park in Paris and the Tokyo DisneySea park in Tokyo. The central element of this attraction is a simulated free-fall achieved through the use of a high-speed elevator system. For safety reasons, passengers are seated and secured in their seats rather than standing. Unlike most traction elevators, the elevator car and counterweight are joined using a rail system in a continuous loop running through both the top and the bottom of the drop shaft. This allows the drive motor to pull down on the elevator car from underneath, resulting in downward acceleration greater than that of normal gravity. The high-speed drive motor is used to rapidly lift the elevator as well.

Question: What is the name of the elevator attraction at the Disney World parks across the world?

Question: What is the main feature of this attraction?

Question: Do ride goers stand or sit?

Question: What unique feature does this ride provide guests?

Question: What type of motor is used?
Passage: The passenger cabs are mechanically separated from the lift mechanism, thus allowing the elevator shafts to be used continuously while passengers board and embark from the cabs, as well as move through show scenes on various floors. The passenger cabs, which are automated guided vehicles or AGVs, move into the vertical motion shaft and lock themselves in before the elevator starts moving vertically. Multiple elevator shafts are used to further improve passenger throughput. The doorways of the top few "floors" of the attraction are open to the outdoor environment, thus allowing passengers to look out from the top of the structure.

Question: How are passenger cabs separated from the lift?

Question: What type of vehicles are the passenger cabs?

Question: What action do the cabs take before the elevator begins to move?

Question: What is special about the doorways of the top floors?

Question: What does this allow riders to do at the top?