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47-474: The space measures just under 18 by 80 feet (5.5 by 24 m). It allows access to the elevator vestibule , Entrance Hall , East Room , Blue Room , Green Room , Red Room , and State Dining Room . The Grand Staircase is visible from an opening directly across from the Green Room. The current architectural appearance dates to the 1952 Truman reconstruction, which recreated much of the 1902 renovation by

94-506: A hoist , although some pump hydraulic fluid to raise a cylindrical piston like a jack . Elevators are used in agriculture and manufacturing to lift materials. There are various types, like chain and bucket elevators , grain augers , and hay elevators . Modern buildings often have elevators to ensure accessibility, especially where ramps aren't feasible. High-speed elevators are common in skyscrapers . Some elevators can even move horizontally. The earliest known reference to an elevator

141-587: A "Chart for determining the number and size of elevators required for office buildings of a given total occupied floor area". In 1920, Howard B. Cook presented a paper titled "Passenger Elevator Service". This paper marked the first time a member of the elevator industry offered a mathematical means of determining elevator service. His formula determined the round trip time (RTT) by finding the single trip time, doubling it, and adding 10 seconds. In 1923, Bassett Jones published an article titled "The Probable Number of Stops Made by an Elevator". He based his equations on

188-541: A building is at its most busy first thing in the morning; however, in more complicated elevator systems, this model does not work. In 1990, Peters published a paper titled "Lift Traffic Analysis: Formulae for the General Case" in which he developed a new formula which would account for mixed traffic patterns as well as accounting for passenger bunching using Poisson approximation. This new General Analysis equation enabled much more complex systems to be analyzed however

235-426: A deeply grooved pulley , commonly called a sheave in the industry. The weight of the car is balanced by a counterweight . Oftentimes two elevators (or sometimes three) are built so that their cars always move synchronously in opposite directions, and are each other's counterweight. The friction between the ropes and the pulley furnishes the traction which gives this type of elevator its name. Hydraulic elevators use

282-461: A floor at the same time, are usually driven by the same motor. The system increases efficiency in high-rise buildings, and saves space so additional shafts and cars are not required. In 2003, TK Elevator invented a system called TWIN, with two elevator cars independently running in one shaft. In 1901, consulting engineer Charles G. Darrach (1846–1927) proposed the first formula to determine elevator service. In 1908, Reginald P. Bolton published

329-1053: A gold border of laurel leaves, medallions, and five-pointed stars, based directly on the carved stone border in the Grand Stairway, was woven into the carpet's border. The current appearance of the Cross Hall is the result of a renovation and refurbishing completed in 1997 by the Committee for the Preservation of the White House , the White House Office of the Curator , and funded by the White House Endowment Trust . A suite of upholstered gilded beech chairs and settées thought to have once belonged to James Monroe are arranged against

376-539: A more compact system. The IGBT also allowed the development of a small, highly integrated, highly sophisticated all-digital control device, consisting of a high-speed processor, specially customized gate arrays, and a circuit capable of controlling large currents of several kHz. In 2000, the first vacuum elevator was offered commercially in Argentina. Some people argue that elevators began as simple rope or chain hoists (see Traction elevators below). An elevator

423-580: A novel tourist attraction which they called the "ascending room", which elevated customers to a considerable height in the center of London, providing a panoramic view. Early, crude steam-driven elevators were refined in the ensuing decade. In 1835, an innovative elevator, the Teagle, was developed by the company Frost and Stutt in England . It was belt-driven and used a counterweight for extra power. In 1845, Neapolitan architect Gaetano Genovese installed

470-577: A small cabinet houses the controller. The equipment is otherwise similar to that of a normal traction or hole-less hydraulic elevator. The world's first machine-room-less elevator, the Kone MonoSpace, was introduced in the year 1996, by Kone . Compared to traditional elevators, it: Its disadvantage was that it could be harder, and significantly more dangerous, to service and maintain. Double-decker elevators are traction elevators with cars that have an upper and lower deck. Both decks, which can serve

517-460: A so-called 'flying chair' built for one of his mistresses at the Château de Versailles in 1743. Ancient and medieval elevators used drive systems based on hoists and windlasses . The invention of a system based on the screw drive was perhaps the most important step in elevator technology since ancient times, leading to the creation of modern passenger elevators. The first screw-drive elevator

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564-588: A successful elevator enterprise in Austria-Hungary. The safety and speed of electric elevators were significantly enhanced by Frank Sprague , who added floor control, automatic operation, acceleration control, and further safety devices. His elevator ran faster and with larger loads than hydraulic or steam elevators. 584 of Sprague's elevators were installed before he sold his company to the Otis Elevator Company in 1895. Sprague also developed

611-420: A variety of factors. Hydraulic elevators are cheaper, but installing cylinders greater than a certain length becomes impractical for very-high lift hoistways. For buildings of much over seven floors, traction elevators must be employed instead. Hydraulic elevators are usually slower than traction elevators. Elevators are a candidate for mass customization . There are economies to be made from mass production of

658-409: A vertical cylinder, allowing the platform, carrying a heavy load, to be raised and lowered. Counterweights and balances were also used to increase lifting power. Henry Waterman of New York is credited with inventing the "standing rope control" for an elevator in 1850. In 1852, Elisha Otis introduced the safety elevator, which prevented the fall of the cab if the cable broke. He demonstrated it at

705-424: Is a weight that, by applying an opposite force, provides balance and stability of a mechanical system . The purpose of a counterweight is to make lifting the load faster and more efficient, which saves energy and causes less wear and tear on the lifting machine. Counterweights are often used in traction lifts (elevators), cranes and funfair rides. In these applications, the expected load multiplied by

752-426: Is applied in high-speed elevators worldwide. The Toshiba company continued research on thyristors for use in inverter control and dramatically enhanced their switching capacity, resulting in the development of insulated gate bipolar transistors (IGBTs) at the end of the 1980s. The IGBT realized increased switching frequency and reduced magnetic noise in the motor, eliminating the need for a filter circuit and allowing

799-446: Is essentially a platform that is either pulled or pushed up by mechanical means. A modern-day elevator consists of a cab (also called a "cabin", "cage", "carriage" or "car") mounted on a platform within an enclosed space called a shaft or sometimes a "hoistway". In the past, elevator drive mechanisms were powered by steam and water hydraulic pistons or by hand. In a "traction" elevator, cars are pulled up by means of rolling steel ropes over

846-518: Is in the works of the Roman architect Vitruvius , who reported that Archimedes ( c.  287 BC – c.  212 BC ) built his first elevator probably in 236 BC. Sources from later periods mention elevators as cabs on a hemp rope, powered by people or animals. The Roman Colosseum , completed in 80 AD, had roughly 25 elevators that were used for raising animals up to the floor. Each elevator could carry about 600 pounds (270 kg) (roughly

893-576: Is thought to be the first office building with passenger elevators. In 1872, American inventor James Wayland patented a novel method of securing elevator shafts with doors that are automatically opened and closed as the elevator car approaches and leaves them. In 1874, J. W. Meaker patented a method permitting elevator doors to open and close safely. The first electric elevator was built by Werner von Siemens in 1880 in Germany. Inventor Anton Freissler further developed von Siemens' ideas and created

940-519: The Red Room , where they could see the large Grant family portrait. 38°53′51″N 77°02′11″W  /  38.897592°N 77.036433°W  / 38.897592; -77.036433 Elevator An elevator ( American English ) or lift ( Commonwealth English ) is a machine that vertically transports people or freight between levels. They are typically powered by electric motors that drive traction cables and counterweight systems such as

987-482: The "Flying chair", an elevator ahead of its time in the Royal Palace of Caserta . It was covered with chestnut wood outside and with maple wood inside. It included a light, two benches, and a hand-operated signal, and could be activated from the outside, without any effort by the occupants. Traction was controlled by a motor mechanic utilizing a system of toothed wheels. A safety system was designed to take effect if

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1034-588: The New York exposition in the Crystal Palace in a dramatic, death-defying presentation in 1854, and the first such passenger elevator was installed at 488 Broadway in New York City on 23 March 1857. The first elevator shaft preceded the first elevator by four years. Construction for Peter Cooper 's Cooper Union Foundation building in New York began in 1853. An elevator shaft was included in

1081-485: The White House collection. The Grants added to this collection, and hung portraits of presidents from Washington to Lincoln in the Cross Hall behind a glass screen. At that time, visitors could come to the White House on weekdays, enter through the north doors, and walk down the Cross Hall past the paintings to the East Room . With a note from a congressman , visitors could view the other "State Floor" rooms, such as

1128-416: The calculations are harder to develop and implement. For very complex systems, the solution is to simulate the building. In this method, a virtual version of a building is created on a computer, modeling passengers and elevators as realistically as possible, and random numbers are used to model probability rather than mathematical equations and percentage probability. Counterweight A counterweight

1175-500: The car does not reach maximum rated speed or acceleration, and added the functionality of express zones. This equation is now referred to as the 'Up peak Calculation' as it uses the assumption that all the passengers are coming into the building from the ground floor (incoming traffic) and that there are no passengers traveling from a higher floor to the ground floor (outgoing traffic) and no passengers traveling from one internal floor to another (interfloor traffic). This model works well if

1222-688: The car passed through them. The first elevator in India was installed at the Raj Bhavan in Kolkata by Otis in 1892. By 1900, completely automated elevators were available, but passengers were reluctant to use them. Their adoption was aided by a 1945 elevator operator strike in New York City, and the addition of an emergency stop button, emergency telephone, and a soothing explanatory automated voice. An inverter-controlled gearless drive system

1269-485: The components, but each building comes with its own requirements like different number of floors, dimensions of the well and usage patterns. Elevator doors prevent riders from falling into, entering, or tampering with anything in the shaft. The most common configuration is to have two panels that meet in the middle and slide open laterally. These are known as "center-opening". In a cascading telescopic configuration (potentially allowing wider entryways within limited space),

1316-463: The cords broke, consisting of a beam pushed outwards by a steel spring. The hydraulic crane was invented by Sir William Armstrong in 1846, primarily for use at the Tyneside docks for loading cargo. They quickly supplanted the earlier steam-driven elevators, exploiting Pascal's law to provide much greater force. A water pump supplied a variable level of water pressure to a plunger encased inside

1363-500: The cross hall and entrance hall. James Hoban's niches in the south wall were retained although their exterior trim was made less overt. Although Hoban had urn-shaped cast-iron stoves placed in them, the current niches contain busts of Presidents George Washington and Abraham Lincoln . During the Kennedy Administration restoration, interior decorator Stéphane Boudin arranged the furnishings to more closely resemble

1410-482: The cross hall at Malmaison . While a red carpet has traditionally been in the Cross Hall since the early 1960s, the carpet has, over time, become more detailed and the color has evolved. The current carpet, manufactured during the Clinton Administration, was designed to be more graphic, and to appear attractively in television broadcasts. The red was made more saturated, the shade slightly warmer, and

1457-590: The design because Cooper was confident that a safe passenger elevator would soon be invented. The shaft was cylindrical because Cooper thought it was the most efficient design. Otis later designed a special elevator for the building. Peter Ellis , an English architect, installed the first elevators that could be described as paternoster elevators in Oriel Chambers in Liverpool in 1868. The Equitable Life Building , completed in 1870 in New York City,

Cross Hall - Misplaced Pages Continue

1504-555: The distance that load will be spaced from the central support (called the "tipping point") must be equal to the counterweight's mass times its distance from the tipping point in order to prevent over-balancing either side. This distance times mass is called the load moment . By extension, a counterbalance force balances or offsets another force, as when two objects of equal weight, power, or influence are acting in opposition to each other. Metronome : A wind-up mechanical metronome has an adjustable weight and spring mechanism that allows

1551-409: The doors roll on independent tracks so that while open, they are tucked behind one another, and while closed, they form cascading layers on one side. This can be configured so that two sets of such cascading doors operate like the center opening doors described above, allowing for a very wide elevator cab. In less expensive installations the elevator can also use one large "slab" door: a single panel door

1598-452: The elevator shaft when the car was not being entered or exited. In 1887, American inventor Alexander Miles of Duluth, Minnesota , patented an elevator with automatic doors that closed off the elevator shaft when the car was not being entered or exited. In 1891, American inventors Joseph Kelly and William L. Woods co-patented a novel way to guard elevator shafts against accident, by way of hatches that would automatically open and close as

1645-482: The equations had now become so complex that it was almost impossible to do manually and it became necessary to use software to run the calculations. The GA formula was extended even further in 1996 to account for double deck elevators. RTT calculations establish an elevator system's handling capacity by using a set of repeatable calculations which, for a given set of inputs, always produce the same answer. It works well for simple systems; but as systems get more complex,

1692-408: The firm of McKim, Mead and White . The Truman reconstruction replaced the golden-hued Joliet stone floors, columns and pilasters with a cool gray marble. Plaster walls divided by a dado and painted cream and gold were also replaced with marble. McKim employed Roman doric columns based directly on the work of the sixteenth-century Italian architect Giacomo Barozzi da Vignola for the screen separating

1739-491: The first book devoted to this subject, Elevator Service . The summation of his work was a massive fold-out chart (placed at the back of his book) that allowed users to determine the number of express and local elevators needed for a given building to meet a desired interval of service. In 1912, commercial engineer Edmund F. Tweedy and electrical engineer Arthur Williams co-authored a book titled Commercial Engineering for Central Stations . He followed Bolton's lead and developed

1786-818: The idea and technology for multiple elevators in a single shaft. In 1871, when hydraulic power was a well established technology, Edward B. Ellington founded Wharves and Warehouses Steam Power and Hydraulic Pressure Company, which became the London Hydraulic Power Company in 1883. It constructed a network of high-pressure mains on both sides of the Thames which ultimately extended 184 miles (296 km) and powered some 8,000 machines, predominantly elevators and cranes. Schuyler Wheeler patented his electric elevator design in 1883. In 1884, American inventor D. Humphreys of Norfolk, Virginia , patented an elevator with automatic doors that closed off

1833-461: The introduction of steel beam construction, worked together to provide the passenger and freight elevators in use today. Starting in coal mines, elevators in the mid-19th century operated with steam power , and were used for moving goods in bulk in mines and factories. These devices were soon applied to a diverse set of purposes. In 1823, Burton and Homer, two architects in London , built and operated

1880-457: The principles of hydraulics (in the sense of hydraulic power ) to pressurize an above-ground or in-ground piston to raise and lower the car (see Hydraulic elevators below). Roped hydraulics use a combination of both ropes and hydraulic power to raise and lower cars. Recent innovations include permanent magnet motors, machine room-less rail mounted gearless machines, and microprocessor controls. The technology used in new installations depends on

1927-412: The theory of probabilities and found a reasonably accurate method of calculating the average stop count. The equation in this article assumed a consistent population on every floor. He went on to write an updated version of his equations in 1926 which accounted for variable population on each floor. Jones credited David Lindquist for the development of the equation but provides no indication as to when it

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1974-538: The walls; two Empire pier tables are placed opposite the Madison suite of furniture and the gilded pier table from Monroe's original purchase for the Blue Room and restored by Jacqueline Kennedy is in the adjacent Entrance Hall. The tradition of hanging presidential portraits in this hall dates to President Ulysses S. Grant . The Buchanan administration first began the tradition of keeping paintings of presidents for

2021-512: The weight of two lions) 23 feet (7.0 m) up when powered by up to eight men. In 1000, the Book of Secrets by Ibn Khalaf al-Muradi in Islamic Spain described the use of an elevator-like lifting device to raise a large battering ram to destroy a fortress. In the 17th century, prototypes of elevators were installed in the palace buildings of England and France. Louis XV of France had

2068-403: The width of the doorway that opens to the left or right laterally. These are known as "single slide" doors. Some buildings have elevators with the single door on the shaftway, and double cascading doors on the cab. Elevators that do not require separate machine rooms are designed so that most of their power and control components fit within the hoistway (the shaft containing the elevator car), and

2115-554: Was built by Ivan Kulibin and installed in the Winter Palace in 1793, although there may have been an earlier design by Leonardo da Vinci . Several years later, another of Kulibin's elevators was installed in the Arkhangelskoye near Moscow . The development of elevators was led by the need for movement of raw materials, including coal and lumber , from hillsides. The technology developed by these industries, and

2162-448: Was first proposed. Although the equations were there, elevator traffic analysis was still a very specialist task that could only be done by world experts. That was until 1967 when Strakosch wrote an eight step method for finding the efficiency of a system in "Vertical transportation: Elevators and Escalators". In 1975, Barney and Dos Santos developed and published the "Round Trip Time (RTT) formula", which followed Strakosch's work. This

2209-506: Was the first formulized mathematical model and is the simplest form that is still used by traffic analyzers today. Modification and improvements have been made to this equation over the years, most significantly in 2000 when Peters published "Improvements to the Up Peak Round Trip Time Calculation" which improved the accuracy of the flight time calculation, making allowances for short elevator journeys when

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