Hyperloop
Hyperloop is a proposed high-speed transportation system for both passengers and freight. In 2013, the concept was published by entrepreneur Elon Musk in a white paper, where the hyperloop was described as a transportation system using capsules supported by an air-bearing surface within a low-pressure tube. Hyperloop systems have three essential elements: tubes, pods, and terminals. The tube is a large, sealed, low-pressure system. The pod is a coach at atmospheric pressure that experiences low air resistance or friction inside the tube using magnetic propulsion. The terminal handles pod arrivals and departures. The hyperloop, in the form proposed by Musk, differs from other vactrains by relying on residual air pressure inside the tube to provide lift from aerofoils and propulsion by fans; however, many subsequent variants using the name "hyperloop" have remained relatively close to the core principles of vactrains.
Hyperloop was teased by Elon Musk at a 2012 speaking event, and described as a "fifth mode of transport". Musk released details of an alpha version in a white paper on 22 August 2013, in which the hyperloop design incorporated reduced-pressure tubes with pressurized capsules riding on air bearings driven by linear induction motors and axial compressors. The white paper showed an example hyperloop route running from the Los Angeles region to the San Francisco Bay Area, roughly following the Interstate 5 corridor. Some transportation analysts challenged the cost estimates in the white paper, with some predicting that a hyperloop would run several billion dollars higher.
The hyperloop concept has been promoted by Musk and SpaceX, and other companies or organizations were encouraged to collaborate in developing the technology.
A Technical University of Munich hyperloop set a speed record of in July 2019 at the pod design competition hosted by SpaceX in Hawthorne, California. Virgin Hyperloop conducted the first human trial in November 2020 at its test site in Las Vegas, reaching a top speed of.
In 2023, a new European effort to standardize "hyperloop systems" released a draft standard.
Hyperloop One, one of the best known and funded players in the hyperloop space, declared bankruptcy and ceased operations on 31 December 2023. Other companies continue to pursue hyperloop technology development.
History
Musk first mentioned that he was thinking about a concept for a "fifth mode of transport", calling it the Hyperloop, in July 2012 at a Pando Daily event in Santa Monica, California. This hypothetical high-speed mode of transportation would have the following characteristics: immunity to weather, collision free, twice the speed of a plane, low power consumption, and energy storage for 24-hour operations. The name Hyperloop was chosen because it would go in a loop. In May 2013, Musk likened Hyperloop to a "cross between a Concorde and a railgun and an air hockey table". By 2016, Musk envisioned that more advanced versions could potentially be able to go at hypersonic speed.From late 2012 until August 2013, a group of engineers from both Tesla and SpaceX worked on the modeling of Musk's Hyperloop concept. An early system conceptual model was published on both the Tesla and SpaceX websites which describes one potential design, function, pathway, and cost of a hyperloop system. In the alpha design, pods were envisioned to accelerate to cruising speeds gradually using linear electric motors and glide above their track on air bearings through tubes above ground on columns or below ground in tunnels to avoid the challenges of grade crossings. An ideal hyperloop system was estimated to be more energy-efficient, quiet, and autonomous than existing modes of mass transit in the 2010s. The Hyperloop Alpha was released as an open source design. Musk invited feedback to "see if the people can find ways to improve it". The trademark "HYPERLOOP", applicable to "high-speed transportation of goods in tubes" was issued to SpaceX on 4 April 2017.
On 15 June 2015, SpaceX announced that it would build a Hyperloop test track located next to SpaceX's Hawthorne facility. The track was completed and used to test pod designs supplied by third parties in the competition.
By 30 November 2015, with several commercial companies and dozens of student teams pursuing the development of Hyperloop technologies, the Wall Street Journal asserted that "'The Hyperloop Movement', as some of its unaffiliated members refer to themselves, is officially bigger than the man who started it."
The Massachusetts Institute of Technology hyperloop team developed an early hyperloop pod prototype, which they unveiled at the MIT Museum on 13 May 2016. Their design used electrodynamic suspension for levitating and eddy current braking.
An early passenger test of low-speed hyperloop technology was conducted by Virgin Hyperloop by two employees of the company in November 2020, where the unit reached a maximum speed of.
In January 2023, the European Committee for Electrotechnical Standardization released the first technical standard for hyperloop systems. Hardt Hyperloop demonstrated a Hyperloop lane switch without moving components in the infrastructure in June 2019 at its test site in Delft, The Netherlands.
As of 21 December 2023, Hyperloop One, the former, rebranded Virgin Hyperloop, has terminated operations.
Theory and operation
The much-older vactrain concept resembles a high-speed rail system without substantial air resistance by employing magnetically levitating trains in evacuated or partly evacuated tubes. However, the difficulty of maintaining a vacuum over large distances has prevented this type of system from ever being built. By contrast, the Hyperloop alpha concept was to operate at approximately of pressure and requires the air for levitation.Initial design concept
The hyperloop alpha concept envisioned operation by sending specially designed "capsules" or "pods" through a steel tube maintained at a partial vacuum. In Musk's original concept, each capsule would float on a layer of air provided under pressure to air-caster "skis", similar to how pucks are levitated above an air hockey table, while still allowing higher speeds than wheels can sustain. With rolling resistance eliminated and air resistance greatly reduced, the capsules can glide for the bulk of the journey. In the alpha design concept, an electrically driven inlet fan and axial compressor would be placed at the nose of the capsule to "actively transfer high-pressure air from the front to the rear of the vessel", resolving the problem of air pressure building in front of the vehicle, slowing it down. A fraction of the air was to be shunted to the skis for additional pressure, augmenting that gain passively from lift due to their shape.In the alpha-level concept, passenger-only pods were to be in diameter and were projected to reach a top speed of to maintain aerodynamic efficiency. The design proposed passengers experience a maximum inertial acceleration of 0.5 g, approximately 2 or 3 times that of a commercial airliner on takeoff and landing.
Proposed routes
Several routes have been proposed that meet the distance conditions for which a hyperloop is hypothesized to provide improved transport times: under approximately. Route proposals range from speculation described in company releases, to business cases, to signed agreements.South Korea
An agreement was signed in June 2017 to co-develop a hyperloop line between Seoul and Busan, South Korea. The project was shelved in early 2024 after the Korean government withdrew public funding due to questions over the venture's economic viability.In April 2025, the government launched a research project to develop maglev propulsion technology for the Hypertube, a proposed next-generation high-speed train system, between Seoul and Busan.
United States
The route suggested in the 2013 alpha-level design document was from the Greater Los Angeles Area to the San Francisco Bay Area. That conceptual system would begin around Sylmar, just south of the Tejon Pass, follow Interstate 5 to the north, and arrive near Hayward on the east side of San Francisco Bay. Proposed branches were shown in the design document, including Sacramento, Anaheim, San Diego, and Las Vegas.No work has been done on the route proposed in Musk's design; one cited reason is that it would terminate on the fringes of two major metropolitan areas, Los Angeles and San Francisco. This would result in significant cost savings in construction, but require passengers traveling to and from Downtown Los Angeles and San Francisco, and any other community beyond Sylmar and Hayward, to transfer to another transportation mode to reach their destination. This would significantly lengthen the total travel time to those destinations.
A similar problem already affects present-day air travel, where on short routes the flight time is only a rather small part of door-to-door travel time. Critics have argued that this would significantly reduce the proposed cost and/or time savings of hyperloop as compared to the proposed California High-Speed Rail project that will serve downtown stations in both San Francisco and Los Angeles. Passengers traveling from financial center to financial center are estimated to save about two hours by taking the Hyperloop instead of driving the whole distance.
Others questioned the cost projections for the suggested California route. Some transportation engineers argued in 2013 that they found the alpha-level design cost estimates unrealistically low given the scale of construction and reliance on unproven technology. The technological and economic feasibility of the idea is unproven and a subject of significant debate.
In November 2017, Arrivo announced a concept for a maglev automobile transport system from Aurora, Colorado to Denver International Airport, the first leg of a system from downtown Denver. Its contract described potential completion of a first leg in 2021. In February 2018, Hyperloop Transportation Technologies announced a similar plan for a loop connecting Chicago and Cleveland and a loop connecting Washington and New York City.
In 2018, the Missouri Hyperloop Coalition was formed between Virgin Hyperloop One, the University of Missouri, and engineering firm Black & Veatch to study a proposed route connecting St. Louis, Columbia, and Kansas City.
On 19 December 2018, Elon Musk unveiled a tunnel below Los Angeles. In the presentation, a Tesla Model X drove in a tunnel on the predefined track. According to Musk, the costs for the system are. Musk said: "The Loop is a stepping stone toward hyperloop. The Loop is for transport within a city. Hyperloop is for transport between cities, and that would go much faster than 150 mph."
The Northeast Ohio Areawide Coordinating Agency, or NOACA, partnered with Hyperloop Transportation Technologies to conduct a $1.3 million feasibility study for developing a hyperloop corridor route from Chicago to Cleveland and Pittsburgh for America's first multistate hyperloop system in the Great Lakes Megaregion. Hundreds of thousands of dollars have already been committed to the project. NOACA's Board of Directors has awarded a $550,029 contract to Transportation Economics & Management Systems, Inc. for the Great Lakes Hyperloop Feasibility Study to evaluate the feasibility of an ultra-high speed hyperloop passenger and freight transport system initially linking Cleveland and Chicago.