Journal paper - Council on Tall Buildings and Urban Habitat

ctbuh.org/papers

Title: Maglev Goes High Rise? The Potential of Horizontal Maglev Technology
for Vertical High-Rise Elevators
Authors:
Antony Wood, Executive Director, Council on Tall Buildings and Urban Habitat
Subject: Corey Baitz, Council on Tall Buildings and Urban Habitat
Keywords:
Vertical Transportation
Publication Date:
Original Publication: Technology
Paper Type: Vertical Transportation

2007

CTBUH Journal, Fall 2007

1. Book chapter/Part chapter
2. Journal paper
3. Conference proceeding
4. Unpublished conference paper
5. Magazine article
6. Unpublished

© Council on Tall Buildings and Urban Habitat / Antony Wood; Corey Baitz

Maglev goes high rise? The Potential of horizontal Maglev technology for
vertical high-rise elevators

Within the past ten years magnetic levitation fig 1. Magnetic Levitation forces in the metal rod repelled fig 2. Typical Maglev Train, Shanghai. Source: Transrapid
(maglev) technology has gained substantial by opposite forces below. Source: Levitating bar. [Online Shanghai maglev train. [Online Image] Available http://
interest and significant development Image] Available www.flyingmagnet.com/usindex2.html. en.wikipedia.org/wiki/Maglev_train
internationally. Most notably is the application
of maglev technology to trains. In Asia and Maglev Trains fig 3. Maglev train – detail of side contact point. Source:
Europe maglev trains ride on air and reach Throughout the world, maglev trains are being Maglev train section. [Online Image] Available http://
speeds up to 250 mph. This technology also used as an alternative to traditional www.transrapid.de/cgi-tdb/en/basics.prg?session=d82f8
has great potential in other applications, such combustion engine trains. Maglev trains use 833463f50c9&a_no=41
as elevator systems – not only for greater electromagnetic forces to suspend, propel and
energy efficiency, but also in offering the brake their cars creating a smooth, quiet, While the car is suspended off the track, it is
potential for non-vertical routing. Steps have frictionless ride. The most notable commercial propelled and braked with a linear
recently been taken to develop the first application of a high-speed maglev line is in synchronous motor.
maglev elevators. The elevator moves via the Shanghai, China (Fig. 2). The train transports
same means as maglev trains creating a passengers 18.6 miles (30 km) to and from the Linear Synchronous Motor (LSM)
smooth and quiet ride, but rather along a airport in under 8 minutes at an operating A linear synchronous motor works due to the
vertical path. This development has opened speed of 268 mph (430 km/h). Other interaction of two concentrated magnetic
up a number of opportunities with regard to applications are running in Japan and fields; one permanent and one of changing
elevator system design, elevator travel, and Germany, while systems under construction strength and direction. The permanent
ultimately, high-rise building design. and in proposal can be found throughout Asia, magnets on the train car are aligned so that
Europe, India and the United States. the resulting magnetic field is concentrated to
Principles of Magnetic Levitation one surface of the alignment while the
Magnetic forces occur due to the movement The maglev line in Shanghai was developed resulting force on the opposite surface is near
of electrically charged particles. Magnetic by Transrapid International and provides a zero. This alignment is known as an Halbach
fields are formed and exert attractive or good example of applied magnetic levitation Array.
repulsive forces on other materials. This and propulsion. Transrapid describes the Discovered by J. C. Mallinson in 1973, the
phenomenon can occur naturally in materials levitation technology (see Fig. 3): pattern of left, up, right, down can be
due to the orbital motion of their electrons, continued endlessly with a resulting ‘one-sided
forming “permanent magnets,” or it can occur Electronically controlled support magnets flux’ (Mallinson, 1973). This concentration of
as a result of inducing an electrical current, located on both sides along the entire length of magnetic field is directed away from the train
know as electromagnetism. An electrical the vehicle pull the vehicle up to the and towards the high-thrust stator located on
current occurs as electrons move from ferromagnetic stator packs mounted to the the track. The stator produces a directional
negative to positive poles and a magnetic field underside of the guideway. Guidance magnets magnetic field through the manipulation of an
forms around it. The direction of the magnetic located on both sides along the entire length of alternating electrical current. Figure 4 shows a
field is dependent on the current so that it can the vehicle keep the vehicle laterally on the portion of a high-thrust stator that would be
be inverted by inverting the direction of the track. Electronic systems guarantee that the located on the track. Electrical current is
current. Also, the strength of the magnetic clearance remains constant (nominally 10 supplied through the wrapping coil to create a
field is in direct relationship with that of the mm). To hover, the Transrapid train requires less
current; the more current, the stronger the power than its air conditioning equipment. The CTBUH Journal | Fall 2007
magnetic field and, similarly, if the electrical levitation system is supplied from on-board
current were switched off, the magnetic field batteries and thus independent of the
would reduce to zero. It is this ability to easily propulsion system. The vehicle is capable of
manipulate a magnetic field by controlling the hovering up to one hour without external
electrical current that gives electromagnets an energy. While traveling, the on-board batteries
advantage over permanent magnets. are recharged by linear generators integrated
into the support magnets.
Magnetic levitation (maglev or magnetic
suspension) occurs when the force of a
magnetic field overcomes forces due to
gravity. This can occur with an attractive or
repulsive force as a material can be attracted
from above or repelled from below (Fig. 1). It is
on these principles that a maglev train hovers
above it track for a frictionless ride.

26 | Maglev goes high rise

directional magnetic field. The magnetic field Moving Into the Vertical plane full-scale prototype maglev elevator for the
travels over the high-thrust stator and interacts MagneMotion, a company located outside of new US Navy aircraft carrier, CVN 21.
with the Halbach array on the train car. The car Boston, MA, is a self-titled “Force in Prototyping is to be completed by late 2007
is then propelled or braked depending on the Electromagnetic Systems.”Their work involves and shipboard installation in mid-2010. As of
direction (an attractive or repulsive force) and the development of maglev systems that use May 2007, MagneMotion has completed a
strength of the stator’s magnetic field. linear synchronous motor technology to corner of a full scale prototype (Fig. 5); one of
Dimensions of the stator and the distance transport goods and people. Successful four posts that lifts, lowers, brakes and holds a
between coil sections (e.g. 2mm) influence the applications include the design-build of transport platform using a linear synchronous
efficiency and performance of moving the car. assembly lines and elevators. Most thoroughly motor system similar to that of the QuickStick
Also, digitally encoded location flags on the developed are their assembly line systems. and maglev trains. The main difference
guideway provide for precise starting and The MagneMotion QuickStick LSM is an between the vertical and horizontal
stopping. Ronald Kaye of Sandia National advanced modular unit used in assembly applications is that, in the vertical, a constant
Laboratories and Professor Eisuke Masada of automation and material handling. flow of electricity is required as the car must
the Science University of Tokyo further MagneMotion’s website (www.magenmotion. consistently overcome the force of gravity by
describe the control and power systems: com) showcases a video library displaying using the linear synchronous motor rather
QuickStick’s numerous system capabilities. than permanent magnets. MagneMotion’s
In order to reduce operational losses and for prototype is equipped with a mechanical
stability of the power supply system, the long Multiple QuickStick motors on the same path emergency braking system in case of a power
stator of the LSM is separated into a number communicate with each other preventing failure. The corner prototype has a lifting
of sections controlled by the section switches. collisions; precision positioning is achieved

fig 4. Section showing propulsion system for typical mag fig 5. Magnemotion’s mag lev elevator platform. Source: fig 6. Diagram of mag lev elevator potential in
lev train. Source: Maglev train elevation. [Online Image] Advanced weapons elevator demonstration. [Image Clip non-vertical routing (image pending).
Available: http://www.transrapid.de/cgi-tdb/en/basics.pr from Online Video] Video Available http://www.
g?session=d82f8833463f50c9&a_no=41, magnemotion.com/products/elevators/main.shtml

The minimum length between two section within a five-hundredth of a millimeter, turning capacity of 12,000 lbs giving the complete
switches depends on the required acceleration corners or switching paths is achieved with system a lifting capacity of 48,000 lbs. It can
and length of a train. The operating frequency turntables; grooved platforms provide for a reach a top speed of 150 ft/min, a dismal
of the section switches becomes high if a large second axis of movement; double-bogie comparison to traditional cable elevators
number of trains are operated on the track vehicles provide the capability to navigate (currently, the fastest elevator is located in
each day. turns; and, most notably, diagonal and vertical Taipei 101 in Taiwan achieving a top speed of
transport paths are achieved with efficient 3,314 ft/min). Dr. Richard Thorton, chairman
The currents in the stator coils must be loading capacities. It is here, in the vertical and CEO of MagneMotion, further describes
synchronized with the train’s position and potential of the technology, that the company’s achievements:
velocity. Proper control of the train can only be MagneMotion developed its maglev elevator
accomplished by sending information to the prototype (see Fig. 5) They [MagneMotion] also take advantage of
converter stations through the use of sensing a careful integration of electrical, electronic
equipment and signal transmission systems. Maglev Elevators and thermal design with major concern for
Because synchronization is essential to the On October 20, 2005 Northrop Grumman manufacturing economies and reliable
LSM, the sensing and signal transmission Corp. announced that the Federal Equipment operation. For elevator applications, an
system must have high precision and Company and their technology partner, important property of the LSM is that the
reliability. MagneMotion, were chosen to develop a individual stator segments operate with low-
duty cycle, so it is possible to get a much »
CTBUH Journal | Fall 2007
Maglev goes high rise | 27

higher thrust than one might infer by scaling much of the penalty of not using QuickStick LSM has managed the diagonal so
the force capabilities of rotary motors. The counterweights. Modern batteries developed why not develop an elevator system that can
ability to overload a LSM without affecting its for hybrid automobiles offer the possibility of also travel along a diagonal path? The concept
reliability is probably the single most even greater smoothing of power could be approached from the standpoint of
important fact that makes these motors requirements while simultaneously providing increasing MagneMotion’s QuickStick’s loading
practical for elevators, (Thorton, 2006). backup power in case of a utility power loss. capacity to handle passengers. And why stop
(Thorton, 2004). there? Elevators could travel in endless
Advantages of Mag lev elevators directions along unique paths. One could
Despite relative low speeds, the linear Other developments imagine a curved path (curved in the
synchronous motor maglev elevator has MagneMotion is not the only company to horizontal, vertical or both) in which the
substantial technological advantages and develop this technology. On January 17, 2006 platform of the elevator car interacts with the
design potential. First, compared to traditional the Toshiba Elevator and Building Systems track with an incorporated ball-joint system
elevator systems, the maglev elevator lacks a Corp. (TELC) announced “it has developed the (see Fig. 6). As the car travels along the non-
cable system or counterweight. The most world’s first elevator guiding system in which linear path the ball-joint system would allow
apparent advantage of this is the capacity for “non-contact magnetic suspensions” has been the interaction to rotate and the platform to
multiple high-speed, independently controlled used to realize smoother riding comfort, and remain level.
cars, or double-deck cars, to operate along a aims for the commercialization of the product
single path. This could dramatically increase in the spring of 2008.” As Toshiba focuses on The ability to travel along non-linear,
the efficiency by which passengers travel the advantages of a smoother and quieter ride, non-vertical paths introduces a flood of design
through the building. Computer software and they also point out that because the car-to- potential when looking at the developments
algorithms could be written so that multiple track relation is contact-less, the functioning of in non-orthogonal forms in recent high-rise
elevators in one shaft would travel in the most the system and movement of the car are not buildings. Tapered, tilted and twisted forms
efficient manner to facilitate the current needs affected by machining accuracy and/or the are increasingly being proposed for tall
within the building. installation of the rails. The company has many buildings, with the need for vertical traditional
advanced engineering projects on the boards elevator shafts stifling the possibilities of
The sharing of hoistways also reduces the in attempts to realize this technology. design somewhat. The degree of twist, turn
footprint dedicated to elevators within a Earthtimes.org reports that Toshiba’s elevator and bend achieved by these buildings are all
building, therefore offering the economic system, when complete, will travel at 984 ft/ limited by needing to include a linear, vertical
benefits of allocating more usable square min, a substantial increase from MagneMotion’s hoistway. Mag lev elevators which can
footage per rentable square footage due to the advanced weapons elevator, but still far traverse inclined or even curving shafts offer
consolidation of elevator cars to fewer shafts. behind Taipei 101’s cable-hoist system. great potential for these new non-orthogonal
buildings.
Furthermore, the lack of cables, gears and Also, on January 13, 2007, the China Economic
wheels provides for a smoother and quieter Information Network reported that China will It is also feasible to imagine elevators changing
ride. This would be beneficial for those riding test its first maglev lift as early as June 2007. hoistways: “the most important future role for
in the car and those within the building. Noise Located in Wuhan, the capital of the Hubei LSM elevator propulsion is for designs that use
pollution at the core of the building due to province, a 128-meter tall tower has begun horizontal switching between adjacent
elevator travel would reduce to nearly zero. construction that will include five elevator hoistways,” (Thorton, 2004). This idea bears
wells, one of which will be used to test a with it images of a continuous loop of elevator
Perhaps the more significant benefits are the maglev elevator. An engineer with the travel throughout a building. The number of
sustainable advantages inherent in the maglev elevator company said that they “have been cars within a continuous loop becomes
elevator. The system would require much less researching and developing the use of maglev unlimited and the efficiency of passenger
electricity to operate than conventional technology on elevators in the past two years.” travel increases dramatically. As an elevator car
elevators. There is also the potential for energy completes it ascent to the top of a building it
generation within the system: The Future switches over to the descending hoistway to
It is possible to imagine the full potential of bring passengers downward. Unnecessary
Energy generated by a descending elevator maglev elevators. The lack of cables, gears and travel in reaching awaiting passengers would
can be used by an ascending elevator, stored counterweights frees up the elevator car so be dramatically reduced, if not completely
in a battery or returned to the mains. When that it can move like never before. As well as eliminated. One could imagine that a
there is more than one hoistway with a central multiple cars within a single shaft, it is possible building’s vertical egress needs, no matter how
controller, one can schedule movement to to imagine an elevator car moving in a tall it is, could be facilitated with one
enhance the probability that regenerated direction other than vertical. MagneMotion’s ascending hoistway and one descending
power from a descending cab can be used to hoistway, substantially reducing the footprint
power an ascending cab, thereby mitigating dedicated to elevator shafts.

28 | Maglev goes high rise CTBUH Journal | Fall 2007

Challenges applied only vertically and thus exert no SHUTOV, M., E. SANDOZ, D. HOWARD, T. HSIA, R. SMITH &
Although the development of maglev horizontal moment on passengers.” (Edgett, S. COLLINS. (2005).
elevators has already advanced significantly 2007). Codes would need to be re-examined A microfabricated electromagnetic linear synchronous
and is beginning to see applications, there are to deal with horizontal emergency braking motor. Sensors and Actuators A: Physical. Elsevier Science.
still a number of issues that need to be and the forces exerted on the passengers. Amsterdam. Vol. A121. No. 2. June 30, 2005. pp. 566-575.
addressed. Even more so, while the ideas of Overall, there are remaining unresolved issues THORTON, Dr. R. (2006). Linear Synchronous Motors for
non-linear paths and horizontal switching with regard to passenger maglev elevators, Elevators. Elevator World. Elevator World, Inc. Mobile, AL.
open up many doors of technological most notably how to achieve a successful Vol. LIV. No. 9. September 2006. pp. 168, 170, 172-173.
potential and design possibilities, they too emergency braking system and how to deal TOSHIBA (2007). “Toshiba Develops World’s First Guiding
bring up new concerns. First, considering that with a variety of new forces experienced by System With Non-contact Magnetic Suspensions – Improved
elevators must conform to an extremely high the passenger. Ride in High-Speed Elevators. [Online] Available http://
standard of passenger comfort, the forces www2.toshiba-elevator.co.jp/elv/infoeng/pressrelease/
endured during travel need to be addressed Conclusion 20060117e.jsp, May 9, 2007.
and resolved. Lacking cables and a Maglev technology has reached a developed UNKNOWN. (2006). Maglev Elevator Under Development.
counterweight, a vertical maglev elevator state. It is currently applied in trains, assembly Elevator World. Elevator World, Inc. Mobile, AL. Vol. LIV. No.
carrying passengers must address the forces lines and prototype elevators with successful 3. March 2006. pp. 46.
resulting in a sudden power loss. Mike results. At the same rate, the full potential of WATTS (2007). This statement has not been published.
Godwin, former head of Lerch Bates, states that the technology and its implications have yet to It derives from email correspondence between
we must find “a possible solution to the be explored. Traditional elevator systems that Mick Watts and the authors.
problem of sudden loss of power with the use cables and counterweights are noisy,
elevator traveling in the up direction and the restrictive with respect to building design, an Websites
physical effect that [a sudden loss of power] inefficient use of space within the buildings
has on the passengers bearing in mind that footprint and consume large amount of Earthtimes.org
they [the passengers] may be traveling at 5 m/ energy to operate (up to 15% of the total http://www.earthtimes.org
s, yet the platform on which they are standing building’s energy consumption). Maglev Elevator World
is arrested with a force greater than 1 g. due to elevators provide a sustainable solution with a http://www.elevator-world.com
friction and magnetic stiction.” (Godwin, 2007) multitude of design possibilities. As maglev MagneMotion
elevators become more economical and the http://www.magnemotion.com
Similarly, if an elevator were to travel with any remaining inherent issues are resolved, this Maglev 2000
component of horizontal direction, new lateral technology has the potential to revolutionise http://www.maglev2000.com
forces would be introduced on the passengers. tall building design. Magplane
These forces would need to be resolved as http://www.magplane.com
they affect a passenger’s balance. Mick Watts References Magtube
of Dunbar & Boardman states that http://www.magtube.com
“accelerations rates have to be very low EARTHTIMES (2007) “Toshiba Elevators to have first Toshiba Elevator and Building Systems Corp.
otherwise people lose their balance and fall magnetic lifts by 2008.” [Online] Available: http://www. http://www.asia.toshiba.com/worldwide
over due to the lateral forces.” He also points earthtimes.org/articles/printstory.php?news=5051, Transrapid International
out that “unlike a transit or subway system May 9, 2007. http://www.transrapid.de
where you know roughly when braking will
occur and hence can maintain balance, in a lift EDGETT (2007). This statement has not been published. Authors
this is a lot more difficult.” (Watts, 2007). A It derives from email correspondence between Antony Wood & Cory Baitz
possible solution to the loss of balance would Steve Edgett and the authors. Illinois Institute of Technology
be to have secure seating similar to that on a S.R. Crown Hall
train, however this increases the time it takes GODWIN (2007). This statement has not been published. 3360 S. State Street
to load and unload the car. It derives from email correspondence between Chicago, Illinois 60616
Mike Godwin and the authors. t: +1 312 567 3307
Another concern facing an elevator traveling e: [email protected]
horizontally is the current elevator codes. KAYE, R. & MASADA, E. (2004). Comparison of Linear
Steven Edgett of Edgett Williams Consulting Synchronous and Induction Motors. Urban Maglev Maglev goes high rise | 29
Group, Inc. states that off-vertical elevator Technology Development Program: Colorado Maglev
travel “is a difficult proposition as elevator Project. Federal Transit Administration. FTA Project
codes all over the planet are based on FTA-DC-26-7002.2004.01. June 24, 2004. pp. 1-22.
emergency stopping theory where loads are
MALLISON, J.C. (1973) One-Sided Fluxes – A Magnetic
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