First stop, Colorado?
magnetically powered train development project funded by
Congress, approved by President
ALBUQUERQUE, N.M.More powerful than an ordinary locomotive
and expected to climb steep mountains without losing traction,
Seraphim - a simpler, less expensive US alternative to the
magnetically levitated (maglev) trains of Europe and Japan
- is now funded for development at the Department of Energys
Sandia National Laboratories.
The fiscal year 2001 Transportation Appropriations Bill
passed by Congress and signed into law by President Clinton
on Oct. 23 allocates $2 million to Sandia for further motor
testing and design of its Seraphim technology, which relies
upon magnetic repulsion to push a vehicle forward. (In mid-September,
Sandia received a FY 2000 appropriation of $1 million, to
build a full-scale prototype of its Seraphim motor.)
The same 2001 bill allocates an additional $2 million to
the Colorado Intermountain Fixed Guideway Authority (CIFGA),
a state planning agency, to perform cost and technical analyses
on an essentially silent, magnetically powered, monorail
transit system for the Denver metropolitan area. CIFGAs
and Sandias intent is to develop an urban 21st century
system robust enough to reach from the Denver International
Airport through downtown Denver to the more mountainous
A Seraphim-based system is expected by backers to decrease
new highway construction, vehicle noise, atmospheric pollution,
and other environmental degradations attendant on more highways
Miller Hudson, Executive Director of CIFGA, a state-planning
agency developing the monorail project, said, We are pleased
that the Federal Transit Administration is funding the Seraphim
prototype. We believe there is a nearly perfect match between
what we need in Colorado and what Sandia is developing.
Angeles, Seattle, Atlanta, San Francisco, Albuquerque?
Other regions in which Seraphim could be used as part
of a cost-effective transit system include Los Angeles,
Seattle, Atlanta, San Francisco, and other locations where
the terrain and distances make it important to travel at
high average speeds within existing rights-of-way, says
Bruce Kelley, project leader of the Sandia effort. Kelley
adds that a transit system using Seraphim would also enable
an all-weather, high-speed connection to be established
between Albuquerque and Santa Fe along the I-25 right-of-way,
when the traffic density and economics justify such a connection.
Key parts of the work to be completed in the year ahead
include analyses of system energy efficiency, construction
costs, and operating costs. Should these analyses lead to
a system design that is economically attractive to one or
more transit agencies, a working system could be riding
the rails at the Pueblo, Colo., Transportation Technology
Center in about 5 years.
The science behind Seraphim was originally developed for
the Strategic Defense Initiative (colloquially referred
to as Star Wars) of the Reagan years, and uses magnetic
forces to hurl projectiles at 20 times the speed of sound.
A challenge for Seraphim researchers was to moderate the
force of propulsion.
Seraphim - an acronym for Segmented Rail Phased Induction
Motor - relies upon electromagnetic forces to push a transit
vehicle forward and to provide braking. The motor generates
vertical forces in addition to the horizontal propulsion
forces and thus is considered a form of maglev but the
completed vehicle probably will rely on wheels - a far cheaper
technology - for support.
Is levitation necessary?
Conventional magnetic levitation is possible, and fascinating
to the public, but costly, says Barry Marder, principal
inventor of Sandias Seraphim technology. The main limitation
to high-speed trains is air resistance, not rolling friction.
So why add all the complexity needed for levitation? The
TGV train in France has demonstrated that wheels are perfectly
good at speeds up to 250 miles per hour. The TGV is a French
acronym for Train a Grande Vitesse.
Sandia researchers will design and test a prototype motor
that can power a test vehicle at speeds up to 125 MPH. This
should permit actual transit at average speeds of 60-70
MPH, including stops, over grades of up to 8 1/2 percent
even in periods of snow and ice accumulation. Conventional
transit systems are limited to grades of a few percent in
good weather conditions, because the reliance on friction
between steel wheels and steel rails limits the grade a
conventional transit vehicle can safely climb.
A five-year stop at the station
In the mid-1990s, Sandia researchers demonstrated a Seraphim
motor prototype that accelerated a two-foot tall aluminum
plate to 34 miles per hour in only 12 feet as it traveled
along rails. However, no funding was available to build
a motor suitable for testing on a vehicle.
Now, after a five-year stop at the station, the propulsion
system will roll the next mile in its development.
Preliminary cost studies have shown that a Seraphim-powered
transit system with the equivalent carrying capacity of
6-8 highway lanes could be deployed for $12-$22 million
per mile depending on corridor geography and construction
conditions. This cost compares favorably with the cost of
an equivalent capacity of new highway lanes in many urban
The system, operated on a guideway such as an elevated
monorail, would operate within existing rights-of-way and
provide significant congestion mitigation for corridors
where the cost of building additional highway lanes is prohibitive.
How it works
The Seraphim motor works by sequentially powering a series
of electromagnetic coils mounted on the vehicle. The powered
coils, by a well-known principle of physics, induce associated
eddy currents and magnetic fields of opposite direction
in passive coils incorporated in the guideway. The resultant
repulsion of the magnetic fields accelerates the transit
vehicle. Sensors monitor the location of the coils on the
vehicle with respect to the coils in the guideway and control
the sequential firing of the powered coils to produce either
acceleration or braking. Compared to the original satellite
launcher, the challenge in designing a Seraphim motor for
transit applications is making it operate efficiently at
A number of transit applications and amusement park rides
use conventional linear induction motors (LIMs) for propulsion.
One example is the low-speed shuttle trains used at Dallas-Fort
Worth International Airport, which operate at about 30 MPH.
A conventional LIM-powered vehicle was tested in the 1970s
by the Federal Railroad Administration at the Transportation
Technology Center in Pueblo, Colo. This vehicle reached
speeds up to 250 MPH, and proved the viability of LIMs for
high-speed transit. The Seraphim motor is a modular, high-performance
extension of LIM technology that could enable cost-effective,
energy efficient transit system deployment within existing
For 2001, says Kelley, expect continued development of
Seraphims motor and controls, as well as work on the safety,
surety, and systems controls aspects of the project.
Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under contract DE-AC04-94AL85000. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major research and development responsibilities in national security, energy and environmental technologies, and economic competitiveness.
Neal Singer, email@example.com,
Bruce Kelley, firstname.lastname@example.org,