The Switch Myth
This article appeared originally in the
Monorail Newsletter, Volume VII:2, Spring, 1996.
It was written by Kim Pedersen, President of the
Monorail Society and David B. Simons, Jr. It is posted
with the newsletter editor's permission.
Once upon a time ... a quaint suspended monorail was
built between the villages of Eberfeld and Barmen in Germany.
United by the monorail system and the River Wupper, the
villages would one day merge to become the city of Wuppertal.
The industrial city would gain recognition and world-wide
fame because of their pioneer monorail. But, the monorail had
a problem ... the switches.
Wuppertal's monorails used double-flanged steel wheels
to run on a single elevated rail. The vehicles are suspended
below. Due to the "hang-over-the-side" design of
the suspended vehicles, switching requires cumbersome
rotating switches. This limits the system to a linear loop in
which trains turn around at each end without the use of a
switch. Spur lines and bypasses don't exist either.
Because of these limitations, an unfair "switch
myth" was created that all monorails have
switching problems. Even though great strides in both track
and switch technologies were made in the 50's, 60's and
beyond, the myth today remains a thorn in the side for
monorail proponents. Partly at fault are the rail consultants
and suppliers that benefit by the continuation of competing
so-call conventional rail. Here at the Monorail Society, we
continue to be surprised by the amount of "rail
experts" that don't have a clue when it comes to the
subject.
One more reason for the perpetuation of the myth is the
continual appearance of it in print. Even today, modern
encyclopedias such as Microsoft's Encarta proclaim that there
are problems with monorail switches. It reminds me of
President Ronald Reagan. His Strategic Defense Initiative
(SDI) as tagged as "Star Wars" by the press. There
was absolutely nothing that the president could do to
remove the negative connotations of their title for his
missile defense proposal. The same mis-information or tagging
continues today with monorail switches and monorails on the
whole.
Switch Defense Initiative
So, at the suggestion of one of our more enthusiastic
tMs members, Dr. Robert W. Selle, it is time to fight back
with facts and pictures. We begin with a brief look at some
of the major switch technologies in use today.
Suspended Monorail Switch -- Both the Safege and
Sipem monorails have advanced switch designs for
monorails far beyond the Wuppertal technology. Safege has
pivoting horizontal plates inside the box beam that act as
running surfaces in either direction of the switch. Sipem
uses technology in which a vertical plate pivots inside the
switch. The load-bearing wheels briefly run on one side of
the beam while the train transits from one beam to the other
(for an extensive discussion of the various features of
suspended monorails, see the
Swedish Flyway website, especially page 34).
Rotary Switch -- Common to peoplemover class
steel-beam monorails, rotating switches replace a straight
section of tract with a curved one.
Beam Replacement Switch -- A straight section
of beam pivots to the side while a curved section moves into
place. Walt Disney World has switches like this that cycle in
twelve seconds.
Segmented Switch -- The segmented switch
is the most commonly used straddle-beam monorail switch in
Japan. The segmented track allows the beam to go from a
straight position to a curved one. This way little space is
used for the switch and the trains can run through them
faster. The
Osaka monorail uses a segmented switch.
Still Skeptical?
Probably the best way to argue that monorail switches
work is to let you know where they are and briefly explain
the importance of them. What follows is a list of monorail
systems operating right now (or very soon) that cannot
operate without the benefit of switches. Without efficient
on-line operating switches, these systems would be
closed!
Alweg straddle-beam technology is used for this
eight-mile dual-beam system. Segmented and new high-speed
crossover switches operate every few seconds. This system has
proven monorail switches reliable in over 30 years of daily
operation.
Shonan , Japan, 1970
A single-line suspended monorail with dual direction
service. How is this done? Trains pass each other at stations
where the track briefly splits, with switches based on the
French Safege technology developed in the 1950's.
Although the WDW system consists of three loops, without
switches the system would be unable to operate. Trains access
all loops via switches starting right from the twelve-train
storage and maintenance facility. Trains transfer from loop
to loop depending on traffic demand. The system carries
hundreds of thousands of passengers each week.
There are a number of switches on this Siemens-developed
suspended monorail. Clever engineering allows for quick
switching in these narrow beams.
Kitakyushu City, Japan (1985)
Another dual-beam Alweg system with lots of segmented
switches.
Chiba City, Japan (1988)
The world's only dual-beam Safege monorail. It includes
a spur line and oodles of switches.
On the way to being the longest Alweg system in the
world. The track will eventually loop the city with switches
along the entire route. A spur line is also under
construction.
Merry Hill, England (1991)
A Von Roll steel-beam monorail runs back and forth along
both dual-beamed and single-beamed sections. Rotary switches
allow for this.
Tampa International Airport (1991)
Tampa's Bombardier
UM III monorail system is a pinched loop with two
switches for direction reversal. One is a seldom-used
backup.
When it opened, the Newark system will became the king
of steel rotary switches. Switch platforms exist at the
terminal stations as well as along the route. This will give
operators flexibility to move trains from beam to beam as
required for direction reversal or the occasional need for
trains to bypass sections of track under maintenance.
Tama, Japan (1998)
If monorail switches were a problem, would the Japanese
have so many systems operating, or in this case, under
construction?
Bombardier is supplying the city with a UM III
peoplemover class monorail system. It will be totally
automated and will also feature many online switches.
Included in the system will be the first passenger-carrying
monorail spur lines in the USA. People, how do you get the
trains onto those spur lines? Efficient switches like those
proven at Bombardier's earlier installation at Tampa Airport,
perhaps?
In Conclusion
Naysayers, please give it up! Monorail switches work
just fine and are doing so as you read this. In fact, when is
the last time you heard of a monorail switch accident? In
comparison, conventional rail switches are quite capable of
causing accidents. Here in the San Francisco bay area, I
recall several incidents in which BART (Bay Area Rapid
Transit) trains have jumped off the rails at switch points.
Some accidents have resulted in system shutdowns or delays.
Monorail switches on the other hand have a clean record. May
the Switch Myth Rest in Peace.
Contact information: Kim Pedersen can be reached at
the
Monorail Society .
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Last modified: November 24, 1997