Maglev's bogus claims
The following is from the TOLL ROADS NEWSLETTER which summarizes an article published in the TRANSPORATION QUARTERLY (TQ, Spring 2002) journal from the Eno Foundation. It is an article that challenges widely held views regarding the potential utility of maglev technology in comparison with conventional rail technology. The full article is now on-line in pdf format.
University of Pennsylvania systems engineers Vukan Vuchic and Jeffrey Casello argue that enthusiasm for maglev is misplaced. Maglev has very few advantages over electric high speed rail (HSR) but major disadvantages in capital cost, operating costs, maintenance, energy consumption, and incompatibility with existing transport networks. Most maglev reports are "deceptive" they say, and are promoted by maglev suppliers and their lobbyists seeking to harvest government grants, not by investors, professional engineers, or transport planners.
The major US Federal Railroad Administration report in support of maglev ("High-Speed Ground Transp for America," FRA, 1997) is "based on confused concepts and incorrect assumptions," they say. The FRA report falsely assumes a 480km/hr (300mph) operating speed for maglev, approximately its experimental speed, while correctly stating HSR operational speed at a third lower - 320km/hr (200mph). But this, Vuchic and Casello say, is an apples and oranges comparison because experimental speeds are always 50 to 80% higher than operational speeds. Maglev has no operational system, but its operational speed should be assumed to be substantially below its experimental speed, as with HSR or any other system.
HSR systems have achieved experimental speeds of over 500km/hr, they say, very similar to those of maglev, so the FRA claim of a major speed advantage for maglev is bogus. There is only a "small travel time advantage" for maglev over HSR, maybe a speed difference of 50km/hr (30mph).
High speed ground transport (HSGT) - whether HSR or maglev - makes little sense for trips with interstation distances of less than 100km (60mi), the authors say. An increase in speed of 50km/hr (30mph) from 250km/hr (150mph) - about the maximum likely attainable by maglev - yields a 9.7min saving at interstation runs of 250km, only 2.6min at 100km station spacings, 1.7min at 50km and 0.7min at 25km - assuming braking rates of 0.75m/sec2 and acceleration of 0.9m/sec2. The last small interstation distances are typical of proposals being supported by FRA! At higher speeds still the time saving gains are even smaller.
A maglev planned for the 292km (180mi) Hamburg-Berlin link with no intermediate stops between Germany's two largest cities was supposedly ideal for maglev. It was passed over in the end because HSR offered far lower costs and almost equivalent service. Vuchic and Casello ask: if not Hamburg-Berlin where?
Claims of greater passenger comfort on maglev are incorrect, they say, citing greater vibration and noise with maglev. Other advantages cited for maglev are an ability to go through curves faster and to negotiate 10% grades versus 4% max grade for rail. The authors say that in practice maglev will need to accommodate standing or walking-around passengers and cabin crew so it will not be able to do tight turns at its potential speed because of the sideways slope (superelevation) required. As for hill climbing they say there are few places where 10% grades are useful.
Maglev switches are clumsy and expensive, dooming it to being mainly a shuttle operation, rather than a networked one. Capital costs of maglev are likely to be about twice those of HSR ($12m to $55m/km versus $6m to $25m/km). Projected mintenance and operational costs are all over the landscape, but the complex electronics on the guideway require very sophisticated, and therefore expensive, maintenance.
Energy savings? Magnetic levitation itself involves considerable energy consumption, and linear induction motors do not match the efficiency of regular rotary motors. These additional energy demands more than offset any energy economies from lack of rolling resistance in maglev. HSR will benefit greatly from its ability to draw on existing rail engineering and manufacturing capabilities. And, within developed areas where speeds will have to be lower it will often be able to make use of existing tracks.
They conclude: "The usually implied superiority of maglev over HSR and its aura as a system of the future are based on an artificially created image of superiority in speed, lower energy consumption and better passenger attraction, none of which is supported by facts at this time." (p46)
Vuchic and Casello think there is a role for highspeed ground transport (HSGT) between major centers that will fit between the majority of road and air journeys in trip length. They think non-stop trips in the range 100km (60mi) to 1,000km (600mi) provide potential for HSGT. HSR similar to Japans Shinkansen, Germanys ACE or Frances TGV is a far better bet than maglev.
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Last modified: May 11, 2003