Why is the monorail system not as widespread?

[zkr123]

With people looking for other forms of mass transit, monorails could be the solution without clearing chunks of land. I'm not talking about airport trains but through towns/cities.

[CSSHEGEWISCH]

This notion has been discussed repeatedly in the past.  Monorails lack flexibility and are not really suitable for anything beyond short loop routes.

[blue streak 1]

Without active controls  ( almost half the cost of a F-16 ) speeds are limited to about 35 MPH MAS

[54light15]

Plus, you're married to the technology of whoever builds the system. Not everyone can build a monorail, yet many manufacturers can make equipment that runs on two rails. 

[NorthWest]

Monorails take up essentially the same amount of space as a conventional railroad, and cannot have grade crossings.

[Firelock76]

All of the above.  In a nutshell, monorails are great in theory, but in fact aren't the panacea everyone thinks they are.

[BaltACD]

Cost/benefit ratio is in the dumpster.

[LNER4472]

It's more of a Shelbyville idea.........

[D.Carleton]

"Sorry, Mom, the mob has spoken."

[Paul Milenkovic]

"The mob has spoken" -- is that a reference to the TV's Simpsons and the Monorail Mania in the ficticious Springfield?

I often find short responses as to why a technology has failed or has not caught on to be deeply unsatisfying.  There is no explanation offered as to what people were trying to do in the first place and how the tech failed to meet those goals.

With a transit system, you can either go below the street (subway -- very expensive), at street level (light rail -- either requires a special right-of-way that still has grade crossings or operates as a streetcar and is stuck in traffic with everybody else) or above street level.

The most well-known above-street level trains are the El, still used in Chicago, once used in New York but replaced by subway lines.  My recollection of the Chicago El (elevated lines) is that they are massive structures that many people feel blight the street and the neighborhood.  The steel-on-steel-on-steel wheel-on-rail-on-elevated structure is also very noisy.

The idea behind monorail-as-elevated-transit is that a more slender, visually appealing, quieter, and (this is a stretch) lower cost concrete beam substitutes for the clunky El.  At least that was the idea behind the Alweg system -- Seattle, Disneyland, (Las Vegas "Strip") monorails.  As mentioned above, one of the problems is a really hard time switching between diverging routes.

 

But the rubber-tire supported Paris Metro, OK, a subway and not an elevated line, has been duplicated in Montreal and other places?  Then there are various airport "people mover" trams using everything from magnetic attraction maglev (which may account for the remark about the complicated control system) to variations on rubber-tire supported trains?  Many of them being elevated lines using concrete beams, but a different guidance system than the Alweg?  Are these "monorails" or do we call them something else?

So maybe monorail is not a technological or financial failure but instead part of a suite of systems that may be a good fit to particular applications where the demand is for an elevated transit system, an easier-on-the-eyes concrete beam guidway, and a lower-noise rubber tire support system?

[BroadwayLion]

Monorails really do not add anything to transit, and the equipment is very expensive and specialized. The system in Seattle has all of the problems of a conventional el and then plenty more.

Modern concrete construction can build elevated strcutures that are just as slender and quiet as anything a mono-rail can do. There is no reason to shy away from modern elevated city transit except of course people's fears that you would be brining back your great-grandfather's el.

LION thinks that the experementation with rubber tiers was a mega-flop which is different from a peta-flop.

Oh well, accoring to LION, with few exceptins, monos are limited to amusement parks.

ROAR

[CSSHEGEWISCH]

Much of the Midway L (Orange Line) is built on concrete superstructure not unlike an elevated highway.  The roadbed on these sections is conventional track and ballast and excessive noise is not a major issue.

[daveklepper]

There is almost off-the-shelf technology that can make an elevated railroad quieter than a surface line.  It involves "Barriers than can become walkways for maintenance."   This is discussed in my paper "Further thoughts on railway noise," in the March-April issue of Noise Control Engineering.   As applied to the approximately 20% of the route mileage of New York City's rapid transit sstem, and excepts follow:

In the first paragraph of the first reference, it is stated that 

noise  barriers  present  a  hazard  to  track  workers,  adversely 

affect mechanized track maintenance, and present a permanent 

visual intrusion....

....possibly the idea shown in Fig. 1 can present an answer to the first two problems in many cases, and keeping the noise sources in the vehicle as low as possible can provide the answer to the third. Figure 1 was prepared for mitigation of one of New York Cityʼs worst noise problems, and applies directly to many “subways on elevated structures” in that city, primarily The Bronx.

 

The need for three tracks on these structures is less great 

than when the structures were built, and the weight savings 

possible by eliminating the center track, by using single track 

bi-directional operation during heavy maintenance periods, and 

by using skip-stop express operation during rush hours instead 

of separate one-way local and express services, which in any 

case are provided on a small fraction of the elevated subway 

lines.

I am confident that such firms as Wenger, Overly, Industrial Acoustics, and Trux can engineer walkable surfaces with efficient sound absorption and durable longitudinal hinges to make the concept practical for many situations. Ten dB Noise Reduction should be realized in many cases. 

Note that the rigid track structures, ties or sleepers imbedded 

in concrete or rails themselves imbedded in concrete (“slab 

track”) is not recommended where noise control is critical. 

Even  where  resilient  surrounds  of  rails  and  ties  and  clips 

are used, the slabs tend to radiate forward and to the rear of 

the passing train. This need not be a problem in subways or 

underground  Metros,  but  can  compromise  noise above  ground.

Back issues of the magazine should be avialable in any engineering library, and I will be glad to send a pdf of the aritcle to anyone askiing at [e-mail].

There is also the concept of the elevated light railway, based on the original Dr.Charles Harvey West Side Patend Elevated Railway from Greenwich and Broom Streets to 9th AVenue and 29th (30th?) St. before crossties were introduced when dummy steam locomotives replaced cable propulsion.  The "skyprint" was and would be in the future, no greater than a monorail, possibly less.   But, wihtout side walkways of any type, and without anything to walk on between rails directly supported resiliently on the two longitudinal beams, a fleet of cherry pickers would need to be on-hand for emergency evacuation.

[Paul of Covington]

   Here is the discussion about monorails from last February:

http://cs.trains.com/trn/f/742/t/227255.aspx

[mogul264]

As I recall, monorails can also be of the suspended design. The suspended rail is atop a series of pylons, and dual rails can be set in the dead middle of divided streets and highways, thus taking NO extra space. The pylon bases aren't very wide and can be separated by 100 or more feet, and can be raised to be routed OVER buildings, parks and other spaces, disturbing no one. The rail can be covered by a snow/ice shield, preventing bad weather from stopping traffic. This raised feature also means NO interference with or from other traffic.Why not use this type of monorail?

[gardendance]

The raised feature, also known as a suspended or hanging monorail, off the top of my head and with my friend google:

must have higher pylons than supported mono, or conventional, rail in order still to get "NO interference with or from other traffic"

and when other traffic still gives it interference, has greater death and injury risk since the collisions will be with the monorail trains, not the structure.

http://www.craneaccidents.com/2008/08/report/wuppertal-suspension-railway-resumes-service-after-accident/

"The mobile crane on the back of a truck sliced open the bottom of a railway car"

has greater danger that a derailment will result in the train plummeting to the ground

http://www.monorails.org/tMspages/Wuprtal.html

"In April of 1999, a derailment of a morning commuter train caused four deaths, the only fatal mass transit monorail accident in the 20th century."

still should have a floor, at least at stations

[cfphoto]

Paul Milenkovic

The idea behind monorail-as-elevated-transit is that a more slender, visually appealing, quieter, and (this is a stretch) lower cost concrete beam substitutes for the clunky El.

Some years ago I happened to be in Kitakyushu in Japan while a monorail system was being built. The station at the end of the line filled the entire street from building to building, just like the old Dover Street station on the MBTA Orange Line. While it may be that a monorail has less visual impact than a 19th century elevated railroad, the stations are likely to be just as blighting as an elevated railroad.

BART trains in the San Francisco Bay Area run on long stretches of "modern" elevated structures. Unfortunately, significant noise is generated because the trains run at fairly high speed. I would not be surprised if a monorail running at the same speed didn't make a comparable amount of noise, primarily rubber tires agains the concrete guide beams.

There is no free lunch.

[Dragoman]

cfphoto

Paul Milenkovic

The idea behind monorail-as-elevated-transit is that a more slender, visually appealing, quieter, and (this is a stretch) lower cost concrete beam substitutes for the clunky El.

Some years ago I happened to be in Kitakyushu in Japan while a monorail system was being built. The station at the end of the line filled the entire street from building to building, just like the old Dover Street station on the MBTA Orange Line. While it may be that a monorail has less visual impact than a 19th century elevated railroad, the stations are likely to be just as blighting as an elevated railroad.

BART trains in the San Francisco Bay Area run on long stretches of "modern" elevated structures. Unfortunately, significant noise is generated because the trains run at fairly high speed. I would not be surprised if a monorail running at the same speed didn't make a comparable amount of noise, primarily rubber tires agains the concrete guide beams.

There is no free lunch.

Be surprised, my friend.  There may be no free lunch, but there is also no comparison between the noise level and footprint of BART versus an Alweg-type monorail, such as the system used at Disneyland in Anaheim.  (Well, one could make a comparison: truck-tractor rig versus Prius.)

I regularly have business near an elevated BART section.  On the ground at some 40-50 feet away from the elevated structure (about 20-feet high), it is impossible to have a cellphone conversation when a train is passing – not at top speed, but at reduced speed approaching a nearby station.

 

By contrast, I have stood directly under a Disney Alweg monorail “track”, about 15-feet high, and not noticed a monorail’s near-silent approach until it had nearly passed.

The BART structure is at least 5 times as massive, held up by pylons that take up nearly 5 times as much space, as the monorail “track” structure.

[daveklepper]

too bad bardt does not implement my ideas for railroad noise control as discussed in march=april 2004 Noise Control Engineering (magazine) peer-reviewed paper:

Technical Note: Additional thoughts on railway noise

David Lloyd Klepper (a)

(Received 2001 December 10; revised 2002 June 12; accepted 2004 February 10)

Primary subject classification: 52.4

1.INTRODUCTION

This  paper  is  intended  as  a  significant  addition  to  the 

Hemsworth–Hubner paper in the 2001 July August issue and 

discusses certain aspects of railway noise control, including 

one new idea, that were not discussed in that very valuable 

and important paper.

1

It is not intended to complete the picture, 

but should provide a basis for an ongoing discussion in this 

journal that can equal the attention that has been given to road 

and aircraft noise control. The reasons why such continuing 

discussion is necessary were presented in the last paragraph of 

this reference, where it is noted that it will “..support the EU 

policy to transfer traffic from road to rail without adversely 

affecting the noise environment....” Europe is not the only 

place with this transfer is being effected. The former Governor 

of California announced the opening of the “last new highway 

to be built in California” with future funds directed to public 

and rail freight transportation.

2

State funds contributed to the 

construction of the Alemeda Corridor to relieve congestion 

for rail freight at the ports of Los Angeles and Long Beach,

3

and the State of Virginia is working with CXS Corporation to 

increase track capacity between Washington and Richmond.

4

More such cooperative ventures are expected, and expansion 

of  rail  commuter,  metro,  and  light  rail  now  has  a  thirtyyear history and continues unabated. In Israel, the Ayolon 

connector and four Tel Aviv railway stations, three constructed 

in the last six years, have dramatically increased commuter rail 

service, and now Ashkalon port congestion has been relieved 

by use of containers on flatcar trains to many transfer points. 

This last concept is important because a rule of thumb in North 

America has been that freight traveling less than 300 miles is 

carried more economically by truck.

5

2.NOISE CONTROL BY VEHICLE SELECTION

Possibly an unstated assumption in the Hemsworth–Huber 

paper is that the freight trains considered were all electrically 

powered. It has been widely reported that for diesel freight 

trains, the locomotive can be the major noise source. The author 

has been an active participant in the railroad scene for wellover half a century, working as a student engineer for ElectroMotive in La Grange the summer of 1952 and then as a diesel 

locomotive test engineer under Ernie Bloss, Superintendent 

of Diesel Locomotives, Railcars, and Automotive Equipment 

(buses, trucks, and railway maintenance of way equipment) 

of  the  Boston  and  Main  Transportation  Company  while 

preparing his SB thesis on diesel locomotive load regulator 

controls.

6

While most involved professionally in architectural 

acoustics, my participation in railway activities permitted my 

subjective evaluation of the reduction in noise levels generally 

experienced when diesel power replaced steam, and then the 

increase in levels, often to where they were, as supercharged 

diesels  supplanted  normally  aspirated  diesels,  as  dynamic 

brakes  on  mountain  railroads  required  high  powered  fans 

for cooling dissipative grid resistors, and as horsepower and 

tractive effort of diesel units climbed to new levels.

7

Electric 

locomotives can be designed to be far quieter, with energy 

conserving regenerative braking replacing dynamic, and with 

all cooling fans mounted reasonably low on the car body to 

allow lower-height noise barriers to be effective.

8

Possibly 

increased concern with air quality, as well as noise control, 

and energy efficiency will spur more electrification of North 

American railways, and the designers of the new locomotives 

should keep noise control in the picture.

3.BARRIERS PIVOTING TO MAINTENANCE 

WALKWAYS

In the first paragraph of the first reference, it is stated that 

noise  barriers  present  a  hazard  to  track  workers,  adversely 

affect mechanized track maintenance, and present a permanent 

visual intrusion....

1

Possibly the new idea shown in Fig. 1 

can present an answer to the first two problems in many cases, 

and keeping the noise sources in the vehicle as low as possible 

can provide the answer to the third. Figure 1 was prepared for 

mitigation of one of New York Cityʼs worst noise problems, 

and applies directly to many “subways on elevated structures” 

in that city, primarily The Bronx.

9

The need for three tracks on these structures is less great 

than when the structures were built, and the weight savings 

possible by eliminating the center track, by using single track 

bi-directional operation during heavy maintenance periods, and 

by using skip-stop express operation during rush hours instead 

of separate one-way local and express services, which in any 

case are provided on a small fraction of the elevated subway 

lines.

It can be shown that the noise reduction provided by barriers 

on both sides of a rail car where the noise sources are under 

the car is:

NR = 10logh- 10log(g+ αh), where

h= height of the railcar or locomotive above ground or 

structure level

g= width of the gap between the side of the car and the 

barrier

α= absorption coefficient of the side of the barrier facing 

the railcar or locomotive.

a)

 

Other assumptions are that the barrier height is ten or more 

times the width of the gap between the barrier and the railcar 

or  locomotive,  and  that  the  barrier  does  not  extend  more 

than  twice  the  gap  width  above  the  floor  of  the  car,  both 

reasonable assumptions.

10, 11

A third assumption, that vibration 

transmission or other flanking paths are minor may or may not 

apply in particular situations. If a barrier is located only on 

one side of the track, neglecting sound passing over the railcar 

or locomotive roof, the noise reduction can be simplified in 

most cases to:

NR= 10logh- 10logg- 3(1 - α).

Although  Fig.  1  applies  to  New York  City  elevated 

structures, it can be adapted to existing structures in Chicago 

and perhaps Philadelphia, and the general concept is applicable 

to new elevated and surface lines. I am confident that such 

firms as Wenger, Overly, Industrial Acoustics, and Trux can 

engineer walkable surfaces with efficient sound absorption and 

durable longitudinal hinges to make the concept practical for 

many situations. Ten dB Noise Reduction should be realized 

in many cases. 

Note that the rigid track structures, ties or sleepers imbedded 

in concrete or rails themselves imbedded in concrete (“slab 

track”) is not recommended where noise control is critical. 

Even  where  resilient  surrounds  of  rails  and  ties  and  clips 

are used, the slabs tend to radiate forward and to the rear of 

the passing train. This need not be a problem in subways or 

underground  Metros,  but  can  compromise  noise  reduction 

outdoors. 



 Continuously welded rail held by Pandroil clips

on resilient tie plates on wood ties on stone

ballast confined by concrete invert with station

platform heights adjusted



Girders formerly supporting center track removed

Sound barriers with hard perforated facing over damped steel

Pivoted at bottom to form walkway when maintenance is

required with handrail and supports pivoting into position

Fig. 1— Noise control modifications for New York Cityʼs “City Built” elevated structures.

 

4.CONCLUSIONS

Adding  to  the  important  wheel–track  interface  noise 

mitigation measures suggested in the first reference, the author 

has suggested noise abatement by the design of the railcars 

and locomotives themselves and by choice of motive power, 

and then suggested one possible innovative approach to barrier 

design. The author hopes for an ongoing discussion that can 

provide new noise control ideas for a very real second railway 

age.

5.REFERENCES

1

B. Hemsworth and P. Hubner, “European cooperation on railway noise,” 

Noise Control Eng. J. 49,185-187 (2001).

2

Personal communication from the transportation consultant, J. William 

Vigrass, Hill International, Inc., Marlton, NJ, U. S. A., July 2001.

3

M. W.  Hemphill,  “Architects  of  the  new  age,” Trains 61:1,  45  (Jan. 

2001).

4

D. Phillips, “Canʼt live with ʻem, canʼt live without ʻem,” Trains 60:6, 12, 

(June 2000).

5

M. W. Hemphill, op. cit. 44.

6

D. L. Klepper, SB Thesis, M. I. T. E. E., Diesel Locomotive Load Regulator 

Controls, 1953.

7

President of the Electric Railroadersʼ Association, Inc. for several terms, 

member 1947 on, also active in Branford Electric Railways Association, 

Inc., and Light Railway Transport Association. Sound system design work 

for Pullman, Long Island Rail Road, and Port Authority Trans Hudson. 

Tour leader in the U. S. A., Canada, and Great Britain to railway shops 

and operations.

8

The  concept  has  been  applied  in  part  to  diesels  for  other  reasons.   D. 

Lustig, “Phoenix-like tunnel motors just keep on working,” Trains, 61:12, 

26 (2001).

9

“City-Built”  structures  meeting  the  design  shown  in  Fig.  1  include: 

Brooklynʼs Mcdonald and New Utrecht Avenues, (“F”, “D”), Fulton Street 

(“J”), Myrtle Avenue (“M”), Livonia Avenue (“3”); Queensʼ Liberty Avenue 

(“A”), Jamaica Avenue (“J”), Roosevelt Avenue (“7”, but possibly this is 

an exception to non-essentiallity of the center track), and the Astoria Line 

(“N”); and The Bronxʼs Broadway (“1”), Southern Boulevard (“2, 5”), 

Westchester Avenue (“2, 5” in one segment, “6” further north), White Plains 

Avenue (“2, 5”), and Jerome Avenue (“4”). In a few cases the structures 

were built without the center track but always with the necessary structural 

strength to add one in the future. These would be logical candidates for 

test installations. Also the design can be modified for the original 1904 

“Manhattenville Viaduct,” on Broadway (“1”) each side of the 125th Street 

Station, which has supports in the roadway. Numbers in quotes refer to 

subway route numbers.

10

L. L. Beranek, Noise Reduction(McGraw Hill, New York, 1960), Chapter 

25.

11

C. M. Harris, Handbook of Noise Control(McGraw Hill, New York, 1979), 

Chapter 33.

6.POSTSCRIPT

The  readerʼs  attention  is  drawn  to  the  paper  by Anders 

Nordborg,  “Wheel/rail  noise  generation  due  to  nonlinear 

effects and parametric excitation,” Journal of the Acoustical 

Society of America, 111-4, April 2002, p.1772-1781. This 

paper  modifies  previously  held  views  and  suggests  that 

continually supporting rails instead of periodically supporting 

them as with conventional wood or concrete ties can in many 

instances reduce noise, wear, and corrugation. This suggests 

possibilities for modifying traditional technology that dates 

to the mid-19

th

Century. I hope that readers will join me in 

exploring such possibilities.

[daveklepper]

Seattle Monorail Project

From Wikipedia, the free encyclopedia

 

 

The Seattle Monorail Project was a proposed five-line monorail system to be constructed inSeattle, Washington as an extension of the existing Seattle Center Monorail. The 14-mile (23 km), 17 station Green Line running from Ballard to West Seattle via Seattle Center would have been the first of the five lines to be built.^[1]

From 1997 to 2005 the monorail project was a highly contentious political issue in the Seattle area. In November 2005, following the fifth voter initiative on the monorail in eight years, the monorail authority agreed to dissolve itself^[2] after having spent $124.7 million in taxpayer funds without beginning any monorail construction.

 

Contents

  [hide] 

• 1 Origins
• 2 Financing troubles & defeat
• 3 External sites
• 4 See also
• 5 References

 

Origins[edit]

The effort to extend the monorail began in 1997 with the 53% to 47% passage of Initiative 41 by Seattle voters.^[3] The initiative proposed a 54-mile (87 km) X-shaped monorail system extending the 1.4-mile (2.3 km) line constructed for the 1962 Seattle World's Fair. The system's construction and operation was to be carried out by a new agency, the Elevated Transportation Corporation (ETC), using private funding.

The ETC quickly determined that private entrepreneurs were not going to build a monorail system without public financial support, leading to a second monorail initiative, allowing the ETC to spend $6 million for additional studies to determine an improved monorail plan with full cost estimates and a funding package to pay for construction.^[4] This initiative passed 56% to 44%^[5] in 2000.

By 2002, the ETC had developed the five-line system plan that came to be called the Seattle Monorail Project. This proposal was put before the voters as Citizens Petition #1 in November 2002 which would proposed to dissolve the ETC, create a new monorail agency, construct the Green Line as the first part of the system, and enact an annual 1.4% motor-vehicle excise tax (MVET) on Seattle vehicles to fund the project.

The 2002 petition drew opposition from groups who argued that: the Green Line ridership would not be significantly different from that already achieved by Metro buses; that building an elevated line with 7-foot (2.1 m) deep concrete beams on Second Avenue in downtown would create a "wall" through the urban core; and that the monorail line should be built along the I-5 freeway corridor, among other complaints.^[6]

Reflecting the increased opposition, Citizens Petition #1 passed by just 877 votes, 50.2% to 49.7%.^[7] With this November 2002 passage, construction was expected to begin in autumn 2005, and be completed in 2009.

Just two years later in November 2004, a recall initiative, I-83, was put forth seeking to halt the project by forcing the city to deny the monorail agency the right to use the air space above public city streets. This fourth initiative in seven years proved unpopular with Seattle voters however, and lost 64% to 36%.

Financing troubles & defeat[edit]

The tax to fund the project began effective June 2003,^[9] and was levied annually on each car registered in the city based on the MSRP of the vehicle and a fixed depreciation table.^[10] In 2005, the average monorail tax per vehicle was $130 annually.^[11]

The project soon fell under intense public scrutiny, when actual revenue from the motor vehicle excise tax came in 30% under projections while projected costs rose by 10%. To bridge the shortfall, the SMP initially proposed extending the tax and bond repayments over a 50 year time horizon, resulting in nearly $9 billion in interest paid on the $2 billion construction. The plan proved highly controversial^[12] and five days later the SMP withdrew its financial plan and the director and board chairman resigned under pressure.^[13]

The then-Mayor Greg Nickels gave the board an ultimatum to create a new plan or lose city support for the project. A new plan was not developed, and on September 16, 2005, Nickels withdrew city support for the project.^[14] While the city of Seattle could not officially stop the project, it could withhold permission to build on or above city land, as had been proposed under I-83 a year earlier. Nickels also called on the Seattle Monorail Project to put a measure on the November 2005 ballot to determine whether or not to continue with the project, marking the fifth time Seattleites had voted on the issue. This measure shortened the initial phase of the Green Line to 10.6 miles (17.1 km) with the remaining 3.4 miles (5.5 km) to be added later, and the SMP said it would dissolve itself if the measure failed.

"Proposition 1" was defeated, 65% to 35%,^[15] and in response the SMP reduced staff, terminated the annual motor vehicle excise tax on Seattle vehicles effective June 30, 2006 (three years after it was first implemented) and began liquidating properties already purchased for the Green Line.^[16]

The Seattle Monorail Authority was formally dissolved on January 17, 2008, after liquidating all of its assets, repaying its debts, and transferring its remaining $425,963.07 to the King County Metro system. The monorail project ultimately cost Seattle taxpayers $124.7 million.^[17]

[Dragoman]

But this was a proposed newer system. The Seattle Center Monorail (originally built at the time of the 1962 Seattle World's Fair) continues to run.

[Dragoman]

And Dave, I too am sorry BART has not looked into your noise-reduction proposals!

[Falcon48]

Dragoman

 

cfphoto

Paul Milenkovic

The idea behind monorail-as-elevated-transit is that a more slender, visually appealing, quieter, and (this is a stretch) lower cost concrete beam substitutes for the clunky El.

Some years ago I happened to be in Kitakyushu in Japan while a monorail system was being built. The station at the end of the line filled the entire street from building to building, just like the old Dover Street station on the MBTA Orange Line. While it may be that a monorail has less visual impact than a 19th century elevated railroad, the stations are likely to be just as blighting as an elevated railroad.

BART trains in the San Francisco Bay Area run on long stretches of "modern" elevated structures. Unfortunately, significant noise is generated because the trains run at fairly high speed. I would not be surprised if a monorail running at the same speed didn't make a comparable amount of noise, primarily rubber tires agains the concrete guide beams.

There is no free lunch.

 

 

 

Be surprised, my friend.  There may be no free lunch, but there is also no comparison between the noise level and footprint of BART versus an Alweg-type monorail, such as the system used at Disneyland in Anaheim.  (Well, one could make a comparison: truck-tractor rig versus Prius.)

I regularly have business near an elevated BART section.  On the ground at some 40-50 feet away from the elevated structure (about 20-feet high), it is impossible to have a cellphone conversation when a train is passing – not at top speed, but at reduced speed approaching a nearby station.

 

By contrast, I have stood directly under a Disney Alweg monorail “track”, about 15-feet high, and not noticed a monorail’s near-silent approach until it had nearly passed.

The BART structure is at least 5 times as massive, held up by pylons that take up nearly 5 times as much space, as the monorail “track” structure.

 

  Based on the kind of track construction BART uses on its open air sections (track on a ballasted deck), BART should be very quiet.  The reason it isn't is because they have a serious problem with corrugated rail which they haven't adequately addressed.  For those who may not know what this is, "corrugation" is a wear pattern consisting of tranverse irregulatorites on the running service of the rail head.  On a transit line, they may be an inch or two apart (you can actually see them. particulary after a light rain).  When a train rolls over them, the interface between the wheels and the corrugation creates an ear splitting vibration, which can't be felt but certainly can be heard.  The solution is to periodically grind the corrugations out.  Obviously, BART is not doing this often enough to properly address the problem  BART's not the only transit system which has this issue (CTA in Chicago has it too), but it's one of the worst.  The cable cars in SF also have it, in spite of their slow speeds.

With respect to the comment about monorails having a more slender, visually appealing structure, that's only true if you don't have emergency/maintenance walkways on the structure.  It's one thing for a small system like the Disneyland monorail to dispense with walkways and to handle maintenance and evacuation like you would on a roller coaster ride, but it's neither practical nor safe for a larger transit system.  You could build nearly as slender, visually appealing a structure for a conventional two rail system if you didn't have walkways.

[mogul264]

If I'm reading your references correctly, there has been, TO DATE, a grand total of only FOUR deaths associated with suspended monorails.......EVER ! Can you cite any OTHER mass transportation means with so horrible a record? The other issues you list can be overcome, I'm sure, with materials and methods available today, including the switching problem!

 

[NorthWest]

Give us deaths per passenger mile, please, for a better comparison. There are few suspended monorails.

[daveklepper]

Despite my positng some negative comments, I feel certain that more monorails will be built, but only when their one advantage outways their major disadvantage, lack of flexibility.  The market place is the final judge.   For urban transit, the ordinary bus is the clear winner, with more routes and more passsengers handled than any other mode.  But light rail, ordinary streetcar, trolleybus, guided bus and guided trolleybus, heavy rapid transit, commuter rail, arial cable tramways (Haifa and Grenoble), funiculars, underground subway funicular (Haifa the only one), combination light rail and funicular (Triest), ferry boats, elevators (Barcelona, Lisbon) all have a place, and so does monorail.

[northamericanexpress]

One of the main reasons that monorail technology has not found widespread appeal in the US is that many individuals still view it as appropriate for amusement parks, zoos and in some cases airports (Newark comes to mind).  Unfortunately, we don't have visionaries like the late Walt Disney (firmly believed that monorails were the wave of the future) to guide us at the moment.  However, if one had the opportunity to travel abroad to either Brazil, Europe, or even Asia, monorails are either already in operation, have been in operation for several decades, or currently being constructed not as stand-alone units, but as part of a larger munincipal or regional transit-oriented system.  For further information please check out the Monorail Society website (http://www.monorails.org).

 

[gkazin]

It's also a capacity issue: Monorail trains like Disney's Alweg systems are relatively small and carry a fraction of the number of passengers that conventional subway and elevated systems can handle.

 

[BOB FREITAS]

I recently rode the monorail at Disneyland in Anaheim. I was a very rough ride. Although the concrete track looked smooth, that was not the case as the speed was increased.

[LNER4472]

As it turns out, the Maryland Rail Heritage Library at the baltimore Streetcar Museum recently was bequeathed a LARGE estate that included a LOT of materials on monorails.  To be blunt, the deceased was a possible model for the "monorail salesman" in the notorious Simpsons episode, "Marge Versus the Monorail."

Monorails are an idea that sound good on paper but fail in execution.  Costs (construction and operational) are usually far higher than estimated; the power-to-weight ratio doesn't work; and too often, by the time a proposed system can be built the traffic patterns that instigated its construction (suburb to downtown, etc.) have changed, with an inflexible system turned into an albatross. One very unusual attempt to hold down costs which was actually installed in several countries--the Aeromovel, using atmospheric compression propulsion rather than electric motors--has not expanded beyond the few test systems in Brazil, Malaysia, Kuala Lumpur, and elsewhere.

I can name at least one major transit monorail project that has been abandoned and dismantled: Sydney, Australia's.