Paul of CovingtonWith all that superstructure, I was wondering--cheaper than what?
Cheaper than grading a whole new 'permanent way' to the standards needed for high speed, or for the 'taking' of real estate in the path of the route!
One point made about the Railplane system is that it was made to go above existing railway lines (as in the case of the test section), so the amount of actual intrusive footprint would be miminized (much as the Schwebebahn is by being over the 'non-buildable area' of the riverbed most of the way).
No question that esthetic standards and concerns were a bit different then!
daveklepperThis goes back to Dr. Charles Harvey's original West Side Patent Elevated Railway from Debrosses Street and Greewich Street to 29th Street and 9th Avenue, 1868, North Amerca's first grade-separated rapid transit line, cable operated. Wood crossties were introduced when steam replaced cable. Around 1870-1871.
The original track was somewhat flimsy looking, I'm not surprised they added ties.
NorthWestThe original track was somewhat flimsy looking, I'm not surprised they added ties.
Nothing flimsy-looking about THAT track structure. But talk about roll-out-the-barrel noise! No damping! No compliance!
They added the ties for noise and shock reduction. And none too soon!
And the noise and vibration came with steam. Cable operation was quiet.
daveklepperCable operation was quiet.
As long as it stayed sl -o-o-o-o-o-w. Get it up above a few mph and it will NOT be quiet. Likewise if any shock introduces oscillation. Now how do you stop the car without putting wear on the wheels?
I think ties -- or some other use of wood damping -- is in that system's 'future' regardless of what system powers it!
My elevated light rail concept uses continiuos neopren pads under both running and guard rails, with the usual Pandroil or other resilient clips to insure resilience doesn't mean ability to get out of gauge.
The noise of Charles Harvey's system was minimized by a 15mph top speed, lightweight cars, and minimum structure to radiate sound. Probably about the same as a San francisco cablecar.
They had regular handbrakes on the cars. They did not have to worry about traffic. While the line was cable operated without ties, it had one passing siding and no intermediate stations. Just two trains, something like a horizontal funicular.
daveklepperMy elevated light rail concept uses continuous neoprene pads under both running and guard rails, with the usual Pandrol or other resilient clips to insure resilience. [That] doesn't mean ability to get out of gauge.
Yes, that ought to go a long way toward solving the problem. Using elastomer isolation in the wheels (if that technique has been reasonably perfected) is even better. As you note, NVH abatement in transit vehicles is a very advanced practice.
I had a somewhat different high-speed track system that likewise used elastomer under the rail and isolating the clamp systems. This provides primary damping. There does need to be some secondary 'damping' to get rid of the transferred energy, but that is not difficult to include in the longitudinal bearers in the guideway. The salient point here is that the natural frequency of the primary damping is not really suitable; compare how a vehicle would ride if all it had were some variant on composite chevron springs. (I always think of poor Mr. Nystrom from the Milwaukee, who thought ride had to get harder the more you optimized your suspension for higher speed...)
You will probably need something much more robust than periodic gauge rods in the track structure, however. I used a modified multiaxis truss for the gauge members, tying into the reinforcement in longitudinal precast/post-tensioned concrete structure. That does not increase the 'skyprint' in any meaningful way, but ensures that all the different forces trying to distort line and surface out of the axis of the continuous beam can be accommodated.
The beams themselves and the Pandroil Clips are sufficient to hold gauge as in any slab street track, common practice. The stainless steel gauge rods are primarily to assure accuracy in track installation, and there can be other methods without any tie of any kind except at the beam supports. This would be particularly true with reinforced concrete beams, rather than simple steel. But unlilke monorail, the reinforced concrete longintudinal beams need be no wider than needed for each to support a running rail and a guard rail, about a half-meter, or 19 inches..
And yes, this is an elevated light railway, so of course the cars have resilient wheels and air-suspension or equivalent, with overall design carefully controled for spaced resonances, including that of the beam and support structure ---which if reinforced concrete, should fairly rigid and damped. If it wasn't, it would develop sags between supports, which cannot be allowed to happen.
While one might assume a San Francisco cable car is quiet, along with one of the coldest winters I experienced being one summer in San Francisco, among the noisiest rail rides I ever experienced were the cable cars I rode during that San Francisco summer, 1991. Was that an unusual year for corrugated track, or whatever contributed to the loud rail grinding type noises I heard?
Patrick Boylan
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I suspect that whatever grease that they used in the sheaves had become thicker due to the cold.
I also believe that was around the Muni Meltdown resulting from system neglect.
Remember that they had to shut down and thorougly rebuild the entire cable-car network just a few years after your ride. But it had the positive result of the historic streetcar festival and this led to the F line
www.streetcar.org
I thought the shutdown and rebuild was before my 1991 ride. What are the dates for the shutdown to which you refer?
You are correct. I missed your 1991 date. Apprix. 1985. www.streetcar.org has the full story. Don't understand, then, why so noisy, except that there are no resilient wheels, no rubber on any sort in the suspensions, noise of cables runniing over sheeves, possibly other matters as well.
Someone pointed out peripherally that there are other Disney monorails...
;-}
I'm not sure what the basis is for the claim that monorails are a "lower cost alternate to elevated railways". A monorail and a 2-rail elevated will require similar supporting structures. A huge disadvantage to monorails vs 2-rail system is that switches on a monorail are very complex and expensive. On a 2-rail system, you merely have to move the running rails. On a monorail, you have to move the entire supporting structure - it's basically a transfer table (that's the way the Disney monorail switches work). I have never seen a crossing of two monorail lines, but I imagine that would require an apparatus similar to a turntable to properly align the supporting structure for the route of movement. The complexity and expense of these devices likely make monorails unsuitable for general transit use with multiple switches and crossings.
With respect to the noise of the SF cable car system, sections of it are, indeed, quite noisy. The reason is that the track in these sections has become very corrugated (i'e', the rail has a wear pattern of small ridges every inch or so at a right angles to the direction of movement). it isn't noisy in places where the cars regularly apply their track brakes, since the friction of the brakes on the rail prevents the corrugation from developing. The solution is periodic rail grinding to restore the original profile, but I don't think they do this on the cable lines. BART has a similar problem on some of its trackage.
The monorail switches for the EWR airport are quite massive.
The way they work is they are on a steel beam about 200 ft long with straight route on one side and curve route on other side.
To switch the beam rotates 180 degrees longitudinal to change the route from straight to curve.
first previous route changes from clear to stop
Sequence is the retraction of 8 pins hydraulically that had locked the beam in place.
Once all pins retracted they activate safety interlocks
Then a hydraulic motor rotates the beam 180 degrees in about 25 - 30 seconds.
So monorail,s previous route is now underneath
Then the locking pins are moved back into place and the logic determines all pins are in place then gives a clear.
When beam returns to previous route beam rotates opposite direction.
Here is another site to look at: www.monorails.org.
I have ridden and studied all 4 major US systems (Las Vegas, Disneyland, Disney World, and Seattle). Their best advantage is being up above traffic. The Epcott line at WDW runs at 40 MPH and is quite smooth. The Las Vegas line had a lot of potential but has the disadvantage of succumbing to local politics and being routed on a serpentine path behind the casinos over a back road like an unwanted stepchild. I drove the route of the Seattle line at rush hour from the Space Needle to the downtown station in 15 minutes, but rode the train back in 5. It's too bad I can't post pictures here because I have several interesting views of ALWEG cars and Bogies.
The best form of track in my opinion is two parallel beams with an emergency walkway between them.
Last Monorail I rode was in Indy. IN. I went out of my way to ride the Purdue- Methodist Hospital Line which is about 2.5 miles long. The ride was not exactly smooth and it was rubber tire on concrete guide way. Being that concrete has a shelf life after curing I assume that in 20 years or so this line will be a fallen flag, Like Jacksonville none of the plans in Indy for rail call for monorails or people movers.
The Indiana University Health People Mover is only 1.4 miles long and operates at a top speed of 30 mph since starting service in 2003.
C&NW, CA&E, MILW, CGW and IC fan
Aside from corrugation, sand is another reason the SF cable car system can be noisy. When it rains, the cable cars drop sand on the rails to facilitate braking. If you ride the cars during or just after a rainy period, there will be a lot of sand on the rails, and the cars will make a loud grinding sound as they operate over it. This is a temporary situation , which goes away as the track gets clean.
Another source of noise is welding repairs I've noticed that track crews often repair worn cable trackage (particularly at special work) by welding a bead on the rail head, in the flangeway (which, near special work, is flange-bearing), or on the face of a guard rail. This results in a rougher (and noisier) surface than the original rail. However, these are typically only short segments. Corrugation appears to be the major culprit.
NorthWestThe Wuppertal Schwebebahn is a very interesting setup, using rail instead of a beam. Unfortunately, it still has the complex switching problems of others. How far did the gyroscopically balanced monorail come?
The Wuppertal Schwebebahn is a very interesting setup, using rail instead of a beam. Unfortunately, it still has the complex switching problems of others. How far did the gyroscopically balanced monorail come?
n012944 The monorails at Walt Disney World have a top speed of 40 MPH on the Epcot line. http://en.wikipedia.org/wiki/Walt_Disney_World_Monorail_System
The monorails at Walt Disney World have a top speed of 40 MPH on the Epcot line.
http://en.wikipedia.org/wiki/Walt_Disney_World_Monorail_System
ATSF2499 Here is another site to look at: www.monorails.org.
MONORAILS are safe. Whether they are of the straddle-beam or suspended variety, modern monorail technology makes derailment virtually impossible. As monorail is elevated, accidents with surface traffic are impossible. Zero accidents with pedestrians or surface traffic translates to no system down time, less liability suits and most importantly, a safer public. Street rail systems with grade crossings (light rail, trams or trollies) can't approach this level of safety, as any study of accident history will show.
The paragraph starts out with an aspect I can agree is unique to monorails, does anybody have info on derailments? The rest of the paragraph though tries to say that only monorails can be grade separated. Can we all agree that there's nothing to stop one from making ANY right of way grade separated, not just monorails, which are very difficult to make anything BUT grade separated?
They continue in this vein, the next paragraph says they don't pollute since they're electric. Is there anyone among us who thinks that power source automatically says anything conclusive about how clean or dirty the transport mode is?
aegrotatio It went as far as when the motorman drove the train at slower than its designed speed, and it fell over as it lost balance. The train was not designed to run at speeds slower than, if I recall correctly, 35 MPH on that particular section of track.
Can I have a detailed reference on this? Particularly about the 35 mph curve business?
Decades ago I remember reading in either Steve Maguire's Trolley Car Treasury, or William Middleton's Time of the Trolley, that the New York Pelham Park monorail did derail while taking a curve too slowly since part of its design was to have the wheels act as gyroscopes and give stability.
I don't know about any specific 35mph limit. Goo goo gives me
http://query.nytimes.com/gst/abstract.html?res=F50717F834591B728DDDAE0994DF405B808DF1D3
The inventor, Howard Hansel Tunis was also the operator, page 1. Page 2 "The curves of the road are built for high speed and if I had put the car around the curve at high speed there might have been no mishap"
gardendanceDecades ago I remember reading in either Steve Maguire's Trolley Car Treasury, or William Middleton's Time of the Trolley, that the New York Pelham Park monorail did derail while taking a curve too slowly since part of its design was to have the wheels act as gyroscopes and give stability.
This story has a different explanation. While I hate to cite Wikipedia, they have a convenient link to the basic story (see Pelham Park and City Island Railway). There is more, I believe, in this classic book (this is the link to read it online).
This is the Tunis system shown at the Jamestown Tercentenary, which really isn't a 'monorail' any more than the Boynton or Lartigue systems are, and is manifestly and painfully non-gyroscopically-stabilized. It's kinda like the Lartigue system upside-down, with the stabilizing rails also being power conductors. This was a rather obvious disaster in the making for a system that had laid much of its bearing-rail structure on sand -- all it took was enough tilt for the contact side-bearing wheel to misalign with its rail, and toppling-over would be imminent...
I had thought you were describing a system like Brennan's, where there is actual gyroscopic stabilization; I don't know offhand of a system that directly depended on gyroscopic moment of the wheels to keep the train stable. I understand Tunis' point about the low speed to be -- this is speculation, mind you -- that the rail was somehow superelevated in curves, and the long overhang of the car resulted in downward and inward shift of the rail, leading to the car losing 'track' on the inside guide rail and then falling over to the inside of the curve. Presumably at higher speed only the outer wheel would have remained in guiding contact, with the deep flanges keeping the car located even with some unevenness of support... but don't ask me to ride the thing -- it's a death trap!
Thanks for pointing this out!
I view mono rails like lateral elevators, meant for a very limited purpose. If after all they were practical there would be many more of them built. I class them in the same category as pneumatic tubes, expensive toys.
History has proven that anything with a fixed consist will become obsolete in a short time. The new Haven comet trainset was a victim of its own success for example. It wasn't long before demand outpaced the limited accommodations of the train and actual locomotive hauled train was substituted.
Maybe that's why the Milwaukee road opted for a conventional train instead of a fixed trainset.
Wasn't there a tube system built in NYC ?
R
Randy StahlHistory has proven that anything with a fixed consist will become obsolete in a short time. The new Haven comet trainset was a victim of its own success for example. It wasn't long before demand outpaced the limited accommodations of the train and actual locomotive hauled train was substituted.
i think you will find that fixed consist passenger trains have been operating very successfully in Europe and Asia for many years to a large degree.
Then the obvious question is , why don't they work here? Or perhaps why is it so different here? I know that Amtrak had some success with the turbo trains but after all , they are not in service anymore and there were no replacements built.
Is the Acela train a fixed consist ?
I'm a freight railroader , pardon my ignorance in passenger train management.
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