Are you ready for tubular rail?

I receive a steady diet of e-mail about future mass transit devices. Most are diverted straight to the trash bin, but some are provocative enough -- by that I mean strange -- that they're worth posting.

Hence, the above photo of tubular rail, the dream of Robert Pulliam and several others of Texas. It's not quite a monorail or train because there is no guideway and there are no rails. Essentially, the big concrete donuts act as the guide for the train and the wheels that keep the train moving are inside the donuts.

I'm no wiz at predicting the future, so I'll refrain from expressing further skepticism, other than saying I think we'll see Tubular Rail in Southern California about the same time that I can purchase a personal rocket pack at Vons. Attentive readers, in fact, will recall that this is a region that takes years to install bike racks.

Questions about tubular rail? The Tubular Rail website attempts to erase your doubts.

-- Steve Hymon

Image: Tubular Rail

Comments

[Mr_Grant]

"why then did you insert this into a discussion about mass transit in the Wilshire corridor?"

I did not. PRT Strategies made a comment about elevated alignment, then Daba Gabbard brought up PRT. You can read the rest.

[Kymberleigh Richards]

A rhetorical question for Mr_Grant:

If, as you say, "PRT has never been seriously proposed as a replacement or competition for an already-effective train corridor", why then did you insert this into a discussion about mass transit in the Wilshire corridor?

[Mr_Grant]

Despite my attempt @October 22, 2008 at 04:06 PM to allay fears of PRT, I'm still sensing a lot of fear.

PRT has never been seriously proposed as a replacement or competition for an already-effective train corridor. Trains excel at carrying large clusters of people between a line of stations, especially when those people cluster at big stations in dense urban centers. PRTs could be station feeders, expanding the ridershed of your stations without building park & rides.

PRT is network transit, not line-haul, passenger per hour per direction metrics aren't comparable. My examples were meant to get you to think about different ways capacity can be distributed. But thanks for the gratuitous name-calling Kymberleigh.

These are the key concepts for an idealized PRT network:

*It might have 4-5 stations per square mile. Thus the goal is not door to door service, but making a rail-like user experience more convenient.
*Stations closer together distribute demand by having smaller ridersheds.
*Only 2ish miles of guideway per square mile is needed to link the stations together, far less than the miles of streets in the same area.
*At Heathrow, guideway costs are $8-12 million per mile. PRT uses lighter engineering and fewer materials, due to light vehicles. As with any transit, cost elsewhere will vary depending on ROW and local cost of construction.
*Riders per hour is projected by dividing 60 minutes by the average trip time, then multiply times the number of vehicles in the fleet, times the average number of people per vehicle. Suppose:

[60"/12" including dwell time between trips] x 5000 vehicles x 1.25 riders = 31,250 riders

*The grid network distributes vehicle traffic because each trip takes the best route between any two stations, not the same corridor. Stations will have more berths where density is higher.

Now, I welcome your skepticism, and I am willing to answer more of your questions. But you should know that PRT engineering _and costs_ have been studied and/or demonstrated by the European Union, the government of Abu Dhabi, and two really big corporations that probably hate to lose money. They all think PRT is a sound concept, and are investing money in it.

But they are also investing money in trains, meaning they see PRT is one of a number of technologies, not a panacea.

So relax, train lovers. Conventional rail transit will continue to have a role. PRT continues to not be a threat to that.

[Damon]

Ohhh snap, Kimberleigh.

Some math, for fun:

Right now, the Blue line is averaging 85,000 boardings per day. Running 18 hours per day, that averages out to about 4,700 per hour, with rather poor headways of 12-15 minutes.

To match that capacity with a PRT system, you would need a daunting 3-second headway. Oh, and that's assuming somehow every car has 4 people, which of course it wouldn't since the point is to have your own private cab.

Assuming an average of 1.3 people per car, similar to driving, the headway would have to be a mythical 1 second.

By the way, capacity on the blue line could be doubled or tripled by reducing the headway, which means even if you could somehow achieve 1 second, you'd suddenly need three PRT lines instead of one.

[Kymberleigh Richards]

Mr_Grant:

Your analogies of warehouses and elevators do not make your arguments for PRT any more logical.

The reason: When you are discussing mass transit solutions, you have to take into account the "mass" part of the equation ... the fact that transit service is based upon (and designed for) large numbers of people who travel along the same corridor. To string enough PRTs together to equal the passenger capacity of a single rail car would mean your "12 elevators" would become more like "100 elevators", only in this case they would each have one or two people and take up fifty times the space. On the Wilshire corridor, that means carrying the existing number of passengers using Rapid bus service would mean your PRT guideway would itself be clogged with a constant flow of vehicles, without break.

If you think anyone is going to fund the infrastructure and then purchase that many vehicles (which would carry a maintenance cost higher than that of maintaining a smaller fleet of higher-capacity rail cars), then you are indeed delusional and we can discount your future arguments on that basis.

Reality trumps pie-in-the-sky, every time.

[Mr_Grant]

@KinOfCain

"the laws of physics state that PRT cannot have the capacity of a shared car."

There is a difference between capacity and ridership (usage).

Consider these examples:

1) Which company has greater capacity? Manufacturer A buys all its component materials far in advance, and builds and operates huge warehouses to store all of it. Manufacturer B has small storehouses, and instead orders materials as needed, timed so the materials arrive at the assembly plant 'just in time.'

2) Skyscraper A has a huge elevator lobby and one huge elevator running at 10 minute intervals. Skyscraper B has a smaller elevator lobby with 12 small elevators. Which is preferable?

[KinOfCain]

@Mr_grant

I really don't mean to sound snarky, but the problem with PRT isn't that it's based on any one particular technology, it's the capacity limitations. Even if you manage to get effective headways down to zero seconds by chaining cars together without slowing any cars down, you're still not going to get near the capacity of people sitting on a train together. Not to mention the capacity of a standing-room only subway car.

Sure, I'd rather be in my own vehicle, but until you figure out some sort of interdimensional transport that allows two cars to occupy the same space at the same time, PRT is a fundamentally flawed concept. Changing the tracks from rail to maglev, elevating them or burying them under the ground, none of that matters, the laws of physics state that PRT cannot have the capacity of a shared car.

[Mr_Grant]

RE: "any projects in the offing there?"

It slipped my mind that Daventry in central England has done a pretty detailed study,
http://tinyurl.com/3lv7lz

They have put out advance notice of a project tender, and could solicit bids next year.

[Mr_Grant]

Heathrow is an airport, so the thing will just be a glorified airport people mover... not urban transport by any stretch of the imagination.

It's supposed to be the world's busiest airport. If the PRT phase one goes well it will be extended to all the terminals, hotels and rail connections. I think this could be analogous to the patterns of a small city.

Abu Dhabi has oil revenues to indulge in fantasy technologies.

Masdar is part of their plan to transition away from oil by developing alternative technologies that can be commercialized. So yes, they have money -- to spend on R&D, and they have an incentive to develop products that cities, companies and other countries can afford to buy,

And Sweden may have certified the design, but are any PRT projects in the offing there?

There is an org called Institute for Sustainable Transportation which is building on work started by the Swedish Royal Institute of Technology. IST has enlisted a group of officials from 10-12 cities who are interested, a few have indicated they want starter systems, others are conducting public discussions. The national government will chip in some money, but the key bottleneck is how much the cities can pay -- a problem no matter the technology being considered. Of course, it helps that the Swedes can go to Uppsala and kick the tires of Vectus PRT located there.

It appears the key flaw is the concept, not any particular project design. Then why have several designs functioned according to specifications, and received safety approval? If you mean _acceptance_ of the concept, yeah obviously. PRT does not look like a train, and most people think that's the only way to achieve economies of scale.

And I love the snide "aren't you smart enough to realize how brilliant our (fill in the blank) technology is" by the various boosters.

It's an attitude I caution against. But consider that what you're seeing is advocacy -- we think we have a great idea. But the ideal vision is probably not what will actually be implemented. PRT will have to pass through the same planning and financial approval processes as train and bus transit. Taxpayers are not going to be sold a PRT that doesn't work, and no one is proposing buying something sight unseen.

Plus, PRT will necessarily be deployed to cooperate with conventional modes. In short, I don't think there is a need to fear PRT.

[Dana Gabbard]

Mr. Grant:

Mea culpa as to confusing Raytheon and Siemens.
As to your examples, Heathrow is an airport, so the thing will just be a glorified airport people mover which is certainly a useful application but not urban transport by any stretch of the imagination. Abu Dhabi has oil revenues to indulge in fantasy technologies. And Sweden may have certified the design, but are any PRT projects in the offing there? Your examples prove it isn't just America that so far has not exactly been rushing to get on the PRT bandwagon. It appears the key flaw is the concept, not any particular project design. And I love the snide "aren't you smart enough to realize how brilliant our (fill in the blank) technology is" by the various boosters. That will really win over people.

[Mr_Grant]

Dana Gabbard:

As to PRT, Siemens some years ago created a test track outside Chicago

It wasn't Siemens, it was Raytheon.

only to eventually concluded it wasn't commercially viable and dropped the whole thing.

Raytheon's version wasn't commercially viable due to design mistakes identified after the cancellation. Current designers are trying to avoid repeating them, and most appear to be succeeding.

by all signs that is where PRT is going--nowhere despite the ardent passion of its boosters.

And yet construction has finished on Phase 1 of a PRT at Heathrow, and Sweden has given safety certification to another PRT design. And the Masdar zero-carbon city project in Abu Dhabi is planning a citywide PRT network.

Maybe you mean PRT (like monorail) is going nowhere in America. Maybe you should ask yourself why America is such a difficult climate for newer transit technologies to gain acceptance.

[Kymberleigh Richards]

This does not appear to me to have the passenger capacity necessary for the Wilshire corridor, and that photoshopped picture looks as offensive to me as the one that Metro did showing elevated light rail or monorail.

But it is the capacity issue that has driven the discussion as to what mode to use on Wilshire. This is just a monorail with a different propulsion mode, and a mode that has been pointed out by others to have many more potential failure points. Get over it, people. It has to be a subway or it will be inadequate for the corridor's needs from the opening day.

I'll also remind proponents of a different technology that there isn't anywhere to put a storage/maintenance yard for "something new" on the Westside, whereas Metro already has the subway yard adjacent to the Amtrak yard east of downtown, so no problem there.

[Mary K Mackanin]

With an economy rapidly sinking and people getting laid off, including the righteous engineers and other white collar workers, perhaps a project such as tubular rail would offer a 21st century solution similar to the CCC of the post depression 20th century. It would be an economic plus for the US. An eye sore? Get real do you enjoy highways of 18 wheelers lined up for miles as you sit looking at their back ends for hours waiting for the train congestion to clear at the rail crossing? Open your minds people and for all the engineers I think it was in kindergarten that we learned the saying put on your thinking caps girls and boys. Let's get moving forward.

[Ken Alpern]

It's...tubular, dude!

[Aaron]

Engineers would rightly call this silly thing "a solution in search of a problem."

[Robert Pulliam]

Steve,
Thank you for posting info on Tubular Rail. I hope your readers will take the time to visit the web site http://www.tubularrail.com/
which should answer most of the usual questions. I recently spent some time in the LA and San Diego, a lot of it on the 710. If LA and the rest of the world are going to do something about the triple threat of climate change, congestion and cost of infrastructure then the nay sayers will have to open their eyes a bit and see the future. Tubular Rail's future is built on sound engineering, the cantilever beam was popularized by Frank Loyld Wright after all, and existing. readilly available mechanical and electrical equipment. The end result is that a city can avoid the battle over roads or rail and can have, for the most part, both. The fact that Tubular Rail is essentially 95% air space is reflected by University (Darmouth) reviewed costs estimates of 20 million dollars a mile versus say the Expo line at 175 million a mile. But hey, California has got lots of money right?
I hope California will make it further than Texas and Florida did with their High Speed Rail efforts but remember the lesssons of those two projects, it isn't the train that costs all that money, its the tracks.
Best Regards,
Robert Pulliam
Tubular Rail Inc.
Houston TX

[Paul]

My God, that's an eyesore.

PRT Strategies sounds like an angry company.

[KinOfCain]

Sheesh, I keep coming up with reasons why this is a stupid idea:
5: Rain, snow, whatever. The function of the guideway on systems like light rail or elevated heavy rail, is not just to support the train, but it also acts as a catch basin for crap that drips off the train. Stuff like oil, or dirty rain water, or snow. This might (might) have fewer problems with that than a normal train, but it's still an issue. Although since it can't turn, it probably doesn't need much grease to lube up those joints.

[KinOfCain]

4: And I completely forgot: The motors are in the o-rings, not attached to the train, so instead of buying, say a half-dozen motors per train, you need to buy and maintain hundreds if not thousands of motors in the field. And you can't just pull a train off the track to service the motor, you have to shut down that line.

This is a half-baked idea at best.

[KinOfCain]

1: It's the Zoolander of rail systems: It can't turn left, actually, it's worse, it can't turn right either. Actually it probably can, but the turning radius is likely huge. Their site shows a classic-style "roundhouse" to make tight turns. Which is hilariously insufficient.

2: This isn't even close to being manufactured. So really we're talking about an idea, not a plan.

3: I can't imagine the structural rigidity that each train would need to have to keep from flexing between the o-rings. It wouldn't be difficult to make a train strong enough to do that, but it would be incredibly difficult to make a train stiff enough that it wouldn't oscillate so obnoxiously in the cabin that anyone would want to ride in it. You'd have massive, massive motion sickness issues in the front and rear cars.

[Dana Gabbard]

This tubular thing looks like an accident waiting to happen.

As to PRT, Siemens some years ago created a test track outside Chicago only to eventually concluded it wasn't commercially viable and dropped the whole thing.

I tire of technology boosters and their selective arguments. For PRT to have any value we would have to construct an extensive regional network that would cost hundreds of millions of dollars plus have to overcome serious challenges regarding maintenance, liability, funding, etc. It just isn't going to happen. And by all signs that is where PRT is going--nowhere despite the ardent passion of its boosters.

[PRT Strategies]

The point that should have been made here is that this system is ELEVATED -- not buried, not at-grade. Whether or not this specific technology makes sense is less important than the idea that it occupies its own space in the illustrated urban environment and does NOT interfere with other modes like surface traffic. It therefore causes NO additive congestion or degradation of surface speeds.

Neither would it likely cost the HUNDREDS OF MILLIONS of dollars that light rail requires as current plans in LA County call for it to be primarily below ground. Further, this system only interacts with itself -- and wouldn't likely be meeting a freight train coming in the other direction.

Of course, the naysayers will immediately respond that the "visual intrusion" won't be acceptable, yet there are plenty of opportunities to place transit in places that are just as useful as arterial streets -- for example, LA and Orange counties have over 600 miles of flood and river channels -- valuable citizen-owned property that could be used for purposes beyond its parochial design.

[Gary Kavanagh]

Any word on how such a system would say make a turn?

Well actually after looking it over they have a system for turning, but the whole things sounds precarious. I'm doubtful of Earthquake safety considering all it takes is one of those loops to go out of alignment for the whole thing to be screwed.