The most efficient way to launch.

[SKULLY]

I apologize if this has been asked before but this question has been bugging me recently. What is truly the most efficient way for a coaster to launch regarding instillation costs, maintenance costs, downtime, power usage, or any other factors? I would assume that the power required to launch would come down to the weight of the train, the acceleration, and the length of the launch. But does anybody have any idea what it really costs a park each time a train is launched using each of these methods?

 

The only real choices nowadays are LIM, LSM, hydraulic, and pneumatic. Each offers a slightly different experience yet they all pretty much have the same job, get the train moving quickly. Out of these, I would assume that LSM or LIM would be more cost effective due to using very few if any moving parts. However, I also have to wonder if the actual cost of sending power to all of the magnets would be more than the other methods. Does anybody have any sort of real numbers or answers to my question? Thanks ahead of time.

[ebl]

My favorite way to launch a train is to let it roll down a tall hill...

 

I know what you're getting at, though. Interestingly, after using cables, then various magnetic methods (LIM, LSM), manufacturers have returned to cables (the Intamin hydraulic launched rides, and Zamperla's flywheel launched rides). And don't forget S&S and their air powered launch.

 

I'm no engineer, but I think a flywheel does just fine. Perhaps not as much speed is attained from it, but its power usage seems to be lower than other types.

 

Eric

[atem122]

Yeah, I don't know if too many people on the site would know the answer, but I do know that having 10 men push you is very efficient!

[megamatt]

I would say LIM's or LSM's but if the earths magnetic polarity reversed launches would brake and brakes would launch!

 

Kidding aside, I would still say LIM's, there power-intensive but with no moving parts there very reliable.

[SKULLY]

It seems that trends seem to shift back and forth regarding magnetic and cable methods for launching. And it's probably no coincidence that the fastest launches, both with acceleration and max speed, are obtained using cables. Yet, the new iSpeed coaster looks to launch with a very close intensity to that of cable launches so perhaps magnetic launches are catching up. After all, cables are old technology and do appear to face much greater wear and tear.

 

Just to clarify, don't LSMs attract and repel the train repeatedly until the max velocity is reached while LIMs simply pull the train along? It also appears that LSMs have a much greater rate of acceleration and I wonder if it is indeed because of the above?

[hyyyper]

LSM and LIM might not have any moving parts, but the electricity bill goes trough the roof for each launch. Air and Hydro can take longer to build up energy and are more efficient in that way.

[Gav]

In terms of energy in versus energy out, then LSMs are the most efficient.

 

The thing to keep in mind is that although Hydraulic / Pneumatic launches have a lower peak load requirement since the electricity is drawn at a constant rate all day long to continuously pressurise the accumulators, they still use more energy overall because it is a less efficient system.

On the other hand, magnetic launches only need power when the train is launching, but the downside is that they need to draw all this power in the space of a few of seconds, which means special infrastructure requirements to deal with this.

[AmyUD06]

Thus the brown-outs that the "east" side of SFGA saw back when they were launching both sides of the Chiller at the same time during the first two years.

[B-RadG]

How about Arrow's efficient Launched Loop method.. use a block running the tracks and have it smack the train away

 

Seriously though, I'd say LSM/LIM. They may be noisy (Superman the Escape....) and may waste electricity, but they don't have nearly as many problems as air/hydraulic launch coasters.

[Sunfire]

Too bad parks can't go old fashioned again. Whatever happened to weight drop launches, such as the one on Greased Lightnin' at SFKK? I remember when CGA had their shuttle loop, this particular type of launch is simple enough to work and deliver a forceful ride.

[exmouse]

On the other hand, magnetic launches only need power when the train is launching, but the downside is that they need to draw all this power in the space of a few of seconds, which means special infrastructure requirements to deal with this.

 

That's not the case any more, Maure Sohne has come up with a way around this, Formule X their first launched coaster installed at Drievliet uses a system to reduce the power load. Here's a quote from their press release.

 

The ride comes with an energy storage system

which cuts the top power requirement to

125 kW and helps to further reduce running

costs.

[nitrofan]

Kidding aside, I would still say LIM's, there power-intensive but with no moving parts there very reliable.

 

I get what you are saying, but look at the nightmare on Chiller.

[ethans_dad06]

And even though the magnetic launches have less moving parts, the magnetic coils do wear out and can burn up. And when a magnetic coil burns up it often times is a very expensive repair.

[PKI Jizzman]

On the other hand, magnetic launches only need power when the train is launching, but the downside is that they need to draw all this power in the space of a few of seconds, which means special infrastructure requirements to deal with this.

 

Tower. of. Terror.

 

It was a fun ride though! I enjoyed it when I wasn't stapled. Stapled it didn't do jack.

[ebl]

^ Same as Superman--The Escape at SFMM. That was a great ride at one time, but its time has passed.

 

Wouldn't it be great if solar power could be collected and saved for LIM/LSM launches?

 

Eric

[Leviathan]

Yeah, I don't know if too many people on the site would know the answer, but I do know that having 10 men push you is very efficient!

 

If only 10 men could run at 120 MPH.

[Gav]

That's not the case any more, Maure Sohne has come up with a way around this, Formule X their first launched coaster installed at Drievliet uses a system to reduce the power load.

I remember Intamin mentioned it too with respect to their LSM ball coasters....Though I was trying to keep matters simple by looking at the standalone systems.

I think down the track we will see manufacturers start tending towards LSMs again, since LSM with power storage would most likley be the most best way of launching these days...Higher efficiency, less moving parts, but still with lower peak load requirements.

[dragsterfan420]

By far the most efficient way to launch a coaster is with compressed air. Now if some company would do it, compressed steam would be even better.

[EnglndPatriots6]

How about strapping a Shuttle engine to them? it wouldn't be top thrill dragsters, it'd be top thril shuttle. I still wouldnt ride it tho lol.

 

I guess to be serious, something thats fast and isnt torturing. Although Top Guns lift at KI which is slow is pretty nice beacuse you get to see the whole park sort of so its got a pretty decent lift.

[rcroques]

As far as power and general acceleration, I'd tend to say that a hydraulic launch would be the most effective at accomplishing that goal.

 

However, I am going to say that LIM is the way to go as far as efficiency. An LSM motor requires the magnet to be electrically charged to alternate between attract and repel to propel the car to it's eventual velocity. A LIM only requires that it be electrically charged to create a magnetic field, thus negating the need for an alternating current; there are no moving parts, making it the more efficient of the launches. However, the cost of failure on ANY launch system is rather high.

 

Keep in mind, I'm not that good with the mechanical aspect of coasters. Everything I say is from my own understanding.

[ahecht]

However, I am going to say that LIM is the way to go as far as efficiency. An LSM motor requires the magnet to be electrically charged to alternate between attract and repel to propel the car to it's eventual velocity. A LIM only requires that it be electrically charged to create a magnetic field, thus negating the need for an alternating current; there are no moving parts, making it the more efficient of the launches. However, the cost of failure on ANY launch system is rather high.

 

That's not true. Both LSMs and LIMs require the current to switch. The difference is that LIMs the current must be constantly alternating in a sine wave at high speed (just like the AC current that comes out of your wall), but with LSMs the magnets just have to switch polarity once as the train passes.

 

Basically, a LIM system induces a magnetic field in the copper plates on the train (hence the "I" in LIM), propelling them forward. Inductance only works with alternating current. In fact, many modern AC motors that you might see around your house (power drills, kitchen appliances, etc) use induction motors because there are no brushes to wear out.

 

The real advantage of LIMs is that they don't require the launch system to know the exact position and speed of the train. The train is basically riding on a magnetic wave which is traveling at a fixed speed down the launch track, and the train will accelerate to catch up to the speed of the wave the same way that people get pushed to the shore in a wave pool. A LSM system requires a huge number of sensors to know exactly when the train passes each magnet so that the polarity can be reversed at the right time.

[Gav]

It seems as if people are using a mixed definition of what 'efficiency' is.

 

Remember, efficiency is the the amount of useful work you get out of the system per unit of energy input:

 

Pout / Pin = Efficiency

 

It is not a measure of how fast it can accelerate things, or how much it breaks down, it is strictly energy in versus energy out.

 

Using the formula for Kinetic energy, I worked out that a 20 tonne coaster train going at 100Km/h carries 100,000,000 J of energy.

Therefore to get it going at that speed the launch needs to provide 100,000,000 J of energy.

 

But the number of Joules of energy the launch system uses depends on Efficiency.

 

If they system was only 50% efficient, then you would need 200,000,000 J of energy per launch.

 

If it were 80% efficient then you would need 125,000,000 J per launch.

 

No mechanical system can be 100% efficient.

 

Also, I found a quote from the Maverick construction blog.

( http://maverick.cedarpoint.com/latest/diary/index.cfm?entry=9e71e6b4-eea8-4b63-8cb5-844a18a0f2a6 )

In case you’re wondering what the difference between LSM and LIM (linear induction motor) launch system is, LSMs give you more power, while LIMs give you faster acceleration. Don’t worry, LSMs still allow the trains to reach the same velocity (speed) as LIMs. The advantage is we want to send Maverick’s trains out with a lot of power.

The reason why LSM gives more power is because more of the electrical energy is being converted into kinetic energy, LSMs are quite good at this.

LIMs can push a train forward quite quickly, but it comes at a great cost as LIMs suffer greater heat and resistive losses.

 

However, I am going to say that LIM is the way to go as far as efficiency. An LSM motor requires the magnet to be electrically charged to alternate between attract and repel to propel the car to it's eventual velocity. A LIM only requires that it be electrically charged to create a magnetic field, thus negating the need for an alternating current; there are no moving parts, making it the more efficient of the launches.

Even though LSM is more complex to operate, the reason you put up with this is because it is a more efficient system, and over the rides life cycle the more complex maintenance is a small price to pay considering what they will save on the power bill.

 

 

One thing that is interesting to note is that LSMs are getting better these days in terms of acceleration performance....iSpeed gets to 100km/h in 2.2 seconds using LSM , Rita gets to 100km/h in 2.5 seconds with Hydraulic.

 

As a final point, there is no way Hydraulic or Compressed Air launches can be the most efficient way...There are many moving parts in these systems, so they suffer higher mechanical and heat losses.

[ethans_dad06]

^ That was very well said! And very informative. All of what you said makes perfect sense though, and really highlights the pros vs. cons of the various systems.

[ahecht]

It seems as if people are using a mixed definition of what 'efficiency' is.

 

Remember, efficiency is the the amount of useful work you get out of the system per unit of energy input:

 

Pout / Pin = Efficiency

 

You're looking at this from a physics/engineering standpoint. From a business standpoint, efficiency is about a lot more than energy in/energy out. It's about cost in/customer satisfaction out. Therefore a system which requires frequent costly maintenance or has a lot of downtime is a less efficient use of the money you spend to buy and run the system.

[ethans_dad06]

Magnetic launches have virtually no moving parts, and moving parts means there is more preventative maintainence Which costs alot when you add it up over the years. Also more moving parts means there is more parts to break which will in turn create more of a gamble when it comes to ride uptime or downtime.

 

When it comes to how a coaster is launched, the average park guest does not care how it's done, just as long as when they are in line it doesn't break down and they get their ride in. But if a park fails to look at long term maintainence costs, and only looks at up front investment then you can be assured that they are in for costly downtime.