Actually, while they're talking about accelerations, since F=MxA it IS a force that they're talking about. Trouble is the exact magnitude of the force will vary with the mass of the rider.
This is where the whole idea of G-force comes in. A force of 1G is equal to a force of 32 pounds per slug, or 9.8 Newtons per kilogram. It's only appropriate to talk almost interchangeably about forces and accelerations because under normal circumstances, the mass is held constant in the system.
Alpengeist is a pretty good example of why this regulation is so meaningless. Alpengeist is a modern, well-designed coaster, and for the convenience of Physics students, Busch Gardens has mounted crude accelerometers to the backs of certain seats.
If you sit in the seat right behind the accelerometer you can see dynamically that the ride doesn't ever exceed +4G, and when it does so, does so very quickly. And New Jersey is talking about limits up to +6G for impulse. So the limits will have no significant effect on new rides, old rides probably already comply...so the new regulation accomplishes nothing.
The "one death in New Jersey" referred to in this discussion is a single death that might possibly be related to ride forces, rather than to some accident (be that accident a mechanical failure or a problem of rider behavior).
Off the top of my head I can think of several ride fatalities in New Jersey in recent years, most recently in...er, I think it was in August of 1999...when two riders were killed in the same incident.
New Jersey has a pretty comprehensive ride safety program to begin with, mostly concerned with the building code. Historically, New Jersey has been mostly over-reactive with their ride code. They had a poorly-engineered and poorly-built bungee tower fall over onto a bumper car pavilion, so now all rides are subject to structural review. They had an incident where a fabrication error on a roller coaster allowed a routine malfunction to turn into a fatal accident, so now they want to review ride designs. I suspect that their desire to establish a force standard is a desire to be proactive for a change. The new regulations are a bit more sweeping than just force limits; if anything, I think the force limits are probably the most benign part of the whole package!
(sorry, that was a thread that ran for two and a half years on news:rec.roller-coaster, mostly dealing with how to count the new millennium)
Cedar Point's Millennium Force is yet another example of why the kind of regulation New Jersey is talking about is a total waste of time. That ride is 310 feet tall. It goes 92 MPH. It might come close to an instantaneous load of +4G. Designers have become really good at this, and because high G-forces tend to create motion sickness in a lot of people, the forces on rides are getting more and more controlled all the time. Taller, faster, scarier, but also smoother, and with more tightly controlled G-forces.
Instead of wasting time yelling about G-forces, why dont the regulators concentrate on something that might actually prevent injuries, such as operator training and certification, or fault tolerance testing of control systems?
--Dave Althoff, Jr.
Slashdot Mirror
Actually, while they're talking about accelerations, since F=MxA it IS a force that they're talking about. Trouble is the exact magnitude of the force will vary with the mass of the rider.
This is where the whole idea of G-force comes in. A force of 1G is equal to a force of 32 pounds per slug, or 9.8 Newtons per kilogram. It's only appropriate to talk almost interchangeably about forces and accelerations because under normal circumstances, the mass is held constant in the system.
--Dave Althoff, Jr.
Alpengeist is a pretty good example of why this regulation is so meaningless. Alpengeist is a modern, well-designed coaster, and for the convenience of Physics students, Busch Gardens has mounted crude accelerometers to the backs of certain seats.
If you sit in the seat right behind the accelerometer you can see dynamically that the ride doesn't ever exceed +4G, and when it does so, does so very quickly. And New Jersey is talking about limits up to +6G for impulse. So the limits will have no significant effect on new rides, old rides probably already comply...so the new regulation accomplishes nothing.
--Dave Althoff, Jr.
The "one death in New Jersey" referred to in this discussion is a single death that might possibly be related to ride forces, rather than to some accident (be that accident a mechanical failure or a problem of rider behavior).
...er, I think it was in August of 1999...when two riders were killed in the same incident.
Off the top of my head I can think of several ride fatalities in New Jersey in recent years, most recently in
--Dave Althoff, Jr.
New Jersey has a pretty comprehensive ride safety program to begin with, mostly concerned with the building code. Historically, New Jersey has been mostly over-reactive with their ride code. They had a poorly-engineered and poorly-built bungee tower fall over onto a bumper car pavilion, so now all rides are subject to structural review. They had an incident where a fabrication error on a roller coaster allowed a routine malfunction to turn into a fatal accident, so now they want to review ride designs. I suspect that their desire to establish a force standard is a desire to be proactive for a change. The new regulations are a bit more sweeping than just force limits; if anything, I think the force limits are probably the most benign part of the whole package!
--Dave Althoff, Jr.
(sorry, that was a thread that ran for two and a half years on news:rec.roller-coaster, mostly dealing with how to count the new millennium) Cedar Point's Millennium Force is yet another example of why the kind of regulation New Jersey is talking about is a total waste of time. That ride is 310 feet tall. It goes 92 MPH. It might come close to an instantaneous load of +4G. Designers have become really good at this, and because high G-forces tend to create motion sickness in a lot of people, the forces on rides are getting more and more controlled all the time. Taller, faster, scarier, but also smoother, and with more tightly controlled G-forces. Instead of wasting time yelling about G-forces, why dont the regulators concentrate on something that might actually prevent injuries, such as operator training and certification, or fault tolerance testing of control systems? --Dave Althoff, Jr.