Little rubber flaps on the back of Intamin trains

Yesterday and today I noticed on TTD, Millennium Force, and Maverick that they all seem to have rubber flaps on the back wheel bogie of all the trains. They almost resemble mud flaps. Anyone know what their purpose is? My guess is some sort of device for determining wear.

I'm not 100% sure but I'm pretty sure they are there to trip the proxy's on the track in order to tell the computer where the trains are on the track.

**EDIT** This post is wrong please ignore it. I knew what it was.... just didn't remember at the time of posting this.

Prox. switches detect metal though, not little rubber flaps.

They disperse the static from the train.

They are there to reduce static electricity.

Really? That's interesting. Is that a problem unique to Intamins or is that a standard feature on most coaster trains that I've never noticed before?

I believe it's due to the nylon/polyurethane materials the wheels are made of. They must generate quite a charge.

They do. On Raptor, sometimes you can actually hear the static discharge crackling off the wheels. And sometimes when you ride Gemini, if you reach out to the other train, you can get a static spark if you get close to another rider.

My GUESS as to why Intamin uses the little drain conductor and the other manufacturers did not is that Intamin uses non-contact magnetic brakes to slow the train, and a rubber tire on an advancing motor to stop it. All of the Cedar Point coasters from other manufacturers use friction brakes with a metal lining. So as soon as the brake contacts the train, any charge built up in the train gets conducted to ground through the brake caliper. On the wood coasters, of course, there isn't any polyurethane or Fiberglas to generate a static charge, and the steel wheels and steel rails are all grounded anyway.

It is kind of interesting that because of the polyurethane wheels, most steel coasters are electrically "floating" most of the time. We don't notice the charge build up when we ride because we are at the same potential as the train, and when the train's charge drains off into the brakes, we don't feel anything (again, we stay at train potential) and when we get off the train we don't get a "poke" when we get back on solid ground. A great example of this was the Zierer kiddie coaster at Geauga Lake. Six Flags equipped the ride with mats on the ground on either side of the track...not because the ground wasn't soft enough to hit with your fingers, but because the mats were non-conductive and could prevent riders from getting unpleasant static shocks.

--Dave Althoff, Jr.

Interesting. I remember getting static shock on Gemini once in a while back in the day. But it's been a long time since I've felt that. Based on this I would think that once a charge is built up, that only the firstperson from each car to slap hands would have the potential for feeling the shock.

Just when you thought you knew everything about roller coasters. Good question Brandon and great post Dave. Very interesting read.

I've never noticed this before so went looking through Walt's pics. Is this what you guys are talking about and is it usually on both sides or just one like in this pic

Jason - sadly it seems that every time I go to the park, there are fewer and fewer people trying to slap hands. It seems a great tradition is falling by the wayside.

Well, it isn't attached in that photo, but it would be attached to that bracket coming off the right-hand rear wheel carrier. I'm pretty sure there is a photo around here somewhere that is a close-up of the drain, but I can't find it this morning.

I think it's typically on one wheel carrier per car, but don't quote me on that. :)

--Dave Althoff, Jr.

You can see it on the back of the train here

It also doesn't appear that any of the other wheel carriers along that side of the train have the bracket for attaching the drain, so it must just be the 1 per train and on the last car.

JuggaLotus said:
It seems a great tradition is falling by the wayside.

Well, I'm not sure if we had any lasting effects. But, during the Coastin' for Kids event, we were very enthusiastic throughout the day. We got most of the GP into it. There were a few strange looks. But, all in all, most people went with the flow.