Tram Curiosity.....

[nace888]

OOOoooooooooooooooookay, I know this will sound stupid, but can anyone tell me how Disney's parking lot trams work?? I know I was in a conversation about this before, but it baffles me that they can make a 180 degree U-Turn (within their perameters of course) and not sway and such, and most definitely don't have the rear car cutting the turn much tighter than the tractor, but at the same radius!!

I know they're trackless trains, but is there anything someone could divulge in on this?? Do the front AND REAR tires of the passenger trailers steer? Is it a swivel connection between the carts?? It just throws me off.....

 

[marni1971]

They're heavy, very powerful, and the tractors short wheel base (and good turning circle) allows nimble turning. Physics dictates that where the drive path is and the drive wheels go the trailing path and wheels will follow. Kind of reassuring when they do the U turn through the planters at the TTC!

 

[Tom]

I too have always been amazed, since I was a child. Everything else in our lives tells us the trailing tires should cut inside the path of those ahead of them. So there's some voodoo magic about the double pivoting axes on the cars.

 

[Phineas]

Maybe it's like the fax machine: it operates using some form of witchcraft that we're not allowed to question. No one will ever know.

 

[Tom]

Maybe it's like the fax machine: it operates using some form of witchcraft that we're not allowed to question. No one will ever know.

Good point

 

[mikeymouse]

The trams were ordered from United Tractor and were supposed to use compressed natural gas, but WED had to switch them to diesel. The originals were a disaster and would not handle any load so Bob Gurr redesigned those to work and WED modified them all. All the overheating, brake, electrical, and transmission problems were alleviated.

 

[FOH Jim]

To answer your question, Yes both he front and rear axles of the passenger cars do steer. The geometry of the steering systems make all the tires track in more or less the same path. This is different from most trailers/wagons the tend to "cut" the corner some in a turn.

Not sure when the natural gas tractors were attempted, But when I first visited WDW in Jan 1973 they were Diesel. Currently they use a 4 cylinder turbo charged CAT engine. The transmission behaves very much like a 2 speed that would be in a Payloader or Dozer. Given the configuration of the engine/drive wheels I suspect it is a payloader drive train, which would make a lot of sense because it would be an "off the shelf" item and easy to get parts.
BTW, Last year I was walking in from the magic kingdom parking lot. I decided to walk because I thought I could beat the tram. As I was approaching the under pass, The tram that I would have been on was just about to overtake me and it suddenly stopped with a mighty "bang" in a great fury of black smoke and steam. That tram was going nowhere without a tow. I suspect a blown head gasket or possibly a turbo failure. Needless to say, I beat the tram to the TTC.

 

[marni1971]

The gas versions were phased out in late 71- early 72 if I recall. Last chance was when one failed to pull its load up the water bridge incline in the rain.

 

[kap91]

The Disneyland trams are natural gas though correct?

Because they're freaking whisper quiet there. Not at all like WDWs roaring engines.

 

[nace888]

Can anyone perhaps link me to a diagram or upload one or something as to how it all works?? I know it's something mechanical in placement, I just don't know what, and I can't seem to find any information on it at all...

 

[kap91]

Can anyone perhaps link me to a diagram or upload one or something as to how it all works?? I know it's something mechanical in placement, I just don't know what, and I can't seem to find any information on it at all...

Basically it's the fact that all the bogeys (where the wheels are mounted) can turn. Most trams and tractors etc aren't like that.

 

[nace888]

Basically it's the fact that all the bogeys (where the wheels are mounted) can turn. Most trams and tractors etc aren't like that.

I figured that, but HOW does it happen? How is each cart connected? How do the front and back axles turn? How?? XD

 

[The Tuna]

I have wanted to go for a ride on a tram for decades. Weird I know. I don't drive down there so haven't been on one since the early 90's I just remember them talking trivia on there. Not sure if they still do or if they have a spiel or what. May have to go for a spin next trip.

 

[FettFan]

Drawbar connections and four-wheel steering on each of the carriages.

From Wikipedia's article on Trackless Trains (and a tad bit of experience, as I once worked for a party company that rented out trackless trains):

As in a regular road vehicles, the tractor unit is steered through the front wheels by a steering wheel operated by a human driver, and powered by its rear single or double axle. The following carriages are then steered through the drawbar couplings between the carriages. Simple trains with few carriages or short in overall length may feature single or double axle carriages with just front axle steering only. Larger or longer trains feature four wheel steering[6] by way of mechanical linkages. Four wheel steering ensures that longer trains need less side clearance while turning, as the carriages are able to maintain the same path, describing a constant radius of arc. This adds to the impression of the vehicle being on rails. The drawbar connections of more complex trains may feature a shock absorber to mitigate the effect of acceleration or braking.[7]

 

[Tom]

I have wanted to go for a ride on a tram for decades. Weird I know. I don't drive down there so haven't been on one since the early 90's I just remember them talking trivia on there. Not sure if they still do or if they have a spiel or what. May have to go for a spin next trip.

Same here! But in 2012 we drove because we were there for a conference off property. I got to ride a tram at DAK - and my wife thought I was crazy for getting so excited. I still want to ride one at the MK/TTC. Like you, it's been since the 90s when my family would go and we'd stay off property. Since 2000 or so, I've stayed on property and ridden Disney transportation everywhere. I miss the trams.

 

[nace888]

Surely it's not as simple as the wiki says, is it? I mean it baffles me how it's possible with such large Tram trains...

 

[The Tuna]

Same here! But in 2012 we drove because we were there for a conference off property. I got to ride a tram at DAK - and my wife thought I was crazy for getting so excited. I still want to ride one at the MK/TTC. Like you, it's been since the 90s when my family would go and we'd stay off property. Since 2000 or so, I've stayed on property and ridden Disney transportation everywhere. I miss the trams.

Do you think they would let me ride from the drop off point out to the cars and back? Would hate to have to get a cab to drive me a mile out to the parking lot. hahahaha

 

[Master Yoda]

Surely it's not as simple as the wiki says, is it? I mean it baffles me how it's possible with such large Tram trains...

It is just that simple. Most of the best ideas are. Simply having the wheels mounted on what is in essence a bogie allows for a very tight turn radius.

 

[nace888]

It is just that simple. Most of the best ideas are. Simply having the wheels mounted on what is in essence a bogie allows for a very tight turn radius.

But on something like what's pictured, the front wheels have a larger turn radius than the back...

 

[Mad Stitch]

I drove these when I worked at WDW. The trailing cars do not follow the same path as the car ahead of them. There is a "whip effect" when going through turns where each car will come out of the turn a little further to the outside than the car in front of them. When taking the tight 180 degree u-turn, the operating procedure was to make the turn at half speed or else the last car could swing out and hit a tree or pole. When nobody was riding mid-day, some stupid drivers would go through the u-turn too fast in an attempt to throw the spieler off the back. I still have my procedures manual somewhere, but I don't think it says much about the trams themselves.