On this last sheave Vodhin, I noticed that most amusement parks have like 4 wheels each side though it does seem to vary. Is this sheave more for aerial tram way cars, as we will have these for ski and non ski resort type themes as has been ratified in the game.

Sheave: the pulley that holds the cable.
Sheave Train: a set of Sheaves.

I assume you mean Sheave Train and the number of sheaves in the train. The number of sheaves in a sheave train, in reality, depends on the diameter of the sheave (typically 14 inches) and the ratio of the load to be supported to the distance between towers. The early skyways, like the bucket gondola of the 1950s at disneyland, were two passenger carriers so if you compare pictures of the towers from that era you'll notice that the towers had fewer sheaves in the sheave tran than in the later pictures when the skyway was retrofitted for the larger 4 passenger carriers.

Besides load and tower spacing, the change of cordangle - the slope of the lift line as it rises or decends from tower to tower - also dictates the number of sheaves in a sheave train: typically 1 sheave per 1 degree of cordangle change. There is a minimum of 5 degrees of cordangle on each side of the tower's crossarm in either travel direction. That's a 10 degree cordangle change, or 10 sheaves. Sheaves pivot in pairs, which pivot in pairs of sheave trains, so 10 doesn't work: there is an even number of pairs on each side of the tower. I'm developing sheave trains in 8, 12, and 16 sheave train sets, which should be fine for the game (other types of lifts will have different arrangements).

Skyways have been built quite differently from skilifts, mainly because of what the lift had to do: A skyway is a pleasure ride, intended as transport and typically built over level ground and would run at slower speed. A skilift, on the other hand, is designed to move people uphill as fast a possible.

Uphill skilifts encounter many more engineering challenges than skyways since the lift must safely offset the exponential forces of gravity as the liftline rises in altitude: the greater the vertical rise, the greater the empty load of the liftline. The placement of the drive terminal causes further stresses on the tower load. A top drive system wants to yank the bottom terminal off the ground and tends to snap the loaded line (the side passengers ride on) when starting up. A bottom drive system snaps the unloaded side when staring, better safety for passengers but wants to pull the towers over as well as yank the top terminal off it's moorings.

In detachable systems, the greatest danger is when loading the carriers on the line at the beginning of the day: as the carriers begin filling one side of the line, the system becomes unbalanced until the carriers start returning down the other side. Depending on the lift's length, rise and other aspects of the overall design, most detachable lifts are filled in by adding a new carrier at every fourth position in normal operation, allowing for the line to balance out before getting overloaded on one side. Enclosed gondolas allways must be unloaded when the lift is not in operation since they have a greater surface area to be blown around by wind. Detachable chairlifts tend not to be unloaded because it's cheaper and they don't have as much surface area to catch the wind.


Anyway, Skyways are not skilifts - at least not the Von Roll system so common in many classic theme parks. In TPB3D, the Von Roll type of skyway has been engineered to closely match real VR systems but I've taken a few liberties since we can do things that never got done in real life. To my knowledge VR never designed a system that could change course; all the VR systems I've ever seen allways travel in a straight line between two terminals, and I've only found one instance where there was a mid station between terminals (Disneyland?). You will be able to build, with reasonable accuracy, any of the VR rides and you will be able to build new skyway designs as if VR was still around, innovating and engineering new features for the VR Skyway.

Actually Jungleland in Thousand Oaks California had during the 60's a Von Roll, but it was a standard chairlift and it was an up and back single terminal system. The end station was just mainly a bull wheel that brought the chairs back towards the station or the return line so loading and offloading was mainly to and from the originating single loading platform only.

POP's "Ocean Skyway" also had a steep climb to the upper terminal atop the volcano mountain at the end of the pier. Also what I found interesting was the POP skyway was askew about 5 degrees. Of course a non grid alignment option for the skyways will solve that.

I'm not sure that Von Roll made fixed Grip lifts- it might have been a retrofit: buying parts such as VR towers and drive terminals, and then hanging fixed grip chairs could be done. A lot of lifts are a hodge-podge of various parts, sometimes rather unsafely assembled.

By "askew" do you mean that the lift line actually moves over a bit between a couple of towers or that the entire lift line is simply at an angle in relation to, say, a path below? I bet if you say the plane you'd see that the terminals are in line with one another.




Now for an update... The main VR1960 Tower parts are done:

The tower:

Designed with a Root Joint at the base and a Crown Joint at the top which can adjust the tower's height.


The Tower Arm for Support Sheave Trains:

Designed with a root joint mean to snap to the tower's Crown joint and an Arm joint at the end.

The Support Sheave Train:

The Root joint here snaps to the Arm joint in the arm for alignment. The sheave and bracket assemblies are jointed to allow the sheave train to flex into the correct arc for the cable path.

The Tower Arm for Depression Sheave Trains:

like the Support Arm, though designed to work with the Depression Sheave Train. Unlike the Support Arm, the end of this arm needs to have its verticies warp with the rotation angle of the Depression Sheave Train, so the "Arm" joint is named "Pivot" and should control the Root Joint in the next model.

The Depression Sheave Train:

Extreemly simple, this model does not flex but instead relies on the Pivot in the Arm model to adjust the angle of the cable (about 10 degrees either way).


In the works are overhead arms for attaching to supports such as an arch tower or the ceiling of a cave or building.

As always, you blow me away Vodhin. You got a great talent. I'm glad you're working on TPB3D.

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We keep moving forward, opening up new doors and
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