MAXIMUM AND MINIMUM VALUES FOR THE LINE CHECKING

When the calculus is finished the table with the maximum and minimum values for the plant’s characteristics becomes available. In the upper part of the screen there is a table which summarize the used calculus hypothesis. Laterally there are 4 buttons that allow (with a simple click) to choose the results for 4 different checking types:

  • Normal check for lines with counterweight (hydraulic or gravity).
  • The check is done considering a variation in the haul rope’s nominal stress, in order to take in account the hydraulic turnbuckle’s regulation range. There are 2 buttons, one for the upper limit and the second for the lower limit.
  • The check is done in the condition of malfunction of the hydraulic turnbuckle, so with a loss of stress for the haul rope

Obviously the selection button works only if the line calculus is already done. It’s important to note that the various checking types can be executed successively, before consulting this maximum and minimum table.

 

 

 

 

 

 

 

 

 

 

The table is composed by two sections: one for the data related to the spans and the other for the data related to the towers. Let’s analyze the content of this table, identified with the name (OOO – blue background)

For the spans:

  • Span ID number (i.e. the number of the two towers)
  • Maximum and minimum stress (on the same column) in the span’s middle point
  • Maximum and miminum rope’s deflection in the span middle point
  • Maximum and minimum rope’s mouth angles (top tower)
  • Maximum and minimum rope’s mouth angles (bottom tower)

maxmin_campate.bmp (409254 byte)

For the towers:

  • Tower number
  • Ts(max-min)    - Maximum and minimum stress (rope- tower); in the sheave assembly’s middle point
  • D(max-min)     - Total rope’s deflection on the tower (difference in mouth angles between the entry and exit point
                             of the rope in the sheave assembly)
  • P(max-min)     - Maximum and minimum rope pressure on the sheave assembly
  • At(max-min)    - Maximum and minimum friction (rope sheave assembly)
  • NR                 - number of rollers
  • Du(max-min)   - unit deflection (for every roller) of the rope on the sheave assembly
  • Pu(max-min)   - unit pressure (for every roller) of the rope on the sheave assembly
  • Test : comparison between the unit pressure and the acceptable value.

maxmin_sostegni.bmp (741254 byte)

Use of the "Start check graph line" button

If the button is active, not only the table is filled, but it’s also executed the graphical line checking (for deflections and vertical distances). In the upper part of the screen there is the print menu ("Print"), the button to downsize the drawing ("Zoom All") and the button used to return to the table "Exit"; the "save" function is not active in this phase. Another menu allows to choose the hypothesis shown in the graph. Two groups of "optional" buttons allow to calculate the deflections and the vertical distances for the different line conditions. For these it’s possible to consider the snowiness and the car height.

The graphic representation of the line can be downsized (zoom) just right clicking with the mouse and then dragging until the desired dimension it’s reached; to return to the original dimension use the "Zoom All" menu. There is no "reverse zoom" possibility!

It’s important to point out that, with the movement of the mouse cursor the user can read (in the table on the upper left of the screen) the values of ground distance, altitude, incline %, vertical distance between the span’s chord and the ground and finally the vertical distance between the rope and the ground (according with the previous settings).  In the following example it’s also defined the snow level (so the vertical distances changes from 4,73 to 13,73 m):

When the mouse cursor is near a tower, the ID of the tower is shown: in this position just double click to get more information about the tower!