Calculation of a Catenary Height Reduction

In the tab Check you can start a calculation to check, if the parameters in the tab "Data" are observed. You can choose whether the calculation should do a height adjustment, or not. There are three alternatives for the calculation:

In you choose Checking Only, the calculation won't do changes on the catenary layout. Sicat Master will show if there are variations or offences against safety clearance or other specifications made in the tab "Data".
If you select the option Adjust Values, Initial Values Unchanged, all support points will be set to the computed height. The heights of the messenger wire and the system height at these support points will remain unchanged. If you leave the dialogue with escape or the cancel button, no changes will be made at the support points.
If you select Adjust Values, Before Calculation Reset To, all support points will be set on the calculated heights, when you close the dialogue. Messenger wire and the system height will be set to the specified heights.

If you leave the dialogue with escape or the cancel button, no changes will be made

Height calculation of the support points, whne the centerfield is calculated

Unlike older versions of this programme it is possible to place support points underneath a structure.

According to the selected option, all support points under the building and the first support points before and after the building will be set to the input data of the tab Data.

If the option Adjust Values, Initial Values Unchanged is enabled, messenger wire and system height of these support points will remain unchanged.

Note: By the calculation messenger wire and system height are just reduced, never enlarged. If messenger wire height and system height should provide bigger values, you should select Adjust Values, Before Calculation Reset To: for the calculation.
The intention of the following operation is to ensure the minimum distance between contact wire, messenger wire and the structure, in case of a worn out contact wire. Sicat Master tries to decrease the system height so far, that the clearance is ensured, and the distance between contact wire and messenger wire is still bigger than the minimum dropper length. If the calculation succeeds, the calculation will end. If the clearance is still too small, step 3 will follow.
With constant system heights contact wire and messenger wire will be reduced together until the minimum safety clearance between messenger wire and all points of the structure is reached, but not below the minimum contact wire height, even if ice load and the resulting deflection is considered. If the calculation succeeds, the calculation will end. If the clearance is still too small, step 4 will be next.
The system height will be reduced, until the minimum safety clearance between messenger wire and all structure points is reached, but only until the distance between contact wire and messenger wire is still bigger than the minimum dropper length. If the calculation succeeds, the calculation will end. If the clearance is still too small, unfortunately there is no solution for this problem.

Height Calculation of the support points, when the boundary fields are calculated

Considering the regulations of maximum slope and maximum change of slope Sicat Master tries to reach the target contact wire height and target system height, stated on the first page of the dialogue, as fast as possible. Therefore the software starts from the structure towards the start supporting point and the end supporting point respectively. If the target values are reached before the start supporting point and the end supporting point respectively is reached, the calculation will be cancelled. The remaining start/end supporting points are not changed in their contact wire height and system height.

Note: If there are several catenary height reduction objects close together, they might alternately destroy the already calculated boundary fields. Therefore it is important to adjust the target values carefully and reasonable.