Marker Balls

The effect of markers balls on a line can be accurately modelled using finite element software. However you can estimate their effect in Poles ‘n’ Wires.

The proposed approach is to create a new entry in the Conductor database representing the combined conductor+balls. This is suitable when:

1. the marker balls are spread evenly along the span, or on all spans in a strain section
2. the balls are the same size and weight

You’ll need to make an entry for each unique span length, or you can use the entry for a strain section if there are marker balls on all spans in the strain section.

1. Determine total area of balls on the span. This will be \(A= \pi r^2 \) x {number of balls}, where \(r\) is the radius of a ball.
2. Divide \(A\) by the span length to give the additional diameter that needs to be added to the conductor diameter. Units are mm.
3. Multiply the weight of each ball by the number of balls in the span. Divide the total weight by the span length. This is the mass in kg/m that needs to be added to the conductor mass.
4. Create a new record in the Conductor database, give it a new Code and copy all parameters from the base conductor record. Then modify the Diameter and Mass as previously calculated.

Adjust as needed if you are modelling a strain section not an individual span.

This approach can also be used to model other attachments such as vibration dampers, as long as the same conditions are met.