# 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:

- the marker balls are spread evenly along the span, or on all spans in a strain section
- 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.

- Determine total area of balls on the span. This will be \(A= \pi r^2 \) x {number of balls}, where \(r\)
- Divide \(A\) by the span length to give the additional diameter that needs to be added to the conductor diameter. Units are mm.
- 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.
- 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.*