At times, Lineardraft positions the height of a catenary wire differently across cantilevers - most notably across different design ranges. Let's see why.
When designing, Lineardraft will always model catenary wires as zero-size line-strings. This means that if a contact wire height of 4.7m is entered, the perpendicular measurement to the contact wire point from the associated rails, will measure exactly 4.7m.
When equipment is introduced at a wire point, the official drawings of the design range will define the placement of the cantilever. Dependant upon which design range is being used, the position in which the contact wire is depicted may change. In some instances, the height of the wire may be shown at the centre of the wire, sometimes it's at the clamped position, and on others it's to the underside of the wire. This means that when viewing multiple cantilevers, across multiple design ranges, there appears to be a discrepancy, as contact wires have an approximate diameter of ~12mm.
For example, Bonomi/Omnia cantilevers in the UKMS range portray the wire height to the underside of the contact wire, whereas the CLever cantilevers in the same range, portray the contact wire height nearer to the centre of the wire diameter. Lineardraft and its catalogues endeavour to model as close as possible to the varying positions across design ranges, meaning that at worst, the wire’s potential deviation from the user’s expected position is <8mm. However, in most cases, it is much lower than this.
Please consult the individual cantilever drawings for a clearer understanding of the position from which Lineardraft models the catenary wires.