When can Form D line 13 be issued instead of Form D line 4?

Form D line 13 can be issued instead of Form D line 4 specifically when the limits of the track exceed what Form D line 4 can accommodate. This means that when the work or the need for track occupancy goes beyond the defined limits of Form D line 4, a Form D line 13 is necessary to accurately reflect the requirements of the situation. Form D line 4 typically provides a more restricted and specific set of limits for track occupancy, while Form D line 13 allows for a broader and potentially less defined range of movement or work on the track.

In a scenario where the work or operations planned involve multiple locations or exceed the typical usage described in Form D line 4, it's essential to use Form D line 13. This helps prevent confusion and ensures that all personnel involved are aware of the wider operational limits in place. Thus, issuing Form D line 13 provides the necessary flexibility and clarity for track operations that go beyond the constraints set by Form D line 4.