Time chainage diagram

The time chainage technique relates to the planning of works of a linear nature where activities are related to, or are identified by, a geographical location. In the construction industry these types of works include projects such as road and motorway construction, railway works, pipelines and tunnels. Therefore the technique is usually associated with civil engineering projects.

Time chainage diagram is very similar to both the bar chart and line of balance but, rather than simply relating an activity to a timescale, time chainage relates activities to both time and location.

Figure 15 illustrates a very simplistic time chainage diagram for bulk dig operations and the construction of a retaining wall. The chainage or distance, in kilometres, is shown along the horizontal axis and the time, in weeks, is shown along the vertical axis. The activities are graphically represented by lines or boxes.

The activity of bulk dig is indicated by a single line which represents commencement at chainage 0 on week 5, with progress to chainage 2 and completion on week 10. Likewise the activity for the construction of the retaining wall commences at chainage 0.5 on week 10, with works at this chainage planned until week 15. These works are indicated as progressing towards chainage 1.0 and being completed at week 20.

Figure 15: Time chainage diagram

The above example is very simplistic and the diagrams used in practice are more detailed and complex. They may therefore be difficult to understand and as such, this technique requires a little practice and experience to become familiar with the layout and the overall philosophy, especially if someone is used to a bar chart.