When constructing telegraph stations, depots, or forts with the armies, the building must be placed within the constructing army’s combat range.
In the below image, the building model is Shown red because the fort cannot be constructed here, as it is outside the army’s combat range.
In the below image, construction is possible, as the terrain is flat and the site is within the army’s combat range. The fort is no longer shown red.
An icon is shown next to the construction site when construction begins successfully, with construction progress shown around it as an orange circle, filling up as time passes. When the circle is full, the building is ready.
A friendly army must be within range of the construction site for the building’s progress to proceed. This does not have to be the army that originally permitted the construction to begin.
You may see detailed information and the estimated duration of the construction process in the tooltip of the construction icon shown below.
You may upgrade depots and telegraph stations by opening the panel when the construction has been completed and clicking on Upgrade, as shown in the image below. This will, again, take time and require resources.