Digging the trench and laying the gaine is one thing but getting the cable into the gaine is something else. The 2.5 mm² cable is light but starts to buckle and then forms a blockage. The 16 mm² is rigid but incredibly heavy so difficult to push through. The 10 mm² is a happy mix of rigidity and weight. Even so, all of them really benefit from someone pushing and someone pulling to get them through. Unless of course, you are alone. Then it is push a couple of metres, wal 50 metres to the other end of the conduit and pull for two metres. Walk back and start again.

The red is for electrical, the blue was for water and the green is for the telecommunications. Not sure they recognise the difference when they are buried or if it makes a lot of difference if you accidentally dig something up. A cable is a cable and if it is dug up it needs to be checked and repaired or, in this case, replaced as joints underground are not a good idea. Still, the colouring is what the European standard demands so that is what I have done.