Underground Cable Laying Methods Explained

Various methods exist for the installation of underground cables. Evaluating the options provided:

• Direct Laying: This technique involves burying the cables directly into the earth within a trench. Protective measures like cover slabs may be used.
• Draw-in System: Here, cables are pulled through pre-laid conduits or ducts (pipes). This method facilitates easier maintenance and replacement of cables.
• Solid System: This method involves embedding cables in solid insulating materials within troughs or conduits.

All three methods – Direct Laying, Draw-in System, and Solid System – are established techniques for laying underground cables. Therefore, the option encompassing all correct methods is the accurate answer.