General Construction of a Cable

       The Fig. 1 shows the general construction of a cable. The cable shown is a single conductors underground cable. Its various parts are,
1- Conductor or core : This section consists of single conductor or more than one conductors. The conductors are also called cores. A cable with three conductors is called three core cable. The conductors used are aluminium or annealed copper. The conductors are stranded conductors in order to provide flexibility to the cable.
2- Insulation : Each conductors or core is covered by insulation of proper thickness. The commonly used insulating materials are varnished cambric, vulcanized bitumen and impregnated paper.
3- Metallic sheath : The insulated conductors are covered by lead sheath or aluminium sheath. This provides the mechanical protection but mainly restricts moisture and other gases to reach to the insulation.
4- Bedding : The metallic sheath is covered by by another layer called bedding. The bedding consists of paper tape compounded with a fibrous material like jute strands or hessian tape. The purpose of bedding is to protect the metallic sheath from corrosion and from mechanical injury resulting due to aemouring.
5- Armouring : This layer consists of the layer of galvanized steel wires which provide protection to the cable from the mechanical injury.
6- Serving : The last layer above the armouring is serving. It is a layer of fibrous material like jute cloth which protects the armouring from the atmospheric conditions.
Fig. 1 General construction of a cable


  1. Very nice your post of Cable Manufacture .Very important article into your post.

  2. important for gtu students thanks!

  3. i am for the first time here. I found this board and I in finding It truly helpful & it helped me out a lot. I hope to present something back and help others such as you helped me.
    Underground Cable

  4. This comment has been removed by the author.

  5. Looking for wire crimping machine ? Then we are the best for you, who suit your expectations. We have huge experience on this field. We are 100% dedicated to find you wire crimping machine.
    We are dedicated to manufacturing and sales of a wide range of wire crimping machines including pneumatic crimping tool for crimp clamps.
    You can find here your best one. If you want to know more, Please check out Cheers Electronic Technical Co., LTD: