1. 1 Welcome Dave Stockton BT Laboratories Cost Benefit Analysis of Modern Cable Installation Techniques

2. 2 Scope Traditional Ducted Methods Comparison Technique Alternative Ducted Methods Sub-duct Issues Direct In Ground Installation Comparison Results Conclusions and Recommendations

3. 3 Traditional Ducted Methods Winched cable Figure-eighting to extend installation length. Step 1Step 2Step 3

4. 4 Comparison Technique Installation time only compared Installation of whole job analysed Man hour requirement for all tasks assigned Tasks grouped into categories for analysis Three representative standard routes used.

5. 5 Task Groupings Preparation Road Works Guarding Gas Testing Rope Installation Sub-duct Installation Cable Installation Entire Job Consists of

6. 6 Rural Standard Route 7 6 5 2 3 1 8 9 10 11 12 13 14 15 16 17 4 18 Exchange Manhole Node Position 0 500 m 2.6 km

7. 7 Task Group Analysis (Man Hours) Traditional Unsub-ducted Installation (Rural Route)

8. 8 BT Duct Environment 90mm bore 6m Length Mid 70’s onward - PVC Pre-Mid 70’s - Mainly Earthenware Similar Bore Shorter lengths

9. 9 Alternative Ducted Methods 1 Cable Blowing Several systems available Longer installation lengths than winching claimed Low tensile force - weaker, cheaper cables Capabilities highly dependant on cable and duct size High cost equipment.

10. 10 Alternative Ducted Methods 1 Standard Sub-duct 25/32mm Requires 50% fill for blowing Loose Tube 96 fibre (18mm) heavy : 300g/m Compact 96 fibre (13mm) light : 100g/m Attractive N/A

11. 11 Alternative Ducted Methods 2 Blown Fibre Precedes cable blowing - on smaller scale Patented by BT. Glass microspheres 4 fibres High modulus outer coating Low modulus buffer layer 1mm Polyethylene Sheath Blown Fibre Tube (3.5/5mm) Aluminium Water Barrier 20mm

12. 12 Alternative Ducted Methods 3 Cable Floating Longer installation lengths than winching claimed Strain on cable is evenly distributed Weaker, cheaper cables can be installed Bulky equipment.

13. 13 Alternative Ducted Methods 4 Mid-assist Capstan Winch Eliminates the need to ‘figure-eight’ Multiple winches if necessary Reduced public disruption.

14. 14 Alternative Ducted Methods 5 Cable Fleeting Machine Direct alternative to ‘figure-eight’ Fleets at up to 100m / minute Reduced public disruption.

15. 15 Sub-duct Issues Long, continuous, low friction route Operational advantages Additional stores cost of the sub-duct Reduced efficiency of duct space usage Self-rodding sub-duct.

16. 16 Installation Time Comparison Results 1 Rural Route 020406080100 Self-rodded & Blown Self-rodded Blown Winched Fleeter Capstan Figure-8 Installation Method Man Hours (Normalized) No Sub-duct Sub-duct

17. 17 Installation Time Comparison Results 2 Urban Route 020406080100 Self-rodded & Blown Self-rodded Blown Winched Fleeter Capstan Figure-8 Installation Method Man Hours (Normalized) No Sub-duct Sub-duct

18. 18 Task group Analysis (Man Hours) 1 Traditional Unsub-ducted Installation (Rural Route)

19. 19 Task Group Analysis (Man Hours) 2 Traditional Sub-ducted Installation (Rural Route)

20. 20 Traditional vs Self-rodded Sub-duct Self-rodded Sub-duct (Rural Route)Traditional Sub-duct (Rural Route)

21. 21 Installed Cost Comparison Summary TechniqueTime SavingCheaper CableEquipment Cost Mid-point CapstanVery LowNoMedium Fleeting MachineVery LowNoMedium Blown CableLowYesHigh Floated CableLowYesHigh Self-rodded Sub-ductHighNoLow

22. 22 Conclusions Alternative cable installation techniques - small time savings Reducing cable cost - high impact Sub-duct - large time savings Self-rodding sub-duct - up to a further 40% time saving.

23. 23 Recommendations Evaluate the whole installation process Consider differences in stores and equipment costs Installed cost comparison if possible.

24. 24 Thank You Dave Stockton BT Laboratories Tel : 01473 642043 Email : STOCKTDJ@boat.bt.com