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

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

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

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

6 Rural Standard Route Exchange Manhole Node Position m 2.6 km

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

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

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

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

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

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

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

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

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

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

24 Thank You Dave Stockton BT Laboratories Tel :