Totnes Overhead Line 33kV Tower Dismantlement & Rebuild Case Study
Context:
Our client’s 33kV overhead line circuit from Kingsbridge to Totnes in Devon was constructed in 1930, consisting of 115 steel tower structures. A complete rebuild was required due to age and condition of the structures.
Approach:
Network Plus was tasked with the dismantlement, removal and rebuild of the circuit. The 12-week programme, covering 11.9km was divided into two phases:
Phase 1:
• Dismantlement and removal of 76 steel structures, recovering over 8km of cable.
• New build installation of 104 wooden stout single and H poles, ranging from 11m to 15m in height.
• Excavation and installation of 140 stay blocks.
• Installation of 8km of 150 AAAC 33kV conductor.
Phase 2:
• Dismantlement and removal of 39 steel structures over 3.9km
• New build installation of 39 wooden stout single and H poles, ranging from 11m to 14m in height.
• Excavation and installation of 50 stay blocks.
• Installation of 3.9km of 150 AAAC 33kV conductor.
Our team included 6 lines people, 1 charge hand and 2 machine operators.
The Challenge:
The work programme included elements such as pre-construction site survey, planning, programme management, wayleave, easements, customer engagement, construction, testing, commissioning, network outage planning, safety documents and as laid plan productions.
It also required a range of stakeholder engagement including multiple landowners for access and egress arrangements, Canal and River Trust for river crossings, and the local highway authority. Changes were made to the original design due to this engagement, and Queen Mary crossarms were implemented to extend span lengths.
Network outages were required, due to the circuit route crossing several existing 11kV crossings. To ensure this was a smooth process, our teams worked closely with the client to arrange and notify relevant customers of any planned interruptions to their electricity supply.
Our team also ably met the challenge of crossing the Habertonford Valley with the removal and installation of a single span of 209m (average span length 106m).
Conclusion:
This is a great example of Network Plus’ experience and capability working on overhead line and steel towers.
In 12 weeks, our teams expertly rebuilt our client’s 33kV overhead line circuit by removing 115 steel tower structures, installing 143 wooden stout single and H poles and 190 stay blocks over 11.9km. They managed all aspects of the programme, navigating potential challenges through stakeholder engagement and a partnership approach with the client.
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