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ESB NETWORKS LTD
October/November 2012 www.esb.ie/em
Catenary Stringing means upgrades without delays
When ESB Networks’ transmission and distribution lines intersect with other infrastructure such as motorways, railways and navigable waterways, overhead line construction or maintenance works become a lot more complex. In the past, motorways or railways were closed for a short period, often at night, while works took.
ESB Networks has now adopted a new work method called ‘Catenary Stringing’, which allows us to safely work over motorways and railways without any need to take control of the ground beneath. This was first successfully deployed in the 2012 Transmission Outage Programme. One interesting example is the Inchicore–Maynooth 200kv line refurbishment.
Catenary Stringing was originally developed in Germany to facilitate unimpeded crossing of its complex autobahn and rail networks. It has since found extensive use by European utility companies. It is recognised as a safe, efficient and effective work method that eliminates adverse impact on third-party operations.
Inchicore–Maynooth Project
The Inchicore-Maynooth 220kV Double Circuit Line is about 19km in length and was originally built using 600mm2 steel reinforced aluminium conductor, known as ACSR. Over the years, industrial and commercial development near the lines has reduced clearances and the maximum operating temperature to 60°C. This imposed significant load capacity restrictions on these lines and limited their effectiveness.
Upgrading both lines by replacing the existing ACSR with newer high-temperature low-sag conductor types (HTLS) would significantly increase the capacity of the line to over 800MVA in winter and an operating temperature of up to 210°C
Some of the main challenges to the project team included multiple motorway and railway crossings, building conflicts and, of course, conflict with our own live overhead lines and stations! This project was an ideal candidate for catenary stringing.
How does it work?
In normal circumstances, overhead conductors are installed and removed using pulley wheels attached to the towers of the powerline. The conductor is allowed to sag between the towers before being finally tensioned and pulled into position and may be lower than its final sag height and in conflict with trucks on the roadway or trains on the railway.
“Daytime working is both safer and more productive than night time work on overhead lines.
Catenary stringing, as the name implies, involves deploying a lightweight, high strength catenary rope in the crossing span, together with special stringing wheels spaced at regular intervals. Together these act as a cradle supporting both old and new conductors during the restringing Operation.
Once the restring has been completed the catenary system is recovered ready for re-use. During the entire operation, everything is kept above the final sag height allowing normal traffic to continue below.
A detailed Catenary Stringing Procedure was developed by Contracted Projects Group in conjunction with HV Services Safety Specialist Kieran Cogan. They tailored the methodology to ESB Networks’ specific requirements allowing us to deliver this project safely, efficiently and on target with the minimum disruption to respective third-parties.
Going Forward
Daytime working is both safer and more productive than night time work on overhead lines. Also, our construction works are no longer as dependent on cooperation from third-parties such as the National Roads Authority and Irish Rail and, in turn, cause significantly less disruption to the travelling public.
ESB Networks plans to use the catenary stringing system widely in the 2013 programme where we feel that it can improve safety and productivity and minimise disruption to third-parties.
Mapping the way ahead
Networks Asset Management initiated a new project in June 2012: upgrading the Networks geographical information system (GIS) solution. The current GIS system, known as DFIS, has served Networks well as a stable and reliable application for over 20 years but it is now nearing its end of life. The main objective of the project is to replace what DFIS does currently with an up-to-date GIS system while maintaining interfaces with existing Networks IT applications.
GIS Upgrade Project
Based in Merrion Square, this project is part of the Networks IT delivery programme managed by John Gallagher. A dedicated group, comprising of staff from ESB Networks and BSC working with Intergraph, the implementation partner, forms the project team managed by Adrienne Behan. The definition phase of the project has commenced and go live is planned for late 2014.
The scope of the project is to replace DFIS (the foundation operations application supporting OMS), GeoDART and Framme Web viewer as well as upgrading and enhancing associated interfaces with SAP (IWM, ARM and ISU), OMS, Synergee and Connectmaster.
The system chosen is Intergraph’s G\Technology solution for network designers and viewers. It will also deliver an application platform with integration modules to SAP for work, asset and customer management and also with Oracle Utilities Outage Management (OMS).
“We fully expect our new system to deliver a solution for the full life cycle management of our network assets while improving workflow efficiencies, including integration with other business critical systems,” says ESB Networks IT Manager John Gallagher.
Project Board and Support
Project Manager Adrienne Behan says, “The key objectives of this project are to work together to replace the current GIS, design tool and browser with a fully supported model, to exploit the new capabilities provided by a modern system and finally to provide a stable platform that enables future projects such as Smart Grid and Mobile.”
A Project Board has been established to guide and support the project consisting of Managers from ESB Networks, Business Support Centre and Intergaph.
Staff from the delivery organisations (D&CS, HVD&C), Asset Management, Networks IT Delivery and BSC have been seconded to the project to support this solution throughout its development.
Other staff will be required as the project ramps up and nears the go live phase at the end of 2014.
“We fully expect our new system to deliver a solution for the full life cycle management of our network assets
Next steps
A Networks Business Implementation Group will be set up to support the implementation of the Project in the various business lines. This group will input to the project, validate decisions, communicate on decisions and prepare for go-live and post go-live support activities. There will be a comprehensive communications plan in place for all staff impacted by the replacement of the existing DFIS solution. Like other IT projects, all users of the new system will be trained prior to go-live and supported after the system has gone live.
The Networks Business Implementation Group will meet shortly and will communicate through the business lines on project scope, system impacts and changes.
