A19 High Mast Scheme
The scope of the project was for SLDS to deliver a consistent and effective strategy for replacement and future management of new lighting assets. An aligned cost-effective approach was required which addressed Highways England 5 Year Safety Plan in relation to safer roads, safer vehicles and safer people.
The original lighting and electrical supplies were over 30 years old and a requirement of the client contract hand back procedure was that any asset not meeting the contract residual life should be replaced.
The lighting asset replacement was determined on condition, age and a risk priority scoring. The added value created by replacing the existing lighting allowed for energy savings and improved safety in removing the flange base plate columns within the central reservation and outside edges of the structures.
The bridge structure forms part of the A19 Tees Viaduct or "Tees Flyover" which is a high level six lane dual carriageway road bridge in the North East of England. The structure carries vehicles north-south across the River Tees and provides access through a grade separated junction for entry and exit slips east and west into Middlesbrough, Stockton and Thornaby.
The final scheme design by SLDS replaced 211 number 10m and 12m sheet steel columns, housing low pressure sodium lanterns which were sited predominantly on elevated plinths resulting in a challenge to maintenance. The new scheme used 25no High Mast lighting columns between 30 and 50 metres in height. To keep a nominal 20 metre mounting height, all of the masts are in locations allowing maintenance without closing the road. Each of the masts support between 2 and 8no Urbis Schreder Omnistar lanterns.
SLDS provided the electrical lighting and power design, mast head configuration, aiming angles and lantern carriage orientation to facilitate ease of access for future maintenance.
We undertook the site RE role to facilitate all electrical elements to the project. The RE role including liasing with Archaeologists, ground investigation teams, Northern Powergrid, CU-Phosco for the provision and installation of the high mast columns and lantern carriages and Balfour Beatty as electrical sub-contractor.
We adopted a collaborative approach on this project and we worked closely with Autolink, the main client, Sir Robert McAlpine Major Maintenance, AECOM as structural designers, CU Phosco and Balfour Beatty to ensure this complex project was delivered.
The key benefits of installing LED high mast lighting compared to a conventional scheme in this location were:
- Future maintenance - this can now be carried out throughout the day at ground level without the need for disruptive road closures.
- Removal of the need for high level night time work over live carriageways, rail lines and waterways whilst carry out maintenance activities.
- Improved quality of LED light in relation to the obsolete Sox lanterns.
- Reduction in maintenance visits due to extended life of the light source.
- Removal of 211 lighting columns and replacement with 23high mast units behind a vehicle restraint system (VRS) set back from the carriageway, reducing the risk of vehicle impact with the lighting infrastructure. Body text (Normal)