The Drax Group is one of the UK’s largest energy producers. They are responsible for generating 7% of the UK’s electricity. Having successfully upgraded the UK’s biggest power station through innovative engineering, they are now a predominantly biomass-fuelled generator. 70% of the electricity they produce – enough to power Leeds, Manchester, Sheffield and Liverpool – is now made using compressed wood pellets rather than coal.
At the start of the tender process for the first contract, Hamon were the second of three bidders behind the Contractor who had held the on-site Maintenance Contract for many years. However, Hamon were able to demonstrate with references, site visits to other working sites and meetings, that we possessed the in-house technical expertise and that we could deliver the Project in a safe and timely manner in the first year of works. This has been further demonstrated and high standards maintained during execution of the works over the further 2 years extension and has resulted in the Client rewarding contracts with continuing extensions for further works.
The original contract was awarded to Hamon in 2014 for the repacking of two Natural Draft Cooling Towers. This included the replacement of all Pack Media (21,000m³/Twr), Drift Eliminator (130km/Twr) and Distribution Pipes (3.75km/Twr) along with the associated timber supports. The contract also included the transport and recycling of the very heavily fouled (with river silt) pack media. Following the satisfactory completion of the works and Thermal Testing by Hamon Thermal Testing Dept. to prove the design of the first 2 Towers at the end of 2014, the Client awarded Hamon a further contract for 4 more Cooling Towers to be completed on the basis of two per year.
The initial programme was relatively short with the requirement to undertake 2 towers at the same time. Planning, coordination and tracking of materials has been a key critical part of the project, ensuring materials are delivered to site in a timely manner in support of the Hamon Site Construction Team.
The existing pack media was very heavy due to silt build up and was collapsing in places. The heaviest Pack weight for one tower removed to date has been 3250Te’s, which has all been dropped by hand, extracted from the basin by Excavators into Lorries and removed to a PVC Pack Waste Recycling Facility for washing and reclamation. The removed timber is transported to a small Energy from Waste processing plant.
Communication with the Site Construction Team and reacting to Lessons Learnt from their feedback from the previous year’s works has been and continues to be vital to the success of the project both in terms of safety performance and timely project execution. Feedback from the site crew has resulted in design changes to material supplies and provision of new equipment that has reduced manual handling.
A high percentage of materials comes entirely from within the Hamon Group (Pack and Eliminator).
Near site gluing of the pack media had to be developed to accommodate non-solvent glue for which we had no previous experience, no suitable gluing machines and no facility to work from. A gluing process including new machines was developed and a temporary manufacturing facility set-up to ensure that manufactured pack could be delivered to Drax Site in accordance with the programme and to the required quality.