The contract included for comprehensive support in the preparation and planning phase of the project to ensure estimates for known scope were relevant and achievable.
These activities also included a review of the Total T & I master schedule and provide feedback on sequence of works optimisation as well as Resource Levelling.
As the managing contractor, Ledwood acted as the focal point for coordination of all other trades: scaffolding; refractory; NDT; insulation; painting and craneage.
Critical planned activities involved the Reactor Internals, Regenerator Internals as well as the Third Stage Separator cyclone removal and reinstallation. Other activities included the following:
Removal of 12x Fin Fan banks for overhaul and then reinstallation
Renewal of the “Burmese House” Fin Fans and associated Pipe Work (substantial emergent works)
Various smaller vessel inspections
Renewal of Sections of 42” PRT Line
Various Pipe Work packages including hydro testing
Various Valve removal and reinstallations
Various Thermowell renewals
The planned scope of works increased significantly throughout the execution of the T & I due to emergent works which contributed to an overall increase in man hours of 47%. Working closely with Total, these extra works were scoped, estimated, schedule impact assessed and incorporated in to the master schedule for implementation. Some of the more significant additional works include: removal of 50” Regen Overhead Line Elbow to afford easier access for the refractory contractor to work multiple work faces to re-line overhead line; specialist Stellite welding of reactor dipleg valves; Regen Secondary Cyclone refractory over boxes – steel lined, refractory filled over boxes due to unforeseen erosion in cyclone to dipleg cone; substantial overplating of Waste Heat Boiler; Disinvestment of redundant elements of Flue Gas Ducting to redundant Heater.
The event was executed over six and a half weeks, and was completed with no Health and Safety issues.