Client: SSE – May 2019

Background:

Lerwick power station is the main producer of electricity for the Shetland Islands and must be available to meet the grid demand at all times. The station has nine diesel generators, two gas turbines and a steam turbine run from superheated steam produced from three waste heat boilers.

Project Requirements:

Removal of No.9 Engine Concrete Block
Dimensions: 10m x 4m x 3m (L x W x H)
Weight: 288 tonnes (approximately)

Corecut were engaged in a contract for the provision of labour, management, and equipment to carefully remove a large concrete, diesel engine block in a very sensitive environment. The block was situated within the ‘A’ station engine hall which is fully operational 24/7, the block was adjacent to one of the main generators. There is also an auxiliary plant adjacent to both sides of the block.

Work Undertaken:

Corecut were required to supply suitably qualified and competent persons to complete the work together with HSEQ CDM site management the necessary tools, access systems, materials and PPE. All work was compliant with SSE plc Lerwick Power Station’s Safe Systems of Work, current Health & Safety, Environmental and other legislation.

Good engineering practice was used throughout the works ensuring minimum disruption to the operation of the adjacent plant and equipment.

Scope of Work:

Mobilising specialist concrete cutting equipment to the site.
Setting up protective barriers and screens around the working area.
Diamond concrete drilling of vertical and horizontal holes through the structure.
Diamond drilling for, and thereafter, the supply, installation and testing of lifting anchors to each of the cut sections to allow them to be removed utilising the overhead crane.
Wire sawing the horizontal cut at the base of the foundation.
Wire sawing the vertical cuts for each section to be removed.
All coring and cutting coolant water was contained within the cutting area so as not to contaminate the site drainage system.
All sections were cut to a size and weight that could be lifted out safely using the station’s overhead 25T crane.
Slinging and lifting out of each section.
Once all the cut sections had been removed the remaining concrete was removed using remote controlled track sawing equipment.
Full dust suppression was used at all times.

With an initial project duration of 5 weeks Corecut were successfully able to complete the project 2 weeks ahead of schedule. With a project completion time of only 3 weeks.