Case Study
Manufacture and Modification of Bespoke Structural Steel Components
Overview
John Tracey Specialist Welding (JTSW) was contracted by Mammoet UK to manufacture and modify bespoke structural steel components, which formed part of a heavy-duty skidding system.
The project involved the fabrication and welding of large, complex steel assemblies, drawing on a number of the team’s key capabilities including bespoke manufacturing, specialist machining, dimensional control, non-destructive testing (NDT) and protective coatings. As a large-scale, complex scope, extensive collaboration between JTSW’s fabrication team, specialist subcontractors, quality personnel and Mammoet representatives was essential.
Scope of Works
JTSW was responsible for the manufacture and coordination of multiple structural steel sub-assemblies, including:
- Large skidding beams, horizontal base beams, vertical legs, extensions and associated structural components
- Fabrication and welding of structural steel assemblies in accordance with approved drawings and welding procedures
- Specialist line boring, drilling, milling and machining of critical interfaces to achieve the required dimensional tolerances
- Dimensional inspection, NDT and trial-fit activities to verify structural integrity and compatibility between assemblies
- Coordination of external surface preparation and protective coating to the specified C4 coating requirements
- Trial assembly of components to verify fit-up and functionality prior to final handover
- Compilation of manufacturing records, inspection reports, material certification and supporting quality documentation
Scale, Precision and Complexity
This was a project of scale, precision and complexity. Some of the larger beams were approximately 15 metres in length and weighed up to 22 tonnes, necessitating the precision planning of all lifting, handling and fabrication arrangements.
The manufacturing of the different components, using different structural steel grades including high-strength S690 materials, required a variety of specialist welding procedures, material traceability processes and strict inspection control. Specialist machining skills were also deployed, including large-diameter line boring, precision milling of machined faces, and machining of associated connection components.
Quality and Collaboration
Across all activities, quality and collaboration were key. Our team collaborated extensively with Mammoet and Lloyd’s Register quality personnel to coordinate verification and inspections, alongside close coordination with a variety of specialist subcontractors, to ensure the specified tolerances were achieved and key milestones met. Precision planning and communication were also important within the JTSW team itself, as manufacturing activities were coordinated across multiple work fronts, with fabrication, welding, machining, inspection and external coating activities undertaken in a controlled sequence.
Regular progress reporting, programme reviews and technical coordination meetings were maintained with Mammoet throughout the project.
Trial Assembly and Handover
Following the successful manufacturing of each of the key components, the team undertook a trial assembly for both the lift table and large gantry beams, designed to verify the fit and interface of the manufactured components, supported by specialist lifting arrangements.
Following completion of the main manufacturing activities, the equipment was retained at our manufacturing premises under an agreed storage arrangement, pending onward client requirements.
The successful and timely delivery of this project highlights JTSW’s ability to take on large-scale, technically demanding fabrication work, combining specialist welding and machining expertise with the careful planning, coordination and quality control required to deliver complex steel assemblies to exacting client requirements.
Client: Mammoet UK
Project: Bespoke Structural Steel Components – Heavy-Duty Skidding System
Structures: Skidding beams, base beams, vertical legs, extensions, lift table and gantry assemblies
Dimensions: Components up to approximately 15m long / 22Te
Materials: Structural steel, including high-strength S690
Quality Assurance: Lloyd’s Register inspection involvement, NDT and C4 protective coatings
Services: Specialist fabrication, welding, precision machining, line boring, dimensional inspection, NDT, protective coating coordination, trial assembly and quality documentation