Precision work down to a millimetre

Convoi recently moved a complete maintenance line on behalf of Tata Steel in IJmuiden, the Netherlands. The distance? A mere few hundred metres... But as certain parts had to be put back with an accuracy of one tenth of a millimetre, the preparations were a rather more sizeable undertaking.

Lifting and assembly work ‘Precision work’ is not the first thing that would come to mind when you hear about a contract at Tata Steel, a company that produces an overwhelming 7 million tonne of steel a year. Yet, that was precisely one of the challenges Convoi had to rise toon this particular occasion. ‘We were asked to move part of a maintenance line for large machine parts that turn liquid steel into steel plates with a thickness of 20 cm’, Marc Smeets, one of the Convoi Project Managers, explains. ‘The maintenance line takes up an area of 60 x 40 metres and consists of stands with steel work galleries that run across two floors’. ‘Where possible, we moved the maintenance line parts as a whole using the plant crane so that assembly could be kept to a minimum.

To give you an idea: the stands (i.e. the basic components) had to be aligned with an accuracy of 0.1 millimetres.’ Intensive preparations The maintenance line had to make way for a new continuous casting machine. To accommodate this latest addition, the existing production area had been extended and the maintenance line needed to be moved from the north to the south of the hall. ‘Child’s play in terms of distance, but another story in terms of preparations’, Smeets continues. ‘First we conducted a feasibility study on behalf of the client. Once the contract was awarded, we had six weeks to finalise the preparations. To add to the challenge, we received an urgent request from Tata Steel before the start of the preparatory work to reduce the operational phase (the actual relocation of the machine) by 40 per cent, from five to three weeks – a tight turnaround time for a complex project.

"We received an urgent request from Tata Steel before the start of the preparatory work to reduce the operational phase (the actual relocation of the machine) by 40%, from five to three weeks – a tight turnaround time for a complex project. "- Marc Smeets, Project Manager at Convoi

For each aspect of this particular assignment, we produced comprehensive working instructions and an extremely detailed planning. Goal zero! The main challenge in this project was ensuring a flawless collaboration with a small army of contractors. ‘We had subcontractors on site to take the measurements and to deal with the hydraulic dismantling and assembly. Relocating the maintenance line also meant that a number of structural modifications to the steel construction had to be made, which was also subcontracted. On peak days, we had a team of thirty people on the day and the night shifts, and our job as main contractor properly and safely coordinating the work of the various parties. To make sure that all the processes dovetailed, we ran a ‘Convoi coordination centre’ at Tata Steel for the duration of the work, from where we organised both our own specialists and all subcontractors.’ As the maintenance line was fully operational again by the given deadline, and as usual, it was once again goal zero! The project was completed without incidents and there has not been a single safety issue’, Smeets concludes. ‘The latter is essential, not only to the client but also to Convoi.’