Fingrid’s Lake Line project is a 300-kilometre transmission line project involving the construction of two circuits and the installation of altogether approximately 5,100 kilometres of conductors.
In such a large-scale project, the safety of conductor works is a priority that is highlighted at all times. The importance of carefulness cannot be overemphasised.
“To date, no accidents have occurred in the project, knock on wood. Human error can cause serious incidents,” says Tommi Olsson, Project Manager at Fingrid.
There are many specific risks associated with conductor works due to induced voltage and working at heights. Especially a live 400 kilovolt power line next to the line under construction can pose a hazard.
“Even though the transmission line being built is de-energised, a voltage of up to 20 kilovolts can be induced from a live parallel line,” Olsson reminds.
Safety is taken seriously at Fingrid worksites. Every employee must strictly follow safety plans and guidelines. In addition, Fingrid organises training on additional earthing at the worksites.
“Training and thorough risk assessment help us avoid accidents. It requires skill and attention from every person on the worksite.”
Safety starts from planning
Ensuring safety begins before the contract is even agreed on, that is, at the bid stage.
Jaakko Hämäläinen, Project Manager at Destia, explains that the worksite area, project schedules and available resources are carefully reviewed in the bid in order to define the requirements of the conductor worksite and how to ensure its safety.
“As part of planning, we map out the environment and any unusual aspects, such as highway or electric railway crossings. They require special attention and precision,” he says.
Fingrid has established worksite safety requirements that its suppliers follow without exception. The planning of additional earthing is a crucial safety aspect of conductor works. Based on Fingrid’s requirements, the plans accurately specify the additional earthing needs of each tower site.
Special attention is required at transmission line junctions. Plans concerning these locations are drawn up and approved separately. After Fingrid approves the supplier’s plan, a detailed work phase plan with a separate risk assessment is prepared before commencing the contract. This plan is reviewed with the entire team, and finally, each employee acknowledges it as approved.
“The work phase plan is always reviewed in dialogue with everyone involved in the operation, and the installation technicians can share their own observations. This ensures that everyone knows what to do and how to do it,” explains Mika Ahonen, Site Manager at Destia.
No one is left alone at the worksite
Once the plans have been approved and reviewed by the team, the contract can start at the conductor worksite.
Safety is constantly taken care of, and attention cannot slip even for a moment.
“We work in pairs to be able to monitor the work of our colleagues and to ensure that no one is left alone,” says Santeri Mäkeläinen, transmission line installation technician at Destia.
He has eight years of experience from conductor contracts. For new employees, Mäkeläinen emphasises that one should always ask if there is any uncertainty about work methods. One should always think before they act.
“You need to pay attention and know what you are doing at all times. Never forget that we are dealing with enormous forces,” Mäkeläinen adds.
Interaction is particularly critical during conductor works. Responsibility for the monitoring of safety does not fall only with work management and the worksite supervisor, but it is shared by the entire team.
“We are in constant contact with each other in a group call, and if the connection breaks for any reason, the work is interrupted immediately,” says Mäkeläinen.
The thing to impress upon everyone is that unearthed conductors should be treated as if they were energised.
“This is vital when you’re working next to a 400-kilovolt transmission line that can induce a life-threatening voltage,” Ahonen points out.
Protective scaffolding is placed at road crossings to prevent conductors from getting into contact with vehicles if they should fall towards the ground for any reason. The purpose is that conductors are always kept tight and firmly off the ground, but this too is a matter better played safe.
“When pulling conductors, no one is allowed under them. There is always a risk that a conductor comes loose or breaks. Teams are given clear instructions on this, and they must be followed without exception,” Ahonen clarifies.
