During shutdowns or turnarounds on chemical and petrochemical plants, the works to the flare are often regarded as high risk. Both safety as well as project risks are identified. Planning the [...]
Although any change in legislation to better protect the safety of your employees is commendable in principle, they naturally lead to new challenges if like Mammoet the use of cranes is your core business. And especially in a case like the one presented below, where the change comes into force right between the preparation and execution phases of your project.
In late 2019, the Conbit was contracted to perform onshore flare tip maintenance. The flare tip was located atop a 75-meter-high stack with no means of access to the flare tip platform or any of the guy wire connection points.
The scope consisted of:
- Replacing the guy wires
- Removing the flare tip for maintenance
- Placing the flare tip back once maintenance was conducted
The execution was initially requested for April 2020 during the scheduled maintenance shutdown of the plant. However, due to the world being put upside-down in the immediate wake of the COVID-19 pandemic, the shutdown was eventually rescheduled to October.
With a crane being required for the lifting of the wires and flare tip, Conbit enlisted the aid of one of the Dutch Mammoet offices, which ended up becoming a sister company during the preparation phase when Mammoet and ALE merged. During this phase, it was planned to use a man basket as the primary means of access – the crane would already be in place, the risk profile was considered equivalent to the best alternative and it would be the most time-efficient solution.
Along came July and the subsequent presentation of our plan to the aforementioned safety advisor. And as the risk profile of using the man basket wasn’t substantially better than a feasible alternative, the plan was rejected and Conbit went back to the drawing board.
To clarify: both the use of scaffolding and a cherry picker was left out of consideration from the start. The former was abandoned because the exposure to the scaffold builders would nullify the risk reduction for our technicians several times over – aside from the technical feasibility of building a 75-meter scaffold around a free-standing flare stack in the middle of a gas processing plant. The latter route was discontinued when, after verifying with one of our country’s leading suppliers, it turned out we would not be able to obtain a model that would give us the reach we required.
Rope access, despite being Conbit’s bread and butter, was initially planned as a secondary means of access. As indicated above, the risk profile was considered similar to using a man basket, with time efficiency being a key element here. Naturally, you want to give your client the most efficient solution in terms of costs, but in this case, time efficiency also means decreased exposure time to the hazards related to rope access and working at height in general.
Because of the project plan being formally rejected, however, rope access was to get a more prominent feature in the execution. This didn’t mean we could say goodbye to the man basket altogether: as indicated, there was no means of getting into the stack to install anchors and access lines, and other conventional methods were impracticable. As such, the project was redesigned to deploy the man basket only as a means of facilitating rope access.
The plan of operation was revised accordingly. Risk assessments and procedures updated making use of both Mammoet’s extensive experience in the use of cranes as well as Conbit’s knowledge of IRATA. To manage expectations, the client was kept in the loop on this process and consulted for approval whenever necessary, as they too are considered under the scope of the revised legislation.
After some discussion and clarification, the revised plan was accepted by the safety advisor, but the reach of the ‘long arm of the law’ didn’t stop there. The advisor’s shared responsibility for the safe execution meant that his own instructions were added to our plan, consisting of delivering proof of meeting the stipulated requirements each day. These included, but weren’t limited to:
- A signed plan of operation;
- A signed toolbox form for the shift’s tasks;
- Pictures of the crane configuration;
- Weather forecast data and actual wind speed measurements;
- Valid inspection certificates of all equipment, and
- A consult upon delivery of the required information to verify readiness.
Due diligence was evidently a key factor here. To the advisor’s credit, the entire process was set up with typical Dutch practicability. In other situations, a person in his position might insist on attending the entire process from start to finish in person and gleefully invoice you for every hour spent on site. In our case, a mode was found where he could ascertain that all requirements were met, and safe operation was guaranteed while minimizing his impact on project lead time.
All in all, despite the weather forcing us to halt operations on multiple occasions, the project turned out a great success. The combination of man basket and rope access allowed for tailor-made access solutions to each part of the stack. The synergy between Conbit’s technicians and Mammoet’s crane operators, as well as between the combined team, the client, and the other contractors on site was excellent. And last but certainly not least, a solution was put in practice that not only allowed for safe and incident-free execution of the works but was also up to date with applicable legislation. The end result was a very satisfied customer and a Conbit team that was able to look back on the entire project with due pride.
By Dennis van Lamoen