My previous job was working in the sewerage industry, and I don’t like people working in confined spaces, such as in tanks, which is potentially dangerous and sometimes unnecessary. It has become my personal quest – if it’s not necessary to put people in tanks in confined spaces, then they shouldn’t be in confined spaces. That’s where my interest in drones comes in. Together with my colleagues from maintenance we set up the overall process based upon this starting point.

SOME BACKGROUND TO ARGENT ENERGY

Argent Energy is a subsidiary of John Swire & Sons, a UK-based, global conglomerate. It consists of three plants manufacturing biofuels, mainly biodiesel. What we do here in Amsterdam is generate biodiesel made from Category 1 materials, so that’s mainly animal waste, but also other feedstocks. Argent Energy has two sites in the UK as well, in Motherwell in Scotland, and in Stanlow in England.

WHAT FACILITIES DO YOU HAVE IN AMSTERDAM?

The terminal consists of the biodiesel factory, which has the capability to produce 100,000 tonnes of biodiesel annually, and a 97,000 m³ stainless steel tank farm. The site has direct access to the Port of Amsterdam. The Amsterdam site also offers tolling services for other customers, where we melt their fats and oils and store it in our tanks for them. There is also a tank cleaning company which is also owned and run by us.

WHAT ARE THE INSPECTION NEEDS AT THE TERMINAL?

We follow the EEMUA 159 regulations for tank inspections. We transfer that into risk-based inspections (RBIs). Annually, we only inspect some of the tanks, but over each ten-year period, all the tanks will be inspected based on their riskprofile. Traditional tank inspection is very expensive, and it’s very time-consuming due to building a lot of scaffolding inside the tanks, to allow the workers to manually inspect the tanks.

WHY DID YOU DECIDE TO USE DRONES?

Spending a lot of money and time on inspections inside tanks, as well as this non-person entry mission from myself, meant traditional methods were not appealing, and we came up with the idea of using drones. We had a few meetings with other providers of drones but we went with Terra Inspectioneering. The company could offer us inspections inside the tanks, high level inspections, and could measure the thickness of the tank wall using non-destructive testing (NDT) methods, adding the final step for us. We first did a trial, just to see how it would work in smaller but high tanks, for Terra and for us, and it was quite successful. We learned a lot, they learned a lot, and in the end, we decided to go for it, and properly started to do the tank inspections.

WHAT IS INVOLVED IN THE TERRA INSPECTION PROCESS?

Once we have cleaned the tanks, Terra Inspectioneering can come in with the drones. The company has used two drones at our site. The smaller one is used for visual inspections. It is easy to handle and easy to operate, an operator can put the drone in the manhole, release it, and it flies in. However, it cannot measure the thickness of the walls, so for that Terra needs the larger drone. This drone cannot fit through the manhole. An operator has to go inside the tank and assemble the drone there, so it’s not completely nonperson entry yet, although the company has nearly completed a full-non-entry version. The operator can then carry out the entire inspection from outside, with only the drone inside the tank. We currently have tanks between 22 and 26 m high and they can do a 360˚ tour on all levels of the tank, and be finished in half a day. That’s great for us.

WHAT OUTPUT DO YOU GET AT THE END OF THE PROCESS?

Terra Inspectioneering first of all interprets the data, then pulls it together into a big inspection report, where we can find everything we need to know according to EEMUA 159. The reports are clear and concise. In the beginning, the company also sent us all the visual graphics from the tank, together with the additional data for us to analyse, but in the end if you’re not used to reading everything and interpreting everything, it’s a lot easier just to have the final report. It shows any current issues, and potential issues for the future. That helps us a lot.

WHAT ARE THE BENEFITS COMPARED TO MANUAL INSPECTIONS?

The lower cost, for one. If there are additional questions, it’s a lot easier to get the drone in again for a second look. Once you have scaffolding up in a tank you have to keep it there until you’re satisfied with the final report. Now with Terra, the drone gets in, does its work, the engineers get their report, and if there is something they want to recheck or something we want to recheck, they just hop in again, and they do it only on that spot. If we noticed a problem after a manual inspection, after the scaffolding has been taken down, then you have to put it up again, and that’s very costly and bothersome. The process is also very flexible and easygoing. What we see in our business currently, is that we are now in in a phase of change in customers. Some customers are leaving now, they’re building their own tank farms, and we’re getting new customers in for a short period. In the current market there are a lot of requests for tank space, so the customers are almost waiting for others to leave so they can get in. In the meantime, we want to do our checks on the tanks. With the drones, you stay flexible. The moment you have a pilot available, you can do an inspection. With scaffolding, you need a team to put up the scaffolding inside your tank etc. and it takes a lot more time. The drone process is cheaper, faster and more flexible.

HOW WILL THIS HELP THE TERMINAL GOING FORWARD?

We can easily carry out more checks on the status of the tanks. If we have more changes of customers and tank turns, in between that you can have a quick check. If we want to see the condition of the tanks, it’s almost in real time. You can do an inspection very quickly. That’s the advantage for us. We have learnt that Terra Inspectioneering is a very skilled and knowledgeable company. We also spoke to other drone companies and some individuals, but they haven’t matured enough in this area of expertise. With Terra you have a completely professional company on board. With Terra, we are ready for the future of EEMUA.

For more information: www.terra-inspectioneering.com www.argentenergy.com