It's a planned class docking. The contract costs are mainly conversion and mobilization, and that's not a big amount this quarter. If you look at payment on borrowing, there's a change in interest-bearing debt. That is mainly debt service on the DOFCON JV. It's some amortization on parts of the DOF Subsea and Norskan, mainly the BNDES facility and repayment of a loan in DOF Subsea. By end of the quarter, the restricted cash of NOK 2.2 million was NOK 155 million. If we move on to next. Looking at the EBITDA, you can see that for the last quarter, the EBITDA has been above 800. This is normally the high season, especially in DOF Subsea, second and third quarter.
The low point was actually in 2018. Looking at the non-current assets, that's our vessels. Substantial reductions since 2017, and that is mainly impairments booked and vessels sold. It's actually a change of NOK nine billion. The equity is still negative and, of course, that's a going concern assumption and the group is dependent on extension of standstill agreement with its lenders. Looking at the debt, the net interest-bearing debt is NOK 9.8 billion compared to NOK 21 billion last year. The change is repayment of debt and also currency impacts. If you go into the balance sheet.
Some of the points is already mentioned, but if I focus on the change this quarter, not much on the non-current assets. Looking at the current assets, you can see that the receivables is increasing and especially compared to year-end and the main reason for that is actually higher activity. The equity is already mentioned and of course impacts the going concern assumption. The non-current interest-bearing debt, that is our portion of the DOFCON JV and some lease debt in DOF Subsea. The current portion of debt that basically represent the debt that is undergoing a restructuring.
This has been impacted by consolidation of Eidesvik which has increased the debt and this has also been reduced by close to the same number, NOK 400 million, after repayment of a loan facility. No big changes on the current portion of the debt. If we move on to next. Here you see the revenue EBITDA firm backlog since 2015 and the last 12 months. Of course, on the EBITDA you can see that it has reduced, but bear in mind that especially 2020 was a very special year on high volatility in currency which has of course impacted our financial result very negatively last year.
Looking at the backlog, we are more or less at the same level by end of September last year, and that is NOK 15 billion in backlog. If we go to the last one. It's approximately NOK 19 billion of the group debt that is undergoing a restructuring. We have standstill agreement with 91% of the secured lenders in DOF Group and 95% of the secured lenders in DOF Subsea. There are also some international banks which are funding the Norskan activity and all these lenders have signed a standstill agreement until end of November. Already mentioned that we paid one loan facility in third quarter. In Norskan Offshore and in DOF Subsea Brazil the debt are served according to a refinancing agreement signed with BNDES in February last year.
However, there are ongoing discussion with BNDES and the other lenders to reach a robust long-term refinancing solution for the group which of course BNDES is a very important part. The dialogue with all the lenders and the bondholders is constructive and the progress has been made during the quarter. A final solution is not yet in place. Thank you.
Yes, then a few words on the market and finally the outlook. We start with the market. This is a slide showing, you know, we have got from Rystad showing what they expect as demand for our type of vessels going forward. Of course, we partly notice this also in the market. We have people around the globe talking to clients, and we do expect activity to continuing picking up. In this slide, it shows that demand for vessels will increase both in oil and gas and in wind and for many years going forward now on.
We also see on the left-hand side that the demand will increase for all type of vessels, anchor handler, PSVs, subsea vessels, and also dedicated vessels for the wind industry. Next slide shows you know it's just a slide on the project we are doing next year on the Norwegian continental shelf. It's called Hywind Tampen, which is 11 wind turbines to be installed on Snorre and Gullfaks. Combined capacity of 88 MW. Of course, what we are doing in this is you know together with our joint venture partner we are responsible for engineering, procurement, construction and installation of 11 floating turbines.
It's a very interesting project for us and, of course, a very good reference for the future in the floating wind market. Our scope will be towage and installation of all 11 units, and we manage all marine activity, both at the quayside and offshore. We will utilize two of our own boats or perhaps more, but Skandi Skansen and Skandi Iceman will utilize for this. We talk around 60 to 80 to 100 days per vessel on these projects. Of course, if you look at the future, it's you know, when you see the floating wind farms planned some years ahead, of course they are much larger.
Of course it shows that the demand for our most advanced and large anchor handlers you know they will get the market in the floating offshore wind. We have a slide showing that on the next page please. It's showing that you know there will be a slow increase until 2024. After 2024 of course we expect that market to become a very interesting market for us. We see in 2024 it's predicted nine or close to nine vessel years in that. Then we of course you see on the right-hand side that it's expected a pretty high increase in the installation of floating wind towards 2030.
It's an interesting segment for us, and of course, this Hywind Tampen is a very good reference. Of course, with experience we have from the oil and gas market with installation and mooring of FPSOs and rigs and so on, it's a segment where we can utilize the full capacity and competence of the group from the engineering side to the design side to the installation side and two of our large anchor handling fleet. On the outlook, I mentioned already that we see increased activity in most regions. We see high tender activity and high activity in Brazil. We have seen the PSV market, especially also, but also the anchor handling market.
We have seen improvement in the quarter and the PSV market in the North Sea are still pretty tight, but we are now in the middle of November. The anchor handling market is more, let's say, variable but we have seen some peaks that has been promising, but still too low utilization in that market. As normal, we expect a weaker North Sea market during the winter, but we expect it to pick up again in the spring. We do expect a better market in 2022 than what we have seen in 2021. On the subsea side, I would say almost globally, the tender activity is high.
Of course, we expect that trend to continue to see higher activity in the subsea market in 2022 compared to 2021. We also see a slight increase in demand within the offshore wind, then, but of course where we see we really wanna take a strong position is on the floating side where we see, as mentioned, our fleet, both anchor handling tug for those so part of the subsea fleet and our competence is very well suited for that market. The backlog for quarter four is NOK 1.9 million. As mentioned earlier, you know, we had a turnover slightly above NOK 2 billion in quarter three. It means that we have a very almost record high order book for quarter four.
We expect, however, that the operational EBITDA will be slightly or a bit lower in quarter four compared to quarter three. All in all, a good backlog as mentioned for quarter four and also for the first months of 2022. As mentioned by Hilde, the dialogue with the lenders concerning a robust long-term financial solution has had progress in quarter three, but still some major items to be agreed on, and the solution is not in place. Of course, we cannot guarantee that there will be any solution in place. That is the end of the presentation. We will not do a Q&A session on this call. However, both Hilde and me are available right now after the call.
If you have questions, please give one of us a call, and we will answer as best as we can. Thank you very much, and have a nice day.