Is the belief that the pressure in the Nordstream 1 pipelines was 165 bar at the time of the explosions based upon confirmation from the pipeline operator or some other reliable source ? Or is it based upon predicted values obtained from project documentation prepared prior to the explosions ?
The settle out pressure if the pipeline had been operating at full capacity was calculated to be 165 bar because the inlet pressure would be 220 bar and outlet 105 bar (this can be obtained from Nordstream project documentation). However, for 3 weeks prior to the explosions the pipeline was operating at 20% capacity which implies that the inlet pressure would have been significantly less than 220 bar; it's been reported that the outlet pressure immediately prior to the explosions was 105 bar so the corresponding settle out pressure would be a lot less than 165 bar.
NS1 pipelines pressure would be expected to be higher than NS2 pipelines at the time of the explosions but maybe not to the degree suggested ie 105/165 bar.
I got this number from a seismologist who had received it from some "source" but he wouldn't tell me what that source was. I have no contact with NS1 AG. I do have confirmation from NS2 that the pressure was 103 bar in their pipeline. I wonder why Reuters said 105.
If consideration is being given to the differences that an internal pressure might have on the resulting damage that is evident at the sites, it might be better to assume the pressure in NS1 pipelines was 135-140 bar. Similarily for any calculations which are sensitive to the properties of methane which change with pressure and temperature (eg density, dynamic viscosity).
This is the value obtained from analysis based upon what is known about the gas delivery in the weeks prior to the explosions.
Although ther is not too much hope, it may be recommended to do some trace sampling on the bottom of the craters with special collectors. If any traces remain thes can be collected in the end.
The interpretation of a 5 depression sequence depends on a few details to be observed:
1. Time sequence
structural defects are refilled in part with ejecta from a relatively younger effect. Bottom current show steady direction and transport regime due to current ripples developed. So this disturbance has to be accounted for too.
2. crater structure, to be comparable similar hardground conditions have to exist. Venting does create energy coupling quite different from sources emmanatig stronger shock waves. Thus resullting in different flow regimes.
The cross section depicts a marked avriation in surface conditions of the crater structures. Here Viaual inspection of the structural defects and sizing of ejecta is mandatory to see how much brisance was involved in the causative processes.
Where is the position of the apex from the bend pipe structure in the cross section sited?
The crater bottoms may still hoöd traces from the initial events in very small concentraions. Ther is some hope left that, with adequate sampling, these traces con be retrieved. Together wir magnetic collection of all metall around.
Just remember thet this spot is a DMM area with about 10.000 metric tons of live chemical agents nearby.
Are there any metal samples from the pipes available?Much of the deformation in the NS1 failure area indicate a not too brisant somewhat distant charge with comparatively long coupeling phase. Meanwhile the damage on NS2 suggests a close contact charge of defined localized energy release. again Confirmation can only be achieved by proper metallographic investigation here.
I did not see any loose metal in the area and I have heard that the Swedish investigation have removed 2 containers with materials. They also have removed large pipe sections that are now stacked up in Karlskrona. I don't see how we could retrieve any metal samples.
1. I think that could have been excluded from very early on. I've only heard it once and that was from a Danish journalist. Andreas Lindqvist, who thought it was hit by "scrapnel" but he walked it back very fast when I told him it wouldn't penetrate 27mm steel and 10cm concrete. Where have you heard this theory? Now we also know there was a serious explosion in NS2AS.
2. I saw Oliver Alexander propose this theory but I think he abandoned it. Now the expediiton he made to the site on June 13 say they found primary explosive damage but I don't think so, The accidental rupture theory I think was based on the observation that this was close to the site where work stopped in 2019 and was resumed 2021. However, you can see in the south of my side-scans something that looks like an installation for the underwater welding when the work was resumed. It's far away form the rupture
3. Good question. My information is that NS1 was pressurized to 164 bars but NS2 to 104. The NS2AD site has the pipe broken in 2 or 3 places and trench is only 100 meters and not 250 meters, and the pipe is still in place, so it could be that this bomb was placed in a different fashion, perhaps on top. But maybe the whole difference is the pressure that wasn't big enough to send the pipe flying that much
4. It could have been the second bomb that was to the south. It's much closer to Poland for instance.
5. Not my expertise, but NS2AS was placed under the mudline, so why use a magnet? Also you don't get close to the steel pipe anywhere, the jacket is 10 cm thick.
Erik, a point of clarification (point 2) regarding the welding performed at the point where the russian lay vessel Akademik Cherski took over from the Allseas Solitaire vessel for the NS2A pipeline.
The tie-in weld is unlikely to have been performed by a subsea welding habitat; there are two reasons for suggesting this.
a) the conventional method, which I understand was actually employed, is to pick up the pipeline from the seabed and to commence welding pipe joints on the pipelay vessel.
b) the hyperbaric welding habitat was engineered for tie-in of pipe sections where there was a change in steel pipe wall thickness which enabled the proper hydrotesting of each section (ie KP0 to KP 300 and KP 300 to KP 630). The deployment of hyperbaric welding is a much more expensive and time consuming method than a surface tie-in on a pipelay vessel and requires specialist vessels for the work; it's questionable whether such vessels and/or the welding habitats were available after 2019 due to sanctions.
(You can contact me by DM on Twitter if you would like to discuss pipeline engineering or construction aspects.)
what's your twitter handle? I'm interested in the subject of structural strength and what it takes to actually rupture the pipeline from bending. Behind the pipelaying it seems to me like the entire pipe just hangs in the water till it reaches the bottom. What's the radius of curvature of the section sinking behind the pipelaying vessel?
Thanks for the clarification. There are some circular marks on the sea bottom about 400 meters south of the explosion site. You see it on the scan from west image. What could that be?
I noticed the marks when I first looked at the image and wondered if they might have been from some equipment used for construction. If they were from a welding habitat and associated lifting frames they would be installed with the pipeline between the feet so that the pipeline weight is central and distributed to the feet on either side. Separate lifting frames would be positioned several metres away from the welding habitat (along the pipeline) so that the pipeline can be aligned correctly for welding. The marks are too close together for that arrangement and are some ten metres to the side of the pipeline.
It's difficult to know for sure given that there's very little information available on what occurred during construction of NS2 and the work in that area was performed by the Russian crewed vessel. The vessel tracks for the period when the Cherskyi arrives at the site just shows the vessel manouvering as expected for a conventional recovery of the pipeline to restart pipelay in that area.
Whatever made the marks was fairly heavy and was on the seabed for some time because there's light sediment build up around what look like circular pads.
They seem too far away from the damage site to be related to last years investigations although it may be an explanation.
Steve, thanks for your clarification. Picking up the heavy pipeline from the seabed sounds like it could potentially damage the pipeline joints... do you think an accidental rupture at the NS2 location south of Bornholm is still a possibility given the available underwater footage?
Oliver Alexander initially proposed such a rupture. Perhaps those who mined the pipelines northwest of Bornholm misunderstood which line was affected and so they destroyed the wrong NS2 line 12 hours later? Or one of the mines malfunctioned.
Recovery of a pipeline off the seabed is a standard operation for a pipelay vessel and done in a controlled manner; so unless there is some very unusual circumstance there is little reason to think that it would cause damage at a field joint.
1. The idea that NS2AS was just damaged by the nearby NS1 blast was also voiced by Oliver Alexander. His initial idea was "accidental rupture at NS2AD => detonation of NS1A&B => damage at NS2AS".
2. Yes the idea of an accidental rupture of NS2AD was based on the location of the hand-over of work from Western to Russian ships. But of course the explosions happened just one day ahead of the opening of the Norway-Denmark-Poland Baltic Pipe, which may not have been accidental.
3. Good point concerning the pressure difference. Also 100m is still quite large actually, I had thought it was an ever smaller leak.
4. The NS2AD location is still a mystery to me. Oliver showed that the NS1 blasts were just outside Danish/Swedish radar range, but NS2AD is well within Danish radar range.
1. I wonder if the 15 second delay between NS1AS and NS1BD can be used to guess some location possibilities for the sonar transmitter. Assume that there was one acoustic signal for both sites. Then, applying some geometry...maybe you can describe a locus of points where the trigger might have been. SOS in water is ~1500 m/sec. Of course there are salinity and temp corrections...and sound will have followed a curved path based on thermoclines and the like. Still...seems like something to play with.
2. It seems very strange how this investigation has basically tried to keep partial findings under wraps and basically stop people from crowdsourcing insights. Even the different countries involved. It's like they don't really want to push too hard to find out.
3. Still seems strange to me that the boot was not recovered and tested forensically (for age, source, serial number, size, fingerprints, fibers, chemical traces, etc.)
I added some text about the seismic location thing. If we could have access to the hydrophone data it would be easy. With only land based geophones the Swedish seismologists did this https://snsn.se/stora/Events_20220926.php before Andreas Köhler did the location computations I mentioned, and I've now written more about if you read again. The boot I think could belong to a diver at Normand Frontier which was chartered by USA and visited all sites November 20 -November 30 2022. We'll perhaps do a second expedition to recover it.
Is the belief that the pressure in the Nordstream 1 pipelines was 165 bar at the time of the explosions based upon confirmation from the pipeline operator or some other reliable source ? Or is it based upon predicted values obtained from project documentation prepared prior to the explosions ?
The settle out pressure if the pipeline had been operating at full capacity was calculated to be 165 bar because the inlet pressure would be 220 bar and outlet 105 bar (this can be obtained from Nordstream project documentation). However, for 3 weeks prior to the explosions the pipeline was operating at 20% capacity which implies that the inlet pressure would have been significantly less than 220 bar; it's been reported that the outlet pressure immediately prior to the explosions was 105 bar so the corresponding settle out pressure would be a lot less than 165 bar.
NS1 pipelines pressure would be expected to be higher than NS2 pipelines at the time of the explosions but maybe not to the degree suggested ie 105/165 bar.
I just got confirmation from NS AG (via the Swedish coast guard) that the pressure in both NS1 lines was indeed 165 bars.
I got this number from a seismologist who had received it from some "source" but he wouldn't tell me what that source was. I have no contact with NS1 AG. I do have confirmation from NS2 that the pressure was 103 bar in their pipeline. I wonder why Reuters said 105.
If consideration is being given to the differences that an internal pressure might have on the resulting damage that is evident at the sites, it might be better to assume the pressure in NS1 pipelines was 135-140 bar. Similarily for any calculations which are sensitive to the properties of methane which change with pressure and temperature (eg density, dynamic viscosity).
This is the value obtained from analysis based upon what is known about the gas delivery in the weeks prior to the explosions.
Although ther is not too much hope, it may be recommended to do some trace sampling on the bottom of the craters with special collectors. If any traces remain thes can be collected in the end.
The interpretation of a 5 depression sequence depends on a few details to be observed:
1. Time sequence
structural defects are refilled in part with ejecta from a relatively younger effect. Bottom current show steady direction and transport regime due to current ripples developed. So this disturbance has to be accounted for too.
2. crater structure, to be comparable similar hardground conditions have to exist. Venting does create energy coupling quite different from sources emmanatig stronger shock waves. Thus resullting in different flow regimes.
The cross section depicts a marked avriation in surface conditions of the crater structures. Here Viaual inspection of the structural defects and sizing of ejecta is mandatory to see how much brisance was involved in the causative processes.
Where is the position of the apex from the bend pipe structure in the cross section sited?
The crater bottoms may still hoöd traces from the initial events in very small concentraions. Ther is some hope left that, with adequate sampling, these traces con be retrieved. Together wir magnetic collection of all metall around.
Just remember thet this spot is a DMM area with about 10.000 metric tons of live chemical agents nearby.
Are there any metal samples from the pipes available?Much of the deformation in the NS1 failure area indicate a not too brisant somewhat distant charge with comparatively long coupeling phase. Meanwhile the damage on NS2 suggests a close contact charge of defined localized energy release. again Confirmation can only be achieved by proper metallographic investigation here.
I did not see any loose metal in the area and I have heard that the Swedish investigation have removed 2 containers with materials. They also have removed large pipe sections that are now stacked up in Karlskrona. I don't see how we could retrieve any metal samples.
Hi, we have heard about some lenght removed and a clean um. Its a pitty if no metal is available, as it will be quite revealing.
Absolutely amazing work. Independent investigations is the way to go! Some questions:
1) The theory that NS2AS was just damaged by the blast at NS1BD can be excluded now?
2) The theory that NS2AD in the early morning was just an accidental rupture can be excluded?
3) Were NS2AD and NS1 really destroyed in the same way? The destruction at NS2AD seems much smaller?
4) If they wanted to destroy both lines of NS2, why place the first bomb 70km to the south?
5) Can the use of a magnetic mine attached to the metallic pipe be excluded?
1. I think that could have been excluded from very early on. I've only heard it once and that was from a Danish journalist. Andreas Lindqvist, who thought it was hit by "scrapnel" but he walked it back very fast when I told him it wouldn't penetrate 27mm steel and 10cm concrete. Where have you heard this theory? Now we also know there was a serious explosion in NS2AS.
2. I saw Oliver Alexander propose this theory but I think he abandoned it. Now the expediiton he made to the site on June 13 say they found primary explosive damage but I don't think so, The accidental rupture theory I think was based on the observation that this was close to the site where work stopped in 2019 and was resumed 2021. However, you can see in the south of my side-scans something that looks like an installation for the underwater welding when the work was resumed. It's far away form the rupture
3. Good question. My information is that NS1 was pressurized to 164 bars but NS2 to 104. The NS2AD site has the pipe broken in 2 or 3 places and trench is only 100 meters and not 250 meters, and the pipe is still in place, so it could be that this bomb was placed in a different fashion, perhaps on top. But maybe the whole difference is the pressure that wasn't big enough to send the pipe flying that much
4. It could have been the second bomb that was to the south. It's much closer to Poland for instance.
5. Not my expertise, but NS2AS was placed under the mudline, so why use a magnet? Also you don't get close to the steel pipe anywhere, the jacket is 10 cm thick.
Erik, a point of clarification (point 2) regarding the welding performed at the point where the russian lay vessel Akademik Cherski took over from the Allseas Solitaire vessel for the NS2A pipeline.
The tie-in weld is unlikely to have been performed by a subsea welding habitat; there are two reasons for suggesting this.
a) the conventional method, which I understand was actually employed, is to pick up the pipeline from the seabed and to commence welding pipe joints on the pipelay vessel.
b) the hyperbaric welding habitat was engineered for tie-in of pipe sections where there was a change in steel pipe wall thickness which enabled the proper hydrotesting of each section (ie KP0 to KP 300 and KP 300 to KP 630). The deployment of hyperbaric welding is a much more expensive and time consuming method than a surface tie-in on a pipelay vessel and requires specialist vessels for the work; it's questionable whether such vessels and/or the welding habitats were available after 2019 due to sanctions.
(You can contact me by DM on Twitter if you would like to discuss pipeline engineering or construction aspects.)
what's your twitter handle? I'm interested in the subject of structural strength and what it takes to actually rupture the pipeline from bending. Behind the pipelaying it seems to me like the entire pipe just hangs in the water till it reaches the bottom. What's the radius of curvature of the section sinking behind the pipelaying vessel?
I'll contact you.
Thanks for the clarification. There are some circular marks on the sea bottom about 400 meters south of the explosion site. You see it on the scan from west image. What could that be?
I noticed the marks when I first looked at the image and wondered if they might have been from some equipment used for construction. If they were from a welding habitat and associated lifting frames they would be installed with the pipeline between the feet so that the pipeline weight is central and distributed to the feet on either side. Separate lifting frames would be positioned several metres away from the welding habitat (along the pipeline) so that the pipeline can be aligned correctly for welding. The marks are too close together for that arrangement and are some ten metres to the side of the pipeline.
It's difficult to know for sure given that there's very little information available on what occurred during construction of NS2 and the work in that area was performed by the Russian crewed vessel. The vessel tracks for the period when the Cherskyi arrives at the site just shows the vessel manouvering as expected for a conventional recovery of the pipeline to restart pipelay in that area.
Whatever made the marks was fairly heavy and was on the seabed for some time because there's light sediment build up around what look like circular pads.
They seem too far away from the damage site to be related to last years investigations although it may be an explanation.
Steve, thanks for your clarification. Picking up the heavy pipeline from the seabed sounds like it could potentially damage the pipeline joints... do you think an accidental rupture at the NS2 location south of Bornholm is still a possibility given the available underwater footage?
Oliver Alexander initially proposed such a rupture. Perhaps those who mined the pipelines northwest of Bornholm misunderstood which line was affected and so they destroyed the wrong NS2 line 12 hours later? Or one of the mines malfunctioned.
Recovery of a pipeline off the seabed is a standard operation for a pipelay vessel and done in a controlled manner; so unless there is some very unusual circumstance there is little reason to think that it would cause damage at a field joint.
is this the underwater welding location you referred to? image link: https://i.ibb.co/FVypnG8/Clipboard01.png
yes! But it might not be a welding location I hear. That was just a guess.
Many thanks Erik.
1. The idea that NS2AS was just damaged by the nearby NS1 blast was also voiced by Oliver Alexander. His initial idea was "accidental rupture at NS2AD => detonation of NS1A&B => damage at NS2AS".
2. Yes the idea of an accidental rupture of NS2AD was based on the location of the hand-over of work from Western to Russian ships. But of course the explosions happened just one day ahead of the opening of the Norway-Denmark-Poland Baltic Pipe, which may not have been accidental.
3. Good point concerning the pressure difference. Also 100m is still quite large actually, I had thought it was an ever smaller leak.
4. The NS2AD location is still a mystery to me. Oliver showed that the NS1 blasts were just outside Danish/Swedish radar range, but NS2AD is well within Danish radar range.
5. Ok, good point.
1. I wonder if the 15 second delay between NS1AS and NS1BD can be used to guess some location possibilities for the sonar transmitter. Assume that there was one acoustic signal for both sites. Then, applying some geometry...maybe you can describe a locus of points where the trigger might have been. SOS in water is ~1500 m/sec. Of course there are salinity and temp corrections...and sound will have followed a curved path based on thermoclines and the like. Still...seems like something to play with.
2. It seems very strange how this investigation has basically tried to keep partial findings under wraps and basically stop people from crowdsourcing insights. Even the different countries involved. It's like they don't really want to push too hard to find out.
3. Still seems strange to me that the boot was not recovered and tested forensically (for age, source, serial number, size, fingerprints, fibers, chemical traces, etc.)
I added some text about the seismic location thing. If we could have access to the hydrophone data it would be easy. With only land based geophones the Swedish seismologists did this https://snsn.se/stora/Events_20220926.php before Andreas Köhler did the location computations I mentioned, and I've now written more about if you read again. The boot I think could belong to a diver at Normand Frontier which was chartered by USA and visited all sites November 20 -November 30 2022. We'll perhaps do a second expedition to recover it.