Naked Science Forum
Life Sciences => Marine Science => Topic started by: Johann Mahne on 13/10/2011 08:23:40
-
We have just had a major oil spill at Papamoa and mt Maunganui beaches.
They are our best beaches in NZ. Surfing,fishing ,swimming, marine reserves.
The public is really angry.
350 tonnes of oil has leaked from a vessel names Rena that has run aground, and is breaking up.
People are trying to clean up, and are getting sick from the smell of the fuel oil.
We are told that the marine life will "bounce back" by December after the clean up.
How has the marine life coped with the recent BP spill and the Alskan Exon Valdez?
-
Certainly the quantities of oil you are describing and those in Alaska or the Gulf are vastly different.
The Valdez released about 260,000 barrels (41,000 m3) - 750,000 barrels (119,000 m3) (37,000 to 104,000 tonnes).
The BP spill in the Gulf of Mexico was about 4.9 million barrels (780,000 m3) (492,000 to 627,000 tonnes)
with a cubic meter of crude oil being a little less than a metric ton.
Apparently 20 years after the Valdez spill, some oil still remains.
http://en.wikipedia.org/wiki/Exxon_Valdez_oil_spill#Oil_still_remains
http://en.wikipedia.org/wiki/Talk:Exxon_Valdez_oil_spill#Recovery_Of_Ecosystem
Although the actual impact of the remaining oil appears controversial. The beaches appear clean unless one is looking for the oil.
In the Gulf of Mexico, there appears to be an increased number of dolphin mortality (above the normal background levels). Although the actual causes of the dolphin mortality is apparently still undetermined.
However, keep in mind that 350 tonnes would put New Zealand quite far down the list of spills.
http://en.wikipedia.org/wiki/List_of_oil_spills
Do what you can do to help the wildlife and clean the beaches. In a few years, you will be ok.
It doesn't hurt to re-evaluate your oil consumption policies, however, around the world, petroleum is still king of the energy reserves.
-
Comprehensive as always Clifford.
I guess we are lucky that the spill could have been from an big oil tanker. There will be more oil leaking out if the main oil tank ruptures.
A small country like ours is always affected more, especially as it's our prime beaches. We don't have many here as it's a volcanic island.
-
Ahhh, yes,
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fnews.bbcimg.co.uk%2Fmedia%2Fimages%2F55963000%2Fjpg%2F_55963034_jex_1195512_de47-1.jpg&hash=dc068f1648cea0b75bad08c22f8ed29d)
So, it is a container ship, with full tanks of fuel.
If the container ship is left full, it will break up and loose everything it is carrying. They need to get the 1368 containers off the ship. Well, they should have done that a week ago, and perhaps the ship could have been towed off the reef. It may be too late now.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fstatic.guim.co.uk%2Fsys-images%2FGuardian%2FPix%2Fpictures%2F2011%2F10%2F12%2F1318423864681%2Fon-the-Astrolabe-Reef-nea-008.jpg&hash=13aea0e5408bd2c05a815b3aa119698d)
Unfortunately the container weight is up to 30,000 kg, 67,000 lbs (for 40 ft container).
The highest capacity helicopter in active use (Russian MI-26) can lift 20,000 kg, 44,000 lbs, and might be able to offload some of the containers, but not all of them.
The Russian V-12 helicopter should have been able to handle the weight with a capacity of about 44,000 kg (88,000 lbs), but unfortunately neither of the two helicopters are in active duty now.
-
Clifford how do you know so much stuff?
-
Clifford how do you know so much stuff?
This is a little off topic, but I have broad interests... and perhaps get distracted easily. I certainly had a "generalist" approach to higher education. I can think of new and unique ways to combine information that I have read. And, of course, there is a lot of reference material on the internet.
I will tinker, and dabble with a number of things. Unfortunately, never an "expert" in anything. And, unfortunately not all of my ideas can be upscaled.
The Gulf BP disaster was very different than what is going on in New Zealand at the moment, but in the case with the BP spill, it became obvious quite early that the ultimate solution was very similar to what I had done replacing my water shutoff valve in my basement under full pressure a few years ago. But, I solved the basement water problem in a matter of minutes. BP took over a month to incorporate a solution that should have been done the first week.
There have been many groundings of ships over the years. However, I haven't been close to the ships. If you think of the Argo Merchant (http://en.wikipedia.org/wiki/Argo_Merchant) which was a sunken tanker. It ran aground on December 15, 1976. They were unable to refloat the ship, and it eventually broke up and sank a week later on December 21, 1976. In that case, much of the oil was apparently washed out to sea, and the impact of the spill was much less than with other shipwrecks like the Valdez.
The Hull of the MV Rena (http://en.wikipedia.org/wiki/MV_Rena) has already been severely compromised, and I would imagine that it will follow much of the same pathway as the Argo Merchant a few decades earlier. I suppose there are several issues with the MV Rena. The weight of the cargo. The oil onboard and potential for a spill. If the ship sinks, you'll also have broken conex boxes everywhere, and there are apparently some unlisted toxins onboard too. The holes in the ship, and now the tear in the side of the ship.
And, of course, the seas can be very unforgiving for a grounded ship, with tides constantly shifting pressures, and storms blowing through at inopportune times.
A ship should be able to float for a significant amount of time with some extraordinary holes in the side as it takes time for water to come onboard. Then it just becomes a battle between inbound water, bilge pumps, and the time to move it to dry dock. With that in mind, if there are no dry docks nearby, I would certainly try to move a floating dry dock into close proximity of the ship. Can the floating dry docks be moved?
-
replacing my water shutoff valve in my basement under full pressure a few years ago
Please explain...
-
replacing my water shutoff valve in my basement under full pressure a few years ago
Please explain...
It is simple.
If you have a pipe under pressure. If you try to install a plug, or turn off the valve before installation, it is very difficult to do as you have to overcome the pressure in the pipe.
If you open the valve 100% open, the water passes through the valve, and it is relatively easy to make the connection. Once you have connected the valve to the pipe, you can close the valve.
I did, however, have a good shower that day [:D]
In the case of BP, they originally chose to try to passively collect oil from open holes in the pipes, but had troubles with methyl hydrates clogging their systems due to cold water and methane mixing. This was something that was new to me, but is also related to other environmental issues that are currently being debated.
Anyway, after dinking around with trying to contain the spill with boxes around the leaks, they eventually chose to cut the pipe a few feet above a perfectly good flange, but they did not have any way to make a good seal with the pipe. It would still have been ok, but they hadn't bothered to get enough processing capacity for the oil at the surface, and thus they ended up restricting the flow at the surface, increasing the pressure beyond what their incomplete seal would be capable of handling, and thus the oil continued to spill. They could, of course, have allowed free flow of oil up the pipe and released it as a fountain at the surface, but they chose to release it subsurface instead.
The final solution, of course, was simply to unbolt the old pipe at the flange, connect a new pipe or pipe connector at the flange with the valves open. Close the valves once a secure connection was made. It is beyond me why it took them over a month to do that.
They did eventually put in a permanent plug, but after getting a good subsurface valve, they likely could have maintained the well open for its typical lifespan of a few years. The greatest risk was that they did not know the integrity of the casing. Had oil leaked up the outside of the casing, it would have been extremely difficult to stop, but the risk of that happening would likely be low. Also, having a system without proper safety equipment might have left them at the mercy of future hurricanes.
There was a lot of discussion about a siphon. Since the density of oil was lower than water, the oil would naturally flow up the pipe without a pump. In fact, the trick should have been how to prevent water from seeping in at the junction due to the higher pressure.
The New Zealand shipwreck, of course, is entirely different.
What a mess!!!
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fmsnbcmedia.msn.com%2Fj%2FMSNBC%2FComponents%2FPhoto%2F_new%2Fpb-111013-newzealand-shipwreck-ps3.photoblog900.jpg&hash=7bd6f0c490fbce7913ba143444baab0d)
-
Any new information?
Most of the info I'm seeing on the WWW is about a week old.
Have they finished pumping out the fuel tanks?
Any luck with unloading the containers before they fall into the ocean?
Has the split in the hull gotten worse?
-
Hi Clifford,
The pumping out of the fuel oil is very slow due to it's viscosity. Only about 160 tons has been pumped out. They are trying to heat it up locally before it gets to the pump. They are using a screw type of pump.
The containers are STILL on board. They are only held by straps.
Many have caused quite a pollution headache due to debris and also there are toxic chemicals in them.
-
Thanks for the update.
I see another article:
300 tons of fuel leaked.
256 tons of fuel pumped out.
1000 tons of fuel left onboard.
http://www.monstersandcritics.com/news/asiapacific/news/article_1670486.php/Calm-weather-raises-hopes-for-New-Zealand-shipwreck
Progress with this kind of an emergency response always seems to progress slower than one might like. While there are many companies that apparently specialize in disaster response, it is as if none of them really practice, or have a good response plan. I think that was BP's major failure. They should have simulated a deep well rupture, and had a planned response, yet they all seemed to be inventing the wheel from scratch at the time of the emergency.
There still seems to be little mention about the cargo onboard, or a good ID of the "toxic chemicals". Some water soluble chemicals might be inactivated by seawater, or be dispersed very quickly.
Perhaps leaving the cargo on the ship helps maintain the stability of the ship on the reef as the oil is being pumped out, but I have troubles imagining what it will be like if thousands of containers eventually fall in to the sea. Access to the containers will be a nightmare.
-
The navy is sweeping the area with asdic to find submerged containers.
There are more hazardous chemicals on board, but no one is really sure how many have already gone overboard.
BP used the excuse that leak was at a great depth and maybe they have a point. I'm not sure why they were granted the license to drill at such a depth, so should the US goverment not carry the blame for this?
-
You might also want to ask the company that supplied the equipment that failed as well as the company that was using it.
It's also fair to say that, to any extent that the government shouldn't have let them drill, the people shouldn't have wanted the oil so badly.
It is rather difficult to do anything in that depth of water.
BTW, it's perfectly possible to replace the water shut off valve without getting wet. I did it on my house a year or so ago. The original stop tap wouldn't close and I couldn't ask the local water supply company to turn off the whole street. So I prepared the system carefully, drained the water out, cut a section out of the the pipe with a pipe cutter and installed a new tap. I don't think I spilled as much as a cup-full of water.
Any guesses how I did it?
Incidentally the way I used wouldn't have worked on an oil blowout
Re "They should have simulated a deep well rupture, and had a planned response, "
They did. The response was that the blowout preventer would actuate and cut off the flow.
The problem was that they trusted it and it failed.
-
You got zero flow in the pipe and froze a plug of ice inside it with either CO2 or lN2, and cut just after the blockage. The freeze plug keeps the water from flowing, but will melt easily when finished. Rapid freezing keeps the ice crystals formed very small.
-
Close enough. In fact the cryogen was tetrafluoroethane
Something like this, but lots of others are available.
http://www.plumbcenter.co.uk/en/tools-essentials/pipe-freezing/artic-spray2-pipe-freezer-spray-240g-61780
-
I would rather use dry ice than R12 in a can.
-
I doubt anyone uses R12 for this any more (if they ever did).
-
Your common freezer spray is R134a, I have seen old cans that were R12. The biggest use of R12 was for blowing polystyrene, and as a solvent to degrease metal.
-
Notes indicate that they are now up to about 737 tons of oil removed from the ship, 650 tons remaining (Oct 26) (http://news.smh.com.au/breaking-news-world/rena-oil-salvage-reaches-halfway-mark-20111026-1mikf.html). That would put it at day 21.
As far as I can tell, the containers haven't been removed. Obviously a tough task at sea with the ship leaning so much.
A "King Tide" (http://www.nzherald.co.nz/environment/news/article.cfm?c_id=39&objectid=10761942) is supposed to hit shortly, which would be a chance of re-floating the vessel if it had been lightened, patched, and pumped out. As it is, it is probably going to just increase the instability of the system.
At this point, I think there needs to be a multi-national maritime safety review. Perhaps a new maritime safety review body.
One of the big problems is that it is like with every accident one must re-invent the wheel from scratch.
I realize that the sea is an extremely unforgiving environment. But, we are doing activities that can contaminate hundreds of miles of coastline and thousands of square miles of marine habitat. And, as far as I can tell, things have gotten bigger over the last few decades, but not necessarily safer.
BP SPILL
- I'm not convinced that drilling 1 mile deep is inherently unsafe. Will we try 6 mile deep wells in the future?
- The equipment needed to be tested in the environment that it was destined to be used before installation.
- They need to have a crew that practices Emergency Response including a simulated mile deep blowout. Build a simulated well a mile deep that pumps seawater through a pipe at 5000 gpm, and train a crew to cap it. Have the necessary materials on hand to do it. Conduct multiple scenarios of possible accidents leading to a blowout. Who knew about the methyl-hydrates? Why or Why Not?
- The best thing would have been preventing the accident. Whether or not they improperly installed the casing and plugs, the accident should have been preventable.
- The first line of protection would be to prevent the blowout from reaching the deck of the drilling rig. Why isn't there a sort of a blowout preventer at the deck of the drilling rig with a pressure diversion to divert the oil pressure off of the rig and away from the people and ignition sources. The advantage of drilling a mile deep is that there should be plenty of time to respond to an accident. If done right, they would have diverted the blowout away from the deck of the Deepwater Horizon. Perhaps sheered their drill pipe, or pulled the bit, sealed the pipe, and shut off the diversion. It would have created a nice black fountain for maybe an hour or so. Worthy of a footnote in the local news, not a headline in the Internal News for weeks on end.
- Were there runaway Diesels? All Diesels should have either a intake shutoff, or a method to shunt exhaust gases to the intake. Exhaust systems should lead off-rig, and away from the oil and methane.
- All electronics should have spark arresting, or if that isn't possible, then an emergency shut-off of any potential sparking equipment.
- Once the spill was underway, and BP was on the road to recovery, it became obvious that their topside processing capacity couldn't keep up with the runaway well below. The Bonga FPSO (http://www.ship-technology.com/projects/bonga-fpso/) can handle up to 225,000 barrels of crude a day. Yet, BP didn't get anywhere near that capacity moved to the Gulf. The problem is that they ended up choking the well's output at the surface, and thus increasing the subsurface pressure, and being unable to seal the joint. While the USA typically doesn't use FPSO ships, several of them should be staged (in use) near offshore fields, so that they could be unplugged from their "normal" wells, and rapidly moved into an emergency response situation.
The Rena
- All fuel tanks for major ships and tankers should be equipped with an emergency drainage system including high capacity pumps that can be remotely powered (and/or powered with a low-grade, wet version of the fuel they are pumping). Can you deal with angles, as well as the limitations of a pump vacuum?
- I still believe the cargo containers should be removed from Rena, but realize that it is treacherous work with the ship listing so much. Perhaps they could build some sort of a bookend to stabilize the stacks of containers, then get a crane onboard to start emptying the ship.
- Don't these container ships have some sort of onboard crane? Why not?
- Any chance of salvage means keeping the ship from breaking apart. I'd start patching the gash in the side the best way possible. I.E. adding lots of heavy sheet-steel and angle iron.
- Bilge Pump Capacity? Or a way to get a really big bilge pump onboard. Does the bilge water need to be treated? They need to be prepared to refloat during the super/king tides.
Anyway, perhaps salvage is ambitious, but it seems like everyone has already given up on rescuing the ship and its cargo.
-
Apparently they had a week or so of calm weather.
But, now have a few days of rough seas.
They now have about 1000 tons of oil offloaded.
With about 350 tons leaked, and about 350 tons left to pump.
They have had a ship/barge to help unload containers onsite for several days, but have chosen to not work on the containers while oil is still being pumped.
Apparently the weather is worsening for the next few days, and the pumping operations have been stopped. There is risk of loss of more containers, or having the ship break up. However, the storm is a mixed blessing as it may help disperse the oil that has leaked, and hopefully direct it away from New Zealand.
-
Latest news:
The stricken vessel Rena is being closely monitored overnight while oil spill response teams and salvors remain ready to respond if the ship deteriorates in forecast bad weather over the next 24 hours.
Maritime New Zealand (MNZ) Salvage Unit Manager Bruce Anderson said a maximum sea state of about 5 metres was predicted overnight, which would cause further stress on the already damaged hull.
He said the conditions were similar to those experienced around 11 October when the hull sustained significant damage and a release of around 350 tonnes of oil.
Salvage operations were suspended yesterday due to the bad weather, and salvors had sealed the tanks to minimise the potential for further oil leaking from the ship. Additional sensors had been placed on the hull to monitor the vessel's movement.
-
There is a discussion that if the ship breaks up, they want to attempt to tow the aft section into shallower water.
Could one get a semi-submersible low enough to snag the part?
Floating drydock?
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.globalsecurity.org%2Fmilitary%2Fsystems%2Fship%2Fimages%2Fblue-marlin-pic3-s.jpg&hash=1559011b42257d1253332181e2957e07)
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.ahoy-boats.info%2Farchives%2Fsailing%2Fimages%2FFloating-dry-dock-thumb.jpg&hash=0caddaa080f30155e3fb5d429b6a40db)
It appears as if there is a limit of the depth most of these machines are designed to operate at, so it might prove difficult. Perhaps one needs to design a fully submersible salvage drydock system.
-
I'm seeing notes that they still have 300 - 400 tons of oil onboard the Rena. It seems like they've been stuck at that level for nearly a week now. Access to the last tank is apparently difficult. They are trying to float the oil out of the tank now.
The decision was to wait on offloading the containers until the oil is emptied, presumably due to concerns about the stability of the ship if it is made lighter. I wonder what the "shippers" are thinking about? I'd hate to have a classic car or something out there at the whim of the tides.
I saw an article titled: Rena forces rethink about fossil fuel (http://www.nzherald.co.nz/environment/news/article.cfm?c_id=39&objectid=10764487). Apparently in light of the earlier BP disaster, the discussion is back about offshore drilling near New Zealand.
However, I would wonder about a discussion earlier on TNS about nuclear powered container ships (http://www.thenakedscientists.com/forum/index.php?topic=40170.msg372093). I would hate to think what the response would have been had this been a nuclear powered ship. What if the reactor core is breached? What if a nuclear powered ship breaks up and sinks?
-
There have been a few cases of nuclear submarines sinking. In all cases the reactors went safe and did not release radiation. A nuclear reactor is rather extremely overengineered for safety in almost all conditions. The Kursk had a massive onboard explosion that almost tore it in half, but the reactors did as designed and safed themselves. A lot better than the daily fires in ship engine rooms. There was a trawler this last week that caught fire and sank. The only thing that saved the crew was that at the last port of call they were forced to buy safety equipment that they did not have - a liferaft and life jackets. Thanks to SAMSA they are alive.
-
A nuclear reactor is rather extremely overengineered for safety in almost all conditions.
There's always a first time when the assumed safe engineering fails. Like in Japan.
-
Perhaps. The reactors are still intact even though they lost all cooling and did melt down uncontrolled. Took weeks to determine that that did happen, and they did do this before the hydrogen explosion in the outer buildings. Now there are random radioactive patches in the surrounding areas, but there are areas around the harbours affected by the tsunami that are badly polluted by industrial wastes that were washed out of refineries and process plants into the areas. Of the two I would take the low level radiation over the toxic sludge.
-
The next step in the Rena operation can now get underway.
Salvors have finished pumping all the oil off the ship and can now start on getting the containers off as well.
By this afternoon, 1350 tonnes of oil will have been removed.
Transport Minister Steven Joyce says removing the containers will be long and arduous and it could take up to a year to finish.
He says some oil may still be released, but the amount is not known.
-
Good to hear that essentially all of the oil is off the ship now. Are they trying to get any remaining drops? Or assuming it isn't enough to worry about.
Now for the shore cleanup. I'm glad to hear that it was only about 300 tons total that was lost.
Whew... A year to empty the ship?
Summer is here... at least down South.
They need to plan on getting the ship empty in the next 3 or 4 months... That would mean by February, or early March it should be empty... I doubt that the ship will last a year. If it is still on the reef in April, it will break up.
I'm surprised to not see a lot of effort to try to reinforce the crack in the hull. There probably isn't a lot that can be done to repair it in the field, but I'd at least try to add some steel plate, angle iron, or channel iron to the accessible part of the gash to try to keep the ship together during the recovery process. I think one could get a reasonably good weld with pieces of angle iron.
Of course, $12 Million into the recovery process, they might decide that it is cheaper to just let the thing sink, and scatter the shipping containers.
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fmedia.nzherald.co.nz%2Fwebcontent%2Fimage%2Fjpg%2F201143%2Fspill-pg.jpg&hash=21a826fd5bbedd90c9ddfae2ad4fc68f)
-
Unless it was carefully designed and implemented a "patch" would act as a stress concentrator and do more harm than good.
-
Calm conditions allowed 15 more containers to be lifted from the rear of the cargo ship Rena on Thursday, Maritime New Zealand (MNZ) says.
That means 18 containers have so far been removed of the 1280 left on the ship after it ran aground off the Tauranga coast last month.
However, MNZ warns the operation is at the mercy of the weather, as winds greater than around 24 knots - or about 45km/h - can halt the operation.
Salvors have now fitted 220 transponders to containers aboard the Rena in case they fall overboard.
Recovered containers will be checked out and if possible, will be put back into use after being cleaned out.
-
Got a few comments for clifford to assist building his massive wealth of knowledge. (apart form the spray freeze pipes for live works)
The Rena
All fuel tanks for major ships and tankers should be equipped with an emergency drainage system including high capacity pumps that can be remotely powered (and/or powered with a low-grade, wet version of the fuel they are pumping). Can you deal with angles, as well as the limitations of a pump vacuum?
Not true these pumps are moderate capacity and there has never been a means of external discharge except via intervention and flexi hoses.
Remote power to a moving object is incredibly high risk doubly so with open fuel tanks near by as well..
Better off floating a fuel barge next to it and pumping from that (they are very high capacity pumps)
BUT fuel for large ships is HFO (heavy fuel oil) and rarely can this be pumped with the traditional pumps (centrif for the capacity) below 30 degC
Tanks are usually tall and thin so angles arent a problem (think it is rolling about all the time anyway)
I still believe the cargo containers should be removed from Rena, but realize that it is treacherous work with the ship listing so much. Perhaps they could build some sort of a bookend to stabilize the stacks of containers, then get a crane onboard to start emptying the ship.
Don't these container ships have some sort of onboard crane? Why not?
Onboard cranes cost money to install, use and carry around, economics is why there isnt a crane onboard Blame Capitalism
Any chance of salvage means keeping the ship from breaking apart. I'd start patching the gash in the side the best way possible. I.E. adding lots of heavy sheet-steel and angle iron.
No chance, super structure is split, ship is now too flexible to actually move anywhere without breaking up, and patches would just present weak points, could be done with gargantuan beams and construct a 'ring' around it, but that may make it too rigid around that point and break up anyway
Bilge Pump Capacity? Or a way to get a really big bilge pump onboard. Does the bilge water need to be treated? They need to be prepared to refloat during the super/king tides.
Lets face it there isnt anyone going to set foot on that ship, I would do it for a few grand and get power and pumps going in about 3 hours of setting foot on there.. (Might need a drop of diesel or two) and be perfectly fine to escape if necessary.. but health and safety they would be doing everything they can from other vessels.. (the problems they are facing is proof of such caution)
For all other Vessel and ship thoughts.. REMEMBER DISPLACEMENT the more weight the more water need displacing (this could be a method of getting the oil out, keep flushing with water, theres plenty of it in the HFO anyway (at least 5-6 % to start with)) So these floating drydocks need huge draughts (depth of hull) to displace enough water for the drydock AND the ship in drydock it would never in a million years be able to get under a vessel grounded on a reef!
-
There's safe and safe. In the case of the Fukushima reactors, they were subjected to an unforeseen stress - total loss of the cooling plant - but ships run aground from time to time and the stresses are entirely calculable. It's possible to design a reactor that shuts down if the coolant fails, not by any engineering mechanism but because the reaction can't continue at high temperature.
Nuclear-powered icebreakers have been in operation for many years with few problems.