If the document does not display above, click here
See this review of other attempts: http://www.nytimes.com/interactive/2010/05/25/us/20100525-topkill-diagram.html?ref=us
The article does point out that the containment domes they have tried so far are not stoppers, but funnels to let them pump the oil. Their "massive containment dome" was a small structure that would not even large enough to go over the entire riser. From what I can tell in the pictures, the dome has 15 ft fins on the bottom to dig into the mud, and then there is another 18 ft above that. The whole thing weighs in at 100 tons, so I imagine that might be a weight they were comfortable maneuvering at that depth. The riser is 48 feet above the sea floor, so the containment structure was never targeted at covering the entire BOP/Riser.
My plan will need a foundation frame to deal with the really soft mud at the bottom. I like the idea of a first level that has the fins on the bottom, like theirs, and ports that will go over the pipes that exist. These first frames will likely sink farther into the mud as weight is stacked on top of it. This issue needs refinement.
Probably it is safest to specify steel covering concrete, which is apparently how the first "Dome" was constructed. Concrete alone is not sufficient to deal with pressures, perhaps, unless the design was far larger than what has been used so far.
The first layer would be perhaps 20 ft high and have panels to give it more stability out to the sides. I would go even farther out than they did since our structure is much taller.
20 Ft. dimension on the "frames" will clear the BOP riser. It may be better to construct a pyramid shape from the start to have better stability in the mud.
I would anticipate that the whole thing would continue to sink into the mud as it is built. From the seafloor, we need at least 50 ft of structure, or about 12 4ft frames, or 6 8ft frames. If they are 8ft, we should guess they will be about 100 tons each.
Total mass of the containment structure is about 700 to 1000 Tons.
As the frames are placed, they need to be securely connected to the frame below it.
Concrete must be poured into the structure once it is built and it has mostly stopped sinking. If we had more information about the thickness and density of the mud, some decisions could be made on this, so we may have to defer any sort of conclusion about the details of establishing a firm foundation.
Once the concrete has sealed the bottom of the containment structure, the lid can be placed on it, and that will stop any further releases.
Even if some oil leaks from the full-containment structure, it will be far better than the leaks of all other attempts.
My point is not that I claim to have the last word on the design of a containment structure, but just to point out that they have not been tried, and we should be putting one into place NOW.
First page of drawings from DHS submission:
Second page of drawings from DHS Submission:
Third pages of drawings, not included in the DHS submission.: