[QUOTE=Alf;38302]Sorry OH, but I missed this earlier.
The Deadman is an automatic system… it requires loss of BOTH hydraulic and electrical signals to the BOP before it will activate.
Correct me if I am wrong… but I believe the testimonies were re the EDS (Emergency Disconnect System) which requires human intervention.
We know the EDS didn’t work (or only partially worked) from the testimonies (and the x-rays they took on the BOP wedgelock).
Why the Deadman didn’t function… I don’t know. I have to speculate that there was still a communcation path… perhaps electrical, after the first explosion.
There is also the big possibility that there is casing in the BOP which prevented any RAM working effectively, which I speculate again could have affected the Deadman system.
kwCharlie would be a better authority than me.[/QUOTE]
It’s like the Peter Sellers Pink Panther line “that’s not my dog”
That’s not my code, and yes it does bite.
I’m telling you, one of the most important documents to look for is the most recent code from the PLC in the two Pods, down on the stack, and in the PLC in the Sub-Sea house. It’s over 2000 lines of code if I remember right and will be a huge task to see what is suppose to happen when this-or-that is done.
PLC commands are sent down glass fiber to the pod and the PLC at Sub Sea (sending the signals by addressable code) should have had a battery UPS that would have kept it alive with the batteries in the pods keeping that PLC communicating, any failure of communication to the pod is a ‘pull the stack’ problem.
The BOP should have been able to operate if the glass or PLC’s were broken BUT I’m not sure to what degree or what doing it from the Bridge had an effect. That shouldn’t have been the problem, when they pushed the buttons the glass to the pods (down either yellow or blue) and the LED that shines down it to command the stack should have been working, that glass fiber is robust and the PLC had UPS’s.
It was reported to the day TP that the Driller was at the Drill Floor BOP controls BEFORE the fire, the commands should have been sent to at least on pod and the processes initiated and once started they should have completed, I think, all depended on how all those lines of code were written.
With today’s equipment almost EVERYTHING has a SOFTWARE and/or HARDWARE solution or cause. You should have seen the fiasco of HiTec and GE getting Active Heave working on the first ship, the DW Pathfinder, I could have sold tickets, and it took 6 months in the GoM. BUT we took the second ship, the DW Frontier, to New Zealand and drilled in 60 foot contentious swells AFTER we worked out all the hardware (my GE Drives) and software (HiTec’s code) issues.
My feeling is the BOP did work, just couldn’t ‘cut it’
Hope that clears it up, sorry, know it didn’t. It’s a nerd thing that even after 35 years on rigs I still can’t overcome AND I’m talking off my focused expertise, the drives and the code that controls them.