Survivability Of The VDR – Voyage Data Recorders.

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July 26, 2010
Damage Black Box - VDR For Ships

A plane crashes scattering debris across the ocean floor and boats, equipped with sonar tracking and ROV’s, begin their search for a black box containing answers. But what happens when a ship sinks?

Eyewitness statements from the Deepwater Horizon’s bridge team have provided clues about the failure of critical safety devices but human memory remains weak, a fact proven by conflicting testimony we heard this week. Realizing the importance of voice recordings to incident investigations the International Maritime Organization passed resolutions in 1997 requiring ships to carry Voyage Data Recorders (VDRs) which record a myriad of digital information including conversations on the bridge. The Deepwater Horizon had a VDR but, while we do not know the fate of the unit, it has yet to be found.One primary difference between aviation and rig disasters is the quantity of fuel carried. Metal objects alone do not create flames, rather it is the fuel contained within an vehicle that provides the means for combustion. When a plane crashes it falls from the sky with a relatively small amount of fuel and once this fuel is consumed the fire naturally subsides. But, connected to an enormous reservoir of fuel, a rig will continue to burn until it sinks and the fire is naturally extinguished. VDRs are required to withstand fire for 10 hours but was the duration and intensity of the Horizon fire enough to melt the unit?

Pictures taken just prior to the rig sinking suggest this is the case or, possibly, the brackets which secured it to the rig’s deck melted off. We’ll have to wait until ROVs dive on the wreckage to know if the VDR survived fire. A few companies manufacture VDRs design to store the data recordings in the vessel’s EPIRB. But EPIRBS require either manual activation, consuming valuable seconds in a high intensity escape, or automatic activation, requiring that the rig sinks prior to the unit melting.

And there are still more problems. Even if the VDR had been recovered we still would not know the primary cause of the blowout because maritime regulations do not require the mounting of microphones in the driller’s cabin or the logging of even the simplest drilling data. Even where microphones do exist there placement can lead to poor audio quality. Traditional VDRs also fail to record other information critical in the digital age like electronic distress messages, emails and telephone calls.

In looking at the next generation of VDRs it’s clear that the spectrum of information stored in these units needs to include drilling data. Microphones in other critical spaces should also be considered. We also have to ask if the storage of data needs to be redundant. Locating a secondary watertight VDR in the hull of a ship could improve the chances of survivability. Another option, on vessels equiped with high speed satellite internet, would be uploading the data via satellite to a secure data center ashore.The silver lining of all incidents is the lessons we learn, the improvements we make and the ideas generated thinking about potential failures. So we ask what features would you like incorporated in the next generation of VDRs? Please leave your ideas in the comments section below.

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