Article by Kevin Robertson, Sales Manager McMurdo

Maritime disasters such as the “Herald of Free Enterprise” and “Estonia” were instrumental in the move to legislate Voyage Data Recorders aboard Merchant vessels. Forensic investigators needed to learn the causes of such disasters and ensure that the lessons learned brought about legislation and good operating practices that would ensure that the risk, of such incidents happening again, was minimised.

 However both vessels sank in relatively shallow water, the “Herald of Free Enterprise” alongside at Zeebrugge and the “Estonia” in 85m of water, en passage between Tallinn and Stockholm (a passage of about 225nm).

 In both cases the incidents were identified to Search and Rescue authorities immediately – whether due to being within the port confines, as in the case of “Herald of Free Enterprise” or through the use of the GMDSS equipment aboard the “Estonia”.  Thus both vessels were identified as being maritime casualties and easy to locate, for the forensic investigation into the disasters.

In the manner that an aircraft flight recorder gives additional information, from interfacing to equipment on board, a Voyage Data Recorder will allow playback of the moments preceding and following the incident from which investigators can add to their weight of knowledge and lessons learned.

In such cases the data storage unit – which is traditionally known as the “black box” - goes down with the ship and in these cases, where the vessel’s location is known, retrieval would not be such a difficult exercise.

 However when you take a total maritime catastrophe, such as aboard “MV Derbyshire”, where the vessel simply disappeared, there are many factors that would make the carriage of a Float Free “black box” a preferable option.

 Firstly all vessels now must carry automatically activated EPIRBs - those aboard the “Estonia” were not activated during the disaster as they were manual devices, though fully functional and proven to be working subsequently

 An automatically deployed EPIRB will activate should a vessel be lost at sea, the approximate position of the sinking will be recorded through the COSPAS-SARSAT system and Doppler shift calculations.  This will allow the Search and Rescue services to alert traffic in the area, through the GMDSS network, and commence the SAR operations.

 Record of the loss however is not sufficient alone to prevent the cause of the loss happening again. There may be inherent design issues in the class of the vessel, there may be cargo stowage or cargo handling issues or the unsafe practise of seamanship.  There is always a cause for an accident it is this cause that needs to be identified and corrected, not simply the loss itself.

The “MV Derbyshire” sank without trace, with total loss of life in September 1980, only 4 years after her delivery the wreck lay undiscovered on the sea-bed for a further 14 years, before being finally identified on June 3^rd 1994.  Until this time no cause for her loss could be recorded.

 However 18 months of vital time had been lost in investigating the cause of the loss and the withdrawal from service of one of her sister ships. During this time three vessels of the same class had continued to trade and possibly place the lives of the crew in danger, due to potential structural faults.

 Sunk in a water depth of potentially 5,200m, location and recovery of a “black box” or Hardened Storage Device (as they are commonly referred to in the maritime industry) is an expensive, timely and dangerous task.  It has yet to be determined who would be responsible for the recovery of such units in these circumstances, who would pay the costs and who the actual recorded data, would belong to.

 To take a cynical view, in the event of no loss of life, would the data be financially worth recovering?

 Given these issues, the IMO have legislated that an alternative to an Hardened Storage Device could be a Float Free Storage Device. This records the same data as the Hardened Storage Device, but is allowed to break free of the vessel and transmit a Distress signal, on the COSPAS-SARSAT 406MHz system, and GPS position for a period of 7 days following automatic deployment.

 This option will ensure that the recorded data of the incident becomes available to the Search and Rescue services and most importantly the forensic investigators within a very short period of time and without the heavy financial cost of mounting an underwater recovery for a Hardened Storage Device.

 Obviously not required to meet the rigorous physical requirements of the Hardened Storage Device, the Float Free Storage Device would probably not survive a total maritime catastrophe, such as a vessel exploding and being engulfed in extreme heat through fire in the cargo.  However such occurrences are, thankfully, extremely rare and Oil and Chemical Tankers and Gas Carriers are covered by legislation that mandates the Hardened Storage Device carriage.

With minimised installation work, the Float Free Storage Device is the ideal choice of medium for vessels to marry to the Data Acquisition Units aboard and meet the S-VDR legislative requirements.

 For more information go to www.mcmurdo.co.uk