top of page

Snap Back Kills Again: Review Your Procedures & Equipment And Maybe Save A Life.

Here’s an accident report from the U.K.’s MAIB that deserves to be read and disseminated widely. On the evening of August 7, 2007 the ferry Dublin Viking was alongside the dock at berth #52 in Dublin, Ireland while the crew was preparing to sail on the overnight run to Liverpool. Wind and tidal conditions were “benign.” The 2nd officer, assigned as the Officer in Charge (OIC) of the stern mooring lines, was standing in the snap-back danger zones near the fairleads because it was where he had to be to have simultaneous visual contact with both the line handlers on the dock and the crew members operating the winches. When a winch operator mistakenly heaved in on an already-tensioned line it snapped and recoiled, striking the officer in the legs, breaking both of them while nearly severing the left. He died six days later.

As with all accidents there are numerous contributing causes that bear varying degrees of responsibility for the final outcome. But there’s a big part of this story that particularly angers and frustrates me because I’ve seen it kill or maim people again and again, and it seems that we’re all way too accepting of it: poor or downright stupid design, installation or repair was a primary cause of the accident. Poor design/installation means people can’t see what they need to see, can’t hear what they need to hear, can’t communicate properly, or have to spend way too much precious time thinking about how something works (as opposed to how it should work) while multi-tasking in a dynamic environment. Thus they have to unnecessarily put themselves or others in harm’s way just to do their jobs. This is mostly because little or no forethought was given to the “human element” and basic common sense.

It’s bad enough that the 2nd had to stand in a well-known dangerous place to fulfill his duties. But the real killer was this: a tired and distracted winch operator, who was doing double duty handling both the stern ramp controls and a mooring winch, was supposed to remember something very counter-intuitive: that the stern ramp controls operated logically but that the mooring line winch controls did not. In fact, they were ass-backwards.

How so? It turns out that the controls for raising and lowering the stern ramp made perfect sense, as up was up and down was down. But the stern line winch controls were reversed: the operator had to pull the handle toward himself to pay out the winch and slack the line, while pushing the control lever away resulted in the winch winding the line in.  It appears that the power supply wiring had been reversed at some point for reasons unknown. This is stupidity of the highest order and is just begging for trouble in an environment that can be very unforgiving.

I quote from section 2.2.3 Winch operation:

“It cannot be determined precisely why the OS operated the stern line winch in the wrong direction, but the following are considered to be factors that combined to distract him:

  1. Concurrent operation of two winches whose controls operated in different directions;

  2. Orders to raise, then lower, then raise the stern ramp immediately prior to the order to veer the stern line winch;

  3. Noise of the machinery ventilation fans and the stern ramp wires being wound onto the winch drum;

  4. The OS was at the end of his second 6 hour duty period that day.”

Unfortunately, the control levers, switches, dials, buttons, etc. for many pieces of important equipment on the vessels I’ve worked aboard over the years had the exact same type of built-in logic flaws. Here’s one I’ve seen repeatedly: every steering jog lever or joystick (NFU) on the tug (both sides of the pilot house, the upper house, the doghouse on the boat deck) but one operates in sync with the rudder. That is to say that moving those controls to the left results in port rudder swing and moving the control to the right results in starboard rudder swing, with the vessel turning accordingly in the desired direction. This makes sense, no? But the full follow-up (FFU) control at the center station and/or the autopilot in the main house operates ass-backwards like on a ship. Why? Why deliberately court trouble when trouble can find us easily enough without any human assistance? Does it make sense to expect this to be remembered in a sudden emergency requiring quick maneuvering? D’oh! I always endeavor to correct this “deficiency” at the first possible opportunity, usually by rewiring the offending control, but it should never happen in the first place.

In general, “backwards” has no place on a vessel, whether it be towing pins, shark jaws, the towing machine, crane, rudder controls or whatever. And I don’t care how long it’s been done that way on ships. I’ll always consider it to be dumb until someone can offer a compelling argument otherwise, and this has yet to happen. But at least if it’s consistently backwards at every station you can eventually adapt to it. Not so when you mix and match as, sooner or later, you’ll make a mistake. I’ve operated z-drive supply boats that were “backwards” in that regard too, at least when going forward, but the consistency of the control stations makes it something that you can quickly learn and become adept at.

In any case I would argue that, notwithstanding all of the other contributing factors, when operating stations and equipment controls are laid out logically and ergonomically, and operate in a straightforward and consistent manner, the odds of making a simple but high-consequence mistake that is control-related will be  mostly eliminated or at least minimized. I’ll also argue that committing the required time and resources to accomplish this end before the vessel is built, converted or otherwise altered is not a waste at all and will, in fact, more than pay back the investment over the life of the vessel. Greater efficiency, the avoidance of delays, fewer incidents of damage and/or personnel casualties are all like money in the bank to any vessel owner. For our part, mariners as a whole should be much less accepting of dangerous or sub-par equipment than has traditionally been the case.

While this was a “ship” accident the principles of what went wrong and the lessons to be learned from it apply equally to tug and barge operations, and particularly to ATB’s with their many winch-operated mooring lines on the barges.

Read the U.K. Marine Safety Forum’s Safety Flash 08-17, and also the complete MAIB Report from which it was derived.

#PartedLine #MarineAccidentInvestigationBranch #SyntheticLineSnapback #DublinViking #UKMarineSafetyForum #MarineAccidentReport

0 views0 comments

Recent Posts

See All
bottom of page