GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS
three EXAMPLES 20 three.eight Strainers for Unloading and Loading Cargo Exchanged by Mistake (1) Overview An LNG provider berthed at an unloading terminal. The deck seamen moved to the port aspect manifold, and eliminated the strainer from its storage field to arrange for the unloading of cargo, and began to suit the strainer.
The particular person in cost turned conscious that the form of the strainer was totally different from the sort usually used, and had the second officer test the specs. Nevertheless, the response from the second officer was that there have been no issues, so the particular person in cost fitted the strainer with out additional affirmation.
After finishing the preparations, the cargo switch was began on the full price of 12,000 m three /h. A short while later, the particular person in cost once more requested the Chief Officer in regards to the specs of the strainer. The Chief Officer, a bit suspicious, carried out the test on website, and found that the strainer for loading cargo had been fitted as a substitute.
The Chief Officer instantly reported the wrong becoming of strainer to the terminal aspect, obtained the approval of the terminal aspect and re duced the unloading circulate price. Subsequently, all involved personnel had a dialogue, determined to droop the cargo unloading work, and stopped the cargo pumps.
The time of departure from the port was delayed by six and a half hours on account of suspending the unloading operation as a result of the mistaken strainer was fitted. On the subsequent investigation, the direct reason behind this accident was discovered to be the storage of the strainer for loading and the st rainer for unloading in mistaken storage bins.
That’s, the strainer used for loading was saved within the storage field fo r unloading strainer, and the strainer used for unloading was saved within the storage field for loadi ng strainer. Usually, since just one strainer is taken out on the unloading website, such errors in storage weren’t anticipated; nevertheless, it was discovered that upkeep work on the related strainer storage bins had been carried out about three months previous to this incident.
At that stage, a ll strainers had been faraway from the bins, and it’s extremely possible that the strainers have been changed within the mistaken bins. Then again, as proven in Fig. three.eight.1, the exterior look of the strainers for loading and unloading don’t resemble one another a lot that distinguishing one from the opposite is troublesome.
Nevertheless, if the crew member sees solely one of many two strainers, it’s extremely possible that the crew member doesn’t have the information to guage whether or not it’s a strainer for loading or a strainer for unloading. An arrow indicating the course of circulate had been stamped on the deal with of the strainer, however there was no title and title tag indicating its utility.
It’s troublesome to tell apart whether or not the strainer is supposed for loading or for unloading from the course of the arrow alone, particularly if one just isn’t notably centered on figuring out it. Strainer for loadingStrainer for unloading Fig. three.eight.1 Strainers for loading and for unloading GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 21 After the incident, the ship proprietor had a reputation tag affixed to every strainer as proven in Fig. three.eight.2, to tell apart the strainers simply, and likewise had a poster displayed on the manifold warning towards becoming the wrong strainer.
To forestall storing the mistaken strainer within the storage field on the other aspect, the storage bins for loading and unloading strainers have been distinguished through the use of totally different colours. Moreover, the storage field for strainer for loading was modified contemplating the variations in form of the respective strainers used for loading and unloading, in order that the unloading strainer couldn’t be saved by mistake within the storage field meant for strainer used for loading.
(2) Dialogue The fundamental ideas to forestall errors in putting in strainers are consciousness and show of data by clearly distinguishable labels. Si nce coloration coding is intuitive and helps in straightforward identification, it’s an efficient methodology to prev ent errors and ought to be carried out as a lot as doable.
As design measures, the next could also be thought of: (1) Show title tags for distinguishing objects by coloration coding. (2) Modify the storage field fo r the strainer for loading and stop bodily storage within the mistaken field. (three) As a lot as doable, use a building in order that the mistaken strainer can’t be fitted on website.
(four) One other risk is to make use of a strainer with mixed loading and unloading capabilities. Fig. three.eight.2 Identify tags for distinguishing strainers GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 22 three.9 Leakage of Carbon Dioxide Fuel used for Fireplace Extinguishing (1) Overview 1) The chief engineer of a ship was conducting routine month-to-month checks of the mounted sort carbon dioxide hearth combating programs within the engine room.
The sleeve of his arm inadvertently obtained caught within the pilot CO 2 pilot bottle isolating valve. Unaware of this, the chief engineer had set the isolating valve to the partially open situation. On this situation, he opened the pilot CO2 bottle stress gauge isolating valve with a purpose to verify the stress of the pilot CO 2 bottle.
The activator of the principle CO 2 bottle activated, the principle CO 2 bottle began changing into pressurized, and CO 2 gasoline began leaking from the neck seal (Fig. three.9.1) of one of many bottles. Happily, the chief engineer turned conscious of the CO 2 gasoline leak and took motion, so the leak didn’t result in a significant accident.
(2) Dialogue The reason for a chunk of apparatus changing into activated by mistake on account of unintentional contact is straightforward to visualise, however issues for stopping such occurrences within the design or set up stage are typically insufficient. For necessary management gear, it’s important to foretell the outcomes of bodily contact with th e merchandise then formulate and implememt ample preventive measures.
As design measures, the next could also be consid ered: (1) Choose applicable places and instructions for CO2 bottles with a purpose to forestall unintentional bodily contact with such bottles (see ASTM F1166-07 5.1.9). (2) Incorporate constructive operations similar to “press and twist.” 1) Supply: Marine Accident Investigation Department of UK, Security Digest 1/2006.
CO2 storage bottle neck seal Fig. three.9.1 CO 2 bottle GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 23 three.10 Chemical Spill (1) Overview 1) Fig. three.10.1 exhibits an unloading pump stress cont rol lever onboard a chemical tanker. The lever of this management machine is slid ahead or aft to start out/cease the pump and regulate outlet stress.
Primarily based on directions from shore throughout unloading work on the ship, the particular person in cost lowered the pump stress tentatively, however one other crew member unintentionally switched the lever to excessive stress when he positioned a measuring instrument on the panel. The consequence was that the shore unloading pipe ruptured, cargo with chemical substances spilled, and large value was incurred in cleansing up the spill.
(2) Dialogue This instance is much like instance three.9. The trigger was the unintentional motion of a lever that led to a mistake within the operation of apparatus. Though the trigger could also be thought of easy, ample precautions are obligatory. As design measures, the next could also be cons idered: (1) Shield the pump stress management lever by a canopy or another bodily barrier.
(2) Present ample resistance to function the pump stress management lever. By doing so, even unintentional mild contact won’t trigger the lever to be moved (see ASTM F1166-07 5.1.9). (three) Provid e a locking mechanism for the pump stress management lever. 1) Courtesy: UK P&I CLUB, photos are extracted from the membership’s video footage-NO ROOM FOR ERROR with permission Low stress lever place Fig. three.10.1 Cargo pump stress management lever GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 24 three.11 Collision of Dive Help Vessel with Breakwater (1) Overview 1) As proven in Fig. three.11.1, a dive help vessel was within the strategy of coming into the harbor.
The grasp supposed to change from the “autopilot” mode to the “handbook management” mode because the vessel made its approach into the harbor, however a later investigation sh owed that he had pressed a special change. The grasp steered the vessel assuming that he had already converted to “handbook management mode”, however the vessel didn’t reply and collided with the breakwater.
(2) Dialogue Different examples even have been reported whereby the mistaken adjoining steering change was pressed nearly resulting in a significant accident. Just like urgent the door opening/closing button by mistake, which happens incessantly in an elevator, there ought to at all times be an consciousness of the hazard of urgent a mistaken adjoining change.
As design measures, the next could also be consid ered: (1) Variations ought to be supplied in measurement, dimensions, coloration or sense of contact for necessary switches, similar to a steering mode selector change, in order that management capabilities are clearly distinguished (see ASTM F1166-07 5.5). (2) Design ought to be such that operation is confirmed by voice.
1) Supply: Marine Accident Investigation Department of UK, Security Digest 1/2005. Fig. three.11.1 Incorrect change GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 25 three.12 Elevator Shaft Accident (1) Overview 1) On 17 January 2007, an issue was reported within the ship’s elevator (see Fig. three.12.1(A)) in a tanker berthed for discharging cargo.
Investigation by the electrician and the third engineer revealed that the issue was with the second deck touchdown door. To carry out repairs, the second engineer and the electrician firstly confirmed that that they had positioned the signal “Don’t function” on the entrance of the elevator on all of the flooring, after which went to the second deck and opened the elevator door.
After bo th individuals completed their examinations, the electrician stepped on the ladder (Determine three.12.1(B) on the appropriate) within the elevator shaft, and advised the second engineer to shut the doorways. Nevertheless, instantly after the doorways closed, th e elevator automobile began touring upward; the electrician was trapped between the elevator automobile and the ladder, and leading to his dying.
The elevator automobile travelled upward as a result of anyone had pushed the button; this was confirmed from the data of the microprocessor management unit. That’s, anyone had ignored or had missed the “Don’t function” signal, and had pressed the button. 1) Supply: Australian Transport Security Bureau, Marine Security Investigation Report No.
235, June 2007. (A) Fig. three.12.1 Elevator and vertical ladder within the elevator shaft (B) GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 26 (2) Dialogue Stories of accidents similar to carelessly eradicating the stopped situation of an elevator through the use of the emergency cease button have been reported elsewhere, as properly.
Foolproof measures are obligatory as a result of this sort of accident can have disastrous outcomes. As design measures, the next could also be consid ered: (1) Show of indicators indicating “Beneath Restore/Inspection” ought to at all times be positioned on the name button on every flooring when restore/inspection is being carried out.
(2) Covers s hould be put in on name buttons to forestall incorrect operation (see ASTM F1166-07 5.1.9 and Fig. three.12.2). (three) Present a cease button particularly for upkeep and inspection. The design ought to be such that the cease reset of this button might be made solely by the operator who has stopped the operation.
Fig. three.12.2 Instance of measure towards incorrect operation of elevator by delivery firm Cowl for name buttonsInitial preventive measues 1. Make announcement. 2. Place discover on the elevator doorways on all flooring. three. Set up working process inculuding the above two. Extra preventive measue 1.
Elevator name buttons on all flooring to be lined by covers (similar to a plastic cowl) solely throughout upkeep work. GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 27 three.13 Fall of a Quick Rescue Craft (1) Overview 1) A newly-built 165-m lengthy Ro-Ro vessel was present process varied commissioning checks alongside.
One of many checks was to launch a quick rescue craft (FRC) from a davit (see Fig. three.13.1(A)) and to recuperate it. The FRC was related by a single wire to the davit via a fast launch hook (Fig. three.13.1(B)). The hook was operated within the “off-load” mode in order that when the FRC was lowered into the water, the hook routinely launched as soon as the burden of the FRC on the hook was diminished to lower than 12 kg (after touchdown within the water).
In accordance with normal working process, the FRC was lowered right down to the embarkation deck the place two of the crew members boarded it. From right here, the FRC was lowered to 1 m above the waterline and the crew ready for the ultimate reducing and launch of the hook. At a top of 1 m above the waterline, the cr ew indicated to the winch operator that the FRC could possibly be lowered into the water.
The FRC then began to decrease and nearly instantly stopped. At this level, the short launch hook opened and the FRC fell into the water. The gradual velocity operation of the winch was zero.6 m/s and the excessive velocity was 1.three m/s; these two modes have been realized by a two-speed motor. The motor velocity was managed by one push button (Fig.
three.13.1(C)); when this button was partially depressed, low velocity was chosen; when totally depressed, excessive velocity was chosen. Investigation later revealed that when the dav it juddered, the hook modified to the off-load mode and routinely launched the boat. Furthermore, when the winch motor stopped (button launched) from the high-speed situation (totally depressed), th e davit meeting juddered significantly.
This was additionally confirmed from checks. It was thought of possible that the winch operator had depressed the button totally so the FRC was lowered within the excessive velocity situation after which stopped. Due to this fact, the davit juddered significantly, and it’s thought that this motion within the davit arm might have been enough to trigger the off-load launch hook to open routinely.
1) Supply: Marine Accident Investigation Department of UK, Security Digest three/2006. (A ) (B) Fig. three.13.1 Davit, fast launch hook and motor management unit(C) GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 28 (2) Dialogue This accident is presumed to have occurred due to the change from excessive velocity to an abrupt cease, inflicting vibrations which resulted within the off-load situation.
It’s also concluded that an working mode not initially anticipated occurred due to the wrong operation of the push button. A push button having a number of capabilities relying on how far the button is depressed just isn’t really useful as a result of buttons with such specs are more likely to trigger errors.
As design measures, the next could also be cons idered: (1) The management machine operation ought to be checked not solely within the assumed working m odes but additionally in all operations that may be anticipated (as an illustration, from excessive velocity to abrupt cease as on this instance). (2) The motor change ought to be managed by a rotation selector change (see ASTM F1166-07 5.6.7.1).
GUIDELINES FOR THE PREVENTION OF HUMAN ERROR ABOARD SHIPS three EXAMPLES 29 three.14 Engine Room Fireplace (1) Overview 1) An engine room hearth broke out onboard a cargo ship. The hearth brought about main harm to the engine room equipment and gear (Fig. three.14.1(A)). The reason for the hearth was decided to be the loosening and displacement of a securing plate for a major engine gas pump inlet pipe.
The gas pipe turned displaced due to this, and gas at a stress of 5 bars and a temperature of 100 ̊C spewed out, got here into contact with the floor of an exhaust gasoline pipe at a excessive temperature, and ignited. Investigation after the accident revealed that the gas inlet pipe securing plate was incorrectly fitted – the plate was reversed.
(See Fig. three.14.1(B )). Owing to this error, the cap screws have been solely screwed into the gas pump block by 2 and 1⁄2 turns, versus eight and 1 ⁄2 turns when appropriately fitted. It’s seemingly that the securing pl ate labored unfastened on account of vibration and have become displaced. The gas pump had been changed 5 months earlier; throughout this alternative, it’s seemingly that the plate was incorrectly fitted within the reversed course.
(2) Dialogue Becoming the mistaken components or becoming components within the mistaken course or mistaken place incessantly happens throughout the alternative or restoration of opened-up gear or equipment. It’s seemingly that on this accident, the entrance aspect of the securing plate was counterbored (if carried out appropriately), and screws could possibly be tightened as much as eight turns.
Nevertheless, for the reason that fr ont and rear sides have been reversed, the variety of turns of the screw turned smaller by an quantity equivalent to the depth of the counterbored half. To forestall comparable accidents, measures are essential to establish components and to verify their right place and course. It’s also necessary to design components with shapes in order that they can’t be fitted within the reverse course.
As design measures, the next could also be thought of: (1) Establish the entrance face of the securing plate by stamping and so forth. (2) If entrance and rear sides are reversed, the securing plate and the counterbore depth could also be adjusted in order that the screw can’t be turned to make sure by form that a mistake doesn’t happen when re-fitting the half.
(See ASTM F1166-07 17.6.1.2) 1) Supply: Marine Accident Investigation Department of UK, Digest 2/2006. Incorrectly fitted gas inlet backing plate (B)(A) Instance of fireplace harm Fig. three.14.1 Burnt-out engine room and mistakenly fitted securing plate for securing gas inlet pipe