The Case of the Silent Assassin has become a MAC classic confined space safety lesson.
An excellent live action/CGI video version has been produced by IDESS Interactive Technologies.
Ships are dangerous places for the badly trained, the unwary, the careless. In this case two seafarers were killed by almost nothing.
The Pumpman and the Deckboy
We’ll call them Carlo and Rick. Not their real names but they were real people. Like one in five merchant seafarers around the world they were Filipino. Their forebears served the world’s fleets more than eight centuries ago, So, in a sense, the sea was in Carlo and Rick’s blood when they joined the Sapphire. Carlo was the Pumpman and keen to do his job well and impress the ship’s officers. In his sights, perhaps, was promotion: the ship’s third officer, also a Filipino, had been the ship’s pumpman on his previous tour. Part of Carlo’s duties was to clean the tanks after discharge to make them ready for the next cargo and he constantly worried about whether he’d cleaned them well enough. He talked about his concerns so often that the Italian Chief Officer the chief officer assured him “Don’t worry, we’ll still be friends even if the tanks aren’t clean”. Still, Carlo fretted about his tanks. Tanks, of course, are enclosed spaces and ten months before our story Carlo visited the ship’s library and borrowed videos on safe entry into enclosed spaces. Rick joined the Sapphire in the first week of March 1999 and Carlo seems to have taken the young seafarer under his wing. Like the other crewmen, who were also Filipino, Rick often wore a filter mask when handling smelly cargoes and carried the mask on his belt ready for use.
A filter mask of the kind carried by Rick
|The Sapphire. Central tank 6 is hidden from the bridge by the forward deck structure|
Their ship was the single screw 9,914 gross tonnes oil and chemical tanker Sapphire. She was then a relatively new ship, built in 1997 in Italy. The Sapphire’s trade route took it from the US Gulf to Mediterranean and European ports with its cargo in 16 wing tanks, 8 centre tanks and 2 deck tanks. All tanks had individual venting. Fixed tank-cleaning machines were supplemented by portable machines and hoses.
A Question Of Gas
Two gases are important to our story: nitrogen and oxygen.
Nitrogen is all around us. Almost 80 per cent of the air we breath is nitrogen but what does it do? The quick answer is ‘not much’. It doesn’t react with other chemicals, it doesn’t ignite or explode. Chemically speaking, it’s as near to nothing as you can get, it’s an inert gas. That’s why oil and chemical tankers fill empty cargo holds and air spaces with it, a process called ‘inerting’. Because nitrogen doesn’t do much, you can’t live on it, for that you need oxygen.
Oxygen is everything nitrogen isn’t. It’s highly reactive and it’s all around us. Take a breath. That breath is around 21 per cent oxygen. Much less than that and you die, much more than that and don’t light a match – it will explode. The objective of inerting is to drive oxygen out of the tank so that the atmosphere is not explosive. That also means that the atmosphere in the tank cannot sustain life. Without breathing apparatus you’ll be unconscious within seconds, in four minutes you’ll be dead.
A tag like this on a tank means the atmosphere inside will not support life.
Our story starts in Houston, Texas where the Sapphire’s central tank 6 is loaded with Hexamethylenediamine, HMD, by the Du Pont company. HMD is not especially poisonous but its fumes can irritate the eyes, nose and throat so Carlo and Rick wear their filter masks to protect them. After loading, a chemical data tag is attached to the tank then nitrogen is pumped into the airspace above the cargo to prevent atmospheric contamination of the cargo. The tank cover is closed and a nitrogen warning tag is also attached to the tank.
The top of Central Tank 6
The Sapphire proceeds to Amerli, Turkey, where the cargo of HMD is unloaded and at 15.54 on Friday, April 23, 1999, sets sail for Haifa, Israel to take on a cargo of white phosphoric acid to be loaded into the now-empty central tank 6. Fifty minutes later, Carlo and three crewmen, including Rick, begin washing central tanks 2 and 6. The weekend is coming, so it’s decided to reduce the normal washing cycle in central tank 6 so the crew can be given Saturday and Sunday off. Work finishes at 18.00 but Carlo is still worried about the cleanliness of his tanks so when the crew go for dinner Carlo stays behind, presumably to check the tank. A half hour later Carlo goes to the crew recreation area and confirms that work is finished for the day. Carlo calls the Chief Officer to say that work is complete and everything has been shut down. The Chief Officer asks if the tanks have been vented, Carlo replies that he’s just about to do that, collects Rick from the recreation area and returns to Central Tank 6. They’re last seen alive at 1900 hours heading for the tank. Carlo knows about safe entry procedures from his videos. The atmosphere in the tank should be checked, if necessary self-contained breathing apparatus should be worn, safety and rescue equipment should be placed close to the entry into the enclosed space, a safety checklist must be completed and a permit must be issued, and a new permit issued if work is interrupted. Staying alive means simply following the rules. On the Sapphire, however, the ship’s officers decided for themselves which, if any, of the procedures needed to be followed based on their experience of the cargoes they carried. Sometimes the procedures were followed, sometimes they weren’t. It was also common practice among the ship’s officers to just hold their breath when entering a tank to check its cleanliness rather than go through the bother of the correct procedures. Both the Master and Chief Officer had seen this done and the Third Officer had done it himself when he was pumpman like Carlo. It was a habit that Carlo acquired. Nobody tried to stop it, dangerous though it was. Worried about cleanliness of the tank, Carlo wants to make one last check. Leaving Rick at the entrance, he takes a deep breath, brings out his torch, and climbs into the space. He reaches the first platform in the tank, 4 metres down, inspects what he can see, then goes to the second ladder to go further down into the tank.
Carlo and Rick entered Central Tank 6 through this entrance.
Maybe residual HMD fumes get to his eyes, he trips or slips, and lets go of that last breath He can’t cry out for help. There’s no oxygen. Within seconds he’s unconscious and collapses, his fall only stopped by the safety hoops of the ladder, his feet jammed under the platform. He now has four minutes to live. Rick sees that Carlo is in trouble. He puts on his filter mask and enters the tank. He doesn’t hold his breath because he thinks the filter mask will protect him, so he tries to breath normally. By the time he reaches the platform he’s out of air, there’s no oxygen to keep him alive and he, too, collapses against the railings against the foot of the ladder. He’s dying It was almost an hour later that the Chief Officer noticed that the main tank lid to central 6 was fully open. There was only one reason for the lid being fully open – men were inside. The Chief Officer knew there was nitrogen in the tank. Now he was worried. He called down into the tank. There was no response. Then he saw the bodies of Rick and Carlo. For once, somebody did the right thing, he didn’t climb into the tank. Nor did he raise the general alarm – time was short and sounding the general alarm would have called crew to muster stations, then he’d had had to explain to problem. Instead he raced to the crew recreation room. Nearly all the crew was there and they immediately set about gathering rescue and breathing equipment. They were now expected to do something they’d never been trained for – rescue someone from a tank. The crew had drilled in all sorts of procedures: how to deal with fire in accommodation, fire in the Galley, fire in the Engine room, Cargo fires on deck, breaking away from the jetty during cargo transfer, Abandon ship, Man overboard, Major flooding. One drill they’d never had was to rescue someone from a tank, even though it was required by international rules and regulations. It took up to up to 15 minutes to get the bodies of Carlo and Rick out of the tank. For another 40 minutes attempts were made to revive them before the master, reluctantly, called an end to the efforts it was more than an hour too late for Carlo and Rick.
A Tale Oft Told
This case is almost ten years old, so why am I telling you about it now? The official report issued in 1999 said: “Every time there is a fatal accident involving entry into an enclosed space and personnel being overcome in a non life supporting atmosphere the question is asked as to “how does this keep happening?”. Training and familiarisation should ensure that all crew members are aware of the dangers in entering a space without first checking the atmosphere. Unfortunately it would appear that education is still needed to get the message through“. And those words are as relevant now as they were then.
Follow The Rules And Save A Candle
How could Carlo and Rick have stayed alive? Most obviously, Carlo could have followed safe entry procedures every time, not just when he thought it was necessary. Then he’d have checked the tank’s atmosphere and been wearing the proper breathing apparatus and the Chief Officer, who’d have signed the safe entry permit, would have been aware he was there. If he’d slipped and been knocked unconscious then rescue equipment would have been immediately available to help him. Assuming, of course, that the crew had been given the necessary drills in rescuing someone from a tank.
So rule number one is follow the rules.
Do you know the safe entry procedures on your ship? If you don’t, find out and insist on them. You might be saving your own life.
The rules weren’t followed, Carlo collapsed. What should Rick have done? The biggest danger to Rick wasn’t the nitrogen in the tank but the filter mask he relied on to protect himself. It might have protected him against what was there but couldn’t protect him against what wasn’t there. There wasn’t enough oxygen and the filter mask didn’t provide any. Had he used self-contained breathing apparatus he’d have got out of the tank alive.
Every type of face mask has a different function. Look at the ones available on your vessel and make sure you know what to use them for, and how to use them.
Locker on the Sapphire. Note SCBA and filter masks together. Would you know which one to use?
Even if Rick had used the right equipment, what was he going to do? He didn’t have oxygen equipment to revive Carlo, nor did he have the gear to lift Carlo out of the tank. He didn’t know better because the necessary drills hadn’t been carried out.
Do you know what to do in that situation? If you don’t, then it’s your responsibility to find out.
As the Chief Officer did later, Rick could have gone to the crew recreation area or raised the alarm to get help. Had he done so, both men might still be alive.
Simply, don’t try and rescue someone without someone else around to back you up.
Carlo’s and Rick’s bodies were returned to their home country, the Philippines. There’s a tradition in the Philippines: Every year, on the eve of All Soul’s Day, families light candles and picnic at the graves of their departed loved ones, it’s a way of letting those spirits know they are not forgotten and they’re still part of the family. Being safety aware means making sure nobody’s going to have to light a candle for you.
This is Bob Couttie wishing you safe sailing.