It's very sad that Malaysian Airways flight 370 has been confirmed lost in the southern Indian Ocean with no survivors. But some closure must come to the family and friends of the crew and passengers knowing that the plane has crashed. The most plausible theory about what happened that I read was in Wired
and explained how an electrical fire might have resulted in the loss of the plane and those aboard.
Conspiracy theories were thick in the absence of any factual information. This is a pet peeve of mine and was a partial motivation for making my sculpture, 'It became personal - Catharsis'
' that's currently exhibited at the 2014 Heysen Sculpture Biennial
until April 27. Sometimes bad things just happen, they aren't always the result of a terrorist activity. Remember the Asiana flight 214
plane crash on landing at San Francisco airport last year due to pilot error - the news channels were immediately saying that terrorism wasn't suspected. Well, if it wasn't suspected then why say it? It's so front of mind. Have the terrorists won, consider all the intrusions to our everyday lives by the increased 'security' measures in place to 'protect us.' The other motivation behind making that sculpture was in response to two separate cancer issues for me last year.
One of my many careers in Australia was working as a Remote Operated Vehicle (ROV) pilot/tech for a diving company called Solus Ocean Systems. I was part of a three man crew providing drill support to the drilling company aboard the Diamond M Epoch. The Diamond M was a semi-submersible exploration rig. It had two huge pontoons that were submerged beneath the surface and when mainly filled with water they would stabilise the rig in the ocean. When the rig was being towed to other exploration sites the pontoons were mainly pumped-out to increase the buoyancy of the rig making it float higher in the ocean. The pontoons could also be completely flooded causing the rig to sink, if necessary. That was an option the Company Man considered one night in Bass Straight when problems caused the rig to list to one side which could have resulted in capsizing. That was an exciting night. This book could be the report on what caused that situation.
|Diamond M Epoch from helicopter|
When the rig was on site it was held in place by huge anchors put-out from each corner of the rig. Some of the anchors weighed 13 tonnes and were massive. When bad weather hit the rig the forces were so strong that the chains holding the anchors could break.
A condition of exploration drilling in at least some Australian coastal waters was that after the rig finished its exploration and moved onto a new location the ocean bottom had to be as clean as it was before the exploration drilling. Remember that the number of productive wells producing commercial quantities of 'hydrocarbons' is a tiny fraction of the number of wells drilled. It's an expensive business, and risky.
This is where the connection between a drilling rig and an airplane lost at sea happens. Now that the authorities roughly know where the plane was lost they'll search for it and if possible recover what they can find.
Once the Diamond M Epoch finished drilling in Bass Straight an underwater survey would happen to check for any potential industrial rubbish left on the ocean floor. I was told that some of the areas where the Diamond M drilled were commercial fishing zones where huge nets were dragged behind the fishing boats. If one of the nets caught on an abandoned rig anchor it could cause major damage to the fishing gear and result in costly damage repairs.
Bass Straight is very shallow compared with the southern Indian Ocean, so any exploration and recovery work there is many times more difficult if MH370 is located. The deepest that we operated in was about 800 feet and we thought that was deep.
To scan the bottom in shallow water a small survey boat cruised the target area using a specified search pattern. The boat used a side-scan sonar that would indicate if there were unusual objects on the bottom. When something was found the location was noted for visual inspection by us.
Normally our ROV was mounted onboard the drilling rig with a winch lowering the submarine within a cage through the 'moon pool' hole in the rig's floor down to the water. When the caged sub reached the working depth the winch would stop and the sub was 'flown' out of the cage to the work site. A stainless steel sheathed cable about 40mm in diameter containing power and electronics cables ran from the winch to the cage. In the cage there was another winch that had a smaller and neutrally buoyant cable running from it to the sub, providing a certain working area from the cage.
|Sub in cage aboard Diamond M Epoch|
The motors on the sub were powered by 3 phase 440 VAC and you don't want to mix AC electricity with salt water. There are depth limits to which you can use air-filled containers before they get crushed by water pressure (the pressure increases by 1 atmosphere for every 10 metres of depth.) The electrical motors on the cage and sub drove hydraulic compressors that provided liquid power to the fans that moved the sub around in the water, and to power the actuators that we used to work with items on the drill machinery or objects on the ocean floor. We were sometimes called-on by the rig's welder to find and retrieve his chipping hammer when he dropped it over the side.
|Author with submarine (it was a long time ago)|
In the photo above we fitted a hydraulic-powered cable cutter on the left arm of the sub. The right arm shows a sample bit of cable. At one point during my deployment on the Diamond M we had to have a replacement submarine, cage and winch flown from Singapore to the rig as we lost ours over the side. Long story but I'll just say that once the replacement equipment was installed we sent the new caged sub to the bottom to recover the original equipment. With the cable cutter we could cut the old winch cable and sub cables into manageable pieces then attach a lifting line from the rig to pull them up to the rig. It would not have looked good if we'd left an entire ROV system on the bottom of the ocean when were supposed to be cleaning-up the bottom.
Our crew chief did have some major explaining to do to his boss in Singapore during his call, 'Tim, I've got some bad news.'
'Ya Robert, I hope you're not calling to say you lost another fucking submarine [this does happen in the process of doing drill support]?!'
'Well Tim, um, it isn't just the submarine this time. It's also the cage and the winch...'
You don't want to hear the rest of that exchange. Robert did continue with a successful career with the company and I don't know if he ever lost another submarine.
So after the sidescan sonar finds something on the bottom the submarine, cage, winch and control booth and a big generator are installed on a work boat and sent to to investigate. We lower the caged sub over the side of the workboat and if we find something we bring it back.
|Control booth: Crew chief Kevin flying, George in foreground|
When were were flying the sub we had two video feeds from the sub, and one on the cage. The latter made it easier to return the sub to the cage when we'd finished the underwater work and had to bring it back to the surface.
The two arms on the sub are pretty dextrous. Once, while bored and doing a Blow Out Preventer inspection in about 800 feet some very slow fish lived near the stack because the water was warmer there due to the drilling mud and fluids pumped from the surface, and we caught one of the fish with the sub's actuator. We were probably as surprised as the fish was! The victor writes the history.
One of the arms on the sub has a rotating end effector that lets you do things like tighten-up a shackle pin on a chain. The image below shows the ROV pilot moving one of the arms to attach a hook from a lifting line from the workboat to the shackle at the end of the anchor chain. We were working in 201 feet of water at the time. See the 'OIL' indicator on screen that would indicate any leaks (bad news!)
On this occasion we did locate the lost anchor and were able to attached the lifting cable to it. After a lot of straining by the workboat winch as it had to break the suction of the anchor in the seafloor, they lifted it to the boat and recovered it.
|Trophy shot: 13 tonne anchor recovered by Solus Ocean Systems ROV crew: Rick, Clay, Robert, Doug|
In favourable circumstances debris from MH370 might be recovered using an ROV or even divers, but it gets more and more complicated with greater depth and currents. I wish them all the best and hope the cause of the crash is determined. My condolences and thoughts go to the families and friends of those lost on MH370.