Alaska Ranger sinking

[Randygh]

Sad to hear the news of the Alaska Ranger sinking early yesterday. I wonder if and how losing the rudder is related to it going down? Any thoughts? I read online today that she radioed the first mayday at 0300 and ordered the crew to abandon ship 2 hrs later. Fortunately most aboard were saved and the CG should be able to discern the exact cause of the sinking.

[pkrogh]

I wonder if they lost their rudder and couldn't cork the hole??? Really sad to hear when a hard working ship like that goes down.

Pete

[bradvo]

I wonder if they lost their rudder and couldn't cork the hole??? Really sad to hear when a hard working ship like that goes down.

Pete

kind of what I was thinking that the rudder shaft itself was the problem. My guess anyways.

[Nehalennia]

kind of what I was thinking that the rudder shaft itself was the problem. My guess anyways.

So far it did sound as if they lost a rudder. That can be a 4-8" diameter vertical shaft bearing. Under the weight of the boat the pressure of water would be like one if us attempting to stick a ball point pen in the end of a pressure washer to stop the flow.
One other thing to consider is that most rudder rooms have dogging doors to seal off the rudder room for exactly this reason. My guess is that will be the focus of the investigation but we may never know, as the Captain and Cheif Engineer went down with the ship. The ship won't be recovered obviously.

[Go Aweigh2452]

So far it did sound as if they lost a rudder. That can be a 4-8" diameter vertical shaft bearing. Under the weight of the boat the pressure of water would be like one if us attempting to stick a ball point pen in the end of a pressure washer to stop the flow.
One other thing to consider is that most rudder rooms have dogging doors to seal off the rudder room for exactly this reason. My guess is that will be the focus of the investigation but we may never know, as the Captain and Cheif Engineer went down with the ship. The ship won't be recovered obviously.

I heard on the news that the ship had the ability to dog the rudder compartment water tight... So, hopefully the survivors will be able to shed more light on this... still a tragedy...

[SomeSailor]

On a ship that size the rudder shaft diameter was likely much bigger. I'd guess at least 12" or better hole just opened up in the floor of the rudder room if the pillow blocks broke free and it tore away.

Taking on several hundreds of gallons per minute... it wouldn't take long to lose the stern. We steam with watertight doors set in those areas in the Navy for just that reason. It would only take a few minutes going down the wrong path to cost you the hip in that case. ie: Someone trying to stop the flow instead of giving up the rudder room and then calling for help.

I've been to many damage control schools and was a Repair Party Leader and Lock Officer on a couple of ships and the first thing you have to get good at is assessing a situation and being OK with conceding some losses.

[Nehalennia]

On a ship that size the rudder shaft diameter was likely much bigger. I'd guess at least 12" or better hole just opened up in the floor of the rudder room if the pillow blocks broke free and it tore away.

Taking on several hundreds of gallons per minute... it wouldn't take long to lose the stern. We steam with watertight doors set in those areas in the Navy for just that reason. It would only take a few minutes going down the wrong path to cost you the hip in that case. ie: Someone trying to stop the flow instead of giving up the rudder room and then calling for help.

I've been to many damage control schools and was a Repair Party Leader and Lock Officer on a couple of ships and the first thing you have to get good at is assessing a situation and being OK with conceding some losses.

Mike I think you're exactly correct. I forgot this was a Fishing/Processesor, set up for both. So you are most likely to correct that the dia was bigger.

[Randygh]

How would a ship lose a rudder shaft? Metal fatigue? Rusted and badly weakened? Wouldn't the rudder and shaft be checked by divers on a yearly or semiannual schedule?

Isn't the rudder shaft enclosed in a watertight bearing or some sort of packing (dogs?) where it penetrates the hull?

I haven't heard how deep the water is where she sank. Wonder if the CG or insurance people will put down a submersible to view the ship? It may not be necessary with so many survivors whom can tell the investigators what happened.

[SomeSailor]

Rudder shafts actually rest on pillow blocks. These support the weight of them and there are in stuffing boxes to seal out the wet stuff.

Any of those penetrations has the opportunity to let in LOTS of water... VERY fast.

One of the tasks I had to get signed off to become Surface Warfare qual'd in the Navy was to participate in a Sea & Anchor detail and the raising of the Pit Sword when entering port.

The Pit Sword is a rodmeter that feeds data to the ship's log (logarithmic recorder). It's a large (12' or so) blade that is lowered from the ship's belly and extends into clean water below the hull. When in use the packing glands keep all but a slow stream of water out, but when you raise the pit sword, you're essentially open a 24" x 4" gash in the hull for a few seconds. LOTS of water comes in and you get soaked. Good fun, but it shows you how much pressure is down there.

Wouldn't take long to overcome a space.

[RobS4588]

I never heard of or knew what a 'Pit Sword' was until now.

[dumluck53]

"Pit Sword".....nahhhh, I won't go there.... ;>)