Radiance of the Seas - Propulsion Problems - Engine, Propeller, or Azipod Issue? How long to fix?

[Mm1aca]

💥🚨💥LATEST UPDATE

 

[jcl410]

1 hour ago, graceandlaw said:

What do you all use to track the ships movements? 

I prefer to use marinetraffic dot com.... It shows all vessels in an area that broadcast (Automatic Identification System) AIS data.  Most all commercial, and many pleasure craft use AIS to keep track of other traffic around them.

 

Aloha,

 

John

[sparty18]

12 hours ago, chengkp75 said:

Yes, they do.  Even if the prop is made by someone else, the cruise line would engage ABB to make repairs, and the reps from the prop manufacturer would be subcontracted to ABB.

 

Thanks for the further insight.

I have had really bad experiences with ABB equipment and their poor quality.  The Electrify America ABB chargers have horrendous quality issues to say the least.  Lucky if 1 out of 4 chargers are working at any site and then that 1 charger will only produce 20% or less of the power it's suppose to.  With complex clutches and complex planetary gears in the Azipod's I'm not sure I would rule an issue here out.

[chengkp75]

41 minutes ago, sparty18 said:

With complex clutches and complex planetary gears in the Azipod's I'm not sure I would rule an issue here out.

Historically, the azimuthing system (the only system with clutches and planetary gears) have not been an area of failure.  And, the technology for these azimuthing systems is far more established than the azipod itself, being used a decade before azipods were invented in azimuthing thrusters and z-drives.

 

And, the ABB group is a huge conglomerate that covers many industries, so poor quality control in one area does not translate into poor quality in another, as each industry is a separate corporate entity, many times, as in the Marine division, having purchased other companies to integrate those companies' products into their own line.

[sparty18]

38 minutes ago, chengkp75 said:

Historically, the azimuthing system (the only system with clutches and planetary gears) have not been an area of failure.  And, the technology for these azimuthing systems is far more established than the azipod itself, being used a decade before azipods were invented in azimuthing thrusters and z-drives.

 

And, the ABB group is a huge conglomerate that covers many industries, so poor quality control in one area does not translate into poor quality in another, as each industry is a separate corporate entity, many times, as in the Marine division, having purchased other companies to integrate those companies' products into their own line.

It is hard to say w/o being there and being hands-on.  But I can say on smaller scale systems when the propeller, impeller, or other device connected to the motor has impacted solid mass it unfortunately reverberated through the ancillary connections wiping out the gears and clutches.  I thought I could fix it but ended up scrapping it in the end because for me it was beyond my skills and scope to get everything solidly connected to function under stress/load even though at idle it would function ok.

 

On quality I respectively disagree - it's a corporate culture - Six Sigma Quality, Malcom Baldridge Corporation awards, ect.  ABB has serious issues, change the corporate culture, win a Baldridge type award and I will be a believer too.

Edited September 8, 2023 by sparty18

[chengkp75]

The propeller of an azipod has no gearing or clutches.  The propeller is mounted to the shaft, which is also the motor shaft.  The propeller and motor turn in a 1:1 ratio.  There are two radial ball/roller bearings, and an axial tilting pad type thrust bearing.

 

The only gearing is that the pod itself has a large ring gear, and there are two motors that drive small pinion gears to turn the ring gear and the pod.  There are friction clutches that will slip and prevent damage to the azimuthing motors when the pod is prevented from turning.

 

For nearly all large ocean-going vessels these days, of whatever type (container, tanker, cruise ship), or whatever propulsion means, there are no clutches or gearing between the propeller and the propulsive means (electric motor, diesel engine).  LNG ships are about the only large ships that use steam turbines that need gearing to the propeller.

Edited September 8, 2023 by chengkp75

[strickers]

1 minute ago, chengkp75 said:

The propeller of an azipod has no gearing or clutches.  The propeller is mounted to the shaft, which is also the motor shaft.  The propeller and motor turn in a 1:1 ratio.  There are two radial ball/roller bearings, and an axial tilting pad type thrust bearing.

 

The only gearing is that the pod itself has a large ring gear, and there are two motors that drive small pinion gears to turn the ring gear and the pod.  There are friction clutches that will slip and prevent damage to the azimuthing motors when the pod is prevented from turning.

 

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chengkp75 sounds like he knows what he's talking about.

 

Ask me one on Boeing 737's and I might be able to answer.

 

(Apologies for the thread creep!)

[chengkp75]

The various sized 700+ azipods in service have provided over 20 million operating hours to date.  While I feel that in the marine industry, ABB provides a world class service, based on my years of experience with them, I can't, and shouldn't, extend that approval to something I have no knowledge of, like EV charging stations, nor should criticism go the other way.

[smokeybandit]

2 hours ago, strickers said:

 

⬆️⬆️⬆️⬆️

 

chengkp75 sounds like he knows what he's talking about.

 

Ask me one on Boeing 737's and I might be able to answer.

 

(Apologies for the thread creep!)

Start mounting LEAP engines on a cruise ship, and then things get interesting.

[strickers]

3 minutes ago, smokeybandit said:

Start mounting LEAP engines on a cruise ship, and then things get interesting.

You can probably start a cruise ship engine quicker than you start a LEAP!

[broberts]

1 hour ago, smokeybandit said:

Start mounting LEAP engines on a cruise ship, and then things get interesting.

 

LEAP engine output can be measured in kilowatts. Cruise ship engine output can be measured in megawatts. 

 

1 hour ago, strickers said:

You can probably start a cruise ship engine quicker than you start a LEAP!

 

 

Depends on what is meant by "start". I suspect a cruise ship engine takes at least as long as a turbofan from a cold start to operational power.

[strickers]

3 minutes ago, broberts said:

Depends on what is meant by "start". I suspect a cruise ship engine takes at least as long as a turbofan from a cold start to operational power.

I was being flippant, LEAP is very slow starting compared to the old CFM56. 

[broberts]

1 minute ago, strickers said:

I was being flippant, LEAP is very slow starting compared to the old CFM56. 

 

I forgot to add a 🙂 to my post.

[chengkp75]

31 minutes ago, broberts said:

Depends on what is meant by "start". I suspect a cruise ship engine takes at least as long as a turbofan from a cold start to operational power.

Depends on what you mean by "engine".  Are you talking the azipod, or the diesel engine that drives the generator, that in turn drives the azipod?

 

The diesel engines are maintained in a "standby" mode, so that if either the automation says it needs to start another generator due to an alarm, or the duty engineer pushes the button to start the engine to get ready to leave port, the engine will go from a standstill to full speed, synchronise itself online and be able to generate full power within about 45 seconds.

 

The azipods are not in standby, and will have some automated sequences like running the oil pumps for a minute before starting the motor, and the frequency drive needs to be up and online before the motor can be started, but it's about 2 minutes.

[strickers]

So are the engines diesel electric, the big advantage of using electrical power is the removal of a need for gearing? That is electrical power used to turn the screw and to move the azipod?

[broberts]

20 minutes ago, chengkp75 said:

Depends on what you mean by "engine".  Are you talking the azipod, or the diesel engine that drives the generator, that in turn drives the azipod?

 

I don't think of azipods as engines. My non technical mind thinks of them as propulsion.

 

If a diesel engine was not in standby is it correct to presume it would take significantly longer to get to the point where it could be used to power a generator?

[chengkp75]

1 hour ago, strickers said:

So are the engines diesel electric, the big advantage of using electrical power is the removal of a need for gearing? That is electrical power used to turn the screw and to move the azipod?

No, the big advantage to diesel electric propulsion is that the diesel generators can be used for anything.  They all feed the same switchboard, which powers everything on the ship; propulsion, hotel load, engineering hotel load.  Therefore, you can fine tailor the power capacity on line to the power demand more closely than if you only had generators for hotel load, and diesels for propulsion.  This saves fuel.

 

Most cargo ships these days have diesel engines that are directly connected to the propeller.  These are "slow speed" diesels, that can run from 30-125 rpm, which is optimal for large propellers.

 

The electric drive motors used on cruise ships, whether for azipods or for shafted propellers, need a frequency converter to operate.  Since an AC motor operates at the frequency of the power (typically 60 Hz), it will only operate at one speed.  The frequency converter takes the AC power, converts it to DC power, and then converts it back to AC power at the right frequency to drive the motor at the desired speed.

[chengkp75]

1 hour ago, broberts said:

I don't think of azipods as engines. My non technical mind thinks of them as propulsion.

That is what they are, but many here on CC toss around "engine" and "propulsion" as if they were the same thing.

 

1 hour ago, broberts said:

If a diesel engine was not in standby is it correct to presume it would take significantly longer to get to the point where it could be used to power a generator?

That would depend on how far down you've taken the engine.  If you are doing maintenance on the engine, then it could take days to get the engine back to running.  But, virtually every ship keeps all their generators in standby (unless being worked on), because the automation will sense an alarm or failure of a generator online, and automatically start another to replace it.  So, "standby" is the normal condition of a diesel generator.  The cooling water is kept close to operating temperature, the lube oil is kept near operating temperature, and constantly circulated through centrifuges to remove contaminants, and fuel is circulated through the engine right up to the injectors, to keep the fuel from solidifying, so even if I just finished working on an engine, and wanted to test it, I could press the "start" button, and the lube oil pump would come on to pressurize the bearings, and the starter would engage in about 15 seconds.  Once the engine is running at speed, it can provide full power immediately (it is not recommended, but is possible), and the process to synchronize the generator to the power bus is only a few seconds as well. 

[strickers]

I guess the advantages of multiple generators connected to a central distribution system is not only redundancy but the ability to load shed non-essential services in an emergency? On the Boeing we have 3 generators, one powered by each engine and one powered by the auxiliary power unit. If we lose one of the main ones the aircraft load sheds galley power etc so that essential services are still powered while we start the spare, only takes a couple of minutes. I suppose you could argue on a cruise ship that the galley is an essential service though!!

[chengkp75]

1 hour ago, strickers said:

I guess the advantages of multiple generators connected to a central distribution system is not only redundancy but the ability to load shed non-essential services in an emergency? On the Boeing we have 3 generators, one powered by each engine and one powered by the auxiliary power unit. If we lose one of the main ones the aircraft load sheds galley power etc so that essential services are still powered while we start the spare, only takes a couple of minutes. I suppose you could argue on a cruise ship that the galley is an essential service though!!

Yes, there is load shedding capability, but on a cruise ship, the galley is such a small part of the load that it isn't included in load shedding.  It only takes into account the largest loads, like AC, thrusters, and half of the propulsion power.  But, to be honest, the only time I seen load shedding actually working is when we have to test it annually.  Typically, a new generator is online before a failing one drops off (early warning alarms), so the plant never gets to the need to shed load.

[strickers]

1 minute ago, chengkp75 said:

Yes, there is load shedding capability, but on a cruise ship, the galley is such a small part of the load that it isn't included in load shedding.  It only takes into account the largest loads, like AC, thrusters, and half of the propulsion power.  But, to be honest, the only time I seen load shedding actually working is when we have to test it annually.  Typically, a new generator is online before a failing one drops off (early warning alarms), so the plant never gets to the need to shed load.

But that’s why we plan and train for the worst case scenario. You don’t want to be learning the first time you see it. Only difference is I’m going 300Kts but at least I can turn around quickly. 

[strickers]

Back on topic, she’s pottering around, not sure how they are getting on but fingers crossed. Does anyone else think there’s a missed opportunity for an etch-a-sketch moment here?

[jlstwinmommy]

We just got an update that repairs on continuing. Still plan to sail on 9/15. They will provide another update on Sunday. Really hoping they will sail as I am already in AK and booked my air home through RCL. 🫤

[jcl410]

Jet engines on the Radiance of the Seas is more true than some realize... 

 

The main source of electricity comes from two General Electric LM2500 gas turbine generator sets. Each one can produce up to 25 megawatts of power. They are based around the CF6 turbofan engines used in widebody planes such as the Boeing 767.

 

The waste heat from the LM2500s is sent to a boiler to produce steam for more power.

 

Sometime in the mid-2000s the added a 11MW Wärtsilä 38 engine to provide hotel power while in port.... The gas turbine engines are NOT fuel efficient when running a partial load.

 

Aloha,

 

John

[stobe1]

10 hours ago, strickers said:

I was being flippant, LEAP is very slow starting compared to the old CFM56. 

Isn't that the truth. I'm a 73 driver also and seem to be flying more MAX these days than NGs (based on how I bid). They always seem to light off right at 90 seconds don't they?