Crown Princess - Speed Issues?

[ed01106]

How is this not a safety issue?

How many generators does the ship have?  How many are necessary for the ship to sail?  

If one generator is not working does that mean the other(s) is working harder and for longer than normal?  

If another generator fails is the ship dead in the water?  

I know the company claims there is no safety issue.  But if my car can't go at normal speed I take my car to the mechanic immediately.  I don't wait several months.  If an airplane has four engines and only needs one to fly safely, if a single engine is having trouble the plane lands immediately, rather than risk engine trouble spreading.  

My concern would be that the ship is designed with some redundancy and backup but that redundancy and backup is now compromised and another failure would render the ship into a "Triumph"  type situation.  

I do realize that "Triumph" was not as serious of an issue as an airplane losing power, a ship doesn't sink because the engines fail.  But at the same time, I worry that Carnival Corporation is putting profits before safety and is taking a risk by continuing to sail a ship that is not in 100% shape.   

 

 

[chengkp75]

14 hours ago, ed01106 said:

How is this not a safety issue?  Because the ship is perfectly safe to sail without one generator operating.  Most cruise ships operate for weeks every year with one engine down for overhaul, and no passenger ever knows it.

How many generators does the ship have?  How many are necessary for the ship to sail?  Crown Princess has 6 generators.  It needs less than one for the hotel load at the pier, and can sail, slowly, with two running.

If one generator is not working does that mean the other(s) is working harder and for longer than normal?  No, it just means there is less electrical supply than before, so the electrical users (hotel, propulsion, technical) have less available.  Since the hotel and technical loads are basically fixed, that means that propulsion gets less electricity, and therefore the ship sails slower.

If another generator fails is the ship dead in the water?  No, not until all six generators fail.

I know the company claims there is no safety issue.  But if my car can't go at normal speed I take my car to the mechanic immediately.  I don't wait several months.  If an airplane has four engines and only needs one to fly safely, if a single engine is having trouble the plane lands immediately, rather than risk engine trouble spreading. However, when you take your car to the mechanic, if he does not have the parts needed, or cannot locate them in town, you have to wait for the parts to be shipped in before he can repair the car.  This is the case here.  The parts needed are not "off the shelf" items, but parts that are generally only manufactured when a new engine is ordered, so there is a long lead time, plus shipping time.  Actually, if a plane has an engine problem, depending on what it is, it may or may not "land immediately", but may continue to its original destination and then be down lined for maintenance. 

My concern would be that the ship is designed with some redundancy and backup but that redundancy and backup is now compromised and another failure would render the ship into a "Triumph"  type situation.  As noted, there is redundancy in the six generators and two propellers.  The Carnival Triumph also had six engines and two propellers, but the redundancy was compromised by running the electrical cables from the forward engine room (three engines) through the after engine room (three engines).  A fire in the after engine room burned this cabling, so that even though the engines and generators in the forward engine room were fully serviceable, they could not be used to power the ship as their cabling had burned out.

I do realize that "Triumph" was not as serious of an issue as an airplane losing power, a ship doesn't sink because the engines fail.  But at the same time, I worry that Carnival Corporation is putting profits before safety and is taking a risk by continuing to sail a ship that is not in 100% shape.   

 

 

See my comments in red.  As I noted, all marine diesel engines are torn completely apart for overhaul every 12,000 hours (about 2 years of operating time).  Compare this overhaul to taking your car's engine out, stripping it down to every single moving part, inspecting those parts, replacing those that need replacing (whether actually worn or based on best practices to prevent failure), and then reassembling that engine.  Every two years.  Since the Crown Princess has six engines, that means that any year, there will be two engines overhauled.  These overhauls take 3-4 weeks to complete, and the ship sails for this whole time without that engine available and itineraries are not affected (if needed, they are adjusted long in advance), safety is not affected, and passengers are blissfully unaware.  Additionally, in between these overhauls, there will be periods where the engineers take an engine out of service for routine maintenance (think of your car getting a tune up), and again, safety is not compromised by these outages which can take up to a week at a time.  These scheduled outages of an engine are completely acceptable to the classification societies (the insurance underwriters for the cruise line), the flag state (the nation where the ship is registered), and the port state control agencies like the USCG.

 

The decision as to whether a ship is seaworthy or not is not up to the owner, it is determined by the class society (third party) and the port state control, both of whom can stop a ship from sailing if they feel, based on industry best practices and international safety conventions, that the ship is not safe.

Edited February 25, 2020 by chengkp75

[ed01106]

chengkp75 thank you for the info.  

 

But it still raises some concern.  It makes sense that if the ship has 6 generators it would be designed to be able to function normal with only 5 to allow continuous operations during times of scheduled maintenance or repair.  However, this ship is unable to operate normally and its speed has been greatly reduced,  This suggests to me that it is not operating on 5 generators because if it was passengers would be unaware and there would be no impact.  It suggest that it has 4 or less operating generators, thus its backup and redundancy is compromised.

 

 

[chengkp75]

The ship requires all generators to operate at full speed, but most itineraries don't require full speed. So, being down one generator means that an itinerary that requires full speed would not be met.

[chengkp75]

Let me expand on my previous post, which was from my phone, so brevity was key.  With one engine down for repair, and typically one engine out for maintenance on any given day (it won't be everyday, but there is no way to guarantee that all remaining engines will be available at all times the itinerary calls for them)(normal maintenance happens every 250 hours, or 10 days, as the first level of maintenance, and then at increments of 250 hours for more intensive maintenance), they have changed the itinerary to match the speed the ship is capable of.  Assuming that one engine is supplying the hotel load, that gives 4 out of 5 engines available for propulsion, or a 20% reduction in propulsion power.  This would result in a 2-3 knot reduction in speed, and if another engine is taken down for required maintenance, this is a 40% reduction in power, which cuts the speed another 5-6 knots (power to speed is a exponential relationship, so the last few knots require a whole lot of power).

 

Further, know that cruise ships are virtually the only ships in the world with redundant propulsion, 95% of the world's shipping operates with one engine directly bolted to one propeller, and these are considered to be 100% safe by all regulatory bodies.

Edited February 25, 2020 by chengkp75

[ed01106]

23 minutes ago, chengkp75 said:

 

Further, know that cruise ships are virtually the only ships in the world with redundant propulsion, 95% of the world's shipping operates with one engine directly bolted to one propeller, and these are considered to be 100% safe by all regulatory bodies.

So they shut down every 10 days for maintenance?

[chengkp75]

4 hours ago, ed01106 said:

So they shut down every 10 days for maintenance?

Those ships have separate generators and propulsion engines.  In other words, while a cruise ship only has diesel engines that drive generators which generate electricity that is then used wherever needed on the ship (hotel, AC, propulsion, technical, thrusters, etc), cargo ships have diesel engines that drive generators to provide electricity for everything but propulsion, and there will be 3 of these generators, and the ship can operate fully with only one of these running, in most cases (you typically need more generators when in port for discharging or loading cargo), and yes, these engines require maintenance every 10 days or so, and therefor the engines are rotated so that there is one down for maintenance, one on line, and one in standby.

 

These ships will also have a single diesel engine that drives the propeller.  This engine, on larger ships, will have the same horsepower as three or four of the Crown Princess' engines combined.  These engines are designed differently than generator engines (generator engines are typically called "medium speed" (after the piston speed travelling up and down more than the rotational speed of the crankshaft, actually), while the large propulsion diesels are "slow speed" engines.  These slow speed engines, given that a cargo ship does not have the space limitations of a cruise ship, are typically 30-40 feet high, and twice as long as the cruise ship engines, and therefore are more robustly designed (and the lower piston speed means less wear), so the maintenance intervals are somewhat greater, most maintenance being in the 1000+ hour (40 days) range.  Also, since these engines are not used at all in port, that is the time they can be maintained, and maintenance timing can be adjusted slightly to accommodate the ship's port schedule to the maintenance plan.

[helpsy]

Today I phone Princess Cruises UK Office in concern for a cruise in May on whether the restrictions on speed are still an issue and they said that they are not aware of any propulsion issues with Crown princess and that they would be informing passengers as early as possible if there was. 

[Jules.]

29 minutes ago, helpsy said:

Today I phone Princess Cruises UK Office in concern for a cruise in May on whether the restrictions on speed are still an issue and they said that they are not aware of any propulsion issues with Crown princess and that they would be informing passengers as early as possible if there was. 

Interesting, I’m due to pay the balance on my summer Crown cruise in a couple of weeks. 

[Cash123]

Maybe Princess Cruise should look on here as it appears they might learn what is going on with their own ships, we are on next week's cruise and still havent had any info from Princess 're Princess Cays, I'm still thinking  we will miss it but it would be nice to know before we get on board also would like to know about any different timings on our stops.

[Paula B]

I agree it would be nice to know. We have a private 6 hour tour in St. Lucia and I would like to know if we need to cancel and make other plans. I'm hoping since most the islands are close except for Princess Cays it won't be a problem. 

[shpur]

We just sailed 2/15-2/25 and Bahamas was all that we missed. Some minor changes to arrival times, but no issues with tours, etc

[GonzoWCS]

54 minutes ago, shpur said:

We just sailed 2/15-2/25 and Bahamas was all that we missed. Some minor changes to arrival times, but no issues with tours, etc

Thanks for the update!

[paul929207]

We are currently on the Crown.  We skipped Princess Cays and had some minor schedule  changes. Got $75 pp refundable OBC for disruptions

[Cash123]

Just out of interest when were you made aware you were going to miss Princess Cays, was it before you boarded or once you were on board ?

 

Cheers

Rob

[CineGraphic]

31 minutes ago, Cash123 said:

Just out of interest when were you made aware you were going to miss Princess Cays, was it before you boarded or once you were on board ?

 

Cheers

Rob

For the 2/15 sailing, we received an email from Princess one or two weeks prior to embarking.

Edited February 27, 2020 by CineGraphic

[sunsetme]

on crown now only received notice 3 days prior

[shpur]

Rcvd notification on 1/31/20 from vacations.com. Princess a day or so later. 
wevrcvd an OBC. Of 75. Each

[shpur]

That’s crazy. From what I’ve read on here, this problem occurred in December and may not get repaired until boat is in dry dock- possibly December!! 
mid fight for more upgrades, etc

[MissP22]

1 hour ago, shpur said:

That’s crazy. From what I’ve read on here, this problem occurred in December and may not get repaired until boat is in dry dock- possibly December!! 
mid fight for more upgrades, etc

Unfortunately it's a major problem with the generators that couldn't be resolved until a dry dock. They've been working on it without success and can't seem to get it fixed.

What more would you like them to do?

[shpur]

Give people notice and cancel trips until it’s repaired 

 

That’s crazy. From what I’ve read on here, this problem occurred in December and may not get repaired until boat is in dry dock- possibly December!! 
mid fight for more upgrades, etc

[MissP22]

7 hours ago, shpur said:

Give people notice and cancel trips until it’s repaired 

 

That’s crazy. From what I’ve read on here, this problem occurred in December and may not get repaired until boat is in dry dock- possibly December!! 
mid fight for more upgrades, etc

So if a dry dock isn't available in the mean time your choice is to cancel if you feel that strongly about missing a port. 

We just accept an adjusted port schedule & enjoy the ship. 

They'll never take the ship out of operation for such a problem. 

[Paula B]

Hi Paul929207 thanks for the info! Could you please tell be the port time they have for St. Lucia? Enjoy your  cruise

[pablo222]

On 2/25/2020 at 9:49 AM, chengkp75 said:

The ship requires all generators to operate at full speed, but most itineraries don't require full speed. So, being down one generator means that an itinerary that requires full speed would not be met.

Thank you for your always rational posts.

 

What are 'technical' electrical loads?

 

Thanks.

[Cash123]

13 hours ago, MissP22 said:

Unfortunately it's a major problem with the generators that couldn't be resolved until a dry dock. They've been working on it without success and can't seem to get it fixed.

What more would you like them to do?

For a start be honest with their paying guests, if this problem has been known about since early January and if they know the problem will not be sorted out until the next dry dock then the least they can do is inform all future passengers about this problem and the changes to itinerates including missed ports and timing changes.

 

We have some excursions booked for our cruise next week, some direct with Princess which Im not worried about as im sure they will make adjustments but also have a private tour booked in Barbados and would like to do something in Antigua but as we havnt heard anything from Princess yet im a little worried about sending people deposits without knowing if our time on the island will be cut short. 

 

I don't think that's to much to ask.