Ferry propulsion & mechanics discussion

[Hardy]

Markkarj: "Cookie cutter" is not bad as far as operability/maintenance; for photo enthusiasts, and purists, it is bad. I personally could not see a downside to say adding 3 more Coastals to the fleet for a total of 6 Coastal class ships. As a matter of fact, for reasons I have already stated, I think that would be a good thing. Not because they are German, or because they are double-ended, but because commonality and interoperability.

John: Alberni vs Cowichan is a valid comparison, as they have different engines and different evac systems. I beleive that this means that these two are not the same -- a crew from one could NOT easily jump on the other and sail happily away not noticing the differences. If the difference were just the power plants, then as long as the below-decks crew (engineers etc) were familiar with the differences, then the top-side crew would be able to crew either ship. As for BRIDGE personnel, they would need to know the subtle differences of how the other engines and different ship characteristics affected handling.

Rte-1 seems to be the only real route where you can successfully use a single-ended vessel without too many implications on schedule performance, or so people would have me believe. I fully understand that this has to do with the terminal configurations etc. That being said, would I, if I were in charge, build specialty vessels for Rte-1, or build vessels that could serve Rte-1 as well as Rtes-2, 3, 30?? Easy choice. I'd go with the dual-ended interchangable ships.

This is where someone of Markus' position comes into play -- what is the cost difference between a Coastal as they are built, and a "single-ended-Coastal" or "New Mini Spirit"?? Let's keep the same capacity, to keep the comparison fair ....

A single ender would probably have twin screws aft, a single rudder and less switching/gearboxes. How much less would it really cost though? And is that additional cost worth the "inflexibility" and "limited deployment"?? It becomes a simple Cost-Benefit-Analysis ... but we need some numbers to plug into it to see if it makes sense or not.

Add in that the handling would be different, the bridge layout would be different and you would need to have specifically trained crews. You could probably make the engines and much of the rest of the machinery common between the "New Mini Spirit" and the Coastal to save on maintenace costs and spares ... but would it work out that easy? Good question, valid question.

[Taxman]

Hardy: I thought that the Alberni & Cow/Coquitlam were identical below decks. Did I miss something or did I fall victim to a BC Ferries Myth?

[DENelson83]

hardy said:

(Note: sooner or later, the Spirits will be 2nd boat, if we follow thru with the modernization of the fleet).

The Spirits will definitely become secondary if and when BC Ferries orders the Coastal Experience from FSG.

Say, would the PacifiCats have fared a little better if they had been designed double-ended?

[Hardy]

gunther said:

Hardy: I thought that the Alberni & Cow/Coquitlam were identical below decks. Did I miss something or did I fall victim to a BC Ferries Myth?

I thought that the Alberni was re-engined? I also believe that there is more "weight"/ballast below decks owing to the larger/taller superstructure on her (see Markus' discussion about meta-centric height etc in the CI thread).

Without my other resources at hand right now (on the road), I use the BCF website to get the following (although I find it suspect, as it has the Alberni being lighter than her sisters!)

Alberni - 5863.22 t
service speed 19 kt @ 12,000 hp

Cowichan / Coquitlam - 6551.18 t
service speed 22 kt @ 11,860 hp

I seem to remember someone somewhere saying that the Alberni may also have had some minor hull mods done to increase stability, although my memory is fuzzy on this, and I may have confused that with the New West.

I am sure that the true stats guys will have me corrected in no time flat!

[Hardy]

denelson83 said:

Say, would the PacifiCats have fared a little better if they had been designed double-ended?

I don't think that Catamarans work at ALL in double-ended mode? Could be wrong. I for sure have never seen one!

I think, and this is a hot button issue, that the whole design of them for these particular waters and the service they were going to be put into, was totally ill conceived. They were all but set up for failure from the moment they were designed (never mind launched!). They could not carry any commercial traffic, including buses, bigger than a cube-van (1-ton courier type truck), including 15-pax vans. So this was a flaw - the argument about limiting truck traffic thru HSB notwithstanding.

Go back and read, but: gas-guzzlers, wake problems, poor ride to name three of the key points of why they failed!

[DENelson83]

hardy said:

I don't think that Catamarans work at ALL in double-ended mode? Could be wrong. I for sure have never seen one!

Oh, but you have. Ever heard of the SeaBus?

[Northern Exploration]

Cats work if they have Pod drives. But then you have the extra depth needed to accomodate the pods below.

[Nick]

There's a huge difference between a "catamaran", and a "fast ferry".

A "Fast Ferry" has to get up on a plane in order to go fast and use an acceptable amount of fuel. That was one of the major issues with the Pacificat Explorer, because she had that bow door added on as an afterthought, they had to add a lot of ballast to the stern and it made her too heavy to plane properly. As a result, it used a lot of fuel, created a massive wake, and passenger comfort was sacrificed for weight savings.

A catamaran is any ship that has two hulls. Anything from a Hobie-cat sailboat to the seabus to the NIP are considered catamarans. A double ended catamaran is perfectly plausible if the propulsion system is completely reversible, like with RADs or Z-drives. The pacificats could never be designed as double enders because a boat needs a bow and stern to be able to plane (try getting your ski boat to plane in reverse).

As far as needing a double ender to get into Horseshoe Bay, remember that prior to 1976 the HSB-DPB run was served entirely by single ended ships. Also, I am 99% sure that the Alberni still has her original engines, and is still more or less identical to the Cow/Coq below decks (remember that as these ships age, each one has different "fixes" done to them, so as the years go by they get more and more unique).

Personally, I don't see the advantage to having double enders on both route 1 and 30. Route 30 needs a higher speed ship, which is more efficiently done with a single ender, and there is no difficulty turning in both terminals. Route 1 also has no tight turning areas, so the added fuel consumption of a double ended ship is not beneficial.

And before anybody says that the Alberni is more efficient than the New West, let me point out that the New West was originally designed to go 18 knots, and has been stretched and lifted almost beyond recognition, whereas the Alberni is in more or less original condition (yes, I know she was lifted, but the hull and mechanics are identical to the other Cs, so that is accounted for in the original hull design).

[hwy19man]

denelson83 said:

hardy said:

(Note: sooner or later, the Spirits will be 2nd boat, if we follow thru with the modernization of the fleet).

The Spirits will definitely become secondary if and when BC Ferries orders the Coastal Experience from FSG.

Say, would the PacifiCats have fared a little better if they had been designed double-ended?

A crew member on the SOVI over the Easter weekend told me that if a 4th FSG vessel is built and purchased, the plan is that it would be based at HSB and operating on route 2.

[hwy19man]

coxnnick said:

And before anybody says that the Alberni is more efficient than the New West, let me point out that the New West was originally designed to go 18 knots, and has been stretched and lifted almost beyond recognition.)

I think I remember reading on this board and reading about it in media reports that the New West has had its fair share of problems keeping on schedule, one of them being that she is a single ender.

[Nick]

A single ended boat with the same power plant as a double ender will go faster. A hull with a formed bow and stern is far more efficient than a ship with two bows. For example, the Coastals and the NorEx are roughly the same size and tonnage. They will both travel at 21 knots (design speed). The NorEx is listed as using 34.5 tonnes per day of fuel, whereas the Coastals are listed as using 57.5 tonnes per day. These numbers are from the FSG site.

The New West has difficulties because she is NOT DESIGNED TO GO 20KTS. They put overpowered engines in her to "force" her up to that speed. It is for that reason that she uses more fuel and has difficulty keeping the schedule sometimes.

Here's a good resource for further reading: www.sva-potsdam.de/news/Voith_SVA_DEF.pdf

[hwy19man]

Thank you so much Nick for the link, I have not read it all but it is very interesting. You mention how the New West was not designed to operate at 20 knots. I do recall that speed problem now after the NW was lifted back in the early 1990s. The media reported that heavy and noisy vibrations during the voyage were a major discomfort for crew and passengers.

[Ian]

Okay, here's a valid question, I hope.

The spirits are the biggest in the fleet and very reliable. Why build the fast cats and why build the coastals when we already have such a valid design. If you think about it the turn around at tswassen and swing in at swartz really add at most 10 min, so I don't see that as an issue.

[Political Incorrectness]

igw, that was a question we used to ask before the Coastals came into service. As a matter of fact, I am a little concerned running a Coastal through Active Pass do to it having 1 more meter of width than the Spirits. Car capacity wise may not be justified since the Coastals could get platforms. Passenger wise, you'd have a point hard to beat. Considering the Spirits are licensed to carry 2100 passengers while the Coastals can only carry 1650 is a LARGE difference. That is 450 passengers of difference. However, checking the Flensburg profile, the Coastals have 1800 seats. How many seats do the Spirits have exactly?

My question is based off of how different the passenger comfort is in terms of how many people we could get on one of the Super Cs. Due to them being wider than a Spirit yet only 7 meters shorter, it makes me curious why they would carry less passengers. If the design could be optimized to carry more passengers on the Super Cs, then it might be justifiable for Route 1, but with 1650 in comparison to 1708 passengers with the Vs only carrying 286 vehicles, there might be some passenger issues. (1708 figure from BC Ferries fleet profile, not sure on A license).

[oceaneer77]

Whooa Nick.

On your comment about the pacificats getting up on the step.. sorry but you are way off. Fast cat ferries do not plane! The whole point of a cat is to have 2 slim hulls that due to the slim design of the hulls have a very high hull speed and cut thru the water rather than bashing over it. A planing hull must ride up and over the bow wave and start to support its self on the planning moment rather than its displacement.
Most fast ferries work in a displacement mode. They have slim hulls that manage to push the theoretical hull speed much faster than something like our fat greek ferry.
The Ballast added to the pacificats did not help their speed due tho the weight and the increased surface area that the additional weight added to the underwater area.

oceaneer77

[Dane]

royalcaribbean said:

Okay, here's a valid question, I hope.

The spirits are the biggest in the fleet and very reliable. Why build the fast cats and why build the coastals when we already have such a valid design. If you think about it the turn around at tswassen and swing in at swartz really add at most 10 min, so I don't see that as an issue.

The design is only appropriate for Rte 1 is one huge point; the Spirits could't make the schedule on Rte 2 or 30. Another very big reason: the designis from more or less 1988 -> it's 20 years old. I am not saying it is bad but it certainly doesn't represent the best that we can get now.

[Dane]

ferrymaniac101 said:

igw, that was a question we used to ask before the Coastals came into service. As a matter of fact, I am a little concerned running a Coastal through Active Pass do to it having 1 more meter of width than the Spirits.

The width of vessels passing through Active Pass is certianly a valid concern to be thinking about - however - I am sure, unlike the Fast Ferry project, that a sufficient amount of knowledge and forethought went into this process to ensure that everything will work. The Coastals are shallow hulled in contrast to some of the other ferries of British Columbia, and despite their width shouldn't pose much of a challenge. The manuverability of the Coastals, from what I have heard, is also top notch.

ferrymaniac101 said:

Car capacity wise may not be justified since the Coastals could get platforms. Passenger wise, you'd have a point hard to beat.

I'll beat it The number of passengers on a vessel is set by the safety equipment that is available, amongst other variables but that is essentially the most important. The Spirits, which aren't currently licensed to 2100 I believe (it's around 2000, it was 1900 for almsot 2 years), simply have more equipment for evacuation and larger crews. I am curious to see what the license of a Coastal is if she is assigned to Rte 1 as a number one vessel. Presumably with little work there should be room to sail at the same license as a Spirit if there is a similarly sized crew.

ferrymaniac101 said:

Considering the Spirits are licensed to carry 2100 passengers while the Coastals can only carry 1650 is a LARGE difference. That is 450 passengers of difference. However, checking the Flensburg profile, the Coastals have 1800 seats. How many seats do the Spirits have exactly?

Other than for comfort - the number of seats is irrelevent generally - for a period when the Alberni was licensed for 1300ish she had 700ish seats

ferrymaniac101 said:

My question is based off of how different the passenger comfort is in terms of how many people we could get on one of the Super Cs. Due to them being wider than a Spirit yet only 7 meters shorter, it makes me curious why they would carry less passengers. If the design could be optimized to carry more passengers on the Super Cs, then it might be justifiable for Route 1, but with 1650 in comparison to 1708 passengers with the Vs only carrying 286 vehicles, there might be some passenger issues. (1708 figure from BC Ferries fleet profile, not sure on A license).

The figures on the BC Ferries website for the V Class are inaccurate. The Queen of Esquimalt, on an A License, can sail with 1360 (including crew), the Vancouver is the same and only the Saanich is higher with a special "AA" License for 1672, at an A she is actually the lowest of all at 1308. The difference in licensing for the Saanich is due to additional crew and additional life saving equipment availability.

There's 982 seats on the Queen of Esquimalt. If there's 1800 on a Coastal, then I don't see a huge problem; I'm sure the Esquimalt is in line with the other V's as far is that is concerned. (Although I do think the measure on the Coastal includes outdoor seating, because that's an awful lot of seats ;D - also the Vancouver and Saanich have additional upper level seating, but certainly not 900 seats)

I know we all want to hate on the new ferries, but let's face the awful news that we good a great deal on some great vessels.

Perhaps you could say,

they're awesome only better.

[Nick]

oceaneer77 said:

Whooa Nick.

On your comment about the pacificats getting up on the step.. sorry but you are way off. Fast cat ferries do not plane! The whole point of a cat is to have 2 slim hulls that due to the slim design of the hulls have a very high hull speed and cut thru the water rather than bashing over it. A planing hull must ride up and over the bow wave and start to support its self on the planning moment rather than its displacement.
Most fast ferries work in a displacement mode. They have slim hulls that manage to push the theoretical hull speed much faster than something like our fat greek ferry.
The Ballast added to the pacificats did not help their speed due tho the weight and the increased surface area that the additional weight added to the underwater area.

oceaneer77

Yes, after doing a little more reading, you are absolutely right, I am way out to lunch on that. I was getting my information from another source that dealt with smaller passenger only boats that actually do plane. Unfortunately I don't have the link anymore.

It seems that the fast ferries we are familiar with work on the principle that a long, thin hull can move faster than a wide, short hull (the same principle that makes a canoe faster than a rowboat).

On a slightly unrelated note, the vibration problem in the New West (in particular the cafeteria) was caused by a resonant frequency that was created in the steel when the ship was lifted.

In case anybody isn't aware, everything has a "natural" frequency, that if the object is vibrated at, or close to this frequency the amplitude of the vibration will build on itself. In extreme cases the object will fail.

This part is speculation on my part, but I think that when the New West was lifted, it was a bigger lift than they had done on the Vs, so the natural frequency was different. It happened to be very close to a vibration occurring in the ship from the engines or whatever, and it caused a very large vibration. I do know from articles that were posted on this forum a little while ago that they solved the problem by adding extra steel (changing the mass) to the bulkheads and floor, thereby changing the natural frequency.

[Political Incorrectness]

Dane, I was looking more into logistics, in fact, my love for the Spirits got tarnished with the Coastal Renaissance. She was too beautiful of a ship to pass up. Now why would the number of seats not matter especially when weather is bad outside and people are more likely to sit inside? I have heard stories where people have had to sit on the floor because all the seats were taken. That being said, with passenger comfort, more seats and larger passenger space means more spreading room.

Now as for them being useful on Route 1, how about a pair of 167x24's (meters of course!) for route 2 and put the CR and CC on route 1 full time with platform decks, I don't think Langdale residents would be too happy nor people living on the Howe Sound. At least we would have plenty of spare vessels and enough for summer runs.

[Dane]

ferrymaniac101 said:

Dane, I was looking more into logistics, in fact, my love for the Spirits got tarnished with the Coastal Renaissance. She was too beautiful of a ship to pass up. Now why would the number of seats not matter especially when weather is bad outside and people are more likely to sit inside? I have heard stories where people have had to sit on the floor because all the seats were taken. That being said, with passenger comfort, more seats and larger passenger space means more spreading room.

I was framing the discussion of the number of seats as a function of licensing; the number of seats, I was getting at, does not correspond to the license a vessel sails with. I am curious to know whether it is relevant at all? I would think/hope it does.

[deepsea]

I noticed that not all V class has the same "feel".

I stood over the E's engines and I felt a LOT of vibration! I did the same thing a few weeks later onboard the Vancouver, and the vibrations were lower. Both ships are supposed to have the same engines, right?

So, I can imagine what it would be like to stand over the NW's engines Does anyone know if there are plans to reduce the vibration level on the NW during her Coastalization?

Wouldn't the vibrations cause damage to the vehicles? I was thinking that as I stood on the MCD of both Vancouver and E. I realize that, it's routine to get vibrations as you drive on the road or go over potholes. But in this case, it's continuous vibration for between 1.5 hours to 2.4 hours.

Were there any studies done on the vehicles or people from the effects on ship vibrations, especially on the NW? Also on the ships itself? What would happen to the steel from the resonance vibration?

[Dane]

Corrected post.

Vic/Van have MAK 9 MU 551 AK engines at about 8450BHP
Saan/Esqu have MAK 8 M 551 AK engines at about 9000BHP

I have no clue what the difference in designations is.

[D'Elete BC in NJ]

coxnnick said:

It seems that the fast ferries we are familiar with work on the principle that a long, thin hull can move faster than a wide, short hull (the same principle that makes a canoe faster than a rowboat).

lol, love the description.

oceaneer77 said:

Most fast ferries work in a displacement mode. They have slim hulls that manage to push the theoretical hull speed much faster than something like our fat greek ferry.
The Ballast added to the pacificats did not help their speed due tho the weight and the increased surface area that the additional weight added to the underwater area.

oceaneer77

...remember that a long, fat displacement hull has a similar hull speed as that of a similar length skinny displacement hull, however, a lot more power will be needed to achieve it. Actually, depending on the shape of a hull, you can increase its hull speed by increasing the draft (adding weight)...namely through lengthening the hull length at the waterline. Again, more power is required to achieve the higher velocity due to the larger wetted area, but the maximum hull speed is increased.

[oceaneer77]

Yesterday at 9:24pm, Nick wrote:
It seems that the fast ferries we are familiar with work on the principle that a long, thin hull can move faster than a wide, short hull (the same principle that makes a canoe faster than a rowboat).

lol, love the description.

Yesterday at 7:55pm, oceaneer77 wrote:

Most fast ferries work in a displacement mode. They have slim hulls that manage to push the theoretical hull speed much faster than something like our fat greek ferry.
The Ballast added to the pacificats did not help their speed due tho the weight and the increased surface area that the additional weight added to the underwater area.

oceaneer77

...remember that a long, fat displacement hull has a similar hull speed as that of a similar length skinny displacement hull, however, a lot more power will be needed to achieve it. Actually, depending on the shape of a hull, you can increase its hull speed by increasing the draft (adding weight)...namely through lengthening the hull length at the waterline. Again, more power is required to achieve the higher velocity due to the larger wetted area, but the maximum hull speed is increased.

[font=Verdana]
Sorry BCNJ but you are off here...
Hull speed is a theoretical thing that has do do with how much power it takes to drive a boat thru the water. We define the max hull speed as the point that adding more power starts to achieve a very small result.
If you are using the old 1.34 the SQ of the waterline length formula that is only a rule of thumb formula and is for an average hull design. To get the proper speed and power requirements you need a much more complicated formula having to do with block coefficients / hull shape and even then it is just a guess.. not an art.. or at least in my experience,

The power requirements of an hull to the speed makes a bell curve like graph we commonly refer to hull speed as the place where the bell curve starts to steepen.

You can drive a ship faster than hull speed but the power required for an extra 10% could be 100%-150% or more.

So hull speed is not a hard set and unbreakable thing, just a place on the bell curve. Having said that our fat greek ferry would take millions of horse power, have a bow wave that came over the visor, and a stern that squatted so low that the vehicle deck would be underwater to achevie 35Kts.

oceaneer77[/font][/color]

[Northern Exploration]

Often you can extend a ship and not change the engine and maintain the same speed due to the extra hull length and even in some cases improve efficiency and speed. Many yachts find this when they had a fishing cockpit added or make extentions.