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Post by jimpilch on Feb 24, 2008 18:33:20 GMT -8
One of the tugs I worked on had a 6 cyl Deutz (4 stroke) main engine with a reverse gear and a shaft brake. If you didn't pause in neutral the shaft brake didn't come on. One day we had a piece of wood caught in the nozzle and in an attempt to remove it the skipper went from ahead to astern at about 6 knots. After a few seconds the low oil pressure alarm went off and I went below to see what was going on. The engine room was full of smoke because the engine had started up backwards. Lots of momentum in that 7' wheel. i272.photobucket.com/albums/jj178/Jimpilch/Ferries/Misc/JPinnozzle.jpgI can't remember whether the Tsawwassen has a shaft brake or not, I think it does, but there is a button for each engine labeled "crash stop". If the ship is moving through the water too fast the engine may not stop turning when the control is put in the stop position. By activating the "crash stop" compressed air fills all the cylinders and stops the engine turning over.
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Mill Bay
Voyager
Long Suffering Bosun
Posts: 2,886
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Post by Mill Bay on Feb 24, 2008 20:58:00 GMT -8
The Queen of Tsawwassen also has two rudders... Do you think this would have any added affect when trying to turn the ship using the engines?
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Post by jimpilch on Feb 27, 2008 9:44:09 GMT -8
Ok, I'll bite. Rudders, propellors, engine(shaft) speed, shaft direction, wind, tide and the experience of the skipper all have an affect on the steering of a vessel when coming in to dock. A twin screw ship with controllable (variable) pitch props will handle totally different from one with fixed blades. The shafts of twin screw vessels turn in opposite directions. If they have CPP's they do not stop turning and always turn the same direction but opposite to each other. The blades rotate on the hub to change pitch and direct the water flow either forward, backward or neither if centered. On a fixed pitch propellor the shaft stops and changes direction causing the propellor to direct the flow of water the other way. Because water gets denser as it gets deeper this has the effect of the bottom half of the propellor being more efficient than the top half, enough to cause a sideways motion of the stern of the vessel, usually called "walking". Looking at the stern, standard rotation is clockwise for the starboard propellor and counterclockwise for the port. If the starboard shaft is put into astern (reverse) and the port one left in ahead, both shafts will be turning counterclockwise and the stern of the ship will "walk" to port and the bow will turn to starboard. With CP propellors the bow will still turn to starboard but the stern will not walk. The angle of the rudder, behind the propellor in ahead, will determine which direction the stern moves. Transverse bow thrusters are also used to move the bow of the vessel to port or starboard and are used to counteract wind or tide as well moving the bow away from the dolphins (pilings) when the ship is stern in and about to depart. They are ineffective at speeds above about 3 knots. Double ended ships can use their forward propellor(s) as a bow thruster, directing the force with the forward rudder. They can be effective at higher speeds and used to stop the ship or pull it forward, something transverse bow thrusters cannot do. Another system of propulsion which is now becoming more popular is the angle drive or Z drive also known as an azimuth drive. These units are similar to outboard motor legs and can rotate 360 degrees. They make a ship extremely manueverable. Some of the newer cruise ships use this form of propulsion as do "tractor tugs" used in ship docking.
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Post by kerryssi on Feb 27, 2008 17:13:44 GMT -8
A very good explanation. We set the ship up for docking about a mile out at a dock like TSA. We use the rudder to counter the walking motion of the stern and walk it against the tide. When we exit active pass and dock at VB we also use the ships sideways momentum. You can imagine the amount of windage that is on one of these ships. That must also be taken into account especially since they are basically flat bottomed. We used to say it was like steering a cracker box. We would sometimes aim at dock 5 to hit dock 3.
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Post by Ian on Mar 24, 2008 11:08:47 GMT -8
I'm sure this thread is in existence somewhere but I couldn't find it.
As much as I like the Coastal class, the thing that I dislike about them is the fact that they are double ended. I still consider the Spirit class as the pride of the fleet and would have preferred new spirits even if it meant waiting the turn around times.
I think the new Coastals should have been reserved for route 2 and 30 and maybe have only 2 built. Then build new single enders for route 1.
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Post by DENelson83 on Mar 24, 2008 11:16:39 GMT -8
Double-ended vessels really stand out to me. Also when a vessel is at her maximum turning rate, that's when you get the most vibration.
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Post by Ian on Mar 24, 2008 11:20:10 GMT -8
I'm not knocking double ended ships, but the whole BC Ferry fleet is turning into a double ended fleet. We need variety since we are going to lose all of a single enders pretty soon or have already lost them, ie) Queen of the North, Queen of Victoria, Queen of Sidney
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Post by DENelson83 on Mar 24, 2008 11:41:28 GMT -8
Hey, just about every ship in the Washington State Ferry fleet is double-ended.
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FNS
Voyager
The Empire Builder train of yesteryear in HO scale
Posts: 4,948
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Post by FNS on Mar 24, 2008 11:51:22 GMT -8
Hey, just about every ship in the Washington State Ferry fleet is double-ended. You're right. All are double-enders. Except for the "Mosquito-Class".
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Post by Kahloke on Mar 24, 2008 11:56:21 GMT -8
I'm not knocking double ended ships, but the whole BC Ferry fleet is turning into a double ended fleet. We need variety since we are going to lose all of a single enders pretty soon or have already lost them, ie) Queen of the North, Queen of Victoria, Queen of Sidney What about Northern Adventure, and the upcoming Northern Expedition? Plus, the Spirits are going to be around for a long time, and the major refit of the QoNW tells me that BCF is planning on keeping her around for awhile, too. So, that's 5 single-enders right there that will be in the fleet for a quite some time.
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Post by Canucks on Mar 24, 2008 11:58:21 GMT -8
Most people want to get to their destinations as fast as possible and don't really care what the ship looks like.
I think that the double enders are a lot nicer to look at because they are symmetrical and I find they are a lot more photogenic.
From a business point of view BC ferries probably likes them better because it wastes time and fuel backing out and turning around with a single ender.
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Post by Hardy on Mar 24, 2008 13:47:59 GMT -8
As much as I like the Coastal class, the thing that I dislike about them is the fact that they are double ended. I still consider the Spirit class as the pride of the fleet and would have preferred new spirits even if it meant waiting the turn around times. I think the new Coastals should have been reserved for route 2 and 30 and maybe have only 2 built. Then build new single enders for route 1. What makes Rte-1 more apt for a single-ended boat versus Rtes-2&30?? I could see more of your argument if there was a reasoning behind it, other than personal wishes. And while fleet variety is nice, it also means having to train a set of crews to YET another class of vessel. Having similar vessels lends to interoperability of not only the boat itself, but also the crews which sail her. I am all for matching a ship to its intended route. I see nothing wrong with double-enders on the short-haul mainland-island run (Rtes1,2,30) as well as Sunshine Coast or even Comox-PR. You just don't hit the advantages of the single-enders til you get to a journey time of 3-4+ hours. That is why the NorEx is a planned single-ended boat. Likes and dislikes aside, everyone does have their personal preferences. What I really don't get in your argument is why you single out Rte-1 for having single-ended boats?? Could you clarify this position a bit? I'd also like to hear your take on commonality in terms of ship/crew interoperability. Thanks!
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Post by kylefossett on Mar 24, 2008 14:24:17 GMT -8
Hardy may agree with me on this one.
If you have a fleet of anything, trucks, ferries, aircraft, it is a lot easier for your maintenance department if they are all of the same type. All peterbilts, boeing, coastal class ferries. they only have to stock one type of parts, they are familiar with the maintenance.
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Mirrlees
Voyager
Bathtub!
Deck Engineer- Queen of Richmond
Posts: 1,013
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Post by Mirrlees on Mar 24, 2008 16:00:26 GMT -8
Hardy may agree with me on this one. If you have a fleet of anything, trucks, ferries, aircraft, it is a lot easier for your maintenance department if they are all of the same type. All peterbilts, boeing, coastal class ferries. they only have to stock one type of parts, they are familiar with the maintenance. I agree as well; In the landscaping business, I've standardized on one brand Echo which makes many of the parts interchangeable among the various tools. This helps keep the costs down too.
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Post by Hardy on Mar 24, 2008 16:47:23 GMT -8
Hardy may agree with me on this one. If you have a fleet of anything, trucks, ferries, aircraft, it is a lot easier for your maintenance department if they are all of the same type. All peterbilts, boeing, coastal class ferries. they only have to stock one type of parts, they are familiar with the maintenance. Agree??!! Heck, give me the musical score for it, and I will play the horn part of it! Yeah, I suppose perhaps this did not come across clearly enough in my earlier post (or re-reading it now I forgot to clearly state it!), but commonality is easier on any operation. Not only is your crew 'up to speed' on things, but your supply of spares and replacement parts is much simpler too. Worst case, if you run out of spares, you can always rape one from another vessel/truck/bus/train. Not having to stock 47 of everything to cover all the different combinations makes things easier. Plus, as we have seen with the V's and the C's, if something breaks or wears out on ONE of them, chances are it will on the others. Your learning curve for Preventative Maintenance is much less steep. Down-time is also minimized as your technicians/mechanics are familiar with not only the part, but how to put it in/take it out. If BCFS ever wants to run more single-ended ships, they should try to get as close to the design of the Spirits as possible -- of course, this does not take into account that this design could be "past it's best before date". Seeing how the Spirits handle and what not now, they would probably want to use a different power plant as well, to be more fuel efficient. That being said, I have nothing against the single-ended ships. I just don't see why we necessarily NEED variety just for the sake of variety. Give me a good reason why we need something specific and I am the first one to say "go for it". In the moving/delivery industry, it is ALL ABOUT having the right tool for the right job - I have 3 different styles of 4-wheel dollies for moving things, and 2 different styles of 2-wheel hand-trucks. Don't forget plastic bins, panel carts, piano skids, and appliance trucks. My truck has both a power tail gate (lift) and a walk-ramp. There is no "one size fits all" in my business. Neither is there in the ferry world. However, they do have a fairly decent compromise insofar as the Coastal class; I would see nothing wrong with having 6 or so of these in the fleet to service the Mainland-Island runs, if it ever came to that, capacity wise/sailing wise.
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Post by kerryssi on Mar 24, 2008 20:22:31 GMT -8
If you are crossing the ocean then single ended is best. For a back and forth ferry then ro-ro (double ended) is best for time and economy.
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Nick
Voyager
Chief Engineer - Queen of Richmond
Posts: 2,078
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Post by Nick on Mar 24, 2008 21:21:00 GMT -8
BTW, Ro-Ro refers to the fact that traffic can "roll on" and "roll off". It applies to any ship that the cargo loads itself. It has nothing to do with whether the ship is double ended or not. see here: en.wikipedia.org/wiki/RORO
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Post by WettCoast on Mar 24, 2008 21:41:15 GMT -8
For more on the single versus double ended debate go to this page... ferriesbc.proboards20.com/index.cgi?board=generaltalk&action=display&thread=1184635419&page=6Start with reply #141. From that discussion it appears that the length of Georgia Strait crossings (1.5 to 2 hours) is about equal to the line that divides the efficiencies of single versus double enders. (Meaning that for runs of longer than 1.5 or 2 hours single enders advantages outweigh those of double enders. Obviously, for shorter runs the double enders have the advantage.) As for appearance, I'm on record as favouring ships that have definite bows and sterns.
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Post by Ian on Mar 24, 2008 22:49:21 GMT -8
I'm sure the root of my want for more spirits is the fact that I too favor ships that have a defined bow and stern. Also the reason why I mentioned route 2 as a double route is because hsb does not have a very big turning basin without leaving the bay. However I guess it doesn't really matter on route 30. Anyways, I'll be happy with the . . .
Q of New West Q of Nanaimo Spirit of BC Spirit of VI Northern Adventure Northern Expedition Q of Burnaby And the other minor former ministry vessels
That's about it for single enders, right ?
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Post by DENelson83 on Mar 25, 2008 2:27:12 GMT -8
Tachek, Tenaka, NIP and QPR are single-enders.
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Post by kerryssi on Mar 25, 2008 14:33:08 GMT -8
The ferries refers to all double enders as ro-ro meaning roll on one end and roll off the other ( preferably while in dock)
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Post by Hardy on Mar 25, 2008 17:47:33 GMT -8
The ferries refers to all double enders as ro-ro meaning roll on one end and roll off the other ( preferably while in dock) Sorry to disagree, Kerry, but Nick is right on this case. Ro-Ro means that the cargo is self-propelled/on wheels (cars, buses, trucks, trailers, MAFI etc) - it has nothing to do with one-end loading or double-ended ships. IE: the NorAd is a Ro-Ro ferry as well, with only it's stern ramp, and with or without that little turntable round-about thingie.
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Post by Hardy on Mar 25, 2008 17:52:46 GMT -8
IGW: thanks for the clarification on the routes -- you'd meant it only in terms of terminal accessibility, and not a preference for a certain route to have single-ended ships versus another route, right?
I can understand a personal preference for a certain style of ship. And I am not saying that you are wrong. However, in terms of newbuilds, surely you can agree on the point that from a maintenance and training point of view, it is a lot easier to standardize the fleet. Seeing as how the Coastals are the newest ferries including all the modern efficiencies of design/power etc, it would be slightly impractical to go back and build "last generation" Spirits AT THIS POINT. If, and it could be possible, to design a Spirit II class, similar enough to the 2 existing ones so that they COULD almost be interchangable, then I have nothing against it. However, with the way things are, I think that we are more than likely 'stuck' with potential future vessels being "Coastal"-like.
While it does make the fleet rather COOKIE CUTTER on the major routes, there is still lots of spice and variety in the fleet in terms of what are now becoming "secondary" vessels (Note: sooner or later, the Spirits will be 2nd boat, if we follow thru with the modernization of the fleet).
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Post by markkarj on Mar 25, 2008 19:16:45 GMT -8
Is a cookie-cutter approach a bad thing?
According to the Bannermann book, one of the problems with the original ships is that (at first) they had three different types of engines until the four V class ships moved over to MAK engines.
Then when BC Ferries picked up Black Ball and the other smaller fleets, they mostly had unreliable, obsolete ships... all of different varieties. It sounded like the early days of BC Ferries were an engineering nightmare.
I understand why we'd like to have some spice (makes for good conversation), although I could see a standardized approach from the perspective of crew adaptability and cutting the need for all sorts of different parts inventories.
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Post by Scott on Mar 25, 2008 20:30:50 GMT -8
So are we talking standardization below the car deck? Because we know that we can have standardization as far as hull and engine but different superstructures... ie. the Queen of Alberni vs. the Queen of Cowichan. I guess that doesn't solve the difference between single ender and double ender though. Is it more complicated than having the same or similar make of engines? Does a double ender need vastly different engines and parts than a single ender?
There are good reasons for using single ended ships as has been discussed before. You don't have to double everything, therefore having a more efficient and less costly ship. And for a route like route 1 where the crossing is quite a bit shorter and a 2 hour schedule is easily accomplished despite the need to back out of Tsawwassen and turn around, it seems quite reasonable to use single-ended ships. So what's more important? A cheaper and more efficient vessel to operate or a standard for all major ships on all major routes?
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