To double end or not to double end?

[markkarj]

Hi folks:

Just wondering: why are the S-class ships only single-ended? Does anyone know about why they made that decision?

Reason I'm curious is that it seems BC Ferries has an on-again, off again approach with them... built the C-class ships (double ended), go single ended for the S-class ships, now back to the double ended Coastal class ships.

M

[Barnacle]

I suspect it has to do with the length of the run... if the speed reduction caused by the drag of the forward propeller would lengthen the trip enough to justify the turn-around time, then single-enders it is.

Though I agree, BCF seems to be fickle on the subject. Perhaps it all depends on each CEO's desire to make a mark?

[Hardy]

Might I also add to this conversation the consideration of the two terminals involved, not just the length of the run. Some terminals have tidal and other conditions that are more "friendly" for spinning a single-ender in/out, whereas some terminals are not quite so easy to do this at.

This being said, it IS an interesting comparison to note that we have gone from Single-Double-Single-Double ..... V-C-Spirit-Coastal.

It is my humble and only partially informed opinion that on the "medium-haul" routes that we are talking about (1,2,30) that it really doesn't amount to a whole hill of beans whether you "waste" the time spinning a single-ender around, or slew off speed by shoving the wrong end of a double-ender.

Were we talking about Bowen Island or Langdale (short haul) then the doubles have it. On anything over 2 hours, you'd want the "efficiency" of a good hull-formed single.

These major routes, with their traffic volumes and "medium" distances/time are right in the "catch-22" zone.

HOWEVER, yet ANOTHER consideration, which was only peripherally mentioned earlier in another thread is REDUNDANCY. Say that a rudder kind of gimps up on a Coastal. Set it to a neutral position and operate the boat as a single-ender until the defective rudder is fixed. With a double, you have that option. With a single, if something breaks, you are "dead in the water".

Just my thoughts and interpretation of what I have learned so far!

[Neil]

Markkarj: I do remember reading at the time that it was felt single enders were more fuel efficient on a Strait crossing. Presumably, if there had been an inclination (or the money) to build more vessels at the time for route 2, they would have been single ended as well. Even in the ferry industry, ideas go in and out of fashion.

[Nick]

This is just what I was told at work about the single/double question. When BCF was talking with FSG about the type of ship to build, FSG wanted to build a single ender because, in Europe, generally double enders are only used on runs 60 minutes or less. Of course, after it was explained that Horseshoe bay is a little tight with a single ender, they agreed a double ender was better.

Also, single enders are much more efficient, so can go faster with the same fuel consumption or use less fuel.

The spirits were designed to run on route 1 only, and since it is a longer run (by international standards) with ample turning room at the terminals, a single ender was adequate. Also, I think it is easier to transit Active pass with a bow thruster and double screws than a single screw at each end. Not saying it is impossible, as the super-Cs were designed to transit the pass, but I think it is easier with a single ender.

[Scott]

Would it be a good comparison to a 4 wheel drive and a 2 wheel drive? You have to have all the mechanical and electrical components doubled... one at each end of the ship, which adds to the weight of the vessel.

[Balfour]

admin said:

Would it be a good comparison to a 4 wheel drive and a 2 wheel drive? You have to have all the mechanical and electrical components doubled... one at each end of the ship, which adds to the weight of the vessel.

Exactly why it increases fuel consumption and the cost of the vessel, but the results of the ship's performance are worth it. On time performance is improved mostly because there is no need to turn around.

[Hardy]

qsandwich said:

Exactly why it increases fuel consumption and the cost of the vessel, but the results of the ship's performance are worth it. On time performance is improved mostly because there is no need to turn around.

This statement misses the boat, as it were. As has been stated, SE ships have a faster service speed at the same fuel consumption, and can make up for the delay in the turn-around with the faster transit time between terminals -- ON LONG ENOUGH RUNS. I think that Route-1 falls right at the break even point assuming 17-21 knots service speed average with 5-8 mins of "spin-o-rama" at the terminals. If you up the speed by 2-3 knots, then the turn-around time is easily negated.

All that being said, having a SE boat as opposed to a DE boat then leaves you with terminals where it is not so easy to do the "spin" to get the boat into.

Overall, and all things considered, having the Coastals being DE boats, and assuming that this class will eventually include 5 boats (ASSUMING!) then I think that BCFS has covered it's contingencies and covered route-interoperability rather well.

[Hardy]

coxnnick said:

The spirits were designed to run on route 1 only, and since it is a longer run (by international standards) with ample turning room at the terminals, a single ender was adequate. Also, I think it is easier to transit Active pass with a bow thruster and double screws than a single screw at each end. Not saying it is impossible, as the super-Cs were designed to transit the pass, but I think it is easier with a single ender.

I for one, would like to see how the Coastals handle Active Pass before I pass judgement. I value the technical abilities of the German shipyard contracted (FSG) to build these beasts, and I think with their experience, that they will have given us a good product that can come very close to the capabilities (speed, maneuverability, handling characteristics) of a SE boat when driven through Active Pass. How well they would be suited for other areas (outside Route 1, 2, 3, 30) I would not speak to, as I beleive this was beyond the design criteria. I am almost certain that fuel economy will be MUCH less than an SE boat, but as has been pointed out, I think that this is a tradeoff that BCFS can live with. And, with all the advancements, I don't think that we are sacrificing anything approaching 20% or so that I have heard ballied around for the C-class. I'd be surprised if the Coastals used 8-12% more than the Spirits when all the averaging and conversions are complete.

I am not arguing that DE's can be as efficient as SE's, but I think that FSG has probably given us the best product that they possibly can, and it will meet all the design specs that they were given, perhaps even exceeding a few of them.

[WettCoast]

One needs to remember that double enders are perhaps preferable on route 2 due to the confines of turning around in Horseshoe Bay. On the other hand route 1 has no restrictions for spinning ships at either end. At Swartz Bay docking by the stern is not that difficult an operation at all.

I think that route 30 would be better suited to single enders due in part to the longer run time. I also don't think turning maneuvers at Duke Point are much of an issue.

You could argue about two new boats on route 1 for replacing the remaining V's. Would you be better off with 'Coastals' or with new and improved Spirits. I think that is an interesting question. Personally I think the Spirit SE'ed design is perhaps the better choice.

Lastly, one route that should not be using a single ender is Jervis Inlet. A month ago I watched the Q of Tsawwassen being turned 180^o to get her into her berth at Saltery Bay. The whole process is awkward and very time consuming. Saltery Bay is not spacious and as such not well suited to turning SE'ers. In any case SE'ers on that route will soon be history.

[oceaneer77]

one more factor in single or double...

COST!!

it is way cheaper to build a single.... the cost of running gear (CP propellers and all associated ), and the doubling of all of the bridge gear is a huge capital expence then you have to maintain all of this extra gear.. add a fuel penalty and you have to be quite selective on what routes make sence..
I think they have the right idea with the coastals running where they are and the spirits running thier route... but duke point to swbay should be a single ender.
Hard to belive that i am backing BCFC descision!!

Oceaneer77

[Dane]

For BC Ferries' purposes, remember, that the single enders are the "fastest" in the fleet... not the signel enders. Another uniquely BC thing

[markkarj]

hardy said:

qsandwich said:

Overall, and all things considered, having the Coastals being DE boats, and assuming that this class will eventually include 5 boats (ASSUMING!) then I think that BCFS has covered it's contingencies and covered route-interoperability rather well.

I guess I'm wondering about that assumption... is it your thought that a Coastal class ship will eventually replace the Queen of New Westminster? What about the fifth ship... would they build it simply for extra capacity?

Just an aside, my understanding is that BC Ferries really got a screaming deal on the Coastal class ships... that there'd be no way they could get them now for the prices that they negotiated and locked into several years ago.

[Political Incorrectness]

What about the fourth ship? You can't have a fifth without a fourth

[markkarj]

ferrymaniac101 said:

What about the fourth ship? You can't have a fifth without a fourth

Sorry... to clarify, I thought Coastal Class number four would be the QoNW replacement... but what would Coastal Class number five be if it's built? Would that be a long belated Queen of Victoria replacement?

Actually, speaking of which, in liquidating the Queen of Victoria, did BC Ferries only see minimal increase in demand? Retiring and selling her did eliminate a big chunk of capacity it would seem.