Reply
 
Thread Tools Display Modes
 
Old 10-10-2015, 10:48 AM   #41
Guru
 
koliver's Avatar
 
City: Saltspring Island
Country: BC, canada
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 2,170
One rarely mentioned bonus with twins: When you have a breakdown that requires a trip to the mechanic, you can schedule that trip for a time that you are not using the boat, rather than losing your vacation time or spoiling a trip you have just begun. The only differences; you will be running a little slower, as you now have only 1.2 the hp, and you will need to re-acquaint yourself with the handling of the boat under a side mounted single.
__________________
Advertisement

koliver is offline   Reply With Quote
Old 10-10-2015, 10:50 AM   #42
Senior Member
 
Join Date: Sep 2015
Posts: 204
There's a current engine failure thread on the board wherein three separate owners of singles mention power loss...not including the El Faro. A recent thread spoke of a prop fouling on a twin. Power related malfunctions happen with great regularity to unsuspecting owners who are seemingly very fastidious about maintenance. Happened to me because of a raw water pump that had been rebuilt incorrectly by a very reputable company. Check the archives....there are documented incidents all over the place...many of them in less than ideal circumstances. The tow boat argument doesn't hold water in many (most?) cases.
__________________

go-planing is offline   Reply With Quote
Old 10-10-2015, 10:56 AM   #43
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 3,888
Quote:
Originally Posted by koliver View Post
One rarely mentioned bonus with twins: When you have a breakdown that requires a trip to the mechanic, you can schedule that trip for a time that you are not using the boat, rather than losing your vacation time or spoiling a trip you have just begun. The only differences; you will be running a little slower, as you now have only 1.2 the hp, and you will need to re-acquaint yourself with the handling of the boat under a side mounted single.
And another bonus: With two engines you have about twice the probability of this happening.

And I seriously doubt someone is going to continue a journey with one dead engine. There are sea conditions that can make that a very tough situation.
Ski in NC is offline   Reply With Quote
Old 10-10-2015, 11:04 AM   #44
Senior Member
 
Join Date: Sep 2015
Posts: 204
Quote:
Originally Posted by Ski in NC View Post
And another bonus: With two engines you have about twice the probability of this happening.

And I seriously doubt someone is going to continue a journey with one dead engine. There are sea conditions that can make that a very tough situation.
Advocating single engine airliners?
go-planing is offline   Reply With Quote
Old 10-10-2015, 11:12 AM   #45
Guru
 
koliver's Avatar
 
City: Saltspring Island
Country: BC, canada
Vessel Name: Retreat
Vessel Model: C&L 44
Join Date: Nov 2007
Posts: 2,170
Ski
I mentioned this because




"Ski: And I seriously doubt someone is going to continue a journey with one dead engine. There are sea conditions that can make that a very tough situation."

I mentioned this because it happened to me. My engine failure occurred in June. I scheduled the repair for mid Sept, which allowed the yard to schedule parts and mechanic time well in advance and allowed me to continue my summer trips unimpeded by out of service time. Of course, sea conditions in the protected waters of the BC inside coast were not a factor.
koliver is offline   Reply With Quote
Old 10-10-2015, 11:24 AM   #46
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Quote:
Originally Posted by Bay Pelican View Post
The redundancy factor is not very important as most diesel shutdowns are fuel related and will shut down both engines.
In our experience and observation this is something of a myth. I do not know or know of anyone, power or sail, in our area who has had an engine shutdown due to fuel. We have had five engine shutdowns-- we shut the engine down-- in the 17 years we've had our boat. None of them had anything to do with fuel except one when I let an engine get a slug of air during a fuel transfer.

Our other precautionary shutdowns have all been cooling related. As were almost all of the other engine shutdowns I know about, power and sail. I also know of a precautionary shutdown due to an injection pipe pinholing and a couple due to transmission problems. And I know of some due to running gear damage from hitting or getting tangled up in debris. But shutdowns due to bad fuel or other fuel-related problems (other than running an engine out of it)-- not one.

Now maybe in areas where fuel quality is an iffy proposition fuel-related shutdowns are a more common problem. But in this region where fuel seems to be good just about everywhere I have never even heard discussions about fuel issues on the dock or in our club. It's certainly not anything we give any thought to.

Now if a boat has filthy fuel tanks with years of accumulated crud in the tanks then fuel starvation due to filter clogging could certainly be a potential problem. But even that is unlikely to shut down both engines of a twin unless the boat has a poorly designed fuel system.

So in our experience and observation the likelihood of both engines in a twin being shut down because of a fuel problem, or any other problem frankly, are slim to none.
Marin is offline   Reply With Quote
Old 10-10-2015, 11:30 AM   #47
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,371
A few years ago I met a boater who had one of his transmissions (nope not fuel related) fail on his twin GB. This was in Wrangell and he was from Tacoma. So he carried on to Juneau, Glacier Bay and eventually back to Tacoma all on one engine.
sunchaser is offline   Reply With Quote
Old 10-10-2015, 11:52 AM   #48
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Quote:
Originally Posted by Ski in NC View Post

And I seriously doubt someone is going to continue a journey with one dead engine. There are sea conditions that can make that a very tough situation.
Not true at all. I know several people, including ourselves, who have continued a trip on one engine after a precautionary engine shutdown. Some of these trips have been pretty long-- several hundred miles back down the Inside Passage in some cases, sometimes in snotty weather.

As to the notion that having two engines doubles the risk of an engine shutdown, while statistically that's true I think reality makes that pretty much an armchair theory. The picture it paints of the owners of twin engine boats suffering engine shutdowns on a regular basis is rubbish in my opinion. Most of the owners of twins that we know have never experienced an engine shutdown (yet). We have, although none of them were related to an engine itself. And the things that caused us to shut one of our engines down would have caused us to shut our one engine down had the boat been a single.

But the one "statistic" that is as true in reality as it is in theory is that if you have to shut an engine down in a twin you can continue on the other engine, where if you have to shut the engine down for exactly the same reason in a single you will continue on the end of a rope. Unless, of course, you have the parts, tools, and skills to repair the problem and get the engine going again.

And in this area, anyway, while you are mucking about trying to get that one engine going again the currents will be having a grand time carting your boat to wherever they feel like carting it including the rocks of which there are quite a few up here.
Marin is offline   Reply With Quote
Old 10-10-2015, 12:14 PM   #49
Guru
 
City: gulf coast
Country: pinellas
Join Date: Jun 2014
Posts: 2,199
In 15 years with the same boat had one oil pressure sensor fail, one water hose started to leak and spray around in both cases I just shut down the one engine and continued on to my destination. I could have anchored and dealt with it as well. There were well maintained engines but stuff does happen and because I had twins it was a non stress situation.


Most twins I have seen have two tanks that can be used independently. My ZF trans didn't care about lazy engine operation. The maker told me to check the temps and switch side every two hours. He also reminded me that boats get towed and props spin at docks in current without problems just don't try to go too fast.


Prop protection is a nice feature of singles but it would not have benefitted me over those years.


The dockside maneuverability cant be beat.
bayview is offline   Reply With Quote
Old 10-10-2015, 12:40 PM   #50
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,371
The furthest I have gone on one engine is about 180 miles. Had to beat weather and currents so after shutting down that side it took about 4 days to figure out the problem and solution. It was an after cooler failure so quite simply bypassed it - thanks to NAPA Ketchikan for necessary hoses and fittings - started up and carried on for another 500+ miles.

The rudder offset was about 6 degrees and speed dropped to around 6.5 knots from a normal 8.2. Engine temperatures increased by 10 degrees to around 183F due to now being over propped on that one side. EGTs crept up from a normal 500 to about 650 F. Trailing prop shaft and transmission temperatures steadied out at 120F, only slightly higher than if engine were running.

All in all it was a great learning experience. I had the Engineer from a large yacht help me trouble shoot and he was as initially as befuddled as I was regarding problem/solution. Ultimately the issue was traced to leaks in the after cooler soldering joints due to using a non compatible barnacle removing product. This product was used by a very experienced yard and lead mechanic who has since left the firm.
sunchaser is offline   Reply With Quote
Old 10-10-2015, 12:46 PM   #51
Guru
 
Codger2's Avatar
 
City: San Diego
Country: US
Vessel Name: "Sandpiper"
Vessel Model: 2006 42' Ocean Alexander Sedan
Join Date: Oct 2007
Posts: 5,421
Quote:
Originally Posted by Phyrcooler View Post
Walt - curious if your singles had thrusters?
Both my singles had bow thrusters. (I wouldn't have it any other way!) One was a Mainship Pilot 30 & the other was a Halvorsen Gourmet cruiser 32. My biggest reason for wanting twins is for more speed. Redundancy had nothing to do with my decision.

Years ago when I was earning my multi engine rating, my instructor (an old Navy pilot) told me that wanting a multi engine airplane because it's safer is BS. They require more maintenance, cost more, more skill and knowledge is required and in planes of that day (1967) when you lose and engine, you get to pick your crash site. (I know this was exaggerating but it did hit home.)

Nope, If I could have bought a single engine boat with speed in the high teens & everything I now have in my OA, I would have done it! Singles with bow thrusters and a Tow Boat US membership are great! (Most of them are too slow, however.)
1) Mainship Pilot 30
2) Halvorsen 32 Gourmet cruiser
3) Ocean Alexander 42 Altus
Attached Thumbnails
Click image for larger version

Name:	IMG_2462.jpg
Views:	47
Size:	121.5 KB
ID:	45364   Click image for larger version

Name:	IMG_2106.jpg
Views:	46
Size:	66.1 KB
ID:	45365   Click image for larger version

Name:	OA 42 Sedan.jpg
Views:	46
Size:	149.8 KB
ID:	45366  
__________________
Codger2

My passion for improving my boat(s) exceeds my desire to constantly cruise them.
Codger2 is offline   Reply With Quote
Old 10-10-2015, 01:16 PM   #52
Senior Member
 
Panope's Avatar
 
City: Port Townsend WA
Country: USA
Vessel Name: Panope
Vessel Model: Colvin Saugeen Witch, Aluminum
Join Date: Aug 2014
Posts: 286
I think it is very important for all boats to have more than one means of propulsion. Twin engines satisfies this best. An inflatable dingy with a larger outboard lashed to the hip might do. An outboard motor on a swimstep motor bracket might work for some boats. Small motor boats can use oars. Row boats that loose an oar can be paddled with the remaining oar. A kayak can be moved using hands as paddles.

Sails are a nice choice. Not very useful with no wind. However, emergency situations with no wind tend to be not so much of an emergency.

Steve
__________________
If I visualize my boat without a mast, I see a trawler.
Panope is offline   Reply With Quote
Old 10-10-2015, 01:28 PM   #53
GFC
Guru
 
GFC's Avatar
 
City: Tri Cities, WA
Country: USA
Vessel Name: Beachcomber
Vessel Model: Sea Ray 550 Sedan Bridge
Join Date: Nov 2012
Posts: 2,696
We've had two situations where one engine had to be shut down and we had to go home on one engine. Coincidentally, both happened while we were in or entering the lock at Ice Harbor Dam, and both happened to the stbd engine.


On the first, an o-ring in our hydraulic steering failed and left that engine stuck in reverse. I shut down the engine and we were able to get into the lock and secured on one engine. We then had to get home on that single engine.


On the second, we were tied up in the lock and had a runaway starter motor on the stbd engine. I shut off the batteries for that engine and we came home on one engine.


In both of those situations we'd have been totally screwed if we had only one engine because there's no Sea Tow around here and the USCG won't tow except to prevent loss of life or environmental damage.


I did notice something interesting on the trip home after this last incident. Normally, to cruise around 10-10.5 kts on two engines the tachs are around 1050-1100 (depending on load). When running on just the port engine, to maintain that speed I only had to up the engine rpm to 1250. It required some hard rudder to port to maintain a straight ahead course, but only 150 rpm's more power.


I've owned boats with singles and twins. Never again will I buy a boat above 25' with a single engine.
__________________
Mike and Tina
Beachcomber 1995 Sea Ray 550 Sedan Bridge
GFC is offline   Reply With Quote
Old 10-10-2015, 03:20 PM   #54
Guru
 
dhays's Avatar
 
City: Gig Harbor
Country: United States
Vessel Name: Kinship
Vessel Model: North Pacific 43
Join Date: May 2015
Posts: 5,088
Quote:
Originally Posted by Panope View Post
Sails are a nice choice. Not very useful with no wind. However, emergency situations with no wind tend to be not so much of an emergency.
Steve, I see that exactly the opposite. An engine failure with no wind IS an emergency for me. :-)

In our joint waters, currents will mess you up in a hurry is you lose power in the wrong spot at the wrong time. Because of that, I don't view my sails as a backup to my engine. In a narrow channel or coming into a dock if I lose my engine my sails will not help me, wind or no.

Even so, as I look to moving to a trawler, I see twins as more of a negative than a positive. Like most of us, my opinions are based on my own experience. As a kid, sailing my parents 21-29 foot sailboats with outboard gas engines, suffering an engine failure was all too common. However I have only had one time when I needed to shut down a Diesel engine on a sailboat and that was an overheating issue and I shut the engine down preventively but could have kept it running for a while if we had been in immediate peril. Maybe my small Yanmar is more reliable than the larger engines found in a trawler?

Having said that, the ideal setup is in the GH37 that has two of the 56hp Yanmars that I have in my sailboat. Economical, reliable, easy to maintain, maneuverable and redundancy.
__________________
Regards,

Dave
SPOT page
dhays is offline   Reply With Quote
Old 10-10-2015, 04:44 PM   #55
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 4,817
Quote:
Originally Posted by sunchaser View Post
Speaking of phobias, I heard about a guy who was so OC about the singles vs twins discussion on TF that he removed two perfectly good engines and put in one
Who was that? I had one and replaced it with one.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is offline   Reply With Quote
Old 10-10-2015, 05:08 PM   #56
Senior Member
 
Blissboat's Avatar
 
City: Jacksonville Beach, FL
Country: USA
Vessel Name: Shallow Minded
Vessel Model: Shoal Cat
Join Date: May 2015
Posts: 411
AusCan wrote:

Advantages (in order of importance)

Twins
- Better manoeuvrability
- Redundancy

Single Engine
- Protected prop & rudder
- Better accessibility
- Lower costs


AusCan summed it up neatly. I've operated and maintained twins and singles of various types. To me, a single is preferable for exactly the reasons he lists. As for a bow thruster, in my younger days I used to sniff indignantly at the idea, but lately not so much.
Blissboat is offline   Reply With Quote
Old 10-10-2015, 05:20 PM   #57
Guru
 
O C Diver's Avatar
 
City: Fort Myers, FL... Summers in Crisfield, MD
Country: USA
Vessel Name: Slow Hand
Vessel Model: Cherubini Independence 45
Join Date: Dec 2010
Posts: 4,817
Quote:
Originally Posted by mahal View Post
I believe that a neglectful owner will be neglectful and a meticulous one will be meticulous single screw or twin, so I don't really buy into the "twins are less maintained" argument.
You missed the obvious point. A person who recognizes they are not maintenance focused, may pick twins for redundancy. This has nothing to do with whether a twin engine owner is meticulous. It is a very common occurrence to see boaters with twins who know they have a problem continue to use the boat weekend after weekend because they know they have a second drive train to come home on. The guy next to me had a velvet drive going bad and kept doing canyon fishing trips until it quit. He was hoping to get the last of the season in before pulling the gear. Never let PM get in the way of going fishing.

Ted
__________________
Blog: mvslowhand.com
I'm tired of fast moves, I've got a slow groove, on my mind.....
I want to spend some time, Not come and go in a heated rush.....
"Slow Hand" by The Pointer Sisters
O C Diver is offline   Reply With Quote
Old 10-10-2015, 05:37 PM   #58
Wannabe
 
Britannia's Avatar
 
City: SF Bay Area
Country: USA
Vessel Name: Stillwater
Vessel Model: Kadey-Krogen 54
Join Date: Dec 2014
Posts: 766
Here are my thoughts

As others have said - people will tend to recommend what they have. That's not just because they don't want to admit they're wrong, but also because they may well have put quite a bit of thought into it before they made their purchase.

I think former sailors are more inclined to buy a single engine boat. I'm in that category. Contrary to popular belief a sail isn't much of a backup means of power if you are close to danger. It's more useful on a longer passage.

While twin engines may be easier to maneuver, you shouldn't shy away from a single. My bowthruster is intermittent right now so I'm getting good practice maneuvering my 80,000lb boat without them. Lots of people do this all the time.

If you're going to be continually apprehensive about having a single then get twins. Feeling a sense of confidence (not complacency) is a good thing - if twin engines are what it takes then you should get them.

I bought my boat because I really wanted it! I would have still wanted it had it had twin engines. I am considering adding a hydraulic get home motor driven from my 20kW generator one day. I will probably add one before an ocean crossing, if I ever do one.

I hope the OP is enjoying all the comments!

Richard
Britannia is offline   Reply With Quote
Old 10-10-2015, 06:01 PM   #59
Senior Member
 
mahal's Avatar
 
Join Date: May 2010
Posts: 436
Quote:
Originally Posted by O C Diver View Post
You missed the obvious point. A person who recognizes they are not maintenance focused, may pick twins for redundancy. This has nothing to do with whether a twin engine owner is meticulous. It is a very common occurrence to see boaters with twins who know they have a problem continue to use the boat weekend after weekend because they know they have a second drive train to come home on. The guy next to me had a velvet drive going bad and kept doing canyon fishing trips until it quit. He was hoping to get the last of the season in before pulling the gear. Never let PM get in the way of going fishing.

Ted
"You missed the obvious point." I doubt it. I was responding to an earlier poster that said single screws get first rate maintenance, implying that twins don't. "A person who recognizes they are not maintenance focused, may pick twins for redundancy." What a ridiculous thing to say. Have you really met or heard of someone that picked a twin screw because they're not maintenance focused?
Regarding your neighbor, what he did is not exclusive to twin operators. Just talk to tow boat captains and you'll be amazed at what single screw owners are up to. They are almost 100% of their clientele.
mahal is offline   Reply With Quote
Old 10-10-2015, 06:21 PM   #60
Guru
 
Ski in NC's Avatar
 
City: Wilmington, NC
Country: USA
Vessel Name: Louisa
Vessel Model: Custom Built 38
Join Date: Jan 2014
Posts: 3,888
Quote:
Originally Posted by mahal View Post
"You missed the obvious point." I doubt it. I was responding to an earlier poster that said single screws get first rate maintenance, implying that twins don't. "A person who recognizes they are not maintenance focused, may pick twins for redundancy." What a ridiculous thing to say. Have you really met or heard of someone that picked a twin screw because they're not maintenance focused?
Regarding your neighbor, what he did is not exclusive to twin operators. Just talk to tow boat captains and you'll be amazed at what single screw owners are up to. They are almost 100% of their clientele.
You did miss the obvious point. I was the one that stated my single gets first rate maintenance. And the reason for that is I know I count on that engine exclusively. If I had twins I would not be so anal. That is the point.
__________________

Ski in NC is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off





All times are GMT -5. The time now is 06:48 PM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012