Reply
 
Thread Tools Display Modes
 
Old 01-02-2013, 08:43 AM   #101
Senior Member
 
funangler's Avatar
 
City: Erie PA
Country: USA
Vessel Name: Endless Endeavor
Vessel Model: Custom
Join Date: Dec 2012
Posts: 214
Twin headaches

You will have more days away from the dock with a single then twins. With twins you have twice trouble of keeping them running. Most failure are on start ups not so much running down the bay. I have owned both and I love only maintaining one main engine.
__________________
Advertisement

funangler is offline   Reply With Quote
Old 01-02-2013, 10:53 AM   #102
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 OkSkipper View Post

A properly maintained single engine boat is reliable, more efficient, and less prone to damage by striking something. Most problems encountered are fuel related or are caused by overheating due to a failed pump (impeller usually) or a clogged strainer. Anyone not able to deal with these issues should not be out boating in remote areas where they can't radio for assistance.
Although I can certainly buy in to the advantages of twins on a cruising boat, I still remember what my instructor told me when I was pursuing my multi-engine rating. I always thought I'd be much safer in a twin engine plane than flying a single. He pointed out that you have twice the problems, twice the maintenance, more fuel consumption and longer landing strips in a multi engine plane than you do with a single. Having owned both types, I really enjoyed the simplicity of the single engine plane. (Not to mention the increased PM that I employed to assure that the engine was in the best condition.)

You can paint a pretty good scenario for either the twin or single engine boat. The fact of the matter is, that with an engine failure, you can still limp home in a twin.
__________________

Codger2 is offline   Reply With Quote
Old 01-02-2013, 11:13 AM   #103
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,913
Quote:
Originally Posted by SeaHorse II View Post
Although I can certainly buy in to the advantages of twins on a cruising boat, I still remember what my instructor told me when I was pursuing my multi-engine rating. I always thought I'd be much safer in a twin engine plane than flying a single. He pointed out that you have twice the problems, twice the maintenance, more fuel consumption and longer landing strips in a multi engine plane than you do with a single. Having owned both types, I really enjoyed the simplicity of the single engine plane. (Not to mention the increased PM that I employed to assure that the engine was in the best condition.)

You can paint a pretty good scenario for either the twin or single engine boat. The fact of the matter is, that with an engine failure, you can still limp home in a twin.
Can't speak for anyone else but many are agreeing with me...engine FAILURES are rare on either twins or singles...

Component failures for the handy are rarely even reason to anchor...most things I can change out in minutes or live without until I can moor safely...usually at the place I wanted to spend the night anyway.

Most of us agree that engines are so reliable no with decent maintenance..why are so many worried to begin with???

Single OR twin...
psneeld is offline   Reply With Quote
Old 01-02-2013, 11:17 AM   #104
Scraping Paint
 
City: Fort Lauderdale
Vessel Model: CHB 48 Zodiac YL 4.2
Join Date: Oct 2007
Posts: 3,804
Quote:
Originally Posted by psneeld View Post
..why are so many worried to begin with???

What's the point in owning a boat unless you can find something to worry about?

If we removed every thread that could be defined as based on worry about something, the site would be empty.
RickB is offline   Reply With Quote
Old 01-02-2013, 11:18 AM   #105
Senior Member
 
mahal's Avatar
 
Join Date: May 2010
Posts: 436
"A properly maintained single engine boat is reliable"

Can't argue with that one but wouldn't two of those properly maintained single engines be twice as reliable? There had to be a good reason why Nordhavn required their NAR participants to have a secondary means of propulsion.

My twin engine boat is very reliable but not as reliable as one with three engines.
mahal is offline   Reply With Quote
Old 01-02-2013, 11:30 AM   #106
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,913
Quote:
Originally Posted by mahal View Post
"A properly maintained single engine boat is reliable"

Can't argue with that one but wouldn't two of those properly maintained single engines be twice as reliable? There had to be a good reason why Nordhavn required their NAR participants to have a secondary means of propulsion.

My twin engine boat is very reliable but not as reliable as one with three engines.
Can't argue with that logic....unless you really understand logic and then the thought process goes like this...

If something is already nearing 100 percent reliable...then doubling that reliability gets you no return on your investment so to speak. The concept of hull speed is the same...when you need to double the hp just to get a fractional increase in speed...that's where you are.

If I'm not mistaken..didn't the Lunar Module only have one engine? (well technically one descent/one ascent ...but only one at a time was useable)
psneeld is offline   Reply With Quote
Old 01-02-2013, 11:46 AM   #107
Senior Member
 
mahal's Avatar
 
Join Date: May 2010
Posts: 436
Quote:
Originally Posted by psneeld View Post
Can't argue with that logic....unless you really understand logic and then the thought process goes like this...

If something is already nearing 100 percent reliable...then doubling that reliability gets you no return on your investment so to speak. The concept of hull speed is the same...when you need to double the hp just to get a fractional increase in speed...that's where you are.

If I'm not mistaken..didn't the Lunar Module only have one engine? (well technically one descent/one ascent ...but only one at a time was useable)
Twin engines are 100% more reliable than singles. 3 engines are 200% more reliable than 1 engine but only 50% more reliable than twins.

To me, I get my return on investment, so to speak.
mahal is offline   Reply With Quote
Old 01-02-2013, 12:48 PM   #108
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Quote:
Originally Posted by Andy G View Post
So if you had to chose between speed or twins which would it be. Could you sell your soul for a single capable of say 30 knots?
Not only no but hell no. We will never own a single engine boat. The only way to go is a twin engine boat that goes fast. Or preferably a triple engine boat.
Attached Images
 
Marin is offline   Reply With Quote
Old 01-02-2013, 01:03 PM   #109
Guru
 
City: Carefree, Arizona
Country: usa
Vessel Name: sunchaser V
Vessel Model: DeFever 48
Join Date: Apr 2008
Posts: 6,371
Peter Whiting said:

"When we designed our trawler line, most were designed as single engine with the ability to build them as twins if the client desired. We made this decision because of our personal experience as well as that of our designer and production manager. Steve Seaton (designer) prefers singles. Most true long range trawlers are singles. To my knowledge, Nordhavn has had little if any engine failures."

Good points Peter. On Nordhavns the wing engine is an option. On a price sheet in front of me it is about $45K. Virtually all (maybe 100% even) of Nordhavns built during the past 15 years or so have a wing engine. Certainly resale is a motivator here too. Many have the wing engine installed with a redundant hydraulic pump for thrusters, stabilizers and windlass. Like a seat belt in a car or airplane, the wing engine is there for a hopefully infrequent happening.

But singles do indeed go down. In the past year alone I know of three instances where high end trawlers were towed in due to a grounding, debris in fuel line and failure of shaft coupling.

In Petersburg and Juneau this past summer I talked to several commercial fishing boats who were stuck at the dock for a few days as they sorted out main hydraulic pump issues - the hang ons again. All in a days work they said. The commercial guys are a lot savvier on in the field engine repairs than most of us toy boaters with keeping their singles running - it can be a do or die situation.
sunchaser is offline   Reply With Quote
Old 01-02-2013, 01:34 PM   #110
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,913
Quote:
Originally Posted by mahal View Post
Twin engines are 100% more reliable than singles. 3 engines are 200% more reliable than 1 engine but only 50% more reliable than twins.

To me, I get my return on investment, so to speak.
Maybe your talking engines...I'm talking vessel...if a vessels single engine is 100 percent reliable...adding another engine gets you nothing...

I know that's hard to understand...but give it a try...
psneeld is offline   Reply With Quote
Old 01-02-2013, 01:57 PM   #111
Curmudgeon
 
BaltimoreLurker's Avatar
 
City: Stoney Creek, MD
Country: USA
Vessel Name: Moon Dance
Vessel Model: 1974 34' Marine Trader Sedan
Join Date: Oct 2007
Posts: 2,629
Are there no Reliability Engineers on the forum that can reduce this argument to actual statistics? Or even the proper methodology for determining the MTBF difference for single vs. redundant systems?

Then we can then argue about!
BaltimoreLurker is offline   Reply With Quote
Old 01-02-2013, 02:00 PM   #112
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
Quote:
Originally Posted by psneeld View Post
Maybe your talking engines...I'm talking vessel...if a vessels single engine is 100 percent reliable...adding another engine gets you nothing...
True, but that's assuming a vessel's engine is 100% reliable 100% of the time. Based on the experience I and probably most of us have had with engines over the years--- inboard and outboard boats, airplanes, vehicles, bulldozers, you name it--- that's not an assumption I'm prepared to make.

While I have never experienced an in-flight failure or shut down with the engines in the single-engine planes I've flown, that's not the same thing as saying these engines were 100% reliable. Most if not all of them exhibited problems at one time or another, including a couple of times when I was operating them.

Most of the time the problems I learned or heard about, or in a couple of instances experienced, did not develop to the point of causing an actual failure or shut down. But most of them were sufficient to cause the plane to be taken out of service so the problem could be found and fixed, or in some cases so the engine could be overhauled.

So given that engines tend not to be 100% reliable 100% of the time, I think Mahal's statement stands.
Marin is offline   Reply With Quote
Old 01-02-2013, 02:45 PM   #113
Senior Member
 
mahal's Avatar
 
Join Date: May 2010
Posts: 436
Quote:
Originally Posted by psneeld View Post
Maybe your talking engines...I'm talking vessel...if a vessels single engine is 100 percent reliable...adding another engine gets you nothing...

I know that's hard to understand...but give it a try...
I understand just fine and yes you are correct that if a vessel's single engine is 100% reliable adding another will get you nothing. But until someone invents a 100% reliable engine which will probably never happen (too much of a fantasy), I will only consider boats with twins or a single with a wing engine.
mahal is offline   Reply With Quote
Old 01-02-2013, 04:03 PM   #114
Guru
 
City: Pensacola
Country: USA
Join Date: May 2012
Posts: 748
Horse is beyond dead.
Blue Heron is offline   Reply With Quote
Old 01-02-2013, 04:47 PM   #115
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,913
Quote:
Originally Posted by Blue Heron View Post
Horse is beyond dead.
I guess....while NO vessel is a 100 percent reliable...I guess 99.9 percent isn't good enough for some. They want a second engine for that 0.1 percent of the time an engine stops working and isn't quickly repairable or can be ignored...because that's MY experience with Marine and aircraft engines in 2 separate marine and aviation careers and a lifetime of boating...

I still go back to one of my first posts...who cares single/twin except like Marin said...he just likes messin' with 2...just like the saying that states "people just like messin' around in boats period!"
psneeld is offline   Reply With Quote
Old 01-02-2013, 05:05 PM   #116
Guru
 
Sailor of Fortune's Avatar
 
City: Saint Augustine, Fl.
Country: Port of St Augustine ,FL
Join Date: Sep 2009
Posts: 1,963
Last October I delivered a Bertram 36 SF with very low houred Cummins power and smartcraft electronic controls. The trip was from Southport N.C to Vero Beach. 1 day steaming outside in good wx and 2 days in the ICW. Day 2 both engines dropped from high cruising speed to idle and both came out of gear (loss of propulsion). After several minutes of inspection, both went back into gear and we were on our way. This situation repeated itself several times, with the last time being in Jacksonville where the ICW crosses the St Johns river.
The culprit turned out to be the mother board for the electronic controls. No way to put engines in gear and idle home due to electronic controlled valves on the ZF gear box.
A week lost while board was sent out.
The new owner, an experienced attorney but new to boating was less than happy with his new (2008) boat. For me it was an inconvenience since I live in Jacksonville.
I will take simple cable controls that can be put in gear to at least get to a dock. The single vs twin would put both camps SOL on this one.
Sailor of Fortune is offline   Reply With Quote
Old 01-02-2013, 05:28 PM   #117
Guru
 
SomeSailor's Avatar
 
City: Everett, WA
Vessel Name: Honey Badger
Vessel Model: 42' CHB Europa
Join Date: Oct 2011
Posts: 784
[QUOTE=Marin;123499While I have never experienced an in-flight failure or shut down with the engines in the single-engine planes I've flown...[/QUOTE]

I flew for a living in the Navy and have had MANY routine shut-downs (and loiters) and several emergency shut downs as well. The inability to shut down those engines would have put us at much greater risk (over-speed, compressor failure, rotor burst, catastrophic failure). I never had to ride one into the water for that very reason.

This is the primary reason the US Navy has migrated to multi-engine aircraft over the years. The stakes aren't as high in boats, but I'd still rather limp home on one if something was hinky.
SomeSailor is offline   Reply With Quote
Old 01-02-2013, 05:35 PM   #118
Guru
 
psneeld's Avatar
 
City: Avalon, NJ
Country: USA
Vessel Name: Freedom
Vessel Model: Albin 40
Join Date: Oct 2011
Posts: 15,913
Quote:
Originally Posted by SomeSailor View Post
I flew for a living in the Navy and have had MANY routine shut-downs (and loiters) and several emergency shut downs as well. The inability to shut down those engines would have put us at much greater risk (over-speed, compressor failure, rotor burst, catastrophic failure). I never had to ride one into the water for that very reason.

This is the primary reason the US Navy has migrated to multi-engine aircraft over the years. The stakes aren't as high in boats, but I'd still rather limp home on one if something was hinky.
I flew for a living too in USCG helos...in single engines for 10 years and twins for 10 years....NEVER had an engine burp worth worrying about.

My son flys in Navy H60s and I'm scared for him....it's not the aircraft...it's how it's flown and maintained.

I've only had one significant issue in 50 years of boating and 12 years of commercial marine operations..in vessels used so much harder than recreational craft can imagine....

So keep right on thinking twins are necessary...the economy needs stimulation...
psneeld is offline   Reply With Quote
Old 01-02-2013, 05:47 PM   #119
Senior Member
 
mahal's Avatar
 
Join Date: May 2010
Posts: 436
A hypothetical question to all: If you were employed as a captain by a Brokerage in Florida that needed to move one of their two new Krogen 58's to Costa Rica and the boss gave you the choice of either taking the one with twins or the single screw, which one would you pick?
mahal is offline   Reply With Quote
Old 01-02-2013, 05:50 PM   #120
Guru
 
City: Pensacola
Country: USA
Join Date: May 2012
Posts: 748
I flew in US Navy helo's for 12 years in SH2F and SH3H and SH60B. I had a number 1 compressor failure that exploded and caused a fire in the engine. Resulted in loss of generator and AC bus. If we didn't have 2 engines I would have gotten wet. Very wet and away from home plate by 50 miles.
__________________

Blue Heron 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 10:27 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