Twin vs single

[psneeld]

Easy peezy with spring lines.

My argument would be it might be dangerous in 30 knots of crosswind with only a thruster and someone used to it.

Heck many report their thrusters are marginal in that much wind anyhow..

The best course of action for most recreational boaters in 30knots of wind is find an alternative if they are in tight quarters.

 

[jleonard]

Easy peezy with spring lines.

Well only IF someone on the dock actually knows what a spring line is and how to make it fast to a cleat or piling. None of the boaters in my marina have a clue how to do this. They all insist on holding the line and trying to yank the boat in.

I haven't even been to a fuel dock where they know spring lines.

 

[psneeld]

Well only IF someone on the dock actually knows what a spring line is and how to make it fast to a cleat or piling. None of the boaters in my marina have a clue how to do this. They all insist on holding the line and trying to yank the boat in.

I haven't even been to a fuel dock where they know spring lines.

You are right Jay....In fact the dock attendant at one marina got all pissed off at me and asked me to hurry up and leave because she undid my spring first and I asked sternly what she was doing...it was obvious...then when I told her what to do, she insisted I didn't know how to undock a boat.



So most of the time, I just do it myself...the biggie is are there cleats in good enough positions to use springs....

 

[Mark Laurnen]

There is, obviously, no clear answer to this age old question. Almost anyone, my self included, who had twins can recall a time when they limped home on one. That’s enough to sway my opinion. With a single down, you are relying upon others and must be comfortable with relinquishing self-sufficiency.

 

[psneeld]

Plenty of times I have towed twins home too.


If you are handy, keeping a single on the go can be better than twins if you aren't a frequent flyer of your engine room.


All things equal, sure twins can give flexibility at times.

 

[Mark Laurnen]

I think you just summed it up ... know your engine(s), stay on top of things, carry plenty of spares. However, you said that you have towed in plenty of twins too ... YOU were available to help. That sounds like fuel failure. My rare yanmar problems have never been fuel, have never been predictable, have never occurred bilaterally. Boaters, like you, tend to be generous altruistic souls ... if you boat where there are likely to be others nearby, then all is good. If you venture out, SE Alaska or Haida Gwaii, people are the same , just few and far between. Maybe one’s typical boating local is what we should really be talking about. Similarly, is a life raft really necessary in warm busy water? Would it be more necessary in cold remote water? Different topic, but analogous logic.

 

[psneeld]

In fact few were fuel related and I was an assistance tower.


And yes...it depends on where you boat to determine different needs than others...


Ah yes.... like most topics on TF....it depends...

 

[Mako]

I visited the Annapolis Boat show yesterday. The Krogen 53 had twins and even in such a big boat it was tight in there moving around. The Nordy 63 had a single, but the huge fuel tanks made it even tighter inside.

So there are a lot of factors (and a lot of other equipment) that come into play when it comes to access in the engine room.

For the record, I'm 100% a singles-guy.

 

[Simi 60]

. Never consider a single lacking a thruster!! I know the old salts of the world will see this as a reduced hormone level on my part but try a 30mph cross wind with a margin of error of less than 2 ft some time with the single no BT!

Never had a problem but prudent seamanship dictates we don't go stuffing ourselves into tight spots unless conditions are ideal for doing so.
60ft, single screw and no thruster.

 

[rslifkin]

I visited the Annapolis Boat show yesterday. The Krogen 53 had twins and even in such a big boat it was tight in there moving around. The Nordy 63 had a single, but the huge fuel tanks made it even tighter inside.

So there are a lot of factors (and a lot of other equipment) that come into play when it comes to access in the engine room.

For the record, I'm 100% a singles-guy.

I feel like outboard access for twins is very much dependent on what other stuff the builder wants to squeeze into the engine room. In my case, the outboard side of my twins isn't the best place to work, but there's plenty of room to crawl over there, sit down and work on something (several feet from engine to hull). The generator is the one with a couple of really tight spots, but it's easy enough to pull the floor above it and just stand in the hole for better access.

Now keep in mind, I don't have saddle tanks, hydraulics or as much other equipment in the engine room as some boats on here. So that helps a lot.

For those mentioning inline engines being better for access, that's not always the case. If you look at an inline compared to a similar displacement or power output V block, the inline is usually not all that much narrower once all of the manifolds, etc. are installed. Particularly if it's a crossflow head inline where the intake and exhaust manifolds are on opposite sides.

 

[Group9]

I owned a GB 36 with a single engine, no BT for 6 years and have owned a MS 34 trawler with twins for 3 yr. Although this may never happen, when faced with a choice between twins or single with a BT I would go with the boat in the best condition with price always a consideration. The reason I went with the twins was the boats availability at the time and its condition. Never consider a single lacking a thruster!! I know the old salts of the world will see this as a reduced hormone level on my part but try a 30mph cross wind with a margin of error of less than 2 ft some time with the single no BT!

It's just practice. We took two long cruises on our single screw inboard 42 Catalina sailboat (no thruster). The first month, on both cruises, I looked like the biggest noob in the world, trying to back that thing into tight slips, and fuel docks, with no wind or current at all. By the end of the cruise, I was doing it in 30 knots of wind, while I was eating a sandwich, and talking on the phone!

In fact, when we first got back, I helped a friend deliver a new inboard sailboat he had just bought. After watching him try and back into a slip with high winds about three times, I gently suggested he let me try, and I greased it in without even being familiar with that boat.

But, both times, after we were back at home and we started just going out occasionally again, my skills quickly degraded! We sold that boat three years ago, and have twin inboards again. I'm sure I couldn't do it at all today, to save my life!

 

[FF]

OK the boat was 65+ ft or so, but the nicest engine room (for a 6-71) was in front in the bow.

The engine was easy to access from both sides and there was a mechanical PTO from the engine front to the windlass.180HP does a great job with the anchor at idle.

The shaft was truck style drive shafts, quiet and cheap, a CPP was the only expensive addition to gain its thrust bearing and ability to adjust engine loads.

The usual engine room space was used for storage , fuel & water tanks etc.

As most boats ventilate from aft to fwd there was no aroma or heat added to the living areas.

With more modern diesels at 1/4 the weight , I have always wondered why this is not common.

 

[slowgoesit]

What's better, twin or single? The best choice is what you have! Learn how to use it, learn how to maintain it properly, and get out there and have fun!

 

[jimdavi]

Well said, i’ve Had both...

 

[Simi 60]

OK the boat was 65+ ft or so, but the nicest engine room (for a 6-71) was in front in the bow.

The engine was easy to access from both sides and there was a mechanical PTO from the engine front to the windlass.180HP does a great job with the anchor at idle.

The shaft was truck style drive shafts, quiet and cheap, a CPP was the only expensive addition to gain its thrust bearing and ability to adjust engine loads.

The usual engine room space was used for storage , fuel & water tanks etc.

As most boats ventilate from aft to fwd there was no aroma or heat added to the living areas.

With more modern diesels at 1/4 the weight , I have always wondered why this is not common.

Apart from the DD and CPP you have described ours
Walk down into the V fwd cabin (walk in pantry/spares storage) and go aft through a door into the ER.

 

[Mako]

... there was a mechanical PTO from the engine front to the windlass.180HP does a great job with the anchor at idle.

When I was in India all the fishing boats were equipped this way. They used shafts to drive big horizontal capstans in the bow for pulling nets, as well as the anchor rode, which was rope of course.

Very cheap to build also - no expensive windlasses needed.

 

[diver dave]

An unstoppable exposed shaft running the breath of a workboat? What could possibly happen? Don't need no stinkin' OSHA there.

 

[Insequent]

An unstoppable exposed shaft running the breath of a workboat? What could possibly happen? Don't need no stinkin' OSHA there.

"exposed' is your assumption. It was most likely covered or shielded in some way. Yes, my assumption!

 

[w8n4sun]

Having just spent a crap load on impellers, various oil and fuel filters, oil, impeller puller, oil analysis kits for 2 mains, various sized pencil zincs....and still needing to purchase all the above for the 2 generators...I sure wish our boat had a single in it!

 

[Mako]

Having just spent a crap load on impellers, various oil and fuel filters, oil, impeller puller, oil analysis kits for 2 mains, various sized pencil zincs....and still needing to purchase all the above for the 2 generators...I sure wish our boat had a single in it!

[emoji1303] and with the reliability of today’s heavy duty gennies, perhaps even just one of those also

 

[FF]

.I sure wish our boat had a single in it!""


A single that has a dry stack and keel cooling would cut the parts count and maint items even more.

 

[catalinajack]

Well, yesterday's generators work well also, at least on our boat which came with two. One is a Perkins-powered Kohler 12.5kw with 2,534 hours on the clock. The other is a 7.7kw Westerbeke with 3,700+ hours. Both are used regularly and work. How long they will continue to do so, who knows?

[emoji1303] and with the reliability of today’s heavy duty gennies, perhaps even just one of those also

 

[rslifkin]

My old school gas Onan runs just fine too, just under 1400 hours on it. It can be a little bit fiddly at times (likes to have the carb adjustments played with periodically), but it's also about as complicated as a sledgehammer, so it would take a pretty significant failure to reach the point where I couldn't get it to run.

 

[Art]

Gasoline 1977 Kohler 7.5. Hours unknown. Reliability good. Fan belt here, governor spring there, impeller every so often... general maintenance stuff. Keeps great oil pressure and runs strong! Turns out plenty of juice.

Ignition set up can be on load applied auto start, if desired. Being as it is gasoline I do not leave it on that feature setting. I like to be hands on available at all times with this genny. I feel bilge blower needs to run for a while before each start of gen or of the twin engines. Haven't had a problem with unexpected fumes in 12 years... I'm always real friendly with all portions of engine compartment [especially all items that have to do with gasoline]... cause ya just never know!!

 

[rslifkin]

Gasoline 1977 Kohler 7.5. Hours unknown. Reliability good. Fan belt here, governor spring there, impeller every so often... general maintenance stuff. Keeps great oil pressure and runs strong! Turns out plenty of juice.

Ignition set up can be on load applied auto start, if desired. Being as it is gasoline I do not leave it on that feature setting. I like to be hands on available at all times with this genny. I feel bilge blower needs to run for a while before each start of gen or of the twin engines. Haven't had a problem with unexpected fumes in 12 years... I'm always real friendly with all portions of engine compartment [especially all items that have to do with gasoline]... cause ya just never know!!

Agreed on the no auto-start for gas generators. Bilge always gets an in-person sniff during the engine checks before first start of the day (and that's before the blowers are on so any minor fumes will be noticed). Same thing after fueling. And the fume detector gets turned on before startup and stays on while anything is running. I also keep the detector on any time we're away from the dock, even if anchored with everything shut down, that way if I have to start an engine quickly, I've got some confidence that I can pop the hatch, give a sniff, hit the blowers and crank it without anything going boom.

It's funny you mention impellers. I've never had one fail before the 7 year mark on this generator, although we did start changing them a bit sooner than that to avoid failures.

And that reminds me, I've gotta work on a modification to my bilge blower setup for this winter. I want to have some ventilation running in the engine room whenever the generator is running (for cooling and safety), but I hate running the full compliment of bilge blowers the whole time the generator is running, as the Jabsco flange mount blowers I've got are pretty loud (inside and outside). Currently, I tend to shut the blowers off once it's been running for a few minutes if there are other boats nearby, as the blowers are far louder than the generator itself from outside. But unlike the engines, the generator doesn't move a whole lot of air through on its own, so it's not ideal.

 

[Art]

Agreed on the no auto-start for gas generators. Bilge always gets an in-person sniff during the engine checks before first start of the day (and that's before the blowers are on so any minor fumes will be noticed). Same thing after fueling. And the fume detector gets turned on before startup and stays on while anything is running. I also keep the detector on any time we're away from the dock, even if anchored with everything shut down, that way if I have to start an engine quickly, I've got some confidence that I can pop the hatch, give a sniff, hit the blowers and crank it without anything going boom.

It's funny you mention impellers. I've never had one fail before the 7 year mark on this generator, although we did start changing them a bit sooner than that to avoid failures.

And that reminds me, I've gotta work on a modification to my bilge blower setup for this winter. I want to have some ventilation running in the engine room whenever the generator is running (for cooling and safety), but I hate running the full compliment of bilge blowers the whole time the generator is running, as the Jabsco flange mount blowers I've got are pretty loud (inside and outside). Currently, I tend to shut the blowers off once it's been running for a few minutes if there are other boats nearby, as the blowers are far louder than the generator itself from outside. But unlike the engines, the generator doesn't move a whole lot of air through on its own, so it's not ideal.

We went 8 years once before impeller change. Didn't really seem needed - but why not! Often have engine hatches open for sniff test and other items. Bilge blower time before any engine start is 10 min minimum and left on for another ten after start. Luckily our tolly has blower exhaust vent close to 1/2 high slider door just aback of galley sink. So... I can slide that open while blower is on and lean out to get first hand sniff test of ER air. I sniff at blower start time and just before shutting blower down.

 

[w8n4sun]

.I sure wish our boat had a single in it!""


A single that has a dry stack and keel cooling would cut the parts count and maint items even more.

That sounds like something a Nordhavn could provide - a dream boat for sure but out of league for our budget.

And 7yrs between impeller swap outs...I don't have the stomach for that.

 

[Sailor of Fortune]

Somebody needs to tell Richard on Dauntless that he is doing it all wrong!.... He needs to back track across the panama canal, Atlantic twice and get a twin screw boat so he will be safe and covered..

 

[johnma]

we have a single with a bow thruster and do mostly coastal cruising. On odd occasions I'll run offshore about 50-75 miles. Never had a problem but i do have unlimited towing. (never had to use it)
John

 

[Nomad Willy]

My old school gas Onan runs just fine too, just under 1400 hours on it. It can be a little bit fiddly at times (likes to have the carb adjustments played with periodically), but it's also about as complicated as a sledgehammer, so it would take a pretty significant failure to reach the point where I couldn't get it to run.

I have a gas Onan in my motor home.
It has priming problems.
Why do you call yours “old school”?