1971Lou
N/A
sorry steering not brakes
2 engines or 1 engine
- Thread starter 1971Lou
- Start date
Chas25
New member
Think I'd prefer the D6 over the D3's but glad its not me trying to make the decision for a demo boat!!
T43
New member
Scenario ! Car without spare tyre has puncture (stand by side of road & wait for R.A.C/AA = inconvenience).
Boat with engine failure coming out of bembridge harbour on an outgoing tide with a N.E wind (end up high & dry hopefully only on sand and wait for the following tide @ which time sea start may be able to reach you = most people on board panicking).
You can't compare road breakdown with sea, few situations on the road would be either live threatening or cause the loss of the vehicle.
The same can not be said of the sea.
Boat with engine failure coming out of bembridge harbour on an outgoing tide with a N.E wind (end up high & dry hopefully only on sand and wait for the following tide @ which time sea start may be able to reach you = most people on board panicking).
You can't compare road breakdown with sea, few situations on the road would be either live threatening or cause the loss of the vehicle.
The same can not be said of the sea.
Mattwalker
New member
If it costs roughly the same for one big engine as opposed to two smaller engines, what is the difference in fuel consumption between the two?
Ramage
Active member
If cost to purchase is the same I would go for the twin engine setup for reasons of redundancy & low speed handling.
I would be very unhappy to find a shared fuel system, which seems to defeat the object of having two engines.
I understand that some boats cannot be used on only one of the two engines as it is bad for the gearbox of the engine that is not running?
Otherwise, very handy for low speed running on inland waterways such as the Thames....
I would be very unhappy to find a shared fuel system, which seems to defeat the object of having two engines.
I understand that some boats cannot be used on only one of the two engines as it is bad for the gearbox of the engine that is not running?
Otherwise, very handy for low speed running on inland waterways such as the Thames....
Whitelighter
Active member
I can only speak for our boat, but the single uses 33litres and hour at 25knts vs about 39l/hr for the twin D3 190's
Mattwalker
New member
In that case i would go for twin engines i guess.
Whitelighter
Active member
I have to say that is the way I was leaning. Well actually, I fancied twin D4 300's cos the factory have a boat with them in and they make 46knts at 3200 rpm. With a bit of loosening and the remaing 300rpm it might even make the magic 50!!!
oceanfroggie
Well-known member
[ QUOTE ]
what about parking.
[/ QUOTE ]A proper boat handler can park with one or two engines just as well. But for folks who can't handle a boat, even a twin with stern and bow thrusters, there is now IPS /forums/images/graemlins/smile.gif
On safety - the bulk of the UK and Irish commercial fishing fleets are single engined vessels - and they are out all winter in all weather. With two engines there is twice as much to go wrong /forums/images/graemlins/wink.gif Well that was the claim made by a A330 pilot about a 747 /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif
For displacement cruising a single engine makes more sense, but larger planing boats generally need twin screws. Smaller planing boats (ie <32ft) there are some nice single engine options. Put rope cutters on single shaft drives and that deals with most of the rope, nets issues, anyway many displacement single engine shaft driven boats have a keel and skeg to protect the prop and rudder from rope, nets and the odd bottom rub.
I personally like two engines to avoid fuel contamination, filter problems, especially in heavy sea when tanks are getting a good stir and some gunge can get moved in the tanks. But for handling I found single or twin the same. Depends on your cruising area.
If an engine breaks down chuck out the anchor, or drogue while waiting for a tow, and one well maintained engine is better than two unreliable junk heaps
what about parking.
[/ QUOTE ]A proper boat handler can park with one or two engines just as well. But for folks who can't handle a boat, even a twin with stern and bow thrusters, there is now IPS /forums/images/graemlins/smile.gif
On safety - the bulk of the UK and Irish commercial fishing fleets are single engined vessels - and they are out all winter in all weather. With two engines there is twice as much to go wrong /forums/images/graemlins/wink.gif Well that was the claim made by a A330 pilot about a 747 /forums/images/graemlins/wink.gif /forums/images/graemlins/wink.gif
For displacement cruising a single engine makes more sense, but larger planing boats generally need twin screws. Smaller planing boats (ie <32ft) there are some nice single engine options. Put rope cutters on single shaft drives and that deals with most of the rope, nets issues, anyway many displacement single engine shaft driven boats have a keel and skeg to protect the prop and rudder from rope, nets and the odd bottom rub.
I personally like two engines to avoid fuel contamination, filter problems, especially in heavy sea when tanks are getting a good stir and some gunge can get moved in the tanks. But for handling I found single or twin the same. Depends on your cruising area.
If an engine breaks down chuck out the anchor, or drogue while waiting for a tow, and one well maintained engine is better than two unreliable junk heaps
AdeOlly
Active member
[ QUOTE ]
As for things round the props, the boats we are talking about are on stern drives, so rope or fishing line can be cut away from the relative safety of the swim platform or transom by raising the drive to its beach position (the props are virtually out of the water in this mode)
[/ QUOTE ]
Yes, but not much help when that old bit of fishing net gets you in the waiting area at Sovereign Harbour 10 yards from the sloping concrete block revetment which was a lee shore. This happened to me on my first run back there after purchase of my twin engined boat. If it'd happened on the S24 I'd have been in trouble. In any case, it couldn't have been been freed at sea; it was that multistrand nylon netting and was wrapped around the shafts between the duoprops. I had to take the outer prop off to free it. Okay, a freak occurance that'll probably never happen again, (I hope) but no doubt that two engines saved the day for me.
Fuel contamination aside, twins give that extra security, and as I cruise with the whole family the extra costs are something I reckon are worth paying.
It's only comparively recently that powerful singles in the shape of D6-350/370 have become available, and it's natural that folk are wary of being an early adopter only to find they can't sell the boat on.
As for things round the props, the boats we are talking about are on stern drives, so rope or fishing line can be cut away from the relative safety of the swim platform or transom by raising the drive to its beach position (the props are virtually out of the water in this mode)
[/ QUOTE ]
Yes, but not much help when that old bit of fishing net gets you in the waiting area at Sovereign Harbour 10 yards from the sloping concrete block revetment which was a lee shore. This happened to me on my first run back there after purchase of my twin engined boat. If it'd happened on the S24 I'd have been in trouble. In any case, it couldn't have been been freed at sea; it was that multistrand nylon netting and was wrapped around the shafts between the duoprops. I had to take the outer prop off to free it. Okay, a freak occurance that'll probably never happen again, (I hope) but no doubt that two engines saved the day for me.
Fuel contamination aside, twins give that extra security, and as I cruise with the whole family the extra costs are something I reckon are worth paying.
It's only comparively recently that powerful singles in the shape of D6-350/370 have become available, and it's natural that folk are wary of being an early adopter only to find they can't sell the boat on.
EvilChap
New member
Running costs and fuel are less on a single obviously.
Handling, top speed and close quarters stuff is better with two.
Personally I would go with two as my sailing brain says auxilery and fail safes are good. I have however been a victim of bad fuel, and would't fancy the bill of getting it cleaned out of two engines!
Have a go in both, see which gets your juices going. The only way to tell which will suit you really is to try them!
Ben
Handling, top speed and close quarters stuff is better with two.
Personally I would go with two as my sailing brain says auxilery and fail safes are good. I have however been a victim of bad fuel, and would't fancy the bill of getting it cleaned out of two engines!
Have a go in both, see which gets your juices going. The only way to tell which will suit you really is to try them!
Ben
aquaholic
Active member
only ever had single engined boats due to size, all under 30 ft. Just make sure you have a decent auxillary, and no a 5 hp slung on the back aint gonna cut it.... i have a 10hp on the back of my 25 footer which gives me 5 knts against most tides at reasonable revs if I need it, but ideally will change to a 15hp next year.
MedDreamer
Active member
Yes I agree a single engined IPS would be just the thing /forums/images/graemlins/confused.gif
oceanfroggie
Well-known member
/forums/images/graemlins/smile.gif I said a twin with stern and bow thrusters /forums/images/graemlins/smile.gif
BUT now that you mention it - An achilles heel of IPS perhaps? What if an engine breaks down? At least on a twin shaft or twin stern drive you'll get home on one engine and manage to park - with IPS you might spin around in circles. A bit like a car trying to drive with one of the wheels missing!
/forums/images/graemlins/laugh.gif
BUT now that you mention it - An achilles heel of IPS perhaps? What if an engine breaks down? At least on a twin shaft or twin stern drive you'll get home on one engine and manage to park - with IPS you might spin around in circles. A bit like a car trying to drive with one of the wheels missing!
/forums/images/graemlins/laugh.gif
davedpc
New member
These days most of my boating starts in the evening after work and its now almost dark time we get over to Cowes and its certainly dark on the way back. If one of the various alarms was to go off on a single engine installation i would not be so confident that a rescue boat was at hand. If however you boating is not adventureous, in safe waters when plenty of other boats were about or in company i would love the economy of a single engine. If you have ever crossed the shipping lanes mid channel you will appreciate the luxury of 2 engines.
ari
Well-known member
[ QUOTE ]
Scenario ! Car without spare tyre has puncture (stand by side of road & wait for R.A.C/AA = inconvenience).
Boat with engine failure coming out of bembridge harbour on an outgoing tide with a N.E wind (end up high & dry hopefully only on sand and wait for the following tide @ which time sea start may be able to reach you = most people on board panicking).
You can't compare road breakdown with sea, few situations on the road would be either live threatening or cause the loss of the vehicle.
The same can not be said of the sea.
[/ QUOTE ]
If you're going for worst case scenario then do so with both. Howabout high speed front tyre blowout at night in the pouring rain at 70mph in the outside lane of a packed M25. Not life threatening? No panic involved?
Scenario ! Car without spare tyre has puncture (stand by side of road & wait for R.A.C/AA = inconvenience).
Boat with engine failure coming out of bembridge harbour on an outgoing tide with a N.E wind (end up high & dry hopefully only on sand and wait for the following tide @ which time sea start may be able to reach you = most people on board panicking).
You can't compare road breakdown with sea, few situations on the road would be either live threatening or cause the loss of the vehicle.
The same can not be said of the sea.
[/ QUOTE ]
If you're going for worst case scenario then do so with both. Howabout high speed front tyre blowout at night in the pouring rain at 70mph in the outside lane of a packed M25. Not life threatening? No panic involved?
Alrob
New member
Jez
Im surprised you even have to ask the question !!
remember your greek exploits !!
Im surprised you even have to ask the question !!
remember your greek exploits !!
Nat
New member
I broke down twice in my single engined boat, once with the engine & the second time the outdrive. First time got back on the auxilary engine only took six hrs to cover 9 miles. Second time had to get tow as aux had no effect in rough sea, was about 300 metres off rocks & dragging anchor when tow finally showed up, scared the [--word removed--] out of me.
Soon after I sold it & bought twin engined boat. When I damaged one of the outdrives in a storm I returned 120mls back to port on one engine took me 18hrs @ 7- 8knts. give me twins any time. Used to worry about anything over 30mls in the single engined jobbie now I think nothing of longish passages. Just feels like a proper boat & I feel more confident.
Nat
Soon after I sold it & bought twin engined boat. When I damaged one of the outdrives in a storm I returned 120mls back to port on one engine took me 18hrs @ 7- 8knts. give me twins any time. Used to worry about anything over 30mls in the single engined jobbie now I think nothing of longish passages. Just feels like a proper boat & I feel more confident.
Nat
Nick_Pam
Member
Jez
Twin D4-300s.....as you know I've been researching a mobo purchase.....everything I have read points to a UK boater's love affair with twins, and the boat reports always say to specify the largest engines one can afford.......
P.S. Can I have a test when it comes please?????? 50kts!!!!!!!!!!! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
Twin D4-300s.....as you know I've been researching a mobo purchase.....everything I have read points to a UK boater's love affair with twins, and the boat reports always say to specify the largest engines one can afford.......
P.S. Can I have a test when it comes please?????? 50kts!!!!!!!!!!! /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif
captct
New member
I have old twins on a 35 year old express and I love them...most of the reasons have been stated in the above posts.
Certainly the safety of having two is a major consideration.... but it is twice the upkeep.
What ever you are comfortable with is the right choice.Breaking down on a freeway in a car is a hassle.....breaking down on a boat can be life threatning.Fishermen and the like who run their diesel powered vessels daily are in all probability less likely to breakdown as they do it everday and can often tell when its time to tune it up before it craters.Diesels also have a tendency to run until they are turned off....and they love to be run everyday....the more you run a diesel the happier it is.Pleasure craft like mine that run on gasoline and sit around for sometimes months are not as dependable and require more maintenance.
It is with that in mind ....That twins are better for me
Certainly the safety of having two is a major consideration.... but it is twice the upkeep.
What ever you are comfortable with is the right choice.Breaking down on a freeway in a car is a hassle.....breaking down on a boat can be life threatning.Fishermen and the like who run their diesel powered vessels daily are in all probability less likely to breakdown as they do it everday and can often tell when its time to tune it up before it craters.Diesels also have a tendency to run until they are turned off....and they love to be run everyday....the more you run a diesel the happier it is.Pleasure craft like mine that run on gasoline and sit around for sometimes months are not as dependable and require more maintenance.
It is with that in mind ....That twins are better for me
