Need me a Gardner....?

[blodger]

Well thank you for your replies and advice everyone, on and off board. Much appreciated. Plenty for me to digest so I'm going to sit back and consider for a while now.

 

I can see how adding a ton of ballast in the front will raise the back, but the front already draws 18". The crane says the boat weighs 22 tons and it's hard to see where all the weight comes from with just a 10mm bottom. Maybe we have 10mm sides too. The top is 5mm according to KEDIAN who made and fitted two pigeon boxes for us. Maybe I need to lift the beautiful 1" hardwood T&G floor and remove some of the paving stone ballast from amidships and add cast lead (or something dense) to the front. Amidships ballast (assuming I have it) is obviously counterproductive when the boat is already too low in the water both front and back.

 

Anyway, as one or two peeps have suggested three or four cylinder classics I have to say I'm determined to stick with two cylinders, they sound SO much nicer! It's the sound of a two-pot I'm looking for in particular. I'm wondering if I can disable one cylinder on my BD3 to get the same effect.... only (half) joking!

 

Cheers, Mike

18" seems a bit light at the bow if you are 3' at the stern.

 

Mine was similar when I bought it over eight years ago. I took a load of engineering bricks out of the engine bilges. When first in drydock I was advised to add steel and concrete in the gas locker to get the bow down and stern up. I did and it improved the trim by 6/8". Since I have cut holes in the flooring under the bed aft and removed some paving ballast. I still have a few inches trim by the stern but can see the hole atop the rudder breaking water now. I think she handles better. Its only a 17" prop with now about 2'3" draft.

[Athy]

!

 

 

 

Probably the same reason as you decided to get a fifty year old Gardner and not a brand new BD3 or JD3... ;-)

Actually I looked at and listened to a Beta JD3 and decided that it sounded like a tractor. It gave a whole new meaning to "ploughing along the cut".

[casper ghost]

Actually I looked at and listened to a Beta JD3 and decided that it sounded like a tractor.

 

There's a good reason for that...

[MtB]

18" seems a bit light at the bow if you are 3' at the stern.

 

Thanks for your thoughts but we don't have 3ft draught, maybe you read me saying the counter is 3" underwater. The swim is 24" tall so currently we have 27" draught at the stern (ignoring the skeg) and 18" draught at the front. The boat looks about right in the water now. Pushing the front down by 3" to get the back up 3"so the the counter just breaks water (is that how it would work?) would leave the boat almost level in the water and looking wrong, that's before installing a heavier engine!

 

 

Mine was similar when I bought it over eight years ago. I took a load of engineering bricks out of the engine bilges.

 

I'd LOVE it to be that simple! There is no ballast in the back of the boat to remove. I've checked, properly.

 

 

When first in drydock I was advised to add steel and concrete in the gas locker to get the bow down and stern up. I did and it improved the trim by 6/8". Since I have cut holes in the flooring under the bed aft and removed some paving ballast.

 

Yep I've been under the bed ripping the floor up looking for ballast to remove too, but someone had been there before me and done it already. So no ballast present in the back 20ft of boat. (The boat is 68ft by the way.) The middle section of boat is where there probably IS ballast that needs removing but the floor is hardwood T&G on top of marine plywood with a bathroom and kitchen fitted on top of all that. A monstrous job to lift and remove the builder ballast. Would be easier to buy a different boat!

 

I'm concluding that the 2LW alloy crankcase is by far the simplest option as it actually appears to be lighter than my current engine meaning re-ballasting would not be necessary. We're just about happy with the way it sits in the water now and a lighter engine would improve things further. I'd rather keep the project shorter and simpler (if there is such a thing where boats are concerned).

 

Cheers, Mike

 

Actually I looked at and listened to a Beta JD3 and decided that it sounded like a tractor. It gave a whole new meaning to "ploughing along the cut".

 

So you knew already why I want to change mine!

Edited May 11, 2010 by Mike the Boilerman

[MoominPapa]

I have to say I'm determined to stick with two cylinders, they sound SO much nicer! It's the sound of a two-pot I'm looking for in particular.

 

:lol:

 

MP. (Lister FR2)

[John C]

Hi Mike

 

Would a single cylinder Gardner, a 1L2, be of any interest to you, or anyone else? I bought it some years ago with the intention of putting it in a boat but the boat I bought does not have the room so its now for sale.

 

John

[MtB]

Hi Mike

 

Would a single cylinder Gardner, a 1L2, be of any interest to you, or anyone else? I bought it some years ago with the intention of putting it in a boat but the boat I bought does not have the room so its now for sale.

 

John

 

Hi John, hmmm yes that sounds interesting... what does it weigh?

 

There also appears to be that Kelvin K1 still on the market, and a Lister JP1 was discussed here a while ago. The general conclusion was that single cylinders were not a great idea due to the vibration but I'm not convinced about that, and I'm always up for an experiment!

 

 

Cheers, Mike

[richardf]

Hi John, hmmm yes that sounds interesting... what does it weigh?

 

There also appears to be that Kelvin K1 still on the market, and a Lister JP1 was discussed here a while ago. The general conclusion was that single cylinders were not a great idea due to the vibration but I'm not convinced about that, and I'm always up for an experiment!

 

 

Cheers, Mike

 

I know of someone who has a brand new Kelvin P2 for sale if that is of any interest - I have the P4 and have been very impressed with it.

[John C]

Hi John, hmmm yes that sounds interesting... what does it weigh?

 

There also appears to be that Kelvin K1 still on the market, and a Lister JP1 was discussed here a while ago. The general conclusion was that single cylinders were not a great idea due to the vibration but I'm not convinced about that, and I'm always up for an experiment!

 

 

Cheers, Mike

 

I've just looked through the Gardner paperwork I have and it does not give a weight. I would guess it would be about two thirds the weight of a 2L2, anyone else know?

 

John

[casper ghost]

I've just looked through the Gardner paperwork I have and it does not give a weight. I would guess it would be about two thirds the weight of a 2L2, anyone else know?

 

John

 

Don't know about weight but you won't get enough power from a single cylinder Gardner, a boat with one couldn't even go as fast as mine with my Sabb. I've seen a K1 in a 57 foot boat, it sounded fantastic!

 

Casp' (Ruston 2 pot, nearly...)

[Athy]

I remember seeing a Barry Hawkins boat which was powered by a 1L2. The boat was at least a 60 footer and Hawkins Jr. reckoned that it gave ample propulsion power, though it would not drive an alternator.

[casper ghost]

I remember seeing a Barry Hawkins boat which was powered by a 1L2. The boat was at least a 60 footer and Hawkins Jr. reckoned that it gave ample propulsion power, though it would not drive an alternator.

 

The one I knew of did have usual alternator but it was also hydraulic drive which I believe takes a bit of power away. I've always wanted a K1 in my boat...

[John C]

Don't know about weight but you won't get enough power from a single cylinder Gardner, a boat with one couldn't even go as fast as mine with my Sabb. I've seen a K1 in a 57 foot boat, it sounded fantastic!

 

Casp' (Ruston 2 pot, nearly...)

 

It will make sufficient power for a narrowboat on the canals, working boats managed with less, often pulling a butty.

 

John (managing with a couple more horsepower than a 1L2, even on rivers)

[WotEver]

It will make sufficient power for a narrowboat on the canals, working boats managed with less, often pulling a butty.

 

John (managing with a couple more horsepower than a 1L2, even on rivers)

OP said it would have regular use on the Thames.

 

Tony

[AndyV]

Whenever engines are discussed the question of "how much power is needed" always comes up. On the one hand is always the "working boats used less" argument, and on the other there's the " power needed for rivers".

I have always thought that power, beyonf perhaps 10 or 15hp, Is irrelevant. What matters is how fast a boat can go. On a canal this is obviously irrelevant too as it doesn't take much power to do 4 mph but even on a river there is (surely?) no benefit in power in excess of what is needed to reach the speed of the hull. The hull speed is governed by, more than anything, the length of the boat but once that speed is reached then tripling the power won't make it go any faster, it'll just make more mess in the water. When battling a current or whatever it is the speed that matters (speed relative to the water of course) and so I still don't see the benefit of loads of power

The only things that I can see as benefits of power are the acceleration (narrowboat drag racing anyone), towing a string of flats (oddly I have never had to do that) and stopping ability. Even then it is my experience that too much power just causes the prop to "slip" and so an efficient prop would still be a better brake than a heap of power.....I think.

If the above all sounds like my assertions please be assured that they are in fact the sum of my observations and some conjecture. They are also the way I am trying to persuade myself that a 2L2 at 20hp will be enough for a planned heavy 70 footer.

[FadeToScarlet]

Yes, it will, as long as you can swing a proper blade for it. I believe Samuel Barlow's had a few motors with 2L2s and pushed the loaded motor and butties around well. Princess Anne, the tug, got one during the war IIRC as well, to tow several loaded joey boats with.

 

They were rare for working boats, but I have read of a couple.

Edited July 20, 2016 by FadeToScarlet

[MtB]

Whenever engines are discussed the question of "how much power is needed" always comes up. On the one hand is always the "working boats used less" argument, and on the other there's the " power needed for rivers".

I have always thought that power, beyonf perhaps 10 or 15hp, Is irrelevant. What matters is how fast a boat can go. On a canal this is obviously irrelevant too as it doesn't take much power to do 4 mph but even on a river there is (surely?) no benefit in power in excess of what is needed to reach the speed of the hull. The hull speed is governed by, more than anything, the length of the boat but once that speed is reached then tripling the power won't make it go any faster, it'll just make more mess in the water. When battling a current or whatever it is the speed that matters (speed relative to the water of course) and so I still don't see the benefit of loads of power

The only things that I can see as benefits of power are the acceleration (narrowboat drag racing anyone), towing a string of flats (oddly I have never had to do that) and stopping ability. Even then it is my experience that too much power just causes the prop to "slip" and so an efficient prop would still be a better brake than a heap of power.....I think.

If the above all sounds like my assertions please be assured that they are in fact the sum of my observations and some conjecture. They are also the way I am trying to persuade myself that a 2L2 at 20hp will be enough for a planned heavy 70 footer.

 

 

Interesting stuff you have posted.

 

The received wisdom is that it's torque that counts but in my experience this is generally asserted only by posters with a shallow and poor understanding of the effects at play.

 

My personal experience is that blade diameter is far and away the most significant factor. My first but one NB had a 35hp engine and a 16" blade. Performance was pathetic especially in astern. I had to rev the nuts off it to stop in a lock.

 

Then I swapped it (with cash adjustment) for a longer boat also with a 35hp engine but with a 21" blade and slower revving. WHAT a contrast!! AWESOME stopping ability and 7 knots in deep water, easily.

 

I'm inclined to think the blade diameter is the crucial factor. Old working boats with 26" blades and a 18hp JP2 seem to go like the clappers. I'm convinced a modern engine of the same power installed in the same boat with an approriate reduction ratio to drive the same blade would perform in the same way.

 

Just my opinion...

[AndyV]

Your comment re blade size is interesting Mike. I owned and lived on a boat for 11 years (a good few years ago) that had a Thorneycroft marinised Ford XRD sewing machine engine. It was pretty comparable to the engines in many boats that I knew, but with one exception. For various reasons that I won't go into it had a 3:1 reduction gearbox rather than the normal 2:1 on all the other similar engined boats. Because of this it threw a larger (if I remember 21") prop and would stop and reverse unbelievably well. It even made me look like I knew what I was doing. It also had a drop Skeg, so the rudder was large. Since the rudder also had a, probably, excessive balance its area was huge which meant it steered like a butty too. It was the easiest boat to steer that I have ever known.

It does seem to agree with your theory re blade size!

[matty40s]

They are also the way I am trying to persuade myself that a 2L2 at 20hp will be enough for a planned heavy 70 footer.

I can assure you that the 2L2 is more than suitable for this size boat.....and loves rivers.

[Tony Dunkley]

Your comment re blade size is interesting Mike. I owned and lived on a boat for 11 years (a good few years ago) that had a Thorneycroft marinised Ford XRD sewing machine engine. It was pretty comparable to the engines in many boats that I knew, but with one exception. For various reasons that I won't go into it had a 3:1 reduction gearbox rather than the normal 2:1 on all the other similar engined boats. Because of this it threw a larger (if I remember 21") prop and would stop and reverse unbelievably well. It even made me look like I knew what I was doing. It also had a drop Skeg, so the rudder was large. Since the rudder also had a, probably, excessive balance its area was huge which meant it steered like a butty too. It was the easiest boat to steer that I have ever known.

It does seem to agree with your theory re blade size!

 

Low rpm and the biggest diameter that can be swung under the counter are unquestionably the way to go to make the best possible use of relatively small horsepower outputs.

 

The performance of most modern day so-called narrowboats is really quite pathetic.

 

Some of the poor performance is due to the crude and inefficient underwater lines of the hulls, but high revving small diameter propellers are by far and away the main cause, and the origins of those on canalboats can be traced directly back to the early 1970's when British Waterways successfully conned the boating public into believing that the ideal draught for a narrow canalboat was around 2 feet.

Edited July 21, 2016 by Tony Dunkley

[dave moore]

Well said Tony, sad that egg whisks are so prevalent.

 

Dave

[Markinaboat]

Apologies for confusing things, the BD3 weighs 1,078lb according to the link I gave, not 1,078kG. Doh! I've dug out the original engine spec that came with the boat and Beta Marine data sheet says it weighs 520kG (probably including the PRM160 transmission although it doesn't actually say), which is 1,146lb.

 

I also see the 2LW is listed on the engine database twice, once at 1,040lb for a 28hp/1,300rpm version, and 1,800lb for a 24hp/1,200rpam version. Are there really two versions of this engine that different in weight? The lighter version would be fine but there's no way we could use the 1,800lb version.

 

 

A Kelvin J2 would be LOVELY but from reading about Kelvins I suspect there might be difficulties installing a suitable propshaft. The Kelvin K series transmissions rely on prop thrust up the propshaft to keep them in gear I believe. Does this apply to the J series too? Could one be mated to something conventional like our PRM160?

 

And yes we have the engine room to show it off in, it's just a bit too near the back of the boat! The boatman's cabin is only about 5'6" long. Weird.

 

Cheers, Mike

I know Phil Trotter at RW Davis was trialling a hydraulic gearbox conversion on a K3 last year. Maybe worth pinging him an email to get the lowdown if you go the Kelvin route.

[Athy]

I know Phil Trotter at RW Davis was trialling a hydraulic gearbox conversion on a K3 last year. Maybe worth pinging him an email to get the lowdown if you go the Kelvin route.

I believe that, in the six years since he started this thread, Mr.Boiler has equipped himself with a Kelvin K1.

[Markinaboat]

I believe that, in the six years since he started this thread, Mr.Boiler has equipped himself with a Kelvin K1.

Duhhh ... Damned old threads with new posts!

[IanD]

Your comment re blade size is interesting Mike. I owned and lived on a boat for 11 years (a good few years ago) that had a Thorneycroft marinised Ford XRD sewing machine engine. It was pretty comparable to the engines in many boats that I knew, but with one exception. For various reasons that I won't go into it had a 3:1 reduction gearbox rather than the normal 2:1 on all the other similar engined boats. Because of this it threw a larger (if I remember 21") prop and would stop and reverse unbelievably well. It even made me look like I knew what I was doing. It also had a drop Skeg, so the rudder was large. Since the rudder also had a, probably, excessive balance its area was huge which meant it steered like a butty too. It was the easiest boat to steer that I have ever known.

It does seem to agree with your theory re blade size!

It's not just MTBs theory, all the technical data about propellers says that a bigger one turning more slowly is more efficient (and better at starting/stopping) than a small one turning more quickly, and this gets even more so as boat speed decreases -- so for certain the best solution for a narrowboat is the biggest prop you can fit, with either a low-speed engine or a higher reduction ratio gearbox. But as Tony pointed out, this goes completely against the modern trend for keeping draught down to around 2 feet, which allowing for clearances limits the prop diameter to about 18" maximum...