Engine size / pull butty

[bugs]

Hi all,

I need to pick the collective brains and ask; I am buying first boat this year but cost forces it to be smaller than needed, I will within 12mths be adding a second boat (unpowerd butty). The first boat will be under 50 feet and will be my home, the second will be my extention my teenage kids home, this will be around 50 - 60 feet. The butty will be a sailaway hull fitted with 12v system, gas etc. So what size engine will i need to have to safetly pull the second boat and is there a problem physically pulling a butty with a smaller boat? Also what are the implications on licence fee and anything else I will need to consider. I intend to be a permanant cruser using winter moorings at crick. Any info feedback is welcome. Thanks in advance.

[Hairy-Neil]

Working boats seldom had more than 20hp engines. That said the HP is not the most important consideration. Torque is the main requirement and plenty of it. You will need a traditional type engine, something like a Lister HR2. These were made up until c.1987 so spares are not a problem like on some of the older designs.

 

I would also go for the deepest draught you can get away with on the motor perhaps 2' 6" and the shallowest on the butty, you're obviously going to tow it on cross straps...... the idea being the thrust from the motor boat's prop will be pushed underneath the butty. If the water can't get away you'll struggle to make progress anywhere.....

[grunders]

is there a problem physically pulling a butty with a smaller boat? Thanks in advance.

 

Shouldn't be any problem towing with a smaller boat, plenty of tugs are shorter than the boats they tow.

[Guest]

Working boats seldom had more than 20hp engines. That said the HP is not the most important consideration. Torque is the main requirement and plenty of it. You will need a traditional type engine, something like a Lister HR2. These were made up until c.1987 so spares are not a problem like on some of the older designs.

 

I would also go for the deepest draught you can get away with on the motor perhaps 2' 6" and the shallowest on the butty, you're obviously going to tow it on cross straps...... the idea being the thrust from the motor boat's prop will be pushed underneath the butty. If the water can't get away you'll struggle to make progress anywhere.....

Glad somebody agrees with me.

Edited February 13, 2007 by Guest

[Liam]

Hi Bugs,

 

Is this "Butty" of yours going to have a Butty shaped stern, or a conventional motor counter?

[Gary Peacock]

This seems a strange solution if this is going to be residential (Kids in tow so I assume so) and you are not restricted to a narrow canal a broader boat is always going to be a cheaper option. The costs to build it will be less and the costs to operate and moor it will be far less too.

 

But then being able to keep the kids well and truly separate might have it's appeal if the going gets tough you can always "cut them some slack" or cut them loose completely!

[DHutch]

Yeah, sounds about right!

- Slightly odd way of doing it, but no reason no to go for it at all.

 

A i agree that the motor would want to nice and deep draught if poss, with a sizable prop. We're 2ft 8/9 ish swinging a 26*32" prop and with 20 horse can pull a 15ton narrowboat without any hardship.

 

 

Daniel

[carlt]

Yeah, sounds about right!

- Slightly odd way of doing it, but no reason no to go for it at all.

 

A i agree that the motor would want to nice and deep draught if poss, with a sizable prop. We're 2ft 8/9 ish swinging a 26*32" prop and with 20 horse can pull a 15ton narrowboat without any hardship.

 

 

Daniel

 

Does anyone else remember when 2'6" was a shallow draught?

 

On the subject of butties though. I pulled Lucy (72' long, 2" oak planks all round) with Tramella (65' Mkt Harbro, 1.5" mainly larch planks) with a Lister SR3 for a long time with no problems.

 

Umbriel has a 12hp Lister CE2 which drags a full length butty around easily enough and she worked for T&S Elements dragging day boat trains around the BCN (though I'm not sure if it was the same engine).

 

The thing about steering a butty is, it is totally different to steering a motor and, even if you've got the heaviest tug, meatiest engine and biggest prop, if you don't know what you're doing, you can screw it up. Look at Raymond's battle scars for evidence.

[Hairy-Neil]

The thing about steering a butty is, it is totally different to steering a motor and, even if you've got the heaviest tug, meatiest engine and biggest prop, if you don't know what you're doing, you can screw it up. Look at Raymond's battle scars for evidence.

 

Agreed, 90% of the time thesteerer has nothing to do, the butty will literally steer itself. Come 10% time they suddenly have it all to do. What often happens is that when the moment comes trainee butty steerers often realise too late they need action, if they are watching at all. About three years ago NBT's Brighton steerer walloped a bridge with the cabin and did serious damage to the steel work. Had it been the original wooden cabin it would quite likely have taken it right off.....

[Keeping Up]

If the butty steerer does the wrong thing at a critical moment it can turn the motor badly off course, catching out the notor steerer if he wasn't expecting it.

 

I've often wondered if you could steer a pair entirely from the butty (on short straps of course), but I've never quite had the courage to try it.

 

A few years back I noticed an odd effect when towing a relatively light 45ft trip-boat down the Grand Union (on cross-straps). The bridges, for those that don't know them, are broad with the offside pretty well in line with the offside bank, and the towpath side moving across to make the narrowing. I found that almost every time, no matter whether I was central to the bridge or over to either side, as soon as the towed boat was more than half-way through the bridgehole, its stern would move over towards the towpath side. Of course it was easy to correct the effect, particularly when I was expecting it, but the question is why did it happen, and why always towards the towpath side. It must have been something to do with the shape of the canal - but has anyone else noticed the effect, and can anyone suggest an explanation?

 

Allan

[bugs]

Huge thanks to all of these,

I have to be able to cruise / winter moorings near crick so can not go for the widebeam option. It will be a full live aboard for the main boat but the second boat may spend sometime on a permanent mooring in storage so to speak. I want to go this way as the smaller 45-50 foot boat will be all that is needed for 60% of the time. The butty will be a sailaway hull with trad stern not a real (unfortunately) -classic butty. but with a butty type steering set up. So if i buy a off the shelf sailaway 45 foot boat with the standard isuzu type engine this will not work. I was hopping it was like the caravan scenario axle weight so to speak and slightly larger than average engine.

The butty would be pulled behind not side by side and partner steering. except in locks obviously.

Thanks folks back to the drawing board i think, i have waited 20 years to get onto the water and with the expertise on this site will find a good solution.

[magnetman]

So if i buy a off the shelf sailaway 45 foot boat with the standard isuzu type engine this will not work. I was hopping it was like the caravan scenario axle weight so to speak and slightly larger than average engine.

I know for a fact that a Beta Marine BV1505 35HP diesel in a 55ft narrowboat is capable of towing another 55ft narrowboat (both fully cabined and fitted motor stern boats) next to it comfortably, for canal use. I don't know what Isuzu LB fit in a 45 footer but I'd think it would be that sort of HP range.

[DHutch]

I've often wondered if you could steer a pair entirely from the butty (on short straps of course), but I've never quite had the courage to try it.

I have it on good authority that it can be done sucessfully.

- Never seen it done, but i can see that it could work, and have no reason to doubt anyone who has told me its doable.

- Hopefully sometime soo i'll get my act together and have a go stearing my mates motor butty pair and see how that goes!

 

 

I've often wondered if you could steer a pair entirely from the butty (on short straps of course), but I've never quite had the courage to try it.

I have it on good authority that it can be done sucessfully.

- Never seen it done, but i can see that it could work, and have no reason to doubt anyone who has told me its doable.

- Hopefully sometime soo i'll get my act together and have a go stearing my mates motor butty pair and see how that goes!

[Liam]

My little dinky single cylinder 10hp Sabb has pulled a heavy 45ft bugger, and although it was only for a short distance, it coped ok.

 

Do you think you'd be better having two conventional "motors" which would be easier to sell if eventually came to that, as both boats could then move under their own power and/or tow each other depending on which one starts in the mornin!

[alan_fincher]

I've often wondered if you could steer a pair entirely from the butty (on short straps of course), but I've never quite had the courage to try it.

I saw my brothers do this once, when they each owned one half of a pair of boats.

 

I actually saw them do it over quite a lengthy stretch of the GU up above Milton Keynes, but it did require require a more than a bit of coordination between the two, particularly in terms of someone on the motor doing exactly what was required with the speedwheel at the right time.

 

When I saw it it did nearly end in a serious brown trouser moment though, with the motor steerer finally needing to grab the tiller to avert a big bump.

 

I'd certainly not have been prepared to get involved, (......not that they offered to let me mangle their boats, anyway !....)

[Liam]

This sort of method has been mentioned in one of the books I've read...

 

The wharf where a motor and butty were unloading or loading, I can't remember which, was down a short arm with no way to wind at the end. The motor was winded at the junction, and reversed down the arm with the two bows tied tightly together. The Butty then steered both boats down the arm. Once loaded/unloaded the Motor was then heading in the right direction, and pulled the butty backwards, back to the Junction until it was winded so it could go "forwards".

 

Thinking on, I think this was from the book "Windlass in my belt" and was Alec Purcell's boats, Redshank and Greenshank.

Edited February 14, 2007 by Liam

[Hairy-Neil]

Even a loaded butty on a 100 foot cotton line has a steering influence over the motor boat.

[howardang]

The influence of a towed butty on the motor is because the towing point on the motor is too far aft and the tow doesn't allow the tug to pivot correctly. It's because the motor has to act as a cargo carrier as well as a tug and so the towing point is right aft. Compare this to a conventional purpose built tug (harbour or deep sea) where the towing point - either winch or hook - is located almost on the pivot point, which allows the tug to turn sharply under the tow rope. The best point is just a couple of feet abaft the pivot point which then gives some steering stability while still giving the desired manouverability.

 

Howard Anguish

[Hairy-Neil]

There was one time we steered the pair, Nuneaton & Brighton from the butty, but they were breasted up on the Thames at the time. On the southern end of the Oxford Canal on the first trip with the newly aquired butty Brighton around easter 1996, the boss where the motor's rudder joins the tiller had cracked through, it being an inferior later fitment rather than the Yarwoods original. We completed the trip up to Northmoor and then down river Reading, steering mainly with the butty's elum.

[DHutch]

One thing i do fell i should add is that buttys need a far larger rudder that a motorboat.

- And as such, this would most certainly have to be considered if using an addapted motor shell as the basis for the butty.

- Otherwise without the extra flow over the rudder from the prop you will find it had little or no stearing. Butty sterns are diffrent than motor sterns larglely because they have to be. Not trying to put a damper on in, i think its a basis of an idea, but im just keen that you pull it off sucessfully without any expersive mistakes!

 

 

Daniel

[Hairy-Neil]

Yes, agreed Daniel, there is usually a reason why old things look like they do. The butty elum is huge because it needs to be. Far too many people reinvent the wheel and get it wrong....

[bugs]

amazing, I only expected one or two answers!. huge thanks to all. Your comments are taken on board. back boat will have over large rudder and I will look into draught options. Can't wait to try this out.

[carlt]

One thing i do fell i should add is that buttys need a far larger rudder that a motorboat.

- And as such, this would most certainly have to be considered if using an addapted motor shell as the basis for the butty.

- Otherwise without the extra flow over the rudder from the prop you will find it had little or no stearing. Butty sterns are diffrent than motor sterns larglely because they have to be. Not trying to put a damper on in, i think its a basis of an idea, but im just keen that you pull it off sucessfully without any expersive mistakes!

Daniel

The area of rudder under the water of an unladen butty is less than that of a working motor. It's only when the butty is loaded that the size of the rudder is apparent.

[mykaskin]

A few years back I noticed an odd effect when towing a relatively light 45ft trip-boat down the Grand Union (on cross-straps). The bridges, for those that don't know them, are broad with the offside pretty well in line with the offside bank, and the towpath side moving across to make the narrowing. I found that almost every time, no matter whether I was central to the bridge or over to either side, as soon as the towed boat was more than half-way through the bridgehole, its stern would move over towards the towpath side. Of course it was easy to correct the effect, particularly when I was expecting it, but the question is why did it happen, and why always towards the towpath side. It must have been something to do with the shape of the canal - but has anyone else noticed the effect, and can anyone suggest an explanation?

 

Allan

 

I'm guessing here, but there could be three effects...

 

1. The non-symetrical prop wash could be travelling down one side of the butty, and thus in the narrow channel push the butty to the side - going through bridges with the towpath the other side would prove this.

 

2. No matter how hard you tried, you may have been erring on the towpath side of the bridge, and thus the smaller gap caused a low presure point on that side, and pulled the butty into it. Again - going through bridges with the towpath on the other side may prove/disprove this point.

 

3. The boat being towed with not completely symetical, and so was being towed slight askew?

 

 

Cheers,

 

Mike

[Keeping Up]

I'm guessing here, but there could be three effects...

 

1. The non-symetrical prop wash could be travelling down one side of the butty, and thus in the narrow channel push the butty to the side - going through bridges with the towpath the other side would prove this.

 

2. No matter how hard you tried, you may have been erring on the towpath side of the bridge, and thus the smaller gap caused a low presure point on that side, and pulled the butty into it. Again - going through bridges with the towpath on the other side may prove/disprove this point.

 

3. The boat being towed with not completely symetical, and so was being towed slight askew?

Cheers,

 

Mike

I don't think it was (1), whichever side the towpath was on, the butty went that way.

 

(2) is certainly a possibility. I was trying to keep it in the centre but I may have subconsciously always moved towards the centre of the arch (which would be nearer to the towpath).

 

(3) is unlikely, the towed boat was symmetrical and although it may have been leaning over to one side, on some of the bridges that would have made it move to the non-towpath side.

 

I think there may be an explanation involving either the fact that by the time the butty was half way in the bridgehole, the prop was out the other side and was therefore not in the centre of the channel any more so there would be an asymmetrical water flow, OR the fact that my course approaching and through the bridge would not have been in a straight line. But that's just guessing wildly!

 

Allan