Boat stretch

[IanD]

7 minutes ago, peterboat said:

It's why I stretched mine, Johnathan built it originally and he stretched it, the stretch actually made the swim better in his opinion 

As it should, because it was now longer... 😉

[magnetman]

26 minutes ago, IanD said:

 

Evergreen in Suez canal / narrowboat in UK canal

 

Length : 1312' / 48'

Breadth : 193' / 7'

Draught : 48' / 1'9"

Weight : 580Mlbs / 28000lbs

Hull speed : 49kts / 9.3kts

Speed (deep water) : 23kts / 4.4kts

Fast cruise power : 79500hp / 6hp

Canal depth : 79' / 3'

Canal width : 680' / 24'

 

It  "But narrowboats in canals are *different*, stuff about ships is irrelevant!" trope into a cocked hat... 

 

😉

 

The two are completely different types of boat. Maybe the computer says they are the same but they aren't. 

 

Where did you get hull speed 9.3 knots for a 48ft narrow boat? Has this been tested and established or is it computer modelling? 

 

 

As for lengthening I know someone who lengthened a Springer twice from 36 to 50ft then from 50ft to 70ft. 

 

Your calculations completely ignore the real life useage of a typical narrow boat. Is the Suez canal saucer shaped and inadequately dredged ? 

 

 

 

 

Don't forget that the topic is about narrow boats and in the image of the stretched boat it is on a uk canal (,GU I think). 

 

Millions of pounds will have been spent perfecting the shape of a container ship because of how expensive it is to operate. The same can not be said for narrow boats which have far more basic shapes. 

 

 

[IanD]

4 minutes ago, magnetman said:

 

The two are completely different types of boat. Maybe the computer says they are the same but they aren't. 

 

Where did you get hull speed 9.3 knots for a 48ft narrow boat? Has this been tested and established or is it computer modelling? 

 

As for lengthening I know someone who lengthened a Springer twice from 36 to 50ft then from 50ft to 70ft. 

 

Your calculations completely ignore the real life useage of a typical narrow boat. Is the Suez canal saucer shaped and inadequately dredged ? 

 

Don't forget that the topic is about narrow boats and in the image of the stretched boat it is on a uk canal (,GU I think). 

 

Millions of pounds will have been spent perfecting the shape of a container ship because of how expensive it is to operate. The same can not be said for narrow boats which have far more basic shapes. 

 

 

I give up -- you just don't seem to understand how science -- on which pretty much all aspects of life depends -- works, including fundamental laws used and verified worldwide... 😞

[magnetman]

If the hull shape of the Ever Given is the same as an English narrow boat then no I don't understand science. 

 

Maybe this is the problem. I'm using primary senses rather than a machine to arrive at a conclusion. 

[IanD]

3 minutes ago, magnetman said:

If the hull shape of the Ever Given is the same as an English narrow boat then no I don't understand science. 

 

Maybe this is the problem. I'm using primary senses rather than a machine to arrive at a conclusion. 

It's not "the same" but the differences are actually small compared to the similarities.

 

Not a machine/computer, science -- which has been around for far longer, and is inevirably found to be much more reliable than "common sense" which is what you keep (mis-) using... 😉

Edited November 18, 2023 by IanD

[magnetman]

Yes but I don't have a schilling rudder. 

[Guest]

9 minutes ago, IanD said:

I give up -- 

 

Last time you said that in this thread you didn't.

 

Please do.

[IanD]

1 minute ago, magnetman said:

Yes but I don't have a schilling rudder. 

But as you've said (and demonstrated, many times) you don't understand science... 😞

[magnetman]

I understand a lot more than you think about boats. I'm not a big fan of computer modelling because it will throw up basic unexpected errors. 

 

 

What happens in reality is the only thing I find relevant for some unknown reason. 

[Chris G]

27 minutes ago, magnetman said:

 

Where did you get hull speed 9.3 knots for a 48ft narrow boat? Has this been tested and established or is it computer modelling? 

 

 

Hull speed = 1.34 x sq. rt.(Water line length). For a 48' LWL that gives 9.3 kt.

[magnetman]

Yes I know but I don't believe this works with narrow boats because of the hull shape. 

 

It is based on boats with lower block coefficients. 

 

Its got a lot to do with wave formation and narrow boats don't form typical bow waves. 

[Tacet]

1 hour ago, Chris G said:

Hull speed = 1.34 x sq. rt.(Water line length). For a 48' LWL that gives 9.3 kt.

Or, for mental arithmetic, the sq rt of twice the length (in feet) gives a result in MPH or knots or thereabouts

[magnetman]

 

One should probably start talking about the Froude number at this stage. 

 

 

 

 

[IanD]

11 minutes ago, Tacet said:

Or, for mental arithmetic, the sq rt of twice the length (in feet) gives a result in MPH or knots or thereabouts

It's only an approximate number anyway -- as you say it's waterline length not boat length, and in fact it's a bit shorter than that because the bow and stern wakes don't start right at the ends. For a narrowboat this -- together with the facts that the bow is sloped and the stern swim usually stops about 3' short of the stern, and this causes most of the wake -- means you should actually use a rather shorter length than the "official" one.

 

Most narrowboats most of the time are operating far below the "hull speed" anyway, but it still has an effect on the drag (hence longer boats going faster in deep water) which increases more and more rapidly as you get closer to it -- it's not a hard limit, it's where the bow (up) and stern (down) waves add together and the drag goes through the roof, but you can get past it at which point you're starting to plane -- and then drag drops again and you go a lot faster for little more (or less) power.

 

1 minute ago, magnetman said:

 

One should probably start talking about the Froude number at this stage. 

 

Indeed, and that's where the model scaling factors I used come from... 😉

Edited November 18, 2023 by IanD

[magnetman]

2 hours ago, IanD said:

I give up --

 

Out of interest what is the Froude number for a typical 48ft narrow boat ? 

[ditchcrawler]

Now about those square portholes that were mentioned earlier

[peterboat]

I do know that at 3mph whis my normal cruising speed in deep and broad waters 3.3 kws is enough

[cuthound]

On 17/11/2023 at 10:48, IanD said:

Since 4WD cars are so popular nowadays -- better grip etc -- why not put *another* engine in, maybe at the bows? Could even arrange it so it could also be used to move the bows from side to side if required... 😉

 

John Cooper did it with a Mini, it didn't end well.

 

http://www.theminiforum.co.uk/imgreq/img/ba1995be04d9d62405fd6bf0840d9dc612320784/89c2ec4879f339546606be8b218032941cf3fad3.jpg

 

"There were two Twini Mini's (and a Moke). One was built by John Cooper, in which John Cooper had his near fatal accident on the Kingston By-Pass. The other was built by Downton engineering and was the car which raced in the Targa Florio. Is main problem was weight which was not much less than a GTO Ferrari against which it had to race, Cooper's accident was the same week as the Targa."

This is an account of Cooper's accident taken from Rob Golding's book ˜Mini“ Thirty Five Years On.

"Failure seemed to dog the tracks of the Twini and enthusiasm was even further dampened when John Cooper had a horrific accident in a road-going Twini. It was the third in a series of accidents in which Cooper was involved and very nearly his last. He was returning from Fairoaks airport having been to collect his Tri-pacer light aircraft. This had crashed some months earlier when he and Lotus chief Colin Chapman were aboard with a professional pilot at the controls. It had cartwheeled on landing without causing injury to anyone. When he collected it, it had sustained further damage while on the ground. The tailplane was badly bent and had he failed to notice it before trying to take off, he could have been in serious trouble again. As it was, he was in a hurry on his way home to collect his wife, Paula, at Surbiton to join Salvadori for dinner.
The Twini was equipped with two 1300cc engines, which were to have been tweaked up to 135 bhp apiece with fuel injection. Batting along the Kingston bypass at 100 mph, the steering arm that had been welded-up to the rear subframe came adrift. As the rack had been removed, the steering link had been used as a suspension arm. The wheel was suddenly free and made a sharp right turn. The car catapulted end-over-end into a wall, throwing Cooper clear but fracturing his skull. Few who saw him thought he would live. The first car on the scene “one that Cooper had just overtaken“ contained a lady who suffered a nervous breakdown as a result of seeing the accident unfold, and she tried unsuccessfully to claim for compensation from Cooper's insurance."

There is quite a bit about the other Twinis in the book. The first one was a Moke that Issigonis built in early 1963. It had a 950cc engine at the front and an 850cc one at the back. John Cooper was shown the car and he and Issigonis both decided they would build a Mini-bodied version. Cooper completed his one day before Issigonis and had it ready for track testing within weeks. John Whitmore did the test driving. By April 1963 both engines were fully-tuned Coopers and the result was a 2.5-litre vehicle developing 175 bhp, and wheelspin on all four wheels.

 

The pic below is the Twini Mini (931 RFC) on the 1963 Targa Florio, drivers were Sir John Whitmore and Paul Frere. Two separate 998cc engine/gearbox combinations were used....interestingly....when the rear engine failed they just drove it around on the front, hence their poor placing."

You can also see the air vents cut into the bootlid.

 

"There were two Twini Mini's (and a Moke). One was built by John Cooper, in which John Cooper had his near fatal accident on the Kingston By-Pass. The other was built by Downton engineering and was the car which raced in the Targa Florio. Is main problem was weight which was not much less than a GTO Ferrari against which it had to race, Cooper's accident was the same week as the Targa."

This is an account of Cooper's accident taken from Rob Golding's book ˜Mini“ Thirty Five Years On.

"Failure seemed to dog the tracks of the Twini and enthusiasm was even further dampened when John Cooper had a horrific accident in a road-going Twini. It was the third in a series of accidents in which Cooper was involved and very nearly his last. He was returning from Fairoaks airport having been to collect his Tri-pacer light aircraft. This had crashed some months earlier when he and Lotus chief Colin Chapman were aboard with a professional pilot at the controls. It had cartwheeled on landing without causing injury to anyone. When he collected it, it had sustained further damage while on the ground. The tailplane was badly bent and had he failed to notice it before trying to take off, he could have been in serious trouble again. As it was, he was in a hurry on his way home to collect his wife, Paula, at Surbiton to join Salvadori for dinner.
The Twini was equipped with two 1300cc engines, which were to have been tweaked up to 135 bhp apiece with fuel injection. Batting along the Kingston bypass at 100 mph, the steering arm that had been welded-up to the rear subframe came adrift. As the rack had been removed, the steering link had been used as a suspension arm. The wheel was suddenly free and made a sharp right turn. The car catapulted end-over-end into a wall, throwing Cooper clear but fracturing his skull. Few who saw him thought he would live. The first car on the scene “one that Cooper had just overtaken“ contained a lady who suffered a nervous breakdown as a result of seeing the accident unfold, and she tried unsuccessfully to claim for compensation from Cooper's insurance."

There is quite a bit about the other Twinis in the book. The first one was a Moke that Issigonis built in early 1963. It had a 950cc engine at the front and an 850cc one at the back. John Cooper was shown the car and he and Issigonis both decided they would build a Mini-bodied version. Cooper completed his one day before Issigonis and had it ready for track testing within weeks. John Whitmore did the test driving. By April 1963 both engines were fully-tuned Coopers and the result was a 2.5-litre vehicle developing 175 bhp, and wheelspin on all four wheels.

 

The pic below is the Twini Mini (931 RFC) on the 1963 Targa Florio, drivers were Sir John Whitmore and Paul Frere. Two separate 998cc engine/gearbox combinations were used....interestingly....when the rear engine failed they just drove it around on the front, hence their poor placing."

You can also see the air vents cut into the bootlid.

 

 

Edited November 18, 2023 by cuthound
to add image

[IanD]

1 hour ago, magnetman said:

 

Out of interest what is the Froude number for a typical 48ft narrow boat ? 

You could have looked this up for yourself, you know -- 0.4 at the "hull speed", so it's trivial to work out from that depending how long the boat is and how fast you're going, so between 0.1 and 0.15 would be fairly typical on a canal.

 

But I thought you didn't believe in equations and computers?

 

(which are of course what all real ship designers use)

6 minutes ago, peterboat said:

I do know that at 3mph whis my normal cruising speed in deep and broad waters 3.3 kws is enough

How big and heavy is your boat?

[Jon57]

10 minutes ago, cuthound said:

 

John Cooper did it with a Mini, it didn't end well.

 

http://www.theminiforum.co.uk/imgreq/img/ba1995be04d9d62405fd6bf0840d9dc612320784/89c2ec4879f339546606be8b218032941cf3fad3.jpg

 

"There were two Twini Mini's (and a Moke). One was built by John Cooper, in which John Cooper had his near fatal accident on the Kingston By-Pass. The other was built by Downton engineering and was the car which raced in the Targa Florio. Is main problem was weight which was not much less than a GTO Ferrari against which it had to race, Cooper's accident was the same week as the Targa."

This is an account of Cooper's accident taken from Rob Golding's book ˜Mini“ Thirty Five Years On.

"Failure seemed to dog the tracks of the Twini and enthusiasm was even further dampened when John Cooper had a horrific accident in a road-going Twini. It was the third in a series of accidents in which Cooper was involved and very nearly his last. He was returning from Fairoaks airport having been to collect his Tri-pacer light aircraft. This had crashed some months earlier when he and Lotus chief Colin Chapman were aboard with a professional pilot at the controls. It had cartwheeled on landing without causing injury to anyone. When he collected it, it had sustained further damage while on the ground. The tailplane was badly bent and had he failed to notice it before trying to take off, he could have been in serious trouble again. As it was, he was in a hurry on his way home to collect his wife, Paula, at Surbiton to join Salvadori for dinner.
The Twini was equipped with two 1300cc engines, which were to have been tweaked up to 135 bhp apiece with fuel injection. Batting along the Kingston bypass at 100 mph, the steering arm that had been welded-up to the rear subframe came adrift. As the rack had been removed, the steering link had been used as a suspension arm. The wheel was suddenly free and made a sharp right turn. The car catapulted end-over-end into a wall, throwing Cooper clear but fracturing his skull. Few who saw him thought he would live. The first car on the scene “one that Cooper had just overtaken“ contained a lady who suffered a nervous breakdown as a result of seeing the accident unfold, and she tried unsuccessfully to claim for compensation from Cooper's insurance."

There is quite a bit about the other Twinis in the book. The first one was a Moke that Issigonis built in early 1963. It had a 950cc engine at the front and an 850cc one at the back. John Cooper was shown the car and he and Issigonis both decided they would build a Mini-bodied version. Cooper completed his one day before Issigonis and had it ready for track testing within weeks. John Whitmore did the test driving. By April 1963 both engines were fully-tuned Coopers and the result was a 2.5-litre vehicle developing 175 bhp, and wheelspin on all four wheels.

 

The pic below is the Twini Mini (931 RFC) on the 1963 Targa Florio, drivers were Sir John Whitmore and Paul Frere. Two separate 998cc engine/gearbox combinations were used....interestingly....when the rear engine failed they just drove it around on the front, hence their poor placing."

You can also see the air vents cut into the bootlid.

 

"There were two Twini Mini's (and a Moke). One was built by John Cooper, in which John Cooper had his near fatal accident on the Kingston By-Pass. The other was built by Downton engineering and was the car which raced in the Targa Florio. Is main problem was weight which was not much less than a GTO Ferrari against which it had to race, Cooper's accident was the same week as the Targa."

This is an account of Cooper's accident taken from Rob Golding's book ˜Mini“ Thirty Five Years On.

"Failure seemed to dog the tracks of the Twini and enthusiasm was even further dampened when John Cooper had a horrific accident in a road-going Twini. It was the third in a series of accidents in which Cooper was involved and very nearly his last. He was returning from Fairoaks airport having been to collect his Tri-pacer light aircraft. This had crashed some months earlier when he and Lotus chief Colin Chapman were aboard with a professional pilot at the controls. It had cartwheeled on landing without causing injury to anyone. When he collected it, it had sustained further damage while on the ground. The tailplane was badly bent and had he failed to notice it before trying to take off, he could have been in serious trouble again. As it was, he was in a hurry on his way home to collect his wife, Paula, at Surbiton to join Salvadori for dinner.
The Twini was equipped with two 1300cc engines, which were to have been tweaked up to 135 bhp apiece with fuel injection. Batting along the Kingston bypass at 100 mph, the steering arm that had been welded-up to the rear subframe came adrift. As the rack had been removed, the steering link had been used as a suspension arm. The wheel was suddenly free and made a sharp right turn. The car catapulted end-over-end into a wall, throwing Cooper clear but fracturing his skull. Few who saw him thought he would live. The first car on the scene “one that Cooper had just overtaken“ contained a lady who suffered a nervous breakdown as a result of seeing the accident unfold, and she tried unsuccessfully to claim for compensation from Cooper's insurance."

There is quite a bit about the other Twinis in the book. The first one was a Moke that Issigonis built in early 1963. It had a 950cc engine at the front and an 850cc one at the back. John Cooper was shown the car and he and Issigonis both decided they would build a Mini-bodied version. Cooper completed his one day before Issigonis and had it ready for track testing within weeks. John Whitmore did the test driving. By April 1963 both engines were fully-tuned Coopers and the result was a 2.5-litre vehicle developing 175 bhp, and wheelspin on all four wheels.

 

The pic below is the Twini Mini (931 RFC) on the 1963 Targa Florio, drivers were Sir John Whitmore and Paul Frere. Two separate 998cc engine/gearbox combinations were used....interestingly....when the rear engine failed they just drove it around on the front, hence their poor placing."

You can also see the air vents cut into the bootlid.

 

 

Like project binky..https://m.youtube.com/@BadObsessionMotorsport

[magnetman]

Narrow boats are not ships. They are not designed by naval architects. 

[IanD]

9 minutes ago, cuthound said:

 

John Cooper did it with a Mini, it didn't end well.

 

http://www.theminiforum.co.uk/imgreq/img/ba1995be04d9d62405fd6bf0840d9dc612320784/89c2ec4879f339546606be8b218032941cf3fad3.jpg

 

"There were two Twini Mini's (and a Moke). One was built by John Cooper, in which John Cooper had his near fatal accident on the Kingston By-Pass. The other was built by Downton engineering and was the car which raced in the Targa Florio. Is main problem was weight which was not much less than a GTO Ferrari against which it had to race, Cooper's accident was the same week as the Targa."

This is an account of Cooper's accident taken from Rob Golding's book ˜Mini“ Thirty Five Years On.

"Failure seemed to dog the tracks of the Twini and enthusiasm was even further dampened when John Cooper had a horrific accident in a road-going Twini. It was the third in a series of accidents in which Cooper was involved and very nearly his last. He was returning from Fairoaks airport having been to collect his Tri-pacer light aircraft. This had crashed some months earlier when he and Lotus chief Colin Chapman were aboard with a professional pilot at the controls. It had cartwheeled on landing without causing injury to anyone. When he collected it, it had sustained further damage while on the ground. The tailplane was badly bent and had he failed to notice it before trying to take off, he could have been in serious trouble again. As it was, he was in a hurry on his way home to collect his wife, Paula, at Surbiton to join Salvadori for dinner.
The Twini was equipped with two 1300cc engines, which were to have been tweaked up to 135 bhp apiece with fuel injection. Batting along the Kingston bypass at 100 mph, the steering arm that had been welded-up to the rear subframe came adrift. As the rack had been removed, the steering link had been used as a suspension arm. The wheel was suddenly free and made a sharp right turn. The car catapulted end-over-end into a wall, throwing Cooper clear but fracturing his skull. Few who saw him thought he would live. The first car on the scene “one that Cooper had just overtaken“ contained a lady who suffered a nervous breakdown as a result of seeing the accident unfold, and she tried unsuccessfully to claim for compensation from Cooper's insurance."

There is quite a bit about the other Twinis in the book. The first one was a Moke that Issigonis built in early 1963. It had a 950cc engine at the front and an 850cc one at the back. John Cooper was shown the car and he and Issigonis both decided they would build a Mini-bodied version. Cooper completed his one day before Issigonis and had it ready for track testing within weeks. John Whitmore did the test driving. By April 1963 both engines were fully-tuned Coopers and the result was a 2.5-litre vehicle developing 175 bhp, and wheelspin on all four wheels.

 

The pic below is the Twini Mini (931 RFC) on the 1963 Targa Florio, drivers were Sir John Whitmore and Paul Frere. Two separate 998cc engine/gearbox combinations were used....interestingly....when the rear engine failed they just drove it around on the front, hence their poor placing."

You can also see the air vents cut into the bootlid.

 

"There were two Twini Mini's (and a Moke). One was built by John Cooper, in which John Cooper had his near fatal accident on the Kingston By-Pass. The other was built by Downton engineering and was the car which raced in the Targa Florio. Is main problem was weight which was not much less than a GTO Ferrari against which it had to race, Cooper's accident was the same week as the Targa."

This is an account of Cooper's accident taken from Rob Golding's book ˜Mini“ Thirty Five Years On.

"Failure seemed to dog the tracks of the Twini and enthusiasm was even further dampened when John Cooper had a horrific accident in a road-going Twini. It was the third in a series of accidents in which Cooper was involved and very nearly his last. He was returning from Fairoaks airport having been to collect his Tri-pacer light aircraft. This had crashed some months earlier when he and Lotus chief Colin Chapman were aboard with a professional pilot at the controls. It had cartwheeled on landing without causing injury to anyone. When he collected it, it had sustained further damage while on the ground. The tailplane was badly bent and had he failed to notice it before trying to take off, he could have been in serious trouble again. As it was, he was in a hurry on his way home to collect his wife, Paula, at Surbiton to join Salvadori for dinner.
The Twini was equipped with two 1300cc engines, which were to have been tweaked up to 135 bhp apiece with fuel injection. Batting along the Kingston bypass at 100 mph, the steering arm that had been welded-up to the rear subframe came adrift. As the rack had been removed, the steering link had been used as a suspension arm. The wheel was suddenly free and made a sharp right turn. The car catapulted end-over-end into a wall, throwing Cooper clear but fracturing his skull. Few who saw him thought he would live. The first car on the scene “one that Cooper had just overtaken“ contained a lady who suffered a nervous breakdown as a result of seeing the accident unfold, and she tried unsuccessfully to claim for compensation from Cooper's insurance."

There is quite a bit about the other Twinis in the book. The first one was a Moke that Issigonis built in early 1963. It had a 950cc engine at the front and an 850cc one at the back. John Cooper was shown the car and he and Issigonis both decided they would build a Mini-bodied version. Cooper completed his one day before Issigonis and had it ready for track testing within weeks. John Whitmore did the test driving. By April 1963 both engines were fully-tuned Coopers and the result was a 2.5-litre vehicle developing 175 bhp, and wheelspin on all four wheels.

 

The pic below is the Twini Mini (931 RFC) on the 1963 Targa Florio, drivers were Sir John Whitmore and Paul Frere. Two separate 998cc engine/gearbox combinations were used....interestingly....when the rear engine failed they just drove it around on the front, hence their poor placing."

You can also see the air vents cut into the bootlid.

 

 

 

I wonder how fast a twin-engine narrowboat with 270bhp would go? Not 100mph, I expect... 😉

[magnetman]

 

One can't use calculated hull speed numbers for narrow boats because of the shape and construction of the boat. It won't work properly if you rely on this. 

 

 

 

 

 

 

 

[cuthound]

4 minutes ago, Jon57 said:

Like project binky..https://m.youtube.com/@BadObsessionMotorsport

 

Yes, Binky is even more insane than the original, but apart from the bodyshell doesn't use many original Mini parts.

Edited November 18, 2023 by cuthound
Missing letter

[Jon57]

Just now, cuthound said:

 

Yes, Binky is even more insane than the original, but apart from he bodyshell doesn't use many original Mini parts.

Some fantastic engineering. Some without a computer in sight.🤭