g.u wideboat progress

[Mike Tee]

In the drawing in post #144, the length overall is marked as 76'-1". Why would it have been designed bigger than the 71'-6" that is usually associated with the GU canal? Or are all the wide locks capable of this longer boat?

[antarmike]

The craft also has dual steering, A wheel and a tiller , the two being linked by a chain running round a pulley system. Seems experimental, and they wanted to know which was best so both appear on the same craft?

[alan_fincher]

In the drawing in post #144, the length overall is marked as 76'-1". Why would it have been designed bigger than the 71'-6" that is usually associated with the GU canal? Or are all the wide locks capable of this longer boat?

Yes.

 

One set of number I have seen says that up to Braunston will take 76 feet, and the new locks onwards to Birmingham 78 feet.

 

I thought we had already established Progress is several feet longer than a standard GUCCCo narrow boat, but glancing quickly back through the (long!) thread, I can't immediately find the reference.

 

EDIT: FOUND IT!

 

......after all “Progress” is 75ft long.........

Edited December 4, 2012 by alan_fincher

[Tam & Di]

Yes.

 

One set of number I have seen says that up to Braunston will take 76 feet, and the new locks onwards to Birmingham 78 feet.

 

I thought we had already established Progress is several feet longer than a standard GUCCCo narrow boat, but glancing quickly back through the (long!) thread, I can't immediately find the reference.

 

EDIT: FOUND IT!

 

We certainly took Progress to Camp Hill. I'll try to find photos I took, having swung and reversed to the lock so it appears to be a 12'6" boat coming out of a 7' lock. No problems at Knowle either. Well, it seemed amusing at the time, but we were young and foolish then rather than old and stupid.

Edited December 4, 2012 by Tam & Di

[alan_fincher]

We certainly took Progress to Camp Hill.

Clearly you must therefore have got it through the bridge near Knowle that it is claimed BW failed to in 1958.

[pete harrison]

We certainly took Progress to Camp Hill. I'll try to find photos I took, having swung and reversed to the lock so it appears to be a 12'6" boat coming out of a 7' lock. No problems at Knowle either. Well, it seemed amusing at the time, but we were young and foolish then rather than old and stupid.

PROGRESS was Grand Union Canal gauged as 12497 on 05 June 1936. At that time its dimensions were listed as 75'0'' x 12'1½'' with a capacity of 81 tons @ 61.00''. PROGRESS had been health registered as Tring 123 on 06 November 1934 (inspected on 05 October 1934).

[Laurence Hogg]

The craft also has dual steering, A wheel and a tiller , the two being linked by a chain running round a pulley system. Seems experimental, and they wanted to know which was best so both appear on the same craft?

This is not unusual at all, many craft had dual steering and it was in use on canal boats until early 1950's, Yarwood built tug "Nansen 2" being a final narrowboat example.

[Derek R.]

Clearly you must therefore have got it through the bridge near Knowle that it is claimed BW failed to in 1958.

 

It would be interesting to ascertain 'Narrowboat's' claim that BW failed at Knowle. And if they had decided to call it a day, whether it was due to possible perceived damage (unlikely), or that the crew had had enough, or simply that time was against them in an experiment that was not probable that any further confirmation was needed that such a prospect of increased traffic with wide boats would be decided through continuing to Camp Hill. Guesswork.

[Tam & Di]

It would be interesting to ascertain 'Narrowboat's' claim that BW failed at Knowle. And if they had decided to call it a day, whether it was due to possible perceived damage (unlikely), or that the crew had had enough, or simply that time was against them in an experiment that was not probable that any further confirmation was needed that such a prospect of increased traffic with wide boats would be decided through continuing to Camp Hill. Guesswork.

 

We probably took Progress to Camp Hill in about 1964-5. The only width problem we had was that it was tight through Leamington, but that was largely because I raised the coamings by about 9-10" when I converted it for living, and we were essentially an empty boat and quite high. Di stepped off and held it against the towpath so the top offside corner did not rub on the tumblehome on the bridge.

 

We cruised London-Braunston several times. At Blisworth Di cycled over (early morning) and if she saw a boat entering the other end she told them to tell me they were the last one. Otherwise I'd just start off through after an appropriate delay.

 

We did occasionally meet a pair at a bridgehole, so one or the other of us had to hold back. It was after the big freeze winter 1962 which put paid to various freights, so there were even less boats by then, but at the time Progress (and FMC's Pioneer) were built it would have probably caused considerable inconvenience as traffic was so heavy.

 

She may well have been 12'1½" or may have spread a bit. I don't know that I ever measured her sufficiently accurately to be certain. I think I'd just heard/read she was 12'6" and relied on that.

Edited December 5, 2012 by Tam & Di

[chris collins]

Tim, re the spikes, that's a very nice offer, thanks for the thought, I feel that ultimately it may be doomed by postal charges, I'm also thinking that there must be far more deserving cases than mine. However, if there is a way and it does happen, brilliant!!

Lawrence, that's a demon set of drawings, and, placed alongside these of “Progress” would make a good game of spot the difference. It would be really good to get the two sets together for comparison, apart from the obvious constructional details there is again the anchor winch, navigation lights/mast, coamings and hatchboards that would be more at place on the estuary. I'm struggling to read the details on your drawing but it looks as though one of the potential problems with “Progress” is addressed with the stern ballast tanks. For me this is a new and very interesting part of the history of “Progress,” a possible indication that G.U.C.C where intending more than just the one? Certainly would answer the question I had about the availability of timber for more than just a few wooden ones. Incidentally the “Progress” drawing is dated 29-1-34 , drawing number 131, how does this compare?

I appreciate that you'll probably all get a bit fed up with me banging on about the river/ estuary bit but it is worth comparing Lawrence's drawings with the picture of what is, in my humble opinion, the more canal orientated “Pioneer” in post 34.

.Pete, very interesting that “Progress” shows up at 12' 1 ½'' , it is very definitely 12' 6'' on the drawings and in real life, I have never seen the gauging sheet though so it's a little mystery

Re the 1958 trial, thanks for all your input, it's a fascinating scion in the history of the wide motorboat and it would be nice to know the full unadulterated truth, it's quite sad that B.W is held in such low esteem that one bridgehole is regarded as a bridge too far. Hopefully one day solid evidence will surface as to the true intent and result of the event.

 

SPA50312 by chriscollins1, on Flickr

 

SPA50315 by chriscollins1, on Flickr

[mykaskin]

To give you some idea of what the narrowboat version of them royalty plans look like in it's natural environment have a look at my video:

 

 

Cheers,

 

Mike

Edited December 11, 2012 by mykaskin

[bargemast]

To give you some idea of what the narrowboat version of them royalty plans look like in it's natural environment have a look at my video:

 

 

Cheers,

 

Mike

 

 

Hi Mike, I just watched the video of "Victoria", she seems to go quite fast, were you going flat out, and if so, what sort of speed you're doing there ?

 

Peter.

[mykaskin]

Hi Mike, I just watched the video of "Victoria", she seems to go quite fast, were you going flat out, and if so, what sort of speed you're doing there ?

 

Peter.

 

I think she was nearly flat out, but there would be more if I over rode the governor. About 6.5 mph through the water I think.

 

The tug, Major, that I'm filming from has a 110 hp 6L3 in it, and only managed 11 mph

 

Mike

[bargemast]

I think she was nearly flat out, but there would be more if I over rode the governor. About 6.5 mph through the water I think.

 

The tug, Major, that I'm filming from has a 110 hp 6L3 in it, and only managed 11 mph

 

Mike

 

 

Wow, 6.5 mph ! that's pretty impressive for a boat like that with "only" a Lister JP-2, which also shows that most narrowboats are well over-powered.

 

Peter.

[Derek R.]

Long skinny things will go faster through the water for any given horse power than shorter and certainly fatter. There's a formula for working it all out, got a copy buried somewhere. It takes into account length, breadth and draught to arrive at potential hull speed for displacement vessels in 'free' water (not canals!). There's another for prop dimensions for given hulls and engine power/transmission reductions. Bit of a 'black art' by some accounts.

[GUMPY]

Theoretical maximum speed is 1.5xsqrtL

Where L = waterline length

So for 70ft its 12.5knots

60ft is 11.6knots

I dont know of any NB that can even get close to these figures.

[bargemast]

Theoretical maximum speed is 1.5xsqrtL

Where L = waterline length

So for 70ft its 12.5knots

60ft is 11.6knots

I dont know of any NB that can even get close to these figures.

 

 

With the theoretical maximum speed of the new 135 m (411,75') Rhine barges, you get to astronomical speeds.

 

From my own experience, I can tell you that I lost 2 km/h after shortening a barge by 10 m, that had been lenghtened with those 10 m 15 years before.

 

At 33 m, she was able do do 15.5 km/h while empty, and after shortening she was drawing about 4 cm deeper and had a maximum speed of 13.5 km/h empty.

 

Peter.

 

edited to say sorry, I realised a bit late that I'm busy turning the very interesting Progress history of it's tracks.

Edited December 12, 2012 by bargemast

[chris collins]

It's not really the time and place here, but it's an interesting subject that does have ramifications in the narrowboat/ barge world, it will also shed some light on why a tug with 110 hp may “only” reach 11 mph. So, lets go for it.

Lets imagine that we have a fifty foot narrowboat and we set off along any reasonable stretch of waterway, as it gathers speed our boat will set up a series of waves that start quite close together and get further apart the faster we go. If we travel at for instance, 6 knots then the waves will be 20ft apart, 7knots 27.2 ft apart, 8knots 35.6 ft apart. This wavelength is entirely governed by the speed of our boat and would remain constant whether we are steering a narrowboat or a supertanker (not on the BCN of course). If we get tramping along at six knots our boat will be travelling along on three wave crests, one at the front, one at 20 ft and one at 40ft while our friend in the supertanker will have many, many more all spaced at the same 20 ft intervals. All fine and dandy apart from the trail of boats that we have pulled off their moorings (sorry), now lets suppose that we can get to 10 knots, the wavelength is now 55.6 ft, longer than our boat and as a result the front of our boat is supported by the crest of the bow wave whilst the stern is considerably lower in the trough before the stern wave. We are now trying to go uphill ! Any further increase in speed requires an exponential input of energy to achieve, we have achieved ( more correctly exceeded) the hull speed of our boat. Meanwhile Mr supertanker is smugly chugging away at 20 knots still supported by many waves. (225ft apart)!

Because the relationship between wavelength and speed is fixed we can calculate with certainty the hull speed for any displacement boat, 1.34 x the square root of the waterline length gives the speed in knots. So a seventy foot narrowboat will be around 11 knots, Major the tug? Well, we don't know the length of it but if we assumed say, 40ft then the power requirements would rise dramatically to get over 9 knots ( 1 knot = 1.15078 m.p.h)

So how much power does a 40ft tug need ? Well, the second biggest factor is the weight of the boat, if we guess at 15 tons then we need around 5 h.p for 5 knots, 25 h.p for 7knots, 46 h.p for 8 knots and a massive 128 to get to 10 knots!

How much difference does the weight make ? Lets look at that 8 knot speed, if we reduced the weight to 8 tons we would need a mere 26 h.p, conversely add a bit more ballast to 20 tons and we'll be paying to fuel 66 h.p!

Hope that's of interest, next time back to “Progress”

[GUMPY]

Best explanation Ive seen, I got the constant wrong for the speed/length formula

Interesting one is WW2 destroyers that managed speeds well in excess of the thoretical maximum!

[AJLintern]

I suppose the hull shape must make quite a difference as to whether you're pushing the water away to get through it or cutting through the water. A destroyer has a fine, narrow hull shape and will cut through the water much better than a vessel of similar proportions but with bluff bows.

[Derek R.]

There may be a missing factor here - the length times breadth ratio.

 

Long thin hulls are quite capable of exceeding theoretical hull speeds, one reason why destroyers might have done exactly that, as do racing canoes etc. Generally speaking, for a given displacement as the length x breadth ratio becomes greater, the speed potential becomes higher - long and skinny is fast. Fine swims, especially aft, make for efficient passage. Look to Nature in the shape of fast fish and birds, almost without exception, the leading shape is far blunter than the trailing.

 

The Queen Mary was 900ft along the water line. Theoretically her hull would be capable of 37.5 - 40knots depending on the calculation used - 1.25 or 1.34. She actually cruised at 32knots, but we have to consider wave, wind and propulsion in affecting the difference.

 

YARMOUTH, after an 18' rear swim was constructed, was 60' Lwl. On the Trent with the 18hp PD2 she was capable of holding off two other 60' narrow boats with around twice the power, almost certainly due to swim length and shape. Theoretically, the hull was capable of 9.6 - 10knots (about 11mph).

 

Fine shaped bows may seem like the way to go for speed, but most ships built today have huge bulbous noses under water line. The reason I believe is that such a shape actually increases fuel efficiency. I don't know, and whilst it sounds ironic, they may be faster for it. But speed range may also be a consideration. Mostly they are cargo ships. Can't see racing 'eights' going for that one.

 

Complicated subject with 'fiddle factors' needed to arrive at results in respect of what engine hp/torque/reduction/prop pitch and diameter is suitable for a given hull - and waters in which it will be used.

 

OK, it's but interesting.

 

Back to PROGRESS?

[chris collins]

Or nearly back to “Progress”, may be just clarifying a few points and putting it all into an inland waterways context.

I hope that I did infer that Hull speed is an invincible barrier, it is however the point at which the energy input starts to rise dramatically out of proportion to the gain in speed, there are many boats that exceed their hull speed, indeed, the category of “medium speed” displacement craft are recognised as those achieving a speed /length ratio of between 1.6 and 3.

By way of illustration let's consider a 50ft, 15 ton narrowboat; hull speed 1.34 x square root of the waterline length, 48 ft maybe, so; 1.34 x 6.928 = 9.28 knots. Power required for 8 knots = approximately 34 hp, power required for 15 knots = 325 hp!! The craft doesn't vaporise or disappear into a black hole (unlike the steerer who would or should) it would however be using about 18 gallons of diesel per hour, less than 1 mile per gallon!

Clearly unless you own a very short narrowboat most of this is inconsequential and so it might be of more interest to look at the implications that do affect canal craft.

The most influential of these factors is without doubt the weight or displacement of the craft, for whilst the study of wetted area, resistance, prismatic coefficient, laminar flow etc. all have their place, it is the displacement that is by far the overriding factor. If we take a simplified look at this with our hypothetical 50ft narrowboat and make a reasonably educated guess that given an average entry and swim it will probably displace about 0.7 tons per inch of draft and so we can reckon that to achieve 4mph we need;

with 1ft draft ( 8.4 tons) requires approximately 3hp

with 2ft draft ( 16 .8 tons) requires approximately 6hp

with a lovely traditional 3ft draft ( 25.2 tons) requires approximately 9hp.

Note, these figures are approximate (rounded up, rounded down, rounded round) but should give the gist of things.

Maybe of more interest in the history and heritage section is the effect on a loaded or unloaded boat. Lets have a look at “Mimas”, ( National dm2 18.5 hp) theoretically unloaded it should be capable of around 8 mph, load it up with 18 ton though and it's down to about 6mph. From practical experience I can say the theory is a bit optimistic and strangely is probably not allowing for the original and fairly battered and worn cast iron propeller that is fitted, probably doesn't account for B.W's no dredging policy either! Logic says that when it was towing “Ray” it would have been capable of around 3 mph which could be about right.

A quick look at “Progress”? at 4' 6'' draft with a 60 ton load and 30hp engine would give it a top speed of around 5 1/2 mph. Bearing in mind that to the best of my knowledge there was never an intention for a “Progress” butty (although Lawrence could prove me wrong and post a set of drawings for his next post!) that would work on the river (with the tide) but could be moving an uncomfortable amount of water on the canal.

Lastly, Derek, I quite like the theory about long thin boats and the hydrodynamics of fish, however I can't get the figures to substantiate the former (if “Progress was 25' wide and of the same displacement the speed figure is exactly the same!). And the fish? Consider a trout, a sole, an angel fish and an eel and we'd have to think that evolution has more important influences than trying to imitate a boat whizzing along half in and half out of the water. However I am sure that you are correct that for our purposes the shape of the stern is the dominating influence.

Phew! ,hopefully next time it really will be back to “Progress”

[Derek R.]

Point taken Chris - sort of! And whilst I don't have any figures, and this is extreme, a practical thought might be to consider how much effort is involved in pushing a canoe sideways - as opposed to forwards. Same displacement, same Lwl. Would it go as fast given the same propulsive power? As the drag increases by increasing the cross-sectional element of a given hull shape being forced through the water, so the hull speed and power required for a give speed be affected.

 

I don't mean to digress and stretch it out, it's just a fascinating subject - and I'm always keen to learn more about such things.

[Timleech]

It's not really the time and place here, but it's an interesting subject that does have ramifications in the narrowboat/ barge world, it will also shed some light on why a tug with 110 hp may “only” reach 11 mph. So, lets go for it.

Lets imagine that we have a fifty foot narrowboat and we set off along any reasonable stretch of waterway, as it gathers speed our boat will set up a series of waves that start quite close together and get further apart the faster we go. If we travel at for instance, 6 knots then the waves will be 20ft apart, 7knots 27.2 ft apart, 8knots 35.6 ft apart. This wavelength is entirely governed by the speed of our boat and would remain constant whether we are steering a narrowboat or a supertanker (not on the BCN of course). If we get tramping along at six knots our boat will be travelling along on three wave crests, one at the front, one at 20 ft and one at 40ft while our friend in the supertanker will have many, many more all spaced at the same 20 ft intervals. All fine and dandy apart from the trail of boats that we have pulled off their moorings (sorry), now lets suppose that we can get to 10 knots, the wavelength is now 55.6 ft, longer than our boat and as a result the front of our boat is supported by the crest of the bow wave whilst the stern is considerably lower in the trough before the stern wave. We are now trying to go uphill ! Any further increase in speed requires an exponential input of energy to achieve, we have achieved ( more correctly exceeded) the hull speed of our boat. Meanwhile Mr supertanker is smugly chugging away at 20 knots still supported by many waves. (225ft apart)!

Because the relationship between wavelength and speed is fixed we can calculate with certainty the hull speed for any displacement boat, 1.34 x the square root of the waterline length gives the speed in knots. So a seventy foot narrowboat will be around 11 knots, Major the tug? Well, we don't know the length of it but if we assumed say, 40ft then the power requirements would rise dramatically to get over 9 knots ( 1 knot = 1.15078 m.p.h)

So how much power does a 40ft tug need ? Well, the second biggest factor is the weight of the boat, if we guess at 15 tons then we need around 5 h.p for 5 knots, 25 h.p for 7knots, 46 h.p for 8 knots and a massive 128 to get to 10 knots!

How much difference does the weight make ? Lets look at that 8 knot speed, if we reduced the weight to 8 tons we would need a mere 26 h.p, conversely add a bit more ballast to 20 tons and we'll be paying to fuel 66 h.p!

Hope that's of interest, next time back to “Progress”

 

My little 35' tug, when it had a 90hp Kelvin fitted, would happily do 7 knots all day in deep water. If I really opened it up it would just about make 8 knots, but the engine was using serious amounts of diesel. This tallies pretty well with the above.

Present engine is only about 56 bhp, I haven't yet had a proper opportunity to open it up for any distance but I imagine it'll still be able to do the 7 knots fairly comfortably.

 

Tim

[chris collins]

Hi Derek, I'll just try and provide a little food for thought, I'd agree that intuition tells us that long /narrow is good, maybe not just within this particular set of parameters.

Firstly, a quick look at your two questions;

 

“ And whilst I don't have any figures, and this is extreme, a practical thought might be to consider how much effort is involved in pushing a canoe sideways - as opposed to forwards. Same displacement, same Lwl. Would it go as fast given the same propulsive power?”

 

Clearly if we turn a canoe sideways the beam becomes the length and the hull speed becomes correspondingly lower, if we try that with a 70' narrowboat; hull speed 70' = 11.2 knots, hull speed 7' = 3.5 knots.

So, no it wouldn't.

 

“ As the drag increases by increasing the cross-sectional element of a given hull shape being forced through the water, so the hull speed and power required for a given speed be affected”.

 

Ton of lead or a ton of feathers? We cannot increase the immersed cross section without altering two of the three parameters, w/l beam, draft or displacement. For a given displacement then simplistically on a hull of narrowboat shape if we double the beam we will halve the draft – frictional resistance and residual resistance remain unchanged.

So, no, hull speed is dominated by W/L length, and at canal speeds power requirement is dominated by displacement.

So what of intuition? I'll try and simplify this as far as possible – mainly to save me from getting bogged down in figures and calculations, also, hopefully to make it a little more generally useful. please bear in mind that in this simplified form we will will miss out on a bundle of the finer points of boat design.

A 70' boat at canal speed (approx 3 ½ knots ) will expend most energy overcoming frictional resistance, this frictional resistance is directly related to the wetted area, the wetted area can be marginally manipulated by design but is largely influenced by displacement, so, roughly speaking, low speed – displacement = wetted area=frictional resistance. Any increase in speed will see a steady rise in the frictional resistance component.

If we increase the speed to around three quarters of hull speed (approx 8 knots) residual/ wave resistance will be creating a similar amount of resistance to the frictional resistance component, further increases in speed will see a rapid rise in the wave resistance component. This wave resistance is directly related to the W/L length of the hull.

So, two categories of resistance, one fixed by displacement and one by waterline length. Lets now assume that we have the engine power to reach 15 knots, the wave resistance is now by far the greater consumer of energy, clearly if we maintain the same displacement (keep identical frictional resistance) but lengthen the waterline we will reduce the wave resistance and faster we will go.

A victory for intuition, in a roundabout way.Hope this helps.