Boat draught

[MtB]

55 minutes ago, nealeST said:

I have been a bit obsessed with that at the outset of my research, but now very decisively settled on a vintage engine as a must, a deeper draught it will be. A lot of varied feedback on the topic. I watched "The Narrowboat Pirate"  YouTube vlogger Heidi go up and down the length of the Llangollen with 3 foot draught this past autumn/winter. I hadn't thought that possible but then she has 10 years of CC'ing and so experience is everything.

 

 

She is generally right about stuff but her boat somehow doesn't look as though it is 3ft draft. 

 

There are bound to be exceptions but deep-draughted boats tend to have a 'look' about them, usually due to the roofline also being lower than the 2 ft and 2ft 6in boats around them. 

[Silent Flight]

On 05/06/2023 at 20:54, Ewan123 said:

Our Liverpool narrowboat was 2'5" at the last survey.

Good to know. Thanks

On 02/06/2023 at 21:52, Tam & Di said:

 

This is extremely basic, but assuming it is a serious question, the 'swim' is the shape of the hull at the stern as it comes to a more or less pointed shape where the propellor is. The finer this shape is the easier it is for the water to be drawn by the propellor and the less 'drag' created. This means the boat has less wash, less turbulence, greater efficiency and greater speed. The counter is the deck platform above this where a steerer stands on an ex-working boat or anything based on that hull shape.

 

It is much cheaper and easier to build a straight-sided hull until the last moment and come to an abrupt pointy bit for the propellor, but that gives you a far less manoeuvrable craft. At the extreme you can have something that is simply a box shape with no swim at all - simply a propellor poked through the back of the box. You get more internal space but the boat is virtually unsteerable. Working boats have a fairly long and fine swim as ease of steering, fuel economy etc was of prime importance. Most people buying their first boat now only look at the internal space and price, but never do understand why boating is then such hard work for them.

 

Tam

I see! Interesting 

[ditchcrawler]

1 hour ago, Owls Den said:

Good to know. Thanks

I see! Interesting 

See 

 

[GUMPY]

Going back to the subject of "squat" ....

 

Coming down the River Wey with a bit of fresh on we arrived at Broadford Bridge with less air draft than on the way up,  in fact less air draft than Parglena needed to get under the bridge.

As the prow reached the bridge it cleared by a fag paper. All was not over however as the wheelhouse was an inch or two higher than the prow. At the requisite moment I unleashed all 120 horses in forward and Parglena just scraped under the bridge to be greeted by a round of applause from some walkers on the towpath.

 

 

Edited June 7, 2023 by GUMPY

[Alan de Enfield]

2 minutes ago, GUMPY said:

Coming down the River Wey with a bit of fresh on we arrived at Broadford Bridge with less aircraft than on the way up, 

 

Is she an aircraft carrier ?

[GUMPY]

1 minute ago, Alan de Enfield said:

 

Is she an aircraft carrier ?

Bloody autocorrect 

[ditchcrawler]

32 minutes ago, GUMPY said:

Going back to the subject of "squat" ....

 

Coming down the River Wey with a bit of fresh on we arrived at Broadford Bridge with less air draft than on the way up,  in fact less air draft than Parglena needed to get under the bridge.

As the prow reached the bridge it cleared by a fag paper. All was not over however as the wheelhouse was an inch or two higher than the prow. At the requisite moment I unleashed all 120 horses in forward and Parglena just scraped under the bridge to be greeted by a round of applause from some walkers on the towpath.

 

 

I use to watch the pilots doing that taking the hire boats under Potter Higham bridge.

[nicknorman]

On 02/06/2023 at 10:20, MrsM said:

A quick post aimed at those looking for their first narrowboat. There is understandably an emphasis on boat length when you are looking to buy - with 57' the widely accepted most accessible length. However, please bear in mind the boat's draught - ie how deep it is under the water. We are in our 4th season of boating in our 58' NB and are finding ourselves frequently on the bottom, despite a draught of only 2'. Many deeper draughted boats are really struggling. Given the water issues the network faces please take note of your perspective new boat's draught when looking. 

We draw 2’8.5” (32.5”) static. This is quite a lot more than your boat, but we never “really struggle”. Well yes maybe a few years ago between Trevor and Llangollen, but it was “challenging” rather than “struggling”. We overcame the challenge!

 

The up-side of deep draft is a propensity to go where it’s pointing in strong crosswind, and a much more solid feel to the boat. Obviously a deep drafted boat must be proportionally heavier than a shallow drafted boat of the same length. And the other upside is a well-submerged and larger diameter propellor which is more efficient, especially with regard to stopping suddenly and being able to reverse long distances under control.

 

So yes running aground or dragging the bottom can be an issue, but in my opinion the up-sides more than compensate. But you are of course correct, one should be aware of all a prospective boats attribute, not just the length.

[Ian Mac]

I find this discussion all very interesting, our boat draws over 3ft stationary, and pulls down to 3ft 6" under power. We get around the system fairly well with a few exceptions, the mooring below Thrupp by the road wharf, being one, but even that we got throw with a load of rocking and laying on the power and dredging the silt out of the way. Some canals are really slow such as the Northern Stratford currently, and the Shroppie which use to be a motorway is nowt just average.
Thirty years ago we had a 20ton winch on the deck as standard, because we needed it, all over the place. When we report our problems to C&RT we find they are fairly responsive., ie it get fixed within 2 years., It is not coincidence that the locks on the Southern Oxford are being dredged, I suspect!
The Historic Narrow boat club attempt to keep a register of all the places their members stick, its actually not that big a list, but that maybe because our members are poor at reporting problems. The latest addition to that list are the culverts south of Ellesmere Port.
As has been written before 20 years ago most boats passed us with a 6" gap between the boats these days 6ft seems to be classed as close and they do it 1/2 a mile before you meet them. The old boatmen use to twitch the stem over at the very last minute, and they did not slack off, as you passed, the back ends would naturally pull back into the centre of the channel, straightening the boats out. The only time they would slow down is when it was not their blind corner , ie a tight right-hand bend, this was so they could take the inside line, in case they met someone coming the other way. If i am steering and someone pulls over, that well out of the channel, I stay in the middle and slow down a bit and pass them, saying thank you. It is rare these days to be passed properly, and have to move out of the channel.
The channel has moved it use to go around the outside of bends, when C&RT dredge that is where they dredge it, however most modern boats cut the corners ( I think they think they are doing a car racing turn) and this brings the channel in, so one needs local knowledge about when a cut was last dredged.  The thing we most notice is  that when a length is getting near requiring dredging that the approach to any narrows have a silt bar across them , so 5m before a bridge hole we will hit the silt bar for 3m. However we always slack off for narrows, as it lifts the backend, and makes your passage quicker, learnt that tip over 50 years ago, attempting to keep up with a blue line pair on the GU, the boatman laughed when we asked how come he'd been in the pub for over a pint, by the time we caught them up, one evening, and he said "thou's not stacking of for bridge holes", or words to that effect We kept pace with them the following day, just! And NO I cant remember his name or the pair, dyslexia rules KO.
The other really noticeable feature of modern day boaters is that they all think you can moor anywhere. Most canals where built saucer shaped, the cheaper the canal the shallower the saucer is, at the edges, so on canals like the HVNC it is only 18inches deep at the towpath wash wall, except at wharfs. The off side is only 6" deep. BW and C&RT have a policy of installing bollards above and below locks, some think this means there is deep water there, it means you are within 20m of the lock not that the canal profile has been changed. This will not alter, they will not remove the clay to let you get in.

PS like the story about the bridge on the River Wey, pulled a similar trick, by accident going under Lumb Lane bridge on the Ashton Summit, when I discovered the hard way, my mates Lubby was higher that the bottom girder of the bridge, when tanking along, quickish burst of hard astern and then some more, followed by out of gear and we popped under, not sure how, but we did. Unfortunately he did not realise what I had done, so when coming the other way he got caught out by it. Mast rebuild required.

 

PPS when they rebuilt Hurleston that enable us to do the Welsh cut, first time she has been up there since 1964.. The only problems we had were the cutting west of Crick Tunnel and the locks at Marton, and couple of bridge holes below Aston. We did not attempt the feeder, above Trevor.

[MrsM]

When starting this thread I did not intend to advocate that new boaters should only look at shallow draughted boats, but that they should be aware of their boat's draught and how this might affect them and where they wish to take it. I completely get the advantages of a deeper draughted boat and the importance of the waterways being able to accommodate them. We're in our 4th season of boating now and do an average of 600 hours/year. I am a lot more confident steering than I was at the start but am aware that my skills are still very much at the beginner stage compared to many other boaters. It takes a certain amount of time for new boaters such as myself to gain all of the handling skills discussed in this thread, and I'm grateful that I've got a very easy and forgiving boat to learn on. Saying that, I have limited experience of handling other boats and perhaps I would have become a better steerer more quickly with a different boat?

[Mike Adams]

It is quite a strange fact that most narrow boat owners tend to over estimate the draught of their vessels. I owned for something like 25 years a narrow beam tug that initially drew 3ft 7inches until I re-engined it and managed to get it down to 3ft 4 inches. We traveled a high proportion of the waterways and yes we had problems but they were usually caused by an unexpected low level or an obstruction and were only once totally defeated by an obstruction. My current boat is about 2ft 6inches which is probably ideal for handling and it is bliss to never even think about going aground.

The reason most people go aground is because they are going too fast and get out of the channel.

[nicknorman]

Just on the passing boats thing, certainly many people move over far too soon and far too much. The shuffle thing is rather satisfying.

 

But in other news, sometimes the person coming the other way is a nutter. They come along in the middle of the cut. Fine. … fine … fine … they really ought to be moving over now! … CLANG!

 

Had that when passing moored boats with a boat coming other way on KandA - plenty of room but boat coming other way held dead centre of canal. I was squeezed into having about 6” between me and moored boats and still there was a few inches of overlap. Surely he is going to move over a bit? After all there is about 15’ of available canal width on the other side! But no, he drove straight into us, we bounced off and hit the moored boat fairly hard. I asked the idiot why he hadn’t moved over a foot or so. “It’s shallow over there” he said. So presumably having a head on collision is worse than the slight possibility of scraping the bottom. It was of course a shiny and fussily decorated boat. All the gear and no idea.

[Rob-M]

When the passing boat uses their bow thruster as your bows draw level is something I've had done to me pushing my bows sideways in to a moored boat whose owner then appeared to shout and swear at me for hitting their boat.  I don't think they believed me when I told them the idiot going in the other direction pushed me in to them.

[ditchcrawler]

42 minutes ago, Rob-M said:

When the passing boat uses their bow thruster as your bows draw level is something I've had done to me pushing my bows sideways in to a moored boat whose owner then appeared to shout and swear at me for hitting their boat.  I don't think they believed me when I told them the idiot going in the other direction pushed me in to them.

Had that on the Weaver the other week, sitting patiently waiting for them to come out and whoosh, yours truly in the trees 

[David Mack]

11 hours ago, Ian Mac said:

If i am steering and someone pulls over, that well out of the channel, I stay in the middle and slow down a bit and pass them, saying thank you.

And then they complain about the arrogant working boat that refused to move over and forced them into the shallows. You can't win!

[GUMPY]

 

Slow right down when approaching a boat coming the other way? 

Not a chance!

 

If people don't know how to pass another boat in a restricted channel and pull over that's their problem not mine.