Speed limits

[fender]

If road patrol officers were to point a radar gun from a moving boat at a vehicle on a parallel road and then claim the vehicle was speeding, it would not be admissable evidence. Yet this is what the Thames people seem to be trying to achieve. It obviously would be a different situation on a canal as the water has not got any perceivable flow (yes except the Llangollen of course!!!)

 

I've always thought that speeding - up to now - was about common sense, but as I've noticed many boaters do like to go much faster these days.

[magnetman]

If road patrol officers were to point a radar gun from a moving boat at a vehicle on a parallel road and then claim the vehicle was speeding, it would not be admissable evidence. Yet this is what the Thames people seem to be trying to achieve. It obviously would be a different situation on a canal as the water has not got any perceivable flow (yes except the Llangollen of course!!!)

They used to sell speed guns in maplin but they didn't work below about 6mph... I did hear of a case recently where someone proved that a radar gun was not an accurate measure of the vehicle's speed and got off a speeding fine.

Isn't it something to do with the radar gun sensing the engine rpm then cross referencing it with a database of all vehicles, having recognised the vehicle type from its number plate via another database, then estimating the speed which it would be travelling at using tables of information and making assumptions on which gear the vehicle is in from sound pressure levels received by the device. This could be quite innaccurate (and is how I used to think they worked - honest).

Or is it something to do with the difference in wavelength of a reflected beam?

[Howard]

No , its based on a laser that is bounced off the car / hull whatever ....

 

I agree that to do a speed check from a moving boat would be idiocy , thats why they are moored up when they do ....

 

The Agency isn't out to start collecting speeding fines, i mean if you were doing even 10 knots , they probably wouldn't even bother you , it's more based on targeting speeding passenger boats and idiots in speedboats that have launched them for the day and don't know any better.....

 

Not on hassling the average river user who might drift a couple of knots over the limit .....

 

Why do people have this hang up about speed checks on the river ? is it because the police use them to generate revenue on the roads ? it's not the same ....

Edited February 22, 2007 by Howard

[fender]

No , its based on a laser that is bounced off the car / hull whatever ....

 

I agree that to do a speed check from a moving boat would be idiocy , thats why they are moored up when they do ....

 

The Agency isn't out to start collecting speeding fines, i mean if you were doing even 10 knots , they probably wouldn't even bother you , it's more based on targeting speeding passenger boats and idiots in speedboats that have launched them for the day and don't know any better.....

 

Not on hassling the average river user who might drift a couple of knots over the limit .....

 

Agreed these idiots need surpressing - BUT my point (having tried terribly to postualte an analogy of sorts) is that a patrol officer on a moored boat cant measure a boat's speed properly if there are two factors (speed on water plus speed of river flow) so I would have thought that a patrol officer on a moving boat in unison with the speedster (at a fixed distance behind the said culprit) would have achieved a far better reading - though still not accurate enough of course.

 

In other words, whether one measures a speed from the bank, a moored boat, or a moving boat (or even a helicopter or a moving vehicle on the bank) the result can never be accurate.

 

There has to be other ways. And I've always thought one of them to be the amount of wash that is being created - a tried and tested method that surely doesnt have any fault to it??

[WJM]

There is one particular passenger boat on the top tideway / bottom EA river that kicks out a monster wash regardless of the speed, obviously a very poor shape, certainly looks ugly - at totally legal speeds you can sit a canoe on its wash and put your paddles away and just get dragged along for miles. It has been around here for years. I wonder why it is allowed? I guess it is within the speed limit so the EA/PLA cant touch it legally despite all the wear and tear to the banks. So there is the real flaw in using speed limits.

 

 

 

 

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"Isn't it something to do with the radar gun sensing the engine rpm then cross referencing it with a database of all vehicles"

 

A good argument for having an automatic car then (no direct linear connection between engine and wheels) - this would never work

[magnetman]

There is one particular passenger boat on the top tideway / bottom EA river that kicks out a monster wash regardless of the speed, obviously a very poor shape, certainly looks ugly - at totally legal speeds you can sit a canoe on its wash and put your paddles away and just get dragged along for miles.

 

I think I may be familiar with this boat but apparently we aren't allowed to name it because of defamation and legal issues.

I didn't really mean it about the engine rpm etc, it was how I 'worked out' that they operated, a bit like when I asked my dad when I was about 6, having grasped the fundamentals of the operation of an electric motor, how a petrol engine worked. he said "its the same, yes" so I spent quite a few years trying to work out how, if you spray petrol at a cylindrical object with segmented parts (like a commutator) you could get it to turn. Never mind. I bet it was that boat that bust the end of the island at Thames Ditton, Taggs Island that's the one.

 

A 'wash detector' would be worthwhile definitely and not that difficult to organise, it could even generate some 'green' power maybe.

[fender]

There is one particular passenger boat on the top tideway / bottom EA river that kicks out a monster wash regardless of the speed, obviously a very poor shape, certainly looks ugly - at totally legal speeds you can sit a canoe on its wash and put your paddles away and just get dragged along for miles. It has been around here for years. I wonder why it is allowed? I guess it is within the speed limit so the EA/PLA cant touch it legally despite all the wear and tear to the banks. So there is the real flaw in using speed limits.

 

Yes I know of it too always get a right rollicking from its wash when I have been moored up at Kingston

[Big Steve]

Well, I seem to have opened a can of worms here, I didn't meant to, honest! I'm new to canal boating and have just aquired a 52' narrow boat which is currently in Birmingham. It has to be got to the Stainforth and Keadby and I was just trying to get some idea of the journey time, most of which will be on the Trent. Normally I would be quite happy to chug along at 4 mph, but want to get my toy home. Now I've got to organise a mooring, Thorne, Kirk Bramwith, Stainforth? Any ideas?

 

Thanks for all your comments.

 

Steve

[fuzzyduck]

Steve

 

Don't worry about the can of worms, if someone here says "morning" at least 3/4 of the forum check their watches, it makes for a lively, and usually fun atmosphere . Morning by the way.

[Supermalc]

Narrowboat on the Trent to Keadby this time of year; and with a novice Could make for an interesting trip report

[bottle]

Well, I seem to have opened a can of worms here, I didn't meant to, honest! I'm new to canal boating and have just aquired a 52' narrow boat which is currently in Birmingham. It has to be got to the Stainforth and Keadby and I was just trying to get some idea of the journey time, most of which will be on the Trent. Normally I would be quite happy to chug along at 4 mph, but want to get my toy home. Now I've got to organise a mooring, Thorne, Kirk Bramwith, Stainforth? Any ideas?

 

Thanks for all your comments.

 

Steve

 

Hi Steve

 

As has been said maximum speed on canals is 4mph but you may not make a breaking wash so a lower speed may be appropriate.

 

Stock answer for time to travel between two points go here canalplanac and click on 'plan a journey' (left of screen)

[WJM]

http://shop.rivercanalrescue.co.uk/RoutePl...utePlanner.aspx

 

 

 

I think I prefer this one - the layout of the route information is clearer - but both are good

[Keeping Up]

Well, I seem to have opened a can of worms here, I didn't meant to, honest! I'm new to canal boating and have just aquired a 52' narrow boat which is currently in Birmingham. It has to be got to the Stainforth and Keadby and I was just trying to get some idea of the journey time, most of which will be on the Trent. Normally I would be quite happy to chug along at 4 mph, but want to get my toy home. Now I've got to organise a mooring, Thorne, Kirk Bramwith, Stainforth? Any ideas?

 

Thanks for all your comments.

 

Steve

Be careful until you know the boat Steve. It may never have been over 4mph in its life if it's always been on the canals. In fact it may never have been over 2mph. The cooling system may or may not have been adequately built for high-speed running when it was new, and it may or may not be OK now after a few years of running and sludging up. You won't know whether it's OK or not unless either the previous owners can tell you whether they've been on rivers recently and how fast they travelled (and for how long) - or until you've found out by starting slowly and carefully then GRADUALLY increasing the speed.

 

When you get out on to the river, resist the temptation to try to go too fast until you know the boat can take it without overheating. You'll still get there OK even at 3 mph on the tideway, but I've lost count of the number of boats I've rescued after they overheated when running too fast on their first visit to the rivers.

 

Of course you want to get home quickly, but it's better to take your time and enjoy the scenery!

 

Allan

[Big Steve]

Thanks for all your comments folks, I've known the bloke I'm getting the boat off for over 30 years and he's an excellent engineer so I'm sure the mechanics will be fine. Also have an experienced crew to deliver it, thank god, the Trent gives me the creeps. Used to sail on the Clyde a long time ago, no bother, but the Trent makes my little hairs stand up.

[Maffi]

Speaking as one who is on the Thames now it appears to me that all boats are breaking wash except me.

[Supermalc]

Exactly as I discovered, when I first started boating on Naiad. Top speed 6mph. Top speed allowed 6mph.....I could do 6.1mph; I had not lost my GPS. Yet nearly all boats were going faster than me.

 

The bank protection is however well done, as with the river at normal summer levels, the wash does not go over the top, so no bank errosion.

 

 

Breaking wash btw is when the top curls over, as in breakers on a beach. It does not mean disturbing a bit of water that causes a few ripples on the bank.

 

Even with my engine in top form, and my little outboard on, I can't get my boat to do this

 

Maybe I need to get one of these