Tunnel Lights

[Mike Todd]

23 hours ago, David Mack said:

Indeed. But I recall from my A level maths statistics lessons that in large populations with a normal distribution, the mean, median and mode converge on a single value. So when talking in terms of say the entire UK population the difference between the different averages is not material.

That conclusion is dependent on the IQ distribution being of a certain shape (usually considered Normal) but that is as much a consequence of the test design than the underlying phenomenon being measured (or attempted measure). Then add in that public policy seeks to skew the distribution through education. No test is independent of culture, language, education etc (most at least require an ability to read or understand instruction) This also means that at one end of the scale there is very limited possibility of getting a meaningful result.
 

You also should factor in that statistically based tests are usually only valid for population level results and should not be used as an accurate measurement of an individual. That is to say, you could reasonably use the test to compare a group of 1000 boaters with a similarly selected group of non boaters and conclude that the former are 3 IQ points higher than the latter but not that Mike Todd is in the top 1% of the range. You would also have to show that boating does not introduce its own selection bias - brighter people are much more likely to go boating than t hose of below average intelligence (!). It might also be necessary to explain why anyone with a modicum of intelligence should still go boating at 78 in flagrant disregard for all the attendant risks. Despite its appeal to politicians, testing using statistical methods is usually flawed in the application of the results.

[Alan de Enfield]

2 minutes ago, Mike Todd said:

You would also have to show that boating does not introduce its own selection bias - brighter people are much more likely to go boating than t hose of below average intelligence (!).

 

Would there not be a case where that is incorrect ?

 

Making some assumptions and taking 'Big Cities' as examples.

 

Less well educated people in 'service' or hospitality type of jobs are simply living on boats because they are unable to afford 'bricks & mortar' on their minimum wage.

 

I wonder how the IQ of the 5000 liveaboard boaters in London would compare with 5000 liveaboard boaters 'North of Watford Gap' ?

[Mike Todd]

1 minute ago, Alan de Enfield said:

 

Would there not be a case where that is incorrect ?

 

Making some assumptions and taking 'Big Cities' as examples.

 

Less well educated people in 'service' or hospitality type of jobs are simply living on boats because they are unable to afford 'bricks & mortar' on their minimum wage.

 

I wonder how the IQ of the 5000 liveaboard boaters in London would compare with 5000 liveaboard boaters 'North of Watford Gap' ?

I suspect you missed the irony in my selection of an hypothetical example!

[Alan de Enfield]

8 minutes ago, Mike Todd said:

I suspect you missed the irony in my selection of an hypothetical example!

 

 

No, I was just expanding on how easy it is to get the results you want by careful choice of candidates.

 

Although, anyone who buys a boat has questionable common sense and mental ability.

[Col_T]

28 minutes ago, Alan de Enfield said:

 

Although, anyone who buys a boat has questionable common sense and mental ability.

 

Or, to put it another way, more money than sense. 🙂

[Ex Brummie]

So, coming back to tunnel lights .............

[dixi188]

How do you see the boat in front when the tunnel is full of fog as I found a few years ago going through Blisworth tunnel on a hot and humid day? I think the vis was a lot less than 50 yards.

My tunnel light just gave a bright glare.

I go carefully and keep a bright torch to hand to wave or flash at a boat coming along behind if they get too close. You can always shout,( I have a loud voice).

[TheBiscuits]

12 minutes ago, dixi188 said:

How do you see the boat in front when the tunnel is full of fog as I found a few years ago going through Blisworth tunnel on a hot and humid day? I think the vis was a lot less than 50 yards.

My tunnel light just gave a bright glare.

I go carefully and keep a bright torch to hand to wave or flash at a boat coming along behind if they get too close. You can always shout,( I have a loud voice).

 

You could always use the technique required by law in this situation ...

 

General Canal Byelaws

12.

(3) In fog, mist, falling snow, heavy rainstorm or any other conditions similarly restricting visibility whether by night or day, the following signals shall be used:-

 

(a) A power-driven vessel making way through the water shall sound, at intervals of not more than two minutes a prolonged blast.

[Tracy D'arth]

1 hour ago, TheBiscuits said:

 

You could always use the technique required by law in this situation ...

 

General Canal Byelaws

12.

(3) In fog, mist, falling snow, heavy rainstorm or any other conditions similarly restricting visibility whether by night or day, the following signals shall be used:-

 

(a) A power-driven vessel making way through the water shall sound, at intervals of not more than two minutes a prolonged blast.

You could do that in Harecastle tunnel and be still ignored by the volunteers I believe according to a recent emergency there. 

[dixi188]

TB. I didn't know that rule applied in tunnels.

If I do that will all the other boats do the same? And will the sound be sifficiently directional to work out if a boat is coming towards you or going away.

I always do a long blast when entering a tunnel.

[Tracy D'arth]

20 minutes ago, dixi188 said:

TB. I didn't know that rule applied in tunnels.

If I do that will all the other boats do the same? And will the sound be sifficiently directional to work out if a boat is coming towards you or going away.

I always do a long blast when entering a tunnel.

You always turn right when entering a tunnel?  How bizarre!  

[dixi188]

Short blast is "turning right", long blast is "I am here", I think.

[Tracy D'arth]

2 minutes ago, dixi188 said:

Short blast is "turning right", long blast is "I am here", I think.

Please define what is short and what is long.  Its subject to interpretation unless there is a definite answer in the Colregs

[MPR]

21 hours ago, TheBiscuits said:

 

You could always use the technique required by law in this situation ...

 

General Canal Byelaws

12.

(3) In fog, mist, falling snow, heavy rainstorm or any other conditions similarly restricting visibility whether by night or day, the following signals shall be used:-

 

(a) A power-driven vessel making way through the water shall sound, at intervals of not more than two minutes a prolonged blast.

Don't forget the bell if at anchor

[TheBiscuits]

43 minutes ago, MPR said:

Don't forget the bell if at anchor

 

Which byelaw do you think that is?

[doratheexplorer]

22 hours ago, TheBiscuits said:

 

You could always use the technique required by law in this situation ...

 

General Canal Byelaws

12.

(3) In fog, mist, falling snow, heavy rainstorm or any other conditions similarly restricting visibility whether by night or day, the following signals shall be used:-

 

(a) A power-driven vessel making way through the water shall sound, at intervals of not more than two minutes a prolonged blast.

I was at sea in fog recently.  Our boat was the only boat we came across actually doing this.  Canals aren't the only place where people don't bother with correct signals.

[Alan de Enfield]

2 hours ago, Tracy D'arth said:

Please define what is short and what is long.  Its subject to interpretation unless there is a definite answer in the Colregs

 

It is defined.

[tree monkey]

On 28/09/2021 at 11:20, Col_T said:

 

Or, to put it another way, more money than sense. 🙂

When I bought my boat I had absolutely no money, in fact I ended living in an overdraft for a while...

.

.

Not sure I should have admitted that

[ditchcrawler]

8 hours ago, doratheexplorer said:

I was at sea in fog recently.  Our boat was the only boat we came across actually doing this.  Canals aren't the only place where people don't bother with correct signals.

I use to sleep above a foghorn ..._ every 30 seconds if I remember correctly. The marker lights were the same signal every 15 seconds

[StephenA]

2 minutes ago, ditchcrawler said:

I use to sleep above a foghorn ..._ every 30 seconds if I remember correctly. The marker lights were the same signal every 15 seconds

 

Did you learn to ignore it? I used to work on a site with a criticality alarm that ticked once every second - after about 3 months you didn't notice it... unless it stopped

[ditchcrawler]

5 minutes ago, StephenA said:

 

Did you learn to ignore it? I used to work on a site with a criticality alarm that ticked once every second - after about 3 months you didn't notice it... unless it stopped

It was only on when it was foggy which was normally around June for the worst of it. then it could be continues for 3 to 4 days. Normally get to sleep after a couple of hours. I agree about noticing things stop. If the pumps stopped I would be awake before the low flow alarm sounded.

[Ronaldo47]

When I retired, we treated ourselves to a Mediterranean cruise. On the way back we had sea fog for the entire day and a half it took to sail from from Italy to the Straits of Gibraltar. You could get above the fog and sit in the sun on the 11th deck, but the foghorn accompanyment rather spoilt things.

[MtB]

24 minutes ago, Ronaldo47 said:

When I retired, we treated ourselves to a Mediterranean cruise. On the way back we had sea fog for the entire day and a half it took to sail from from Italy to the Straits of Gibraltar. You could get above the fog and sit in the sun on the 11th deck, but the foghorn accompanyment rather spoilt things.

 

Could you have asked her to stay below in the cabin? 

[blackrose]

On 23/09/2021 at 15:36, David Schweizer said:

As far as I am aware there is no legal requirement for either navigation lights or rear facing lights on C&RT canals, although C&RT do suggest some sort of light on the back end (but not a single bright spot) We never had any lights, relying on leaving the back cabin doors open with the cabin lights turned on, that with white and red tunnel bands, the boat should be eaily visible before any following boat risked hitting us, Assuming they could catch us up!!

 

There is no legal requirement but if the OP is fitting lights fit navigation lights, not bike lights or "rear facing tunnel lights" (whatever that is?). They're called stern lights.

 

 

 

Edited September 30 by blackrose