RYA quiz, diesel tanks

[smiler]

Shirley it's wise to keep the tank full for economic reasons - the price will likely increase in the future.

[Oddjob]

9 hours ago, booke23 said:

 

Remember every time a jet airliner flies, the fuel tanks are exposed to extremely low temperatures. Typical air temperature at 35,000 ft is -56°C and the fuel typically cools to -30°C on long flights. This would seriously inhibit any bug growth. It also means any water in the fuel could cause serious problems (2008 British Airways 777 crash landing at Heathrow) even though the fuel passes through a heated filter system.  

Temp at 35 k ft can go do - 65 the issue with the BA777 was 9 hours at cruise alt with no change in engine power setting during flt in jet A1 fuel there is always water in the fuel. Ice built up on the inside of the fuel lines which when the aircraft started to descend started to warm up again the aircraft was still not using big increases in power the on short finals and at max drag a larger demand in power was required the ice broke of and the design of the fuel oil heater allowed to ice to block the inlet to the fuel heater hence no power and the aircraft belly flopped just short of the runway with some classic Ba piloting skills saving the day. 
fuel heat exchanger design now changed to stop this happening again. 
But I still say keep tanks full when leaving the boat

[Murflynn]

14 hours ago, Dr Bob said:

Minimising oxygen in the diesel tank will mean increased oxygen outside the tank which therefore reduces the density of the air inside the boat allowing the ecofan to spin faster and spread the heat better. Everyone wins!

on the other hand, a large volume of air in the tank means there will be much more nitrogen than oxygen, and algae that is dependent on oxygen will not thrive in the nitrogen rich atmosphere.  If you throw a lighted taper into the tank with luck you might burn off all the oxygen, making it even less liable to algae growth. 

 

answer - keep your tanks nearly empty.

 

do I get marks out of ten?

13 hours ago, bizzard said:

Fuel tank needed to be V shaped with pick up pipe down in the V or better still fuel tank on gimbals.

or hang it from the mast-head - it will make the boat less "stiff" which can be more comfortable under certain weather conditions.

Edited November 20, 2020 by Murflynn

[ditchcrawler]

9 hours ago, smiler said:

Shirley it's wise to keep the tank full for economic reasons - the price will likely increase in the future.

Not when someone nicks it all

[Machpoint005]

19 hours ago, bizzard said:

better still fuel tank on gimbals.

 

It'll still slop around on lumpy water, won't it?

 

6 hours ago, Murflynn said:

on the other hand, a large volume of air in the tank means there will be much more nitrogen than oxygen, and algae that is dependent on oxygen will not thrive in the nitrogen rich atmosphere.

 

Why won't the proportions of O2 and N2 be the same regardless of how much of the mixture (air) there is?

Even if there's only a tiny volume, there is still four times as much nitrogen as oxygen.

[Dr Bob]

22 hours ago, Alan de Enfield said:

Well, well, well, bringing the Cat back from Croatia we had almost exactly the same (except it was a F8 and bang on the nose),  in the same area - had to turn back to the mainland and hunker down for the night.

It had been quite a nice sail for us with the wind behind most of the way from Greece but then turning north up  the straights it was also dead against us. By the time I got the engine running again, the thought of trying to beat into the waves meant we turned round and headed south, to anchor off Taomina for the night. I seem to recollect we lost the main halyard that evening as well so headed into the marina at Riposto (on Scicily) to re-thread it. Not our best of days!

[LadyG]

21 hours ago, MartynG said:

They shouldn't be kept reasonably topped up 

A full tank of diesel  in an unused boat will result in greater volume of fuel to deal with if diesel bug occurs

Also bio diesel in the fuel has a shorter shelf life 

Therefore only add fuel if you intend to consume it promptly 

 

By the way the oxygen reason you quoted  is rubbish . For example  in a rectangular tank  the surface area of fuel in contact with the air is the same at any tank level unless the tank is full to the brim.

An alternative view, but falls down when you start to run out, especially important when marinas just suddenly stop selling diesel.

Of course the surface area argument falls down if your tank is spherical.

The idea that oxygen is a bad thing, well why? I thought we would be getting a discussion on the interface of air to diesel molecules, in my mind the bug , a live organism wil require oxygen, but not necessarily as free O 2, but from water. H2 O

 

Obviously a centrally placed spherical, double gimbaled tank for the engine, and another for the heater will solve all these biological problems, maybe an endoscope in the tank to allow the skipper to observe biological activity? Sort of a bit like a fishfinder?

[Momac]

3 minutes ago, LadyG said:

An alternative view, but falls down when you start to run out, especially important when marinas just suddenly stop selling diesel.

Of course the surface area argument falls down if your tank is spherical.

I don't think marinas  are going to stop selling diesel . Or at least  not that marina  where I keep my boat . Marinas  don't sell fuel to make money but to keep their customers happy.

 

How many boats have you seen with spherical fuel tanks?

 

[LadyG]

12 hours ago, MartynG said:

I don't think marinas  are going to stop selling diesel . Or at least  not that marina  where I keep my boat . Marinas  don't sell fuel to make money but to keep their customers happy.

 

How many boats have you seen with spherical fuel tanks?

 

There is no diesel on the Chesterfield, West Stockwith stopped selling diesel a month or so ago ..... ill health and the coming of white diesrl.

I was joking around ....... but you never can tell.

Edited November 21, 2020 by LadyG

[Murflynn]

15 hours ago, Machpoint005 said:

 

It'll still slop around on lumpy water, won't it?

 

 

Why won't the proportions of O2 and N2 be the same regardless of how much of the mixture (air) there is?

Even if there's only a tiny volume, there is still four times as much nitrogen as oxygen.

irony escapes you yet again.

 

....................  but - there WILL BE loads of nitrogen.  in the oil and gas industry we use nitrogen to provide a non-explosive atmosphere.

[Murflynn]

12 hours ago, LadyG said:

An alternative view, but falls down when you start to run out, especially important when marinas just suddenly stop selling diesel.

Of course the surface area argument falls down if your tank is spherical.

The idea that oxygen is a bad thing, well why? I thought we would be getting a discussion on the interface of air to diesel molecules, in my mind the bug , a live organism wil require oxygen, but not necessarily as free O 2, but from water. H2 O

 

Obviously a centrally placed spherical, double gimbaled tank for the engine, and another for the heater will solve all these biological problems, maybe an endoscope in the tank to allow the skipper to observe biological activity? Sort of a bit like a fishfinder?

bugs are not well-known for extracting oxygen from water, or for benefiting from the presence of oxygen in a very stable molecule that usually requires strong electric currents to persuade the atoms to break away and socially distance ...............  if you know some that can do it please let the hydrogen generation industry know.

 

marine fauna and flora use the dissolved oxygen and CO2 in water to perpetuate their organic systems, which is why the deep ocean is incapable of supporting most species of life.

[MarkH2159]

Do the RYA actually know anything about diesel anyway?

[LadyG]

2 minutes ago, Murflynn said:

bugs are not well-known for extracting oxygen from water, or for benefiting from the presence of oxygen in a very stable molecule that usually requires strong electric currents to persuade the atoms to break away and socially distance ...............  if you know some that can do it please let the hydrogen generation industry know.

 

marine fauna and flora use the dissolved oxygen and CO2 in water to perpetuate their organic systems, which is why the deep ocean is incapable of supporting most species of life.

Most flora and fauna wil struggle in any ocean, but not all, try googling deep water worms....

[1st ade]

Back to the original question - I used to helm a 6.5m RHIB (A big inflatable) which had a hundred litre petrol tank in the bow to feed the 140HP outboard at the stern

 

Its handling with 1/2 a tank was "questionable" as the fuel could slosh; minor course adjustment approaching a pontoon and ~50kG of fuel went sideways, then hit the tank wall. There was a definite post turn "jolt". And given the choice of "nearly empty" or "nearly full" I know which I'd choose...

[Alan de Enfield]

3 minutes ago, 1st ade said:

Back to the original question - I used to helm a 6.5m RHIB (A big inflatable) which had a hundred litre petrol tank in the bow to feed the 140HP outboard at the stern

 

Its handling with 1/2 a tank was "questionable" as the fuel could slosh; minor course adjustment approaching a pontoon and ~50kG of fuel went sideways, then hit the tank wall. There was a definite post turn "jolt". And given the choice of "nearly empty" or "nearly full" I know which I'd choose...

That is why most 'big' tanks have baffles built into them - it stops sloshing and weight transfer.

I have 3 tanks, 1x 1000 litres built into the keel and 2x 900 litres as 'wing' tanks. I'd rather not think about what (say) 1000 litres of unrestrained fuel sloshing from side to side would do.

 

There have been a number of ships that have rolled due to movement of water - the Ro-Ro's being particularly bad (Later christened Ro-Ro-Ro - Roll on, Roll over, Roll off)

 

Zeebrugge Ferry Disaster :

 

Roll-on, roll-off ferries, or “ro-ros”, are inherently unstable. Most of the ship is above the waterline, not below. Ro-ros are very flat-bottomed: considered in many quarters not to be “real ships” at all – as if still guided by invisible chain. That is why the Herald’s ingress of water was cataclysmic. You only need to carry an ordinary, water-laden 12-inch dinner plate across your bedroom to understand just how volatile – and wet – the outcome. British Rail’s pioneering ferry, MV Princess Victoria, attempting to traverse the wild Irish Sea from Larne to Stranraer on a fateful night during the even more fateful east coast floods of 31 January and 1 February 1953, went down almost immediately as towering waves beat their way on to its car deck. 133 passengers and crew perished that night, with only 44 survivors: none of those eventually rescued was a ship’s officer. Compare.

 

“[We] had gone out of harbour with a gaping hole in the bow caused by open doors. She was also loaded and tilted [three-foot extra] at the front [due to extra ballast fed into the hull in order to accommodate the Port of Zeebrugge’s incompatible gangways]. As her speed increased ... the bow door ramp was pushed into the water, scooping up every bow wave, so allowing hundreds and thousands of gallons of sea water to pour in ... This water settled on the port side, causing that first roll. [Briefly] the ship then steadied; but as more water rushed in, the extra weight sent the ship into its final death roll. Floating on its side for a minute, it [soon and providentially] settled on the sandbank that [mercifully] saved the ship from turning completely turtle.”

 

 

 

[cuthound]

2 hours ago, MarkH2159 said:

Do the RYA actually know anything about diesel anyway?

 

I would have thought that it would be plain sailing for them! ??

[Momac]

3 hours ago, LadyG said:

There is no diesel on the Chesterfield, West Stockwith stopped selling diesel a month or so ago ..... ill health and the coming of white diesel

Yes I know that from previous conversation.

But in that case the ill health or retirement may be the factor since white diesel hasn't yet become mandatory. Also I don't think he ever  did it for the money making aspect.

The diesel at West Stockwith used to be provided by  C&RT and the old diesel tank is still there (or was last time I looked)  although probably life expired.

 

A marina on the other hand makes its main income  from mooring charges for boats with everything else such as  boat sales brokerage and engineering  a bonus . A marina that doesn't sell fuel is going to be less popular.  In the same way supermarkets sell fuel and probably don't profit directly from it - but the service provided attracts customers who buy other things .

 

 

[Murflynn]

5 hours ago, LadyG said:

Most flora and fauna wil struggle in any ocean, but not all, try googling deep water worms....

I don't recognise any reference to creatures with the ability to extract O2 from H2O which is what you specified.

[LadyG]

2 hours ago, MartynG said:

Yes I know that from previous conversation.

But in that case the ill health or retirement may be the factor since white diesel hasn't yet become mandatory. Also I don't think he ever  did it for the money making aspect.

The diesel at West Stockwith used to be provided by  C&RT and the old diesel tank is still there (or was last time I looked)  although probably life expired.

 

A marina on the other hand makes its main income  from mooring charges for boats with everything else such as  boat sales brokerage and engineering  a bonus . A marina that doesn't sell fuel is going to be less popular.  In the same way supermarkets sell fuel and probably don't profit directly from it - but the service provided attracts customers who buy other things .

 

 

He asked CRT business manager, but no solution, I'd guess thinks the coming of white is the last straw.

[tehmarks]

On 20/11/2020 at 09:26, Oddjob said:

with some classic Ba piloting skills saving the day. 

Tangent: and the captain was subsequently hung out to dry by BA for no good reason, reportedly. A shining example of the famous aviation 'just culture' at work...?

[booke23]

5 hours ago, tehmarks said:

Tangent: and the captain was subsequently hung out to dry by BA for no good reason, reportedly. A shining example of the famous aviation 'just culture' at work...?

 

I'm not sure that is an accurate summary of what happened. He is still flying as a 777 Captain to this day (or at least upto covid).

[tehmarks]

2 hours ago, booke23 said:

I'm not sure that is an accurate summary of what happened.

My apologies: I think I may have conflated a few different articles in my memory. He did leave BA some time after the incident, and he did write that he had been on the receiving end of negative rumours about his performance in the flight deck during the incident. I'd misremembered that that had led to his departure from BA. I think the gutter press may have reported it as so too.

 

This article seems to cover the story fairly.

 

Quote

He said: "They'd (cabin crew) been told by their training school that I hadn't done a number of things in the flight - that I'd actually frozen and hadn't done anything in the flight deck, and I hadn't transmitted that May Day call, and that I hadn't done the evacuation call.

 

[booke23]

3 hours ago, tehmarks said:

My apologies: I think I may have conflated a few different articles in my memory. He did leave BA some time after the incident, and he did write that he had been on the receiving end of negative rumours about his performance in the flight deck during the incident. I'd misremembered that that had led to his departure from BA. I think the gutter press may have reported it as so too.

 

This article seems to cover the story fairly.

 

 

No need to apologise my friend. It was, after all, a few years ago now and as you mention there was quite a bit of tabloid speculation at the time. I remembered that he took voluntary redundancy then about a year or so later he went back to work for BA (rumour is he paid back his redundancy payment), where he has worked ever since. But I had to re-read the article to acquaint myself with the exact details. 

[Bee]

Mythbuster. One of these days I will get some glass bottles (this isn't going where Bizzard was going with his explosive petrol lamps with string wicks) I shall fill them with varying quantities of diesel, seal the tops except for a pin hole breather and see how much condensation gathers in the bottom. My guess? No difference whether full or nearly empty.  Slightly different but be careful when working with a full tank and a disconnected fuel line, if the boat suddenly heels or heat expands the fuel the thing can start to syphon until the tank is empty and the bilge is full.

[Dr Bob]

On 23/11/2020 at 10:19, Bee said:

Mythbuster. One of these days I will get some glass bottles (this isn't going where Bizzard was going with his explosive petrol lamps with string wicks) I shall fill them with varying quantities of diesel, seal the tops except for a pin hole breather and see how much condensation gathers in the bottom. My guess? No difference whether full or nearly empty.  Slightly different but be careful when working with a full tank and a disconnected fuel line, if the boat suddenly heels or heat expands the fuel the thing can start to syphon until the tank is empty and the bilge is full.

I agree. Not likely to see much with glass bottles. Try it with black painted steel ones instead. Glass is an insulator and will not pass the heat or cold from the outside to inside as quickly.