scrotumscratcher:
ok, i wasnt going to answer again as its each to there own but here goes my pennies worth , if you watch the video closely you will see the vapour heating up and creating pressure when this pressure is great enough it opens the safeteyvalve on the top of the tank,look closely as the gas vapour spurts out of the valve it passes through a flame but it is more than a metre above the valve before it ignites into flames and it stays like that until the valve closes ,that is because there is no oxygen in the gas but as it rises and creates a vacuum the vacuum ■■■■■ in the surrounding air .air contains oxygen and when the percentages are right it ignites .this is repeated many times and the liquid gas because of the heat is trying to turn back to a gas thus increasing the pressure in the tank , now because of the heat the metal in the tank is becomming fatigued but at no time up until this point has the liquid gas or the vapour set on fire because it cant because there is no oxygen available for it to do so ,now things are going to change ,the tank cant take any more and bursts the hot gas and liquid start to escape the vapour mixes with oxygen and as the pressure is taken off the liquid gas that then reverts back to being a vapour and follows the path of the original vapour and mixes with oxygen , because you haven,t got a controlled release ,and if you look closely there are two explosions and then it burns it self out the danger with a bleve is the shrapnell ,to have a fire you need three elements fuel heat/ignition oxygen you cannot have a fire without these three components and if you were to ask the fire service what they dread the most although all goods carried under adr regs have there specific problems class 5 is an oxydizing agent creates its own oxygen and is virtually impossible to put out
There’s clearly a difference between an empty tank vapour explosion compared to a full one.In that you’ve got an instantaneous mixture of ‘the remaining liquid’ and the atmosphere when the tank opens up.As it says it’s an explosion of both vapour ‘and’ liquid mixed with the sufficient oxygen in the air.There’s no way that all the remaining liquid could possibly have turned to vapour before the whole mixture ignited in the time of that explosion.The fact is a full tank of fuel caching fire is a much more scary prospect than an empty one in that you’ve got a limitless supply of oxygen if gets open to the atmosphere to burn it all instantaneously.On that note try mixing half a tank of liquid oxygen with half a tank of petrol and then light a match by the hatch and see what happens.Here’s a clue it won’t just be the vapour coming out of the hatch that ignites. 
MrFlibble:
cracker-bar:
I think you’ll find, that you could actually extinguish a lit match with liquid petrol!
There was an episode of Mythbusters where they did exactly that. They poured a load of petrol on a relatively cold concrete floor, then had serious trouble trying to set light to it. They could only get it to burn if they kept a lit blowtorch pointed at it.
that was aviation spirit which is much closer to diesel in volatility.
so, how any of you guys still top load fuels?
What companies and at what places make you top load?
I’ve been thinking about getting into fuel tanker work but the more I read about the more I think it’s not worth it.
qwakers:
MrFlibble:
cracker-bar:
I think you’ll find, that you could actually extinguish a lit match with liquid petrol!
There was an episode of Mythbusters where they did exactly that. They poured a load of petrol on a relatively cold concrete floor, then had serious trouble trying to set light to it. They could only get it to burn if they kept a lit blowtorch pointed at it.
that was aviation spirit which is much closer to diesel in volatility.
‘Aviation spirit’ usually means high octane petrol not kerosene.There’s no real connection between that type of test compared to the type of situation involving a loaded burning tanker.The idea that only ‘vapour’ will ‘burn’ arguably just creates a false sense of security.Realistically given the right ( wrong ) circumstances the fuel,even in it’s pre vapourous liquid state,can be mixed with sufficient oxygen in the atmosphere to burn ( explode ) effectively instantaneously as shown in the video.Which is why the emergency services would require an even more problematic fire fighting operation,in the case of a loaded tanker,than an empty one.In which it’s essential to maintain the integrity of the tank by keeping it cool.Not because they’re bothered about liquid fuel running down the drains but because they know if the tank ruptures the resulting mixture of air and fuel,in whatever state both vapour and liquid,can result in the type of example shown in the video.
For those of you that don’t know wtf they’re talking about (won’t mention any names), I found this pretty informative, enjoy.
youtu.be/7nL10C7FSbE
Carryfast:
qwakers:
MrFlibble:
cracker-bar:
I think you’ll find, that you could actually extinguish a lit match with liquid petrol!
There was an episode of Mythbusters where they did exactly that. They poured a load of petrol on a relatively cold concrete floor, then had serious trouble trying to set light to it. They could only get it to burn if they kept a lit blowtorch pointed at it.
that was aviation spirit which is much closer to diesel in volatility.
‘Aviation spirit’ usually means high octane petrol not kerosene.There’s no real connection between that type of test compared to the type of situation involving a loaded burning tanker.The idea that only ‘vapour’ will ‘burn’ arguably just creates a false sense of security.Realistically given the right ( wrong ) circumstances the fuel,even in it’s pre vapourous liquid state,can be mixed with sufficient oxygen in the atmosphere to burn ( explode ) effectively instantaneously as shown in the video.Which is why the emergency services would require an even more problematic fire fighting operation,in the case of a loaded tanker,than an empty one.In which it’s essential to maintain the integrity of the tank by keeping it cool.Not because they’re bothered about liquid fuel running down the drains but because they know if the tank ruptures the resulting mixture of air and fuel,in whatever state both vapour and liquid,can result in the type of example shown in the video.
It’s correct title is Avgas in aviation, not aviation spirit as its called by the hauliers. It’s 100LL. Used on piston light aircraft. Turbines typically use Jet A1 (fancy kerosene).
Freight Dog:
It’s correct title is Avgas in aviation, not aviation spirit as its called by the hauliers. It’s 100LL. Used on piston light aircraft. Turbines typically use Jet A1 (fancy kerosene).
Lucky you having a job burning jet a1 for a living hey[emoji16][emoji574]️
Can you educate us on the difference between jet a, jet a1 & jet b, do you ever get to use the other 2 in your operations dependent on climate etc?
In basic terms, they are talking about the requirement a fuel source, in conjunction the correct proportion of oxygen to burn the fuel source in.
i.e Vapour!
Petrol for example will burn when mixed within a limited range of oxygen to petrol vapour.
Therefore when petrol is solely a liquid (and not vapour!), it is oxygen free and therefore safe.
However, that scenario is never going to be true, and the problems are really multiplied when an Oxidiser is added to the mix like carryfast’s previous post regarding liquid oxygen. The result of such an explosion would be entertaining if casualty free! 
Pimpdaddy:
Freight Dog:
It’s correct title is Avgas in aviation, not aviation spirit as its called by the hauliers. It’s 100LL. Used on piston light aircraft. Turbines typically use Jet A1 (fancy kerosene).
Lucky you having a job burning jet a1 for a living hey[emoji16][emoji574]️
Can you educate us on the difference between jet a, jet a1 & jet b, do you ever get to use the other 2 in your operations dependent on climate etc?
I’ll be straight up with and say I’d have to look it up (carryfast will google it for us ). Used to know for my exams years ago. We’ve far too much to worry about apart from that. You don’t put anything but Jet A1 in a 747. No one comes up to you and offers 150 tonnes of Jet B by mistake. It’s Jet A1 every time. We order it, big semi trucks turn up. The Engineer completes the fuel distribution and calcs and it’s on. Jet A1 has a temp limit we adhere to in flight. Other than that it’s pretty un exciting. It’s fuel, it’ll be useful in your hurricane lamp when camping and we burn 10 tonnes of the stuff per hour in cruise and 20 tonnes per hour on take off and worry constantly about how much we have left!
Evil8Beezle:
In basic terms, they are talking about the requirement a fuel source, in conjunction the correct proportion of oxygen to burn the fuel source in.
i.e Vapour!
Petrol for example will burn when mixed within a limited range of oxygen to petrol vapour.
Therefore when petrol is solely a liquid (and not vapour!), it is oxygen free and therefore safe.
However, that scenario is never going to be true, and the problems are really multiplied when an Oxidiser is added to the mix like carryfast’s previous post regarding liquid oxygen. The result of such an explosion would be entertaining if casualty free!
That seems to be where the confusion arises.In it’s literal sense the term vapour just means one of the states of the fuel nothing to do with any other stuff.IE technically you could have a mixture of petrol ‘vapour’ combined with C02 or Nitrogen in which case it won’t burn.
Or you could have that tank full of liquid petrol and liquid oxygen.Which,if the theory concerning petrol being safe in its liquid state is correct,won’t burn ( explode ) either if a lighted match is dropped in it because the fuel is in its liquid state.Testing that theory really would be a good bet against myth busters. 
IE petrol alone in whatever state = safe.
Petrol in whatever state + enough oxygen = dangerous.
Open to the atmosphere will always mean ‘enough’ oxygen in that regard.Then it’s just a matter of the more fuel the bigger the bang.
Freight Dog:
You don’t put anything but Jet A1 in a 747.
Ok, it’s an exam question that’s all[emoji16]
So what’s the advantage/disadvantage of the winglets on the 400 as opposed to the raked on the -8?
Numbum:
In answer to the first question about if tanker drivers live to old age I drove tankers from 21 years old in 1966 until I retired at 65 and have never had to tie a knot on a rope.
I started on tar/ creosote/ acid tankers which were loaded up to the level of various washers hanging on a wire dangling from the manlid which meant that when it was getting near the level I had to put my head in the steam and fumes to try and see the level. These fumes I now know are carcinogenic which is why you can not get creosote for the garden fence anymore. I always had a lovely sun tanned looking face though.
I also used to help with the repairs on the trucks and blew out countless brake drums with the airline breathing in all that dodgy dust as well. All the valves and manlids on the tankers were packed with asbestos . A lot of pipework was lagged in asbestos that we used to mix up like plaster and smear on the pipes by hand. Old stuff was removed by smashing it off with a hammer. All of this with no mask of course.
I moved onto petrol tankers in 1976 and spent years breathing in the lead and fumes as you had to hold the lever open on the loading arm and were right next to the manlid. If there was no management about you could wedge the lever open with a dipstick and stand back in the fresh air.
Must have been the late eighties when all this additive was introduced and we had a tank of it in the lorry yard.We would carry a bucket full of it up the ladder and pour one in each compartment before going round to the fuel depot and load. This was replaced with a tank carried on the tanker and it was injected while unloading. I had this tank leak on the road one day and someone rang the fire brigade who guessed which supermarket I was heading for and arrived in force the same time as me. Turns out the additive is carcinogenic as well and they put all the safety gear on to deal with it. The additive tanks were done away with not long after.
I had a few years of breathing in Benzine fumes before bottom loading became the norm and survived to retirement.
I am now 71 and have just got home from my house in Portugal where I had to move about 5ton of sand and chippings with a wheel barrow because they have not heard of dumpy bags and it was dumped in the road.
I do admit to getting a bit breathless nowadays though, I wonder why.
Regards All Phil.
Some of your genes would do for me, sir!
Pimpdaddy:
Freight Dog:
You don’t put anything but Jet A1 in a 747.
Ok, it’s an exam question that’s all[emoji16]
So what’s the advantage/disadvantage of the winglets on the 400 as opposed to the raked on the -8?
first ones made of chicken wire and paper, the second balsa wood. Bit more sturdy, don’t get soggy in the rain but harder to get inside your garage.
Freight Dog:
first ones made of chicken wire and paper, the second balsa wood. Bit more sturdy, don’t get soggy in the rain but harder to get inside your garage.
Ok, do you fly the -8? Do you do much hand flying?
Pimpdaddy:
Freight Dog:
first ones made of chicken wire and paper, the second balsa wood. Bit more sturdy, don’t get soggy in the rain but harder to get inside your garage.
Ok, do you fly the -8? Do you do much hand flying?
Yes and yes. A fair amount.
Freight Dog:
Yes and yes. A fair amount.
Nice[emoji16] Do you need differences training for the -8 or are they pretty much the same?
Pimpdaddy:
Freight Dog:
Yes and yes. A fair amount.
Nice[emoji16] Do you need differences training for the -8 or are they pretty much the same?
Differences course, some sim and line training.
Freight Dog:
Differences course, some sim and line training.
Any idea if mtow on cargo ops are higher than on pax ops? Are there structural differences etc?
Freight Dog:
I’ll be straight up with and say I’d have to look it up (carryfast will google it for us ). Used to know for my exams years ago. We’ve far too much to worry about apart from that. You don’t put anything but Jet A1 in a 747. No one comes up to you and offers 150 tonnes of Jet B by mistake. It’s Jet A1 every time. We order it, big semi trucks turn up. The Engineer completes the fuel distribution and calcs and it’s on. Jet A1 has a temp limit we adhere to in flight. Other than that it’s pretty un exciting. It’s fuel, it’ll be useful in your hurricane lamp when camping and we burn 10 tonnes of the stuff per hour in cruise and 20 tonnes per hour on take off and worry constantly about how much we have left!
I was often criticised for sourcing my fuel from supermarkets instead of proprietary brands, have you ever bought supermarket Jet A1 and noticed a marked difference in miles per tank or acceleration or increase in servicing costs ? 
Pimpdaddy:
Freight Dog:
Differences course, some sim and line training.
Any idea if mtow on cargo ops are higher than on pax ops? Are there structural differences etc?
Not aware of the mtom on the Dreamliner. I operate the 8F and it’s 447700 kilos. Main deck floor on freighter is strengthened and fitted with a powered loading system. Looks more like a cargo ship inside. Everything is heavy duty.