Hideous Injury from being a Mechanic..?
Discussion
carinaman said:
http://www.stripes.com/news/air-force-captain-dies...
It never occured to me that tyres could be that dangerous before I heard about that.
http://www.youtube.com/watch?v=Vqw4ZooBzLwIt never occured to me that tyres could be that dangerous before I heard about that.
Skip to 4:30
Shows what happens when a tyre shard from a lorry flies off at 80mph.
It's alos the reason i never sit in a lorry's blind spot.
Check this out (tyre safety video), makes me shudder....
http://www.youtube.com/watch?v=eFQW1r6viZk&fea...
http://www.youtube.com/watch?v=eFQW1r6viZk&fea...
And some slow-mo footage in HD....I had no idea how dangerous compressed air could be!
http://www.youtube.com/watch?v=dKlJJqHFfoQ&fea...
http://www.youtube.com/watch?v=dKlJJqHFfoQ&fea...
Globs said:
Lots of energy in it.
A car tyre typically sits at 30psi, a lorry tyre is way bigger and sits at 100psi - so about 15x - 20x the energy.
It is frightening to think of the force contained within a tyre. I work with compressed air a lot at work - a lot of air-driven machinery, most of which operates at fairly low pressures with internal regulators in the machines to bleed off only as much air from the line as they need to operate, but we have high powered compressed air lines fed all around the facility. In some rooms, we have hoses coming from the walls with a jet end, it looks like a small petrol-pump head, and when you squeeze the handle the air jets from a small nozzle, we use them to blow debris out of hard to reach parts of the equipment that get into to moving parts and cause jams. If you squeeze that handle you better let everyone know you are doing it or there will be some soiled underpants in the room! Also, everyone needs to stand clear of what you are blowing as despite a lot of plastic shields to protect personnel working with the equipment, a small fragment of broken glass, a metal nut etc can become quite a nasty projectile when accelerated by such a powerful jet of air. Not to mention, if you got the jet in your eye at short range, it would probably rupture your eyeball! Needless to say, we take a lot of precaution when operating those jets.A car tyre typically sits at 30psi, a lorry tyre is way bigger and sits at 100psi - so about 15x - 20x the energy.
Another thing we do is pressure testing liquid filters, these are wetted with a variety of wetting agents (they don't work properly if the membranes in them are too dry) and then hooked to a machine hat tests then with a ramped pressure program that increases the pressure from atmospheric pressure up to 5000mbar, which is about 72.5psi or 5bar, which is not an insignificant figure. The actual content of air within the testing line is quite small though (usually <50mls), so the kinetic potential of the line is limited. The filters are connected to the testing line and secured with jubilee clips; only once have I known one burst off as the system reached it's 5000mbar test pressure, but the noise was incredible. I was on the other side of the facility and it sounded like a rifle going off, it was ridiculously loud. When I consider the fact that an HGV tyre is another 25psi + on top of the pressure I test my filters at, and given the construction of a tyre, they really are bombs waiting to go off. I know complacency stops people using the cages to protect themselves but it really seems unfathomable to me!
As a smaller humorous anecdote, I attended a training course for a certain piece of equipment that uses a disposable plastic filter. The stated "maximum safe operating pressure" from the manufacturer is about 40psi. They had a customer in France complain repeatedly complain that the filter cylinders were failing explosively during operation, they asked the customer what pressure he was running them at and he said it was "within safe limits". The guy leading the course would not tell us what the pressure they failed at unless someone felt tempted to try and replicate it themselves for a laugh, but he did say that the 40psi limit gave the company a large safety margin to prevent accidents. As I mentioned earlier, shattered plastic, when accelerated with such force, can become a very dangerous projectile. Later on in the course, we watched a video about how the filters were made, at and one point they showed a brief clip of a "test to failure" taking place in their testing lab, where a cylinder was shown violently exploding within a safety chamber. The pressure indicated on the screen on of the test chamber, only briefly visible, was 114psi!
J4CKO said:
If we are on dangerous jobs, check this out, I find it difficult to watch !
http://www.youtube.com/watch?v=2A_h2AjJaMw
I'm addicted to high things, chiefly because they scare me shttp://www.youtube.com/watch?v=2A_h2AjJaMw
tless - but free climbing at that height? fk that.TonyHetherington said:
My company makes control valves, and so we deal with pressures a lot. Whether it's the way we control the valves, through to the calculations we make in understanding what's going through it.
In our training courses we have a lump of lead that is 1" square on it's base, and weights 1 pound. i.e.; when it's resting on your hand it is 1psi. It's a bloody heavy bit of metal. When you then explain to people that 50 of those are what's going through that little line in the training room, and up to 3500 of those are going through the valve itself when in the field, it certainly puts it in perspective!
Always wondered why people use the word weights when they mean weighs? I'm not trying to be an aIn our training courses we have a lump of lead that is 1" square on it's base, and weights 1 pound. i.e.; when it's resting on your hand it is 1psi. It's a bloody heavy bit of metal. When you then explain to people that 50 of those are what's going through that little line in the training room, and up to 3500 of those are going through the valve itself when in the field, it certainly puts it in perspective!
hole, it's just something that's always confused me.I will stand away from my tyres from now when inflating after reading this thread.
ShampooEfficient said:
J4CKO said:
If we are on dangerous jobs, check this out, I find it difficult to watch !
http://www.youtube.com/watch?v=2A_h2AjJaMw
I'm addicted to high things, chiefly because they scare me shttp://www.youtube.com/watch?v=2A_h2AjJaMw
tless - but free climbing at that height? fk that.king fk that.
My Uncle who sadly passed away in 2010, used to work for Cornwall County Council as a Refuse Collector in Truro back in the 70's/80's (as did most of my Uncles) when I was a kid, one day at the depot he was refuelling one of the vehicles and spilled petrol on his trousers, he walked in to the office and said "Look I've just spilled petrol on my trousers" one of his work colleagues turned around and said "Here you go Pete, a match to go with it" and at the same time struck a match and flicked it at my Uncle. As you can imagine unfortunately the match struck home and my Uncle went up in flames.
I can't remember the percentage in burns he received but I do remember he spent months in the special burns unit in Plymouth and in the early stage almost died a few times.
I don't recall what happened to the guy that did it, he probably got a good hiding from the family, my Uncle was one of 13 Brothers and Sisters!
Probably one of the most unbelievable things I will ever experience in life.
Stef
I can't remember the percentage in burns he received but I do remember he spent months in the special burns unit in Plymouth and in the early stage almost died a few times.
I don't recall what happened to the guy that did it, he probably got a good hiding from the family, my Uncle was one of 13 Brothers and Sisters!
Probably one of the most unbelievable things I will ever experience in life.
Stef
...StefanVXR8 said:
My Uncle who sadly passed away in 2010, used to work for Cornwall County Council as a Refuse Collector in Truro back in the 70's/80's (as did most of my Uncles) when I was a kid, one day at the depot he was refuelling one of the vehicles and spilled petrol on his trousers, he walked in to the office and said "Look I've just spilled petrol on my trousers" one of his work colleagues turned around and said "Here you go Pete, a match to go with it" and at the same time struck a match and flicked it at my Uncle. As you can imagine unfortunately the match struck home and my Uncle went up in flames.
I can't remember the percentage in burns he received but I do remember he spent months in the special burns unit in Plymouth and in the early stage almost died a few times.
I don't recall what happened to the guy that did it, he probably got a good hiding from the family, my Uncle was one of 13 Brothers and Sisters!
Probably one of the most unbelievable things I will ever experience in life.
Stef
I think it is the petrol vapour that is flammable, so theoretically the petrol should not have lit. Obviously in your Uncle's case there was still vapour present as it is very dense. Not something you would try on a person. I can't remember the percentage in burns he received but I do remember he spent months in the special burns unit in Plymouth and in the early stage almost died a few times.
I don't recall what happened to the guy that did it, he probably got a good hiding from the family, my Uncle was one of 13 Brothers and Sisters!
Probably one of the most unbelievable things I will ever experience in life.
Stef
One of my Uncle's friends caught fire after pouring petrol on a fire and when he lit the match he lit the vapours and engulfed himself in flames.
High pressure steam from a pin hole in a pipe in a ship's engine room. An old guy I know told me about this. Absolutrly lethal and invisible apparently.
There was my uncle who worked building big tractor loader diggers in the 1970s and early 1980s. A tyre went off on one while being inflated and the poor guy lost his head. My uncle had to do the cleaning up once the authorites had finished their reports etc.
There was my uncle who worked building big tractor loader diggers in the 1970s and early 1980s. A tyre went off on one while being inflated and the poor guy lost his head. My uncle had to do the cleaning up once the authorites had finished their reports etc.
I've seen a dowel pin shoot through a welders hand and gauntlet.
In one of out pipehandler tools he was removing a dowel pin and thought he'd heat it and pull it out, so he was heating the bottom while holding the top and trying to pull it out. The air under the pin (pins are interference fit) heated up and expanded forcing the pin out straight through his palm and up and through the roof.
Dangerous thing compressed air.
In one of out pipehandler tools he was removing a dowel pin and thought he'd heat it and pull it out, so he was heating the bottom while holding the top and trying to pull it out. The air under the pin (pins are interference fit) heated up and expanded forcing the pin out straight through his palm and up and through the roof.
Dangerous thing compressed air.
McSam said:
rob1234 said:
I know of a guy who knocked the handbrake off on a CVR(T) when he was getting out. Jumped down, realised the vehicle was moving and jumped up again, using the top of the track as a footstep. Error - his foot was dragged with the track until his lower leg jammed the front sprocket. He was know an as 'chock' after that...
The front sprocket? fk me, that's a good twenty feet of track away.zb said:
spaximus said:
The very worst work accident I knew of was years ago at Booths scrap yard in Rotherham. A guy was burning up old oxygen and acetelyn bottles in the yard. His mistake was to see one left and started to burn that one as well, unfortunatly it was his own full acetylene bottle which reduced him to bits.
One of the most dangerous things in a garage in the 70's and 80's was the pit. Many people died when they went into them and went to sleep. Carbon monoxide is heaveier than air and collects in the pit. When the mechanic gets in he slowly goes to sleep and if not found dies. Others in a pit got burnt to death when a fuel leak or such got ignited (lamps were good for this) usually blocking their escape route.
Carbon monoxide is less dense than air, therefore, slightly lighter. One of the most dangerous things in a garage in the 70's and 80's was the pit. Many people died when they went into them and went to sleep. Carbon monoxide is heaveier than air and collects in the pit. When the mechanic gets in he slowly goes to sleep and if not found dies. Others in a pit got burnt to death when a fuel leak or such got ignited (lamps were good for this) usually blocking their escape route.
air is 78% nitrogen in N2 pairs, empirical mass 14+14 = 28
They are about the same mass but for reasons I cannot remember since A-level Chemistry the CO sinks through air - thats why they always say if you have a faulty boiler leaking Co then go upstairs
Vladimir said:
I did heavy demolition work on a site on Bristol - we took down half an office block.
Part of it was taking down a 6ft thick, steel reinforced concrete base section that supported a lot of internal glass. So we used approx 3" diamond drill cutters, "bursters" (stick into the hole cut by the cutters, apply 20 tonnes of pressure, crack the hole open wider), then a combination of kangos, drills and wrecking bars to take away the concrete. We were then left with hundreds of steel reinforcing rods to cut and remove. The result was something my namesake, Vlad the Impaler, would be proud of - steel spikes sticking at 45 degrees from the ground.
One hardened demolition nutter was kangoing away, he slipped and a steel spike went into his arm at the elbow. He then fell forwards ripping his entire forearm open. He went sheet white, puked everywhere then had to be caught before he fell onto more spikes. Luckily the Bristol Royal Infirmary was only 200 yards away and he made a pretty rapid recovery but that image will always be burnt onto my mind.
Thinking back, that was a b***ard dangerous job! I used to shift 8-10 tonnes of concrete a day in wheelbarrows (to a skip) as well as the demolition itself. My appetite was slightly insane and cost me most of my wages!
Which building was that then? Not the old hospital block they've just finished demolishing at the corner of St Micheals Hill and Tyndall Avenue?Part of it was taking down a 6ft thick, steel reinforced concrete base section that supported a lot of internal glass. So we used approx 3" diamond drill cutters, "bursters" (stick into the hole cut by the cutters, apply 20 tonnes of pressure, crack the hole open wider), then a combination of kangos, drills and wrecking bars to take away the concrete. We were then left with hundreds of steel reinforcing rods to cut and remove. The result was something my namesake, Vlad the Impaler, would be proud of - steel spikes sticking at 45 degrees from the ground.
One hardened demolition nutter was kangoing away, he slipped and a steel spike went into his arm at the elbow. He then fell forwards ripping his entire forearm open. He went sheet white, puked everywhere then had to be caught before he fell onto more spikes. Luckily the Bristol Royal Infirmary was only 200 yards away and he made a pretty rapid recovery but that image will always be burnt onto my mind.
Thinking back, that was a b***ard dangerous job! I used to shift 8-10 tonnes of concrete a day in wheelbarrows (to a skip) as well as the demolition itself. My appetite was slightly insane and cost me most of my wages!
Oxygen has a higher density than Nitrogen - this is why air is "thinner" at the top of a mountain pass (for example) - 0.001429g/cm^3 vs 0.001251g/cm^3, both at 20C and 1 atmosphere pressure. It tends to concentrate at lower levels 
.
However, assuming that the atmosphere is, simplistically, 80% Nitrogen and 20% Oxygen (not quite, but...) that would give an atmospheric density of 0.001286g/cm^3 at 20C etc.
Now Wikipedia tells us (
it once said that Fred West was a landscape gardener and good with patios but bear with me) that the density of gaseous Carbon Monoxide is 1.145kg/m^3 at 25C or 1.250kg/m^2 at 0C and 1 atmosphere. Making an assumption of a linear relatonship, this equals 1.166kg/m^3 or 0.001166g/cm^3 at 20C (to compare with the above figures).
Wikipedia also tells us that the density of air at sea level and 15C is 1.225kg/m^3 (so I wasn'tr far off ) - Carbon Monoxide's density at 15C and 1 atmosphere, making the assumption of a linear relationship, would be 1.187kg/m^3 at 15C and one atmosphere.
So Carbon Monoxide is less dense than air...
I've still got a nagging feeling that it sinks into garage pits though
! Certainly, petrol fumes do, but I'm sure I was also told that CO fumes would "get you" in a garage pit every time 
.
Not to contradict myself, or anything
.
Wikipedia also says that the average 'molar mass' of the atmosphere is 28.8, so yes - I am contradicting myself and CO (as per earlier posts, having a 'molar mass' of 28.00) is "lighter than air". QED.
For my next trick, I'll prove that black is white and get run over on the next level crossing I try to use ...
.However, assuming that the atmosphere is, simplistically, 80% Nitrogen and 20% Oxygen (not quite, but...) that would give an atmospheric density of 0.001286g/cm^3 at 20C etc.
Now Wikipedia tells us (
it once said that Fred West was a landscape gardener and good with patios but bear with me) that the density of gaseous Carbon Monoxide is 1.145kg/m^3 at 25C or 1.250kg/m^2 at 0C and 1 atmosphere. Making an assumption of a linear relatonship, this equals 1.166kg/m^3 or 0.001166g/cm^3 at 20C (to compare with the above figures). Wikipedia also tells us that the density of air at sea level and 15C is 1.225kg/m^3 (so I wasn'tr far off
) - Carbon Monoxide's density at 15C and 1 atmosphere, making the assumption of a linear relationship, would be 1.187kg/m^3 at 15C and one atmosphere.So Carbon Monoxide is less dense than air...
I've still got a nagging feeling that it sinks into garage pits though
! Certainly, petrol fumes do, but I'm sure I was also told that CO fumes would "get you" in a garage pit every time .Not to contradict myself, or anything
.Wikipedia also says that the average 'molar mass' of the atmosphere is 28.8, so yes - I am contradicting myself and CO (as per earlier posts, having a 'molar mass' of 28.00) is "lighter than air". QED.
For my next trick, I'll prove that black is white and get run over on the next level crossing I try to use
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