My B.F. McDonald aluminum hard hat was manufactured in 1935, one year before the patent was granted. It was handed down to me by my grandfather, (my mothers' side of the family) in 1982 when I turned 18 years old. I have worn that safety helmet on logging crews, oil riggs and all sorts of construction sights over the decades and have kept the original liner safely stowed away as a keepsake. That antiquated piece of equipment saved my skull more than once and is still giving me great service.
Another thought i had was the fact that the carbon fiber did NOT deform leads me to think MORE energy would be transferred to the head. Where the fiberglass would absorb some energy by deforming. Just a thought
The suspension system transfers the load around the head well enough that neck compression is a bigger concern. If the hat bends an inch and a half on impact, your skull is taking that impact directly and you'll wish you just had a neck injury.
More energy is distributed to the head, but in the case of the gfrp it would deform and if it made direct contact with the head then you would have a transfer of energy
You don't want the hat to deform, that causes brain and skull injuries. The suspension in the hard hat is to absorb and distribute the energy. It's not a car, where its designed to crumple.
Yes just to take the initial blow. I have a plastic Chinese made American branded hard hat which took big hits from tree debris. On all events it was hard on my head but saved me. If it was a New Zealand made certified hat it would had split but safer. Anyways I'm happy with it.
There is a reason the vast majority of loggers and professional Sawyers use an Aluminum Skull Bucket.. it "absorbs" the impact to reduce injury. You want the material to "give way" to some degree to reduce shock. I still have mine to this day and would never trade it for any plastic or fiber ones. The only realm that this changes is those involved in or around electrical hazards.
I agree. There needs to be a real world test done. Drop a common construction item from at least 20 feet. I’m a believer in the carbon fiber. It’s an all around stronger material and it’s lighter.
Not sure if there is a professor guiding you guys but it should be an impact test. An static 550lb load the size of a brick on a jobsite is quite impractical.
well...slow compression testing says nothing about material strength or dimensional stability when you want to make a statement about "hats getting hit in a construction environment" (0:43) rather do an impact test
Does one want a hat that is unbreakable or should it break under some force to absorbs the energy transferred to the neck while the suspension system suspends the dent away from the skull?
I wouldn't call it very accurate. In industry anything that strikes your head is falling. So a test of slow over time weight test sure shows how strong the material is but doesn't do much to show if it obsorbs impacts. Plus hard hats primarily work hand in hand with the retention straps also stretching and obsorbing some of the impact energy. Like a seatbelt.
I disagree with the conclusion. The aluminum hat absorbed energy. The Carbon hat would transfer that energy. If it was a puncture test, sure, the Carbon hat would be better at preventing that. This test itself doesnt show the carbon hat to be safer than the aluminum.
Yup, there's a reason they don't make mountain bikes out of fiberglass, jokingly referred to as "feebleglass" in the marine industry. I'd be interested in seeing an aramid weave go up against the carbon.
So a rigid helmet is better than a softer one? DUH. So what happens to the brain and neck when ALL of the impact energy is transferred to the human instead of the helmet absorbing some of the energy. Broken neck and brain damage!!
Compression TESTING is a lot different that COMPRESSION testing (note the ALL CAPS) What is compression? In general compression testing is all about what happens to a file as it is compressed. TESTING the differences in compression rates of a file, together with its size, and how it compares to other files with the same compression rate. Compression slows down files as you compress them. That means the file ends up taking a bit longer to download and uncompress each time you load it. It also means a lot more bits are potentially lost in the compression process, which is why compression is generally applied on very small files first, then worked up to the more frequent load of larger files. I don't really know what COMPRESSION of FILES has to do with IMPACT of HELMETS... sorry you need to go back to school
I'm probably way off-base, but wouldn't you *want* the helmet to have some measure of deformation (within reason)? Sort of like the crumple zones on a modern automobile?
the carbon fiber is more resilient for certain, but when you're talking about safety gear like a helmet, it's to act like a crumple zone in a car and absorb the shock, not transfer it into the body of the user. you see it time and again, terrible injuries sustained by people in cars with little to no visible damage, but a car that just blows apart they walk away from.
Typically when people say "wet layup", as they did in the video, it means they laid the carbon fiber by hand by combining dry fiber with epoxy (ie not pre-preg). It is unlikely that they used an autoclave to cure it.
I love HELMETS and really know that they PROTECT and SAVE. However, as some of you have pointed out, the armor of Helms isn't being paid a great deal of attention by some in today's PC and PlayStation communities. Specifically, I've noticed that many people are reluctant to trade or sell their HELMETS because of the lack of IMPORTANT SHOP SERVICE provided by other players in the community. This can be quite frustrating when you are looking for a GATHERING of NEEDED PREP or LUBRICATE ingredients (imagine a small but wondrous place that automatically completes all your requests with the help of other players)
Test failure. Despite testing for material hardness, the test fails to account for compression of neck vertebrae. Regardless of hat material hardness, a broken or severe neck injury can occur. Most engineering designs, in general, have design flaws. Tests performed such as this justifies the need for scientists to develop safety gear as well as other technologies.
Make the fiberglass hat thicker and it'll be stronger per pound than steel. I also doubt that the aluminum hat is 6061, which is pound per pound stronger than steel, probably some cheap alloy.
Sory, but if you had used the same Layer thickness, glassfiber would have won (especialy if youd had made a impact test, where it can make use of its lower youngs modulus and thus absorb more energy than the carbon fiber) because E-Glass has about the same tensile strength than generic carbon fibre. Dont make tests where you have a desired result and manipulate the test till you get the results you desire. Be honest, be scientific.
The TENSILE STRENGTH of glass is nothing compared the the MORAL STRENGTH of the UNITED STATES. - Donald J. Trump (@realDonaldTrump) July 27, 2013 This probably wasn't what Trump had in mind. On Thursday, the presumptive GOP nominee tweeted: "Dishonest media" and "phony media," followed by, "Failed @nytimes story on women in the w/meeting was just exposed as false on refutation by Chief of Staff. More soon. #FAKE NEWS." The president of the free world manipulates TRUTH, so this was just patriotic!
That’s not an accurate test. If that is simulating a brick hitting your hard hat, how high is this “brick” falling from? The “brick” doesn’t land on your hard hat and continue to apply force to your hard hat. So you have to say for example “it’s simulating a brick falling from 10 feet or 20 feet. “
Man I hope they learned more physics and mechanism of injury and impact transferring energy. A deformation absorbs energy. A hard shell transfers. This actually show the exact opposite of what they learned.
1:16 what a pointless test. No one give a rats ass about a hat crushed on a table. A hard hat rides on a suspension and the concern is impact loading not perceived crush weight.
