Helium?

Crazy-J

New Member
Is it class legal to fill your hull with helium? Would filling your hull with helium make your laser sit higher in water, thus reducing friction on some bits of the hull. In theory making you go faster?
 
I have pumped air into my boat to prevent make it cut through the water better but i never have heard of helium......
 
I thought it was a neat idea and would be something test. But you know what i mean about floating higher, right?
 
Just add some foils, a nice 2 element wing, and a carbon fiber/nomex hull, should be good to go... Shoot, forgot, add a trapeze and carbon mast..
 
if you're going to try this, be very careful... a little bit of pressure can rip your boat apart at the seams
 
I would argue that the Fundamental Rule would say its not class legal since you would need to modify the boat to make it airtight (in particular sealing the air hole under the hiking strap). But in the end it would be the interpretation of the Chief Measurer that would matter.

That said, I wonder if it would really make a difference? Don't forget that most of the "weight" of a floating Laser is in the hull/spars/sail (we'll come back to the sailor in a moment). Assume an order of magnitude guess of about a cubic meter of volume inside the hull, that's around a couple of pounds of air. So even if you could create a vacuum in your hull you could at best save around a couple of pounds out of an all up weight of something like 150 lbs (hull plus spars plus rigging plus sail minus sailor). In the end its a bit hard for me to believe that a couple of pounds will make a difference...

... because, when you add in the sailor you typically more than double the weight of the boat. And depending on conditions, the gear that a sailor wears can weigh a fair bit too. These are variables that can be more easily controlled, with greater overall impact, than trying to do something fancy with the boat. At least in my opinion, reinforced by noting that regatta results generally depend on sailor weight to the 10's of pounds level, not the 1's of pounds.

That's just off the top of my head, maybe the naval architects can weigh in.
 
considering i'm 78 pounds. And gases are compressible... you have to figure out how compressed you can get it per meter cubed, and figure out how much that gas weighs in total. Take the lifting force of gas per meter cubed and subtract gas weight and hull, spars and sailor weight = how much boat could potentaily weigh. Thats just my guess at a way to figure that stuff out. equation is as follows(in my opinion):

modifiedweight = ((gas per cubic meter x volume of hull) x lifting power of helium per cubic meter density) - (sailor weight+ spars + gear + sails) =modified weight

theory= displacment(in pounds) - modified weight

^^ not acurate im just guessing and throwing stuff
 
What I thought would be a good plan in addition to the hull filled with helium is....

To use a completely sealed top section, filled with helium.
Thus lowering the centre of gravity and making it easier to stay upright in strong winds.
=P
 
Thats a good point. What if you injected helium into your top section spar and compressed it and sealed it? Would that not have the same effect but not on same scale?
 
It is true that gases are compressible but i wouldn't want to have any sort of pressure in my hull even something as small as 1 psi could split your boat in to pieces. If you think about it 1 pound per square inch is a lot of total pressure when you also think of the amount of square inches that this pressure would be exerted on. i don't actually know how many square inches it would inside the laser hull but just as a small example 1psi on something that is 700 square inches is equal to 700 pounds of force,and the amount of space in a laser is probably a lot more then 700 square inches and these amount of pressures could surely tear your boat apart.
 
considering i'm 78 pounds. And gases are compressible... you have to figure out how compressed you can get it per meter cubed, and figure out how much that gas weighs in total. Take the lifting force of gas per meter cubed and subtract gas weight and hull, spars and sailor weight = how much boat could potentaily weigh. Thats just my guess at a way to figure that stuff out. equation is as follows(in my opinion):

modifiedweight = ((gas per cubic meter x volume of hull) x lifting power of helium per cubic meter density) - (sailor weight+ spars + gear + sails) =modified weight

theory= displacment(in pounds) - modified weight

^^ not acurate im just guessing and throwing stuff


Remember, helium has no special "lifting" property to it, other than its mass. So, for example, an airship achieves neutral buoyancy and "floats" in air because the mass of air displaced by the the volume of the airship equals the weight of the airship. The standard gas used in an airship is helium because it is the second lightest element, is readily available and doesn't combust (hydrogen gas, if you like, is half the weight but, of course, we all still remember what happened to the Hindenburg).

Also note that you want to equalize pressure in an airship - overpressuring does you not good as it simply adds weight to the airship, decreasing its bouyancy. (Ok, skipping some details related to atmospheric pressure at different altitudes...)

Here's an example (and for this thread think of the block of wood as a Laser, the oak block as a Laser filled with air and the pine block as a Laser filled with helium). Anyway, the point remains that it is the difference in the mass of the volume of air that is changed out that matters, and I'd think that would be small here.
 
Thats a good point. What if you injected helium into your top section spar and compressed it and sealed it? Would that not have the same effect but not on same scale?
Compressing the gas would just add weight.
For the mast, pulling a vacuum would be lighter and cheaper. Difference in weight would be hard to measure anyway (grams I would guess).
Pulling a vacuum in the hull would crush it.
Happy New Year!
E
 
But if you inject helium into your top section and seal it, would that not make top section want to stay up right. Thus helping you boat stay up right
 
So I guess we could pump enough helium into our masts and get our Lasers to fly!
I think this discussion is three months and one day early.
 
No want im getting at here is that would it help them stay up right? Plus i don't understand 3 months and 1 day early.
 
No want im getting at here is that would it help them stay up right? Plus i don't understand 3 months and 1 day early.
April Fools. You've already had a rocket scientist in this thread indicate that it won't work.The mast section is too heavy to be affected by the amount of helium that you could get into it. Do you see the tank of compressed helium at the balloon store trying to float away? You can't achieve the necessary neutral buoyancy.
 
New Year's resolution:

Let's all sail to Geneva (CERN) and find the boson!

Nobel prize in Physics to the lucky one(s)...
 
Maybe what we need to do is to eliminate the dark matter from all the builder supplied parts - now that would really reduce the weight of everything.
 
I had a good chuckle all the way through this thread...the only scary thing is that the OP appears to be serious about wanting to do this......
 
I had a good chuckle all the way through this thread...the only scary thing is that the OP appears to be serious about wanting to do this......
Agreed.

I do wish sometimes people read the fundamental rule, which essentially says that everything you think of to change your laser whether it makes it faster or not, is illegal unless there is a specific rule that says you can make that change. Anyway, even if you did fill your Laser with helium, it wouldn't impact on the buoyancy as the volume of the boat is bugger all and anyone who saw the Myth Buster’s episode would be aware that a huge amount of helium is required to left a person, only probably 20% heavier than a laser.
 
I had a good chuckle all the way through this thread...the only scary thing is that the OP appears to be serious about wanting to do this......

He did name himself Crazy-J, and just in case he is wondering, we do love you Crazy-J!
 
Agreed.

I do wish sometimes people read the fundamental rule, which essentially says that everything you think of to change your laser whether it makes it faster or not, is illegal unless there is a specific rule that says you can make that change. Anyway, even if you did fill your Laser with helium, it wouldn't impact on the buoyancy as the volume of the boat is bugger all and anyone who saw the Myth Buster’s episode would be aware that a huge amount of helium is required to left a person, only probably 20% heavier than a laser.

Next on LaserBusters:
- Is the Intensity Sail actually faster than the class sail?
- How heavy is too heavy for a Radial?
- And can you really kick all the water out from the bottom of the cockpit?
 
Next on LaserBusters:
- Is the Intensity Sail actually faster than the class sail?
- How heavy is too heavy for a Radial?
- And can you really kick all the water out from the bottom of the cockpit?

And coming soon on LaserBusters:
- How much faster is a carbon tiller?
- Is it legal to tie three stopper knots in the mainsheet?
- Would taking the sleeve out of the boom and removing the grab rails make your Laser sit higher in water, thus reducing friction on some bits of the hull, in theory making you go faster?
 
What I want to know is, if you beat yourself over the head with a bent top section enough that they had to put a big steel plate in the top of your skull would that help with your hiking and make you faster? Would it be class legal?
 

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