Underdog88

Used to be a drag car in Ohio called Natural Gasser owned by an oil drilling company. Very fast and reliable. I've thought the same about a CNG boat but you would need a couple big heavy cyls installed. I was looking at putting them under the settees. My thoughts were for sponsorship when wanting to race my boat a few years back. Now w/all the fracking going on here I've rethought this project...

dba900

My father bought a couple of dual-fuel F-150s from the state (state surplus auction). Their tanks appear to be made of a composite material. I'd think you could mount those under the floor without too much difficulty.

looseconnection

Good thing about cng vehicles is that if the tank is ruptured the ng goes up and away instead of leaking out on the pavement waiting for a spark. Same with boat other than the weight of the tank, the fuel is very light, maybe with spun fg or cf tanks it would make sense.

LC

stevesxm

geeze.. im not sure a lot of this is correct... first i would check your equivilancy calculation... i think you are going to find that the dollar/BTU number for both fuels is a lot closer than you think. and the fuel tanks run at very high pressure... 2 to 3000 psi and those tanks aren't light AND they are big... AND i would be willing to bet that you aren't just going to whip one up and then show up at a fill station and expect them to fill it... ill bet that there is some sort of pretty serious certification process for those fuel tanks that , unless you have it you get no fuel... NEVER MIND coast guard certification or your insurance company... i have seen some of the kits they sell to convert cars and truck and they have all manner of certification stickers all over them....

could you do it ? yes. no question and there are some serious benefits to the fuel but to be cost effective ? that is a VERY tough call and if you are out on the water, im not sure you can just pull up to a fill station at a marina and tank up... it might make an interesting experiment for a mcguyver type more interested in the hardware than enjoying his boat but in a practical analysis i think the idea might fail.

Keith Atlanta

CNG has very few filling stations and a loss of 10% for horsepower.

What about propane? Readily available and less HP loss...

altamate

Propane, Same 10-15% HP loss as CNG, heavier than air so it if it leaks it will sink to your bilge waiting for an ignition source. Storage is 300psi tanks and bulky but not as bad CNG. Fuel range will still be an issue compared to Gasoline.

Might be able to find on the water refueling. Could consider dual fuel to increase range. Use up the propane/CNG first switch to gas till you find a fuel station.

I've had cars set up like this, but propane was super cheap then~ 25- 30% the cost of gas. With propane 60-70% the cost of gas and the 15% loss in HP/fuel economy it's not really worth it anymore.

looseconnection

[QUOTE=stevesxm;3820425]geeze.. im not sure a lot of this is correct... first i would check your equivilancy calculation... i think you are going to find that the dollar/BTU number for both fuels is a lot closer than you think. and the fuel tanks run at very high pressure... 2 to 3000 psi and those tanks aren't light AND they are big... AND i would be willing to bet that you aren't just going to whip one up and then show up at a fill station and expect them to fill it... ill bet that there is some sort of pretty serious certification process for those fuel tanks that , unless you have it you get no fuel... NEVER MIND coast guard certification or your insurance company... i have seen some of the kits they sell to convert cars and truck and they have all manner of certification stickers all over them....

could you do it ? yes. no question and there are some serious benefits to the fuel but to be cost effective ? that is a VERY tough call and if you are out on the water, im not sure you can just pull up to a fill station at a marina and tank up... it might make an interesting experiment for a mcguyver type more interested in the hardware than enjoying his boat but in a practical analysis i think the idea might
fail.[/

I am not sure where you read where I mentioned build your own tanks, tank weight is marginal and btu per volume is equal. Geeze...

keith2500hd

refuel takes some time unless facility has cascade system to push into tanks. you buy station($2500-4000) to take natural gas or propane to higher pressure and refuel tanks(overnite). you can rebuild engine to use(CNG's) higher equvilent octane rating and gain back some energy loss. if a marina finds out you have tanks installed, be prepared to moor outside. a propane tank has volume of about 60 tanks then volume to get to explosive lower limit would cover roughly an acre, nobody wants that around hence warnings in tunnels. propane, natural gas and cng are going up in price due to everybody wanting to use it, so expect price to go up. power plants consume large amounts, instead of coal due to epa and expect this percentage to go up. tanks and equipment require inspections, so research that so as not to get burned on expensive fees or unservicable equipment. fumigation on diesel, seems to have best return on investment.

stevesxm

gee... im sorry... i guess youre just going to bop on down to home depot and grab a couple of EPA, DOT, CARB, CG and FED approved fuel tanks off the shelf... they can't be much more than a couple hundred each...

and CNG has 900 btu per gallon as opposed to gas that is roughly 14,000 which gives you a GGE ( thats gallon gas equivilent) of 126 to 1 ....
so... my boat holds 250 gallons of gas and the tanks have a volume of about 34 cubic feet.... so lets assume you have 34 cu ft to work with ... an 8 GGE tank at 3000 psi takes up about 6 cu ft... so my new 34 cu ft armor plated , NASA approved fuel tank will hold about the equivilent of 45 gallon of gas in CNG

a reduction in range per volume of about 80 % ....

maybe i also missed the part about the fuel barge you were going to tow behind you...

im sorry again if the arithmetic confuses you but thats often how 1/2 baked ideas originate

keith2500hd

are you building rocket or addapting boat, nasa can approve for rocket. they have nothing todo with private/commercial boat. approvals are to application, not use. most mass transit place tanks on roof for a reason. approvals would go UL, FM, CE, SOLAS then USCG. UL (lead test agency) has never approved compressed flamable gases "below deck" on any public vessel; reason has never past test phases. the dragster, mentioned earlier spent good part of season to get approved by NHRA. search for propane tank explosion "BLEVE". that is what fire depts train about. food for thought.