Fuel Tank in Tight Inaccessible Hard to Reach Places

My dog Sammie, the greatest beagle ever, just passed away yesterday so I'm pretty sad over it; but it was time. I'm trying to get my mind on other things that are fun and that led me to thinking about my boat design and how to get some extra fuel tank capacity tucked away into the stern area if I can.

I tried to find some information on this but was not successful... Sam's death may not have me at my best, but I tried to look. So I wanted to ask for advice either how to best design tanks in hard to reach places and/or any links that I'm not finding on the subject if it's been talked about extensively.

I can only think of 4 possible solutions to get them cleaned out occasionally:

1. Try to provide access points from the deck/floor above if possible
2. Provide a way to pump a cleaning solution through the tank and attach a large pipe to the lowest point so that you can suck the junk out at a more handy location.
3. Sliding rack, rails, or wheels to slide the empty tank out occasionally (if possible)
4. Resealable tank with plastic bag insert (described below)

It seems that you could make a tank that can be reached at some point, and then unseal that access point, and stuff a double walled plastic bag inside to hold the fuel; the bag would be attached to a cap that seals the bag, and provides access for the filler tube, and fuel line outlet. The vent is placed on the external tank. If the tank then several smaller bags could be connected together toward the bottom, linked to a long hose to reduce the fuel sloshing about. Perhaps a block is placed at the rear of the tank and a line used to pull the bag in and secure it a bit.

I guess these are the only 4 basic things that I can think of the clean out a fuel tank that is not very accessible.

Any ideas are appreciated and I ponder how to fit all the pieces together. I have a nice design from Ted Brewer, but now I'm just trying to make some decisions where I'd like to modify the stock design (although he was able to make up a new sail design for me since I'm stretching her).

Thanks.

 

Very sorry to hear about your Beagle, Sammie. That's a tuff one.

Sounds like you've got the fuel tank thing figured out.

What was your question?

Gas or diesel?

-Tom

 

Bahama, sorry bought your dog.

You really need to give a bit more information. What kind of boat are we talking about, Why do you need more fuel?

Putting fuel tanks in the stern of a boat is generally not a good idea from the standpoint of loading and handling of the boat.

If you need extra fuel only once in a while then a pillow tank that folds up when not in use could be placed low in the boat or possibly on deck for those few times that extra fuel is needed. These tanks are for sale at reasonable prices.

 

What dimensions?

 

The final dimensions are 42' LWL, 49' 2-5/8" (15m) LOA, 14'2" beam, and 6'0" draft; ballast will be 13000 Lbs. Here is the basic look http://www.tedbrewer.com/sail_aluminum/orca.htm. I'm stretching her 4'.

My Nautical Architect, My NA,is semi-retired and so I have limited access to him. He recommended that I go with aluminum throughout this boat, and so that's what I'll do. I've not decided upon the best choices of marine grade aluminum (not many choices here anyway). He says that I'll need to leave a frame space abaft the present ballast to add about 4,000 Lbs more lead and to use as a bilge sump. So any tanks that I put in there need to allow for that.

Regarding my tank design, I'm looking for advice on what you think would be the best choice for easiest maintenance and any pitfalls/risks that I need to be aware of as I try to add some extra fuel capacity into the stern/fin area.

I will provide as much access as possible via the floor in the owners cabin. and I'll even rig up some mechanism to raise the bed up about 18" in the aft and tilt up its foreward end 3' to 4' to provide great access to the tanks if I really have to get in there. Obviously I want to avoid having to do this, but the access where be there if I have to.

OK, so now I've planned access to the tank(s), but now I want to REDUCE my need to inspect them very often. The best idea that I can think of is to make this to be a large "backup" or secondary day tank--that way it's getting clean fuel directly from the engine, and then it feed into the primary day tank that can be inspected more easily.

Do you think this is a good appoach?

Also, since I'm now planning to give myself inspection access to ALL of my tanks, should/can I use the hull as my outer tank wall? The added fuel capacity is great if I use the walls directly, but I don't want to do so if this is not a good idea.

 

I meant what are the tank dimensions.

Why do you want to increase fuel capacity?

Gas or deisel?

-Tom

 

The USCG has some views on tanks that you should read. Either read what you NA's ABYC book has to say or get the CG COMDPUB P16761.3B "Safety Standards For Backyard Boat Builders", which is easy to get.

 

I'll check around in some books and browse some other sites, I'm sure that I'll find the answer. This publications, which a nice 53 page safety read with a few formulas on capacity, didn't offer much for my questions that I seek.

Thanks though.