Packing 3k gallons of fuel

[trawlercap]

We just loaded 3,000 gallons (3,500 mile range) onboard. I did it for several reasons. The boat is designed to carry this, and I wanted to see how she settled on her lines. And if the ride/speed would be affected by the extra weight.
Twin 1,500 gallon tanks are in the middle of the boat, as well as the engine room. This centers weight, the load made no difference in for and aft trim, just a tad lower and sitting even.
I did some digging back to the original plans (1950 Bill Garden) They show 3,750 lbs. per inch of immersion. This is a packing mule!
I would encourage anyone to know your weight/per inch of immersion. It's critical fora lot of reasons, and a very good tool to have in your box.


After fueling up


From this dock literally thousands of voyages have launched into the N.Pacific/Bering Sea


Fuel tanks from the walls of the engine room.

 

[slowgoesit]

Sweet! Makes our soon to be boat seem like a piker as she only holds 2,100 gallons!

 

[Simi 60]

We just loaded 3,000 gallons (3,500 mile range) onboard. .

Have to ask, is that at an economical cruise speed?
3000 gallons is 11,500 litres
For us that'd pretty much get us 5200 miles @ 7.5 knots

We only hold 1850 gallons/7000 litres, good for 3500nm.
Would love to hold more.

Add: just spotted twin engines, may be the difference in burn.

 

[Simi 60]

You should notice a difference in ride, we definitely do, more weight the better.
See no real difference in speed for same rpm.

 

[Nomad Willy]

Two 50 gal tanks for our little boat. Can almost make it to Ketchikan w that.

I told the yard to fab 35 gal tanks ... but no listen.
So we still have 100 gal. Kinda stupid. The fuel just sits in there getting stale.

But now that We’re no longer making the runs up and down the coast to Alaska you’d think we even have less use for all that fuel.
But it gives us an option that we otherwise would not have had .. at least to the extent we now have.
The advantage now is that we can fuel up here in northern Wa and cruise 800miles in central BC and back to LaConner w/o taking on more fuel.

Fuel management, anchor management and dinghy management. It never ends.

TrawlerCap,
“Jo Ahna K.”
You already changed her name?
2nd pic Fisherman’s Wharf .. Seattle?

 

[Jay N]

"I would encourage anyone to know your weight/per inch of immersion."

Without builders/designers plans, but confirmed by 23 years of observation, I've always used 1000 lbs per inch of immersion. This for a semi-displacement design with a 100% wet weight of 34000 lbs.

Of course, the fuel/water tanks are towards the stern, so as fluids are consumed, free board aft increases disproportionately.

And I do notice about .35 knot slower speed at 100% wet vs 40% wet (2400 lbs). But I think this is representative with this type of design and weight.

Interestingly, it looks like your lbs per inch of immersion vs displacement is about the same factor (3%) assuming around 125000 lbs.

 

[trawlercap]

Have to ask, is that at an economical cruise speed?
3000 gallons is 11,500 litres
For us that'd pretty much get us 5200 miles @ 7.5 knots

We only hold 1850 gallons/7000 litres, good for 3500nm.
Would love to hold more.

Add: just spotted twin engines, may be the difference in burn.

7 gph on the flow scan meters making 8-9 knots on my first run over six hours.

 

[trawlercap]

You should notice a difference in ride, we definitely do, more weight the better.
See no real difference in speed for same rpm.

Good call, yea. Rides real nice, no diff in speed or fuel burn

 

[trawlercap]

TrawlerCap,
“Jo Ahna K.”
You already changed her name?
2nd pic Fisherman’s Wharf .. Seattle?

Nomad Willy, second shot is Ballard Oil, center of the Alaska fishing fleet universe.

We changed the name after we bought it yes.

 

[trawlercap]

"I would encourage anyone to know your weight/per inch of immersion."

Without builders/designers plans, but confirmed by 23 years of observation, I've always used 1000 lbs per inch of immersion. This for a semi-displacement design with a 100% wet weight of 34000 lbs.

Of course, the fuel/water tanks are towards the stern, so as fluids are consumed, free board aft increases disproportionately.

And I do notice about .35 knot slower speed at 100% wet vs 40% wet (2400 lbs). But I think this is representative with this type of design and weight.

Interestingly, it looks like your lbs per inch of immersion vs displacement is about the same factor (3%) assuming around 125000 lbs.

Very cool, I never heard that ratio before. Yes we are 130,000 designed displacement. Driving square stern commercial fishing trawlers and crab boats over 30 years, I could ballast using big fish/crab tanks. The rule was always "get the stern as high as you can, bow down. I went round and round with the designer, and he swore nose down, ass up was best for speed and efficiency. For those boats he was right. I haven't had my yacht long enough to know, I think the pinched back end will slip through without extra drag either way, and I can't be moving ballast around like that....

 

[trawlercap]

"I would encourage anyone to know your weight/per inch of immersion."

Without builders/designers plans, but confirmed by 23 years of observation, I've always used 1000 lbs per inch of immersion. This for a semi-displacement design with a 100% wet weight of 34000 lbs.

Of course, the fuel/water tanks are towards the stern, so as fluids are consumed, free board aft increases disproportionately.

And I do notice about .35 knot slower speed at 100% wet vs 40% wet (2400 lbs). But I think this is representative with this type of design and weight.

Interestingly, it looks like your lbs per inch of immersion vs displacement is about the same factor (3%) assuming around 125000 lbs.

Very cool, I never heard that ratio before. Yes we are 130,000 designed displacement. Driving square stern commercial fishing trawlers and crab boat, we could ballast using big fish/crab tanks. The rule was always "get the stern as his as you can, bow down. I went round and round with the designer, and he swore nose down, ass up was best for speed and efficiency. I haven't had my yacht long enough to know, and I can't be moving ballast around like that.

Your boat looks like a sweet ride!

 

[Simi 60]

7 gph on the flow scan meters making 8-9 knots on my first run over six hours.

Yep, ours does similar if doing 1350rpm for 9 knots
Drop a bit below hull speed doing 1150rpm for 7.5 knots and we get a bit under 4 gph based on running 1000 litres/265 gallon through her.

 

[Easternshore]

Wow, my knees get weak just filling our twin 125 gallon tanks @ 2.70/gallon, don’t want to think about 3,000 gallons!

 

[rslifkin]

But now that We’re no longer making the runs up and down the coast to Alaska you’d think we even have less use for all that fuel.
But it gives us an option that we otherwise would not have had .. at least to the extent we now have.
The advantage now is that we can fuel up here in northern Wa and cruise 800miles in central BC and back to LaConner w/o taking on more fuel.

Being able to skip expensive fuel stops is definitely a nice benefit. I wish I could do that more often, but unfortunately I go through my 420 gallons a bit too quickly.

As far as immersion, I figure my boat to be somewhere around me 1000lbs/in. My fuel and water tanks are all pretty far aft, so I see about a 2 inch drop at the stem from half tanks to full (about 1600 extra pounds), but basically no change at the bow.

 

[BandB]

I would have bet on it all going well on a Bill Garden boat. Huge Garden fan here.

 

[trawlercap]

I would have bet on it all going well on a Bill Garden boat. Huge Garden fan here.

I have been pleasantly surprised every single day I am aboard. Some killer "Oh Wow look how they did that. Or I see why he did that" to "smallest of details that I just go, this is soooo once!"

We are parked next to a Garden conversion. From offshore tuna boat to a yacht, just killer details and craftsmanship.

All Bill Gardens on our dock (there may be more.) If it would hold off raining I will get better images.

 

[South of Heaven]

Twin 1500 gallon tanks are in the center? That's interesting. Do big tanks like that have baffles inside?

 

[trawlercap]

Twin 1500 gallon tanks are in the center? That's interesting. Do big tanks like that have baffles inside?

I suspect they must, they are full length of eng. rm. tall and narrow.

 

[woolf]

I suspect they must, they are full length of eng. rm. tall and narrow.

View attachment 112211

That is the ideal position for a fuel tank – just short of integral bottom tanks in metal hulls. Do you have another center line fuel or water tank(s) forward, for longitudinal trim?

 

[sunchaser]

I suspect they must, they are full length of eng. rm. tall and narrow.

Original steel tanks?

 

[Juliet 15]

I used a lot of fuel up over the summer. In Aug I filled up from about 1/3 full to 100% full and I noticed a significant change in how she handles when docking. Underway, not too much.

Obviously her momentum is now higher, so getting her started and stopped was different and took more planning. Steering was slightly less effective/took longer, as did hovering turns.

Speed was a little lower for a given RPM setting, but I didn't look closely to determine the change.

 

[OldDan1943]

With 3000 gal of fuel onboard, the handling may be different than with 2000.
Starting on a long voyage, sure, load it up.
I personally dont want or see the need to drag around all that extra weight unless necessary.

 

[Marco Flamingo]

Our 120 gallon tanks hadn't been filled for years. But the price of diesel was good so I filled them. When filled, I developed a pinhole leak and had to have one tank lined ($2,800). Also, I now have a little bit of a "sweat" from one of the ball valves, maybe from the pressure. About a drop a week. I need to burn 120 gallons (700 miles) during Covid in order to drain the tank to work on the ball valve. I didn't look to see the effect on my waterline. Too many other issues. Next time I'll check out attitude and performance.

Turns out that filling the tanks proved to be a fuel system stress test more than a money saver.

 

[HeadMistress]

Several years ago I was asked to survey and troubleshoot the sanitation system on a 46' trawler. Among other problems, half of the vented loop for the master toilet, tucked away in a compartment in the hull, was below the waterline. "WHO installed THAT???"

It turned out that it had been installed when the fuel and water tanks--2 800 gal fuel tanks and 1 500 gal water tank--were empty and was at the right height above the waterline at the time. They were full when I found the loop...Filling them had raised the waterline almost a foot.

Something to consider when adding above-waterline loops, thru-hulls or other devices.


And as long as I have the floor for a moment. HAPPY NEW YEAR to all of you...and may 2021 be a huge improvement over 2020!

--Peggie

 

[Nomad Willy]

For efficiency any time you can get the stern up w a transom boat the better efficiency.

Got a “tinny” ? You’ll be able to row it much faster w one person aboard and most all the alum skiffs had the oarlocks/seat fwd. Or even backwards. If you can control it.

The main thing is to get the square and usually submerged flat transom higher up.

Thank you Peggie and too you as well.

 

[Circumnavigator]

I hope those of you who are buying 1,000 gallons or more at a time negotiate a good price. We typically pay US$0.50 over the New York Harbor Spot Price for diesel if we buy 1,000 gallons or more and pay by check, not credit card. That would be US$1.98 today.


I also hope you have the connection and piping for a high speed fuel pump -- our dealer supplies most of the commercial boats, fire boats, and Coast Guard in Boston Harbor and, pre-covid, did 15,000 gallons a day. They deliver fuel at 75 US Gallons per minute. That sure beats an ordinary pump all hollow.


Jim

 

[Sailor of Fortune]

Twin 1500 gallon tanks are in the center? That's interesting. Do big tanks like that have baffles inside?

yes, they most assuredly are baffled. Free surface effect would get ugly otherwise.

 

[trawlercap]

That is the ideal position for a fuel tank – just short of integral bottom tanks in metal hulls. Do you have another center line fuel or water tank(s) forward, for longitudinal trim?

Yes Woolf, sorry for my late reply. The Alaska Steel crab boats all have double bottom tanks. Our 123' commercial trawler had two 10,000 gallon tanks full length. We burned that fuel last (If ever) The double hull bottom save a few boats that went on the rocks.

My little 58' has two 200 gallon water tanks just forward of the engine room.

 

[trawlercap]

Original steel tanks?

Yes they were blasted and epoxied in 2002

 

[trawlercap]

Our 120 gallon tanks hadn't been filled for years. But the price of diesel was good so I filled them. When filled, I developed a pinhole leak and had to have one tank lined ($2,800). Also, I now have a little bit of a "sweat" from one of the ball valves, maybe from the pressure. About a drop a week. I need to burn 120 gallons (700 miles) during Covid in order to drain the tank to work on the ball valve. I didn't look to see the effect on my waterline. Too many other issues. Next time I'll check out attitude and performance.

Turns out that filling the tanks proved to be a fuel system stress test more than a money saver.

Better to find any weak spots at the dock rather than pounding at sea I bet.