Fuel Tank Configuration Albin 40 Double Cabin

[Major Tom]

Hi Everyone:

I am the new owner of a 1988 Albin 40 Double Cabin trawler, and I'm having trouble figuring out how the fuel system works. There are two 160 gallon side tanks and one 80 gallon center (day) tank. The fuel gauge on the center tank always reads 3/4 full regardless of the state of the other two tanks. Fuel is consumed much faster from the Port 160 gal tank than from the Starboard 160 gal tank. There is what appears to be a custom fuel manifold with input and output values for each of the three tanks. I have tried various valve configurations but the center tank always stays about 3/4 full.

Is the center day tank fed from the 160 gal Port fuel tank?

Any help or suggestions would be most appreciated.

Best wishes,

Tom

[jleonard]

Fuel Control to Major Tom

Your circuit's dead, there's something wrong

Can you hear me, Major Tom?

Sorry, couldn't resist

I have not seen nor heard of a system like that from the factory on an older trawler so I'm thinking it was custom. That said I would think the day tank would be fed by one of the main tanks and the return from the engine would go to the day tank.
The main tanks should have an equilizing line that should keep them at the same level. That might be shut off? Opening that valve if it exists, would solve one of your issues.
If the gage always says 3/4 it may be stuck/not working.

Reminds me of a story from the place I worked for 25 + years. One of the set up guys in the factory was a great wprker and he was in charge of many machines, one was a big power press that had an automatic oiling system. After 10 years the main crankshaft was worn so bad the machine would not run properly. It was not getting oil for many years. We asked the set up guy why he never oiled it. His reply (in broken Vietnamese/English) was "I check oil tank every day...always full". Seems the copper line from the pump was crushed and it could never pump oil, hence the resevoir was always full.


Maybe no fuel is being drawn out of the day tank??

[Major Tom]

Its a twin engine boat (Cummins 6BTM's) so that adds to the confusion regarding fuel return lines, etc.

I had considered that the fuel gauge on the day tank might be stuck or defective but on the other hand if its gravity fed from one of the main tanks then the level in the day tank should be constant until the feeder tank runs out. I can't see the tank nor how its fed so I am in the dark here. A custom configuration would not be welcome but if that's what I have...

There is a provision for connecting the starbard and port tanks together and I may well resort to that tactic. I read somewhere that the Coast Guard regs, or some other regs, don't permit the connecting the tanks in that way, but perhaps I am msitaken.

Best wishes,

Tom

[jleonard]

The purpose of a day tank is that it contains FILTERED fuel only. I would doubt someone would plumb it to gravity feed thru a filter.
If it is gravity feed then it is simply an additional tank, not a day tank perhaps?
All the old trawlers are connected at the tank bottoms. Perhaps it's not kosher any more, but it was thru the mid 80s.
6BTs (210 hp) don't return much fuel, but I don't have those specs in front of me.

[Chuck Waygood]

Nice looking boat, Tom. Congratulations on your purchase. My guess is that your two larger tanks fee the smaller, which in turn provides the fuel to the engines through a Raycor filter. My 2003 35te is set up that way. In addition, the feed from one tank may be preferential, either by design or because of blockage in the fuel line or vent of the other. In any event, the smaller center tank will remain either fairly full or at 3/4 as you have experienced. Check the line that flows to the Raycor filter to see if it indeed comes from the center tank. Good luck with the new boat.

[Major Tom]

Thanks Chuck and Jay.

The port tank runs low on fuel faster than the starboard so only the port tank is connected to the smaller center tank, either by design or because of a closed valve or obstruction. The center tank is located beneath a large custom made fiberglass and stainless battery box and it would be a major effort to remove it for closer inspection.

Note that all three tanks connect to a custom manifold with 3 valves on the input side, one for each of the tanks. On the output side of the manifold fuel then flows thru another set of 3 values connected to 1) port Racor then port engine, 2) starboard Racor then starboard engine and 3) generator without benefit of Racor filtration. Someone obviously went through a lot of trouble to set it up like this and I can see some advantages in the design.

I like the suggestion of tying the port and starboard tanks together for a self leveling system. There appears to be valves near the bottom of the tanks for this purpose. Is this where the tanks should be connected?

Tom

[jleonard]

I like the suggestion of tying the port and starboard tanks together for a self leveling system. There appears to be valves near the bottom of the tanks for this purpose. Is this where the tanks should be connected?

Yes, that's where mine are located. Aft end of the tanks, connected by 3/8 copper tubing so equalization will be a little slow.
When I bought my boat I had 1/2 full tanks when I got to my marina. I borrowed a fuel filtering rig and filtered the port tank into the starboard, then filtered all of the starboard tank back into the port side. It was listing bad, so we decided to have party on the boat and make everybody (as many as we could) sit on the port side of the boat to force the tanks to equalize. It was a successful excersize, and after about 2 hours only the party participants were listing.

[Major Tom]

Superb. Tha'ts where my valves unused are too, bottom rear. Perhaps 1/2 fuel line for the equalizer will make it flow a little better.

[Chuck Waygood]

I love that story Jay. I should have thought of the same before trying to solve the problem and naming it "A-List". Looking forward to your passage through Pamlico Sound TB. Be careful.