We ran out of diesel during this morning’s generatorrun. For some reason I thought we weredrawing off of only one tank, and therefore had been very lax in monitoringfuel levels. I guess I had been waitingfor this to happen. It was a little disconcertingto learn that we were dry on both sides. Oh well.
We already had a trip to the fuel dock planned in the comingweeks before we leave for the Bahamas. I’mglad we ran out when we did because I probably would have gone on the fuel runwithout checking how much we had.
Running out underway would have been seriously inconvenient. Even though we can see the fuel dock from ourmooring, there’s an overhead wire we’re too tall to go under, and we have to gothe long way around Boot Key.
On the bright side, this is a good opportunity to graduatethe fuel gauges and dipsticks, and find out how big the tanks really are. We’ve been operating on the assumption thatthe tanks are 100 gallons each, but don’t really know for sure. And when the gauge says 50%, we don’t knowhow much that really is because the tanks are not a uniform shape. Nor do we know how much fuel the generatorand engines really use. So we don’treally know much at all.
Truth be told, we do have a fuel transfer pump, so we couldhave found some of these things out before now.
But it will be easier with the calibrated high speed pumps at the fueldock, if we can get them to let us sit there long enough.
We do know that the fuel tanks are clean. First, we had the fuel polished before deliveringthe boat from Fort Lauderdale. This iswhere they cycle the fuel by running it through a filter and blowing it back inunder pressure to loosen up more gunk. Iwas not there to witness the process, but I have since been told the only wayto really get it clean is the open them up and scrub them out. So we did that and found there was quite abit the polishing didn’t get.
Interestingly, there was a pile of something granular under thestarboard fill pipe. I figured it waseither sand or sugar. Either way, itseems someone was attempting to sabotage the boat. Not telling when it happened, but fortunatelythere were no ill effects. With thetanks now empty, we can see that the bottoms are still squeaky clean.
So if we had 200 gallons when we filled up 140 days ago,that would be a burn rate of 2.8 gallons per day, which doesn’t seem verygood. Most of it is generator usage, butthere is also probably about 300 miles of motoring in there too. Unfortunately, we don’t have functional hourmeters on the engines. The generator hasone, but I don’t think it is correct because it is way high.
I’ll dinghy over the fuel dock today (it is time for thatanyway) and get 5 gallons of diesel. I’llput that in one of the tanks and see how much generator run-time that gets us. Then we’ll start keeping track of the generatorhours, and I’ll install new engine hour meters so we can keep track of thosetoo.
The gallons per hour calculations should produce pretty gooddata. Even though an engine burns fuelat different rates depending on load, our loads are fairly constant. Our battery chargers max out at 33% generatorcapacity and only charge at that rate for a short time. So the generator is just loafing most of thetime. When underway we usually run theengines at about the same RPM, which is easy because its right below the point where they smoke and shake the boat. We generally only use two for manueverability or to power into wind and waves. Otherwise, we go about the same speed with just one.
Getting the boat to the fuel dock might be a challenge. It is going to take a good amount of fuel, orvery flat water, to keep the pickups submerged.
The weather pattern we’re in makes it pretty bouncy outside. Too bad there isn’t a fuel delivery boat herelike they have in Fort Lauderdale. MaybeI’ll run them out of jerry jugs instead of the tanks. Yeah, that sounds pretty good.
Once we get to the fuel dock, the plan is to fill the tanksin 10 gallon increments, at which points we’ll mark both the dipstick and thefuel gauge for each tank. The dipsticks aremade of smooth stainless steel rod and it is very difficult to see the fuel onit. We plan to score the rod with a Dremeltool and a cutoff wheel. Hopefully themarks will retain a little bit of fuel that will be easier to see when pulledout, and still be visible through the inspection port.
With meaningful graduations, maybe I'll actually look at the fuel gauges more often. And armed with burn rates I can put together a nice spreadsheet to predict when we'll run out again.