Still better than most days I ever spent in an office (long)

[abcandjrc]

We took our R21-EC out for some fishing yesterday, our grandson, his father, and me. It was blowing pretty well on Mobile Bay and the wind was against the tide and river flow, ala the dreaded norther on The Gulf Stream. Probably 1 foot base wave, with the typical 3 footer thrown in for good measure once in a while, and with a short period. We departed with the fuel gauge registering between 1/4 and 1/2. I realize fuel gauges are not precision instruments, but I estimated we had between 4 and 5 gallons, easily 8 hour running time, maybe 48nm available.

I have a spreadsheet accounting for all fuel purchases and we average 1/2 gallon per hour and probably cruise at 6 knots. After this, I will keep a "last hours at fill" number on board to supplement the fuel gauge's guesstimate. Even though this time it appeared my estimates based on the gauge were correct.

We ran out to a gas platform in the bay, first stopping to fish an artificial reef. That was a 13.5nm trip.

We headed back into the wind and wave and about a mile out from the rig, the engine died. It sounded like fuel starvation. Thinking "That's strange!", I never-the-less added the contents of our 2 1/2 gallon reserve container. That should have given us another 5 hours and 30nm range. After several attempts, including using high-throttle settings with the transmission locked out, the engine restarted.

We traveled another mile or so, and the engine died again. I installed a new fuel filter on the assumption that the fuel tank was being well agitated and the filter, 2 months in place with only 16 hours of use, may have gotten fouled. I always carry a spare, and one time had to make a change half-way to the The Bahamas in the aforementioned Gulf Stream in our Crealock 37 (don't ask why the engine was running). I bled the filter, happily proving fuel really was available, and again, after several attempts, the engine started. (The old filter looked like new.)

Another mile or so and it died again. This time, after starting, I had my grandson drive at full throttle (on the assumption we would burn more fuel but the pump might be more effective and we would have a shorter swim to shore the longer we were underway). I rode the bow to keep the boat trimmed at its best point for the speed, getting soaked and fairly cold in the wind. We made it back to our entrance to Mobile Bay and smooth water and the engine ran like a top after that, idle, fast, whatever.

We added 12.1 gallons of fuel on the way home. That means we still had roughly 6 gallons in the tank. Assuming we burned 2 gallons on the trip back of 11nm (pessimistically) and accounting for the 2 1/2 gallons I added, that means we should have probably had nearly that many gallons at the point where the engine first died. That is not good!

My conclusion is that the boat was pitching and rolling enough that the pickup was occasionally sucking air, starving the pump momentarily, and resulting in stalls. Cranking these great Yanmar engines was sufficient to clear any air and got us going.

We anchored with each stall to minimize lost ground which made the boat more stable, so it appears that allowed the pickup to stay in the fuel. Keeping the boat trimmed and running at full speed and a bit more stable seems to have done the same. Anyway, be aware it could happen to you.

I'm a pretty steady hand in an emergency, but with the prospect of spending the night anchored in the bay with those two lubbers and then probably having a $500 charge to have a service bring me 5 gallons of fuel was not a happy one. Even I sighed in relief when we reached the calmer waters off Mobile Bay and the engine behaved normally.

 

[sportner]

I hate that helpless feeling. The same thing happened to us several years ago in our C-Dory, after changing the fuel filter I finally tracked it to a pinched fuel line. Ever since I have been over prepared for the unexpected and if the weather and seas are marginal I always have the crew put their life vests on and have the anchor ready for deployment.

This is the first time I have heard of a problem like this with a Ranger. Sounds as though you handled the situation as best as possible, glad things worked out.

 

[RProffer]

The factory has a mod for the fuel pickup on the R21-EC. It is a longer hose that lays at the bottom of the tank. Contact the factory and they can fix you up.

 

[mlull]

Since it's a safety issue why don't they (Ranger) offer the fuel line modification to all?????

 

[Andrew Custis]

This is unfortunate but the R21 fuel tank comes one way from the manufacturer. Ranger strategically placed the fuel tank in the center of the vessel to keep the sloshing effect down but cannot always be avoided. The pickup is long enough to reach the bottom of the tank but if you are in that rough of water, it would be possible for fuel to slosh away from the pickup tube. Ranger Tugs has asked the fuel tank manufacturer to change the pickup to a flexible style that could prevent this from happening. Unfortunately this flexible conversion doesn't work with all existing setups. We are more than happy to provide you with a flexible style pickup but this will only work with the threaded in fuel pickups. Not the "pop" in style. Please contact parts@rangertugs.com and Richard can assist you. You may also reach Richard at 253-839-5213.

 

[abcandjrc]

Thanks, Andrew.

I have always assumed that the tank is not baffled since it appears to be blow-molded. Not much can be done to stop sloshing. We were really rolling, and once we had the problem it was a toss-up whether to alter course and maybe not have enough fuel if that was the real problem, or to keep rolling and cross our fingers that we could always restart.

Like I said, I have been impressed with how forgiving both of our Yanmar engines have been about purging minor amounts of air on their own.

My plan is to always keep levels above half which should really cut down on the probability of introducing air. Generally I do not top up a partial tank because of the accompanying problem of the vent leakage. KInd of a Hobson's choice.

 

[SlackwaterJack]

First thing I'd do is inspect the interior of the tank to see if the suction hose is actually the problem and there wasn't something randomly suctioning onto the intake or the intake line was displaced by sloshing.( but you probably already did that) The biggest problem with plastic boat tanks is the inadequate or non-existant baffling thats needed to prevent violent sloshing of a partially full tank. I've read of some folks filling their fuel tanks with with "wiffle balls" (guage won't work though) on white water jet boats, dune buggies, Baja racers etc...


I had one boat that (due to the tank orientation/pickup location,) when you got below a 1/3 tank and slowed down from cruising speed, the bow dropped/stern rose and the engine stalled...if the tank hit the 1/4 mark before you dropped the bow the engine would stop and the pick up would be above the fuel so you were adrift untiil you could add more.That taught me to never trust a fuel guage on a boat ever again (I've owned a lot of boats and have never had a reliably accurate read from a fuel guage). I suppose a fuel flow meter would be more accurate though on a diesel I don't know if it would account for the fuel returned to the tank, but that would be a good margin of error.

 

[abcandjrc]

........I've read of some folks filling their fuel tanks with with "wiffle balls" (guage won't work though) on white water jet boats, dune buggies, Baja racers etc...

..........That taught me to never trust a fuel guage on a boat ever again (I've owned a lot of boats and have never had a reliably accurate read from a fuel guage). I suppose a fuel flow meter would be more accurate though on a diesel I don't know if it would account for the fuel returned to the tank, but that would be a good margin of error.

I wonder how insoluable those things are. I also wonder how much of the 18 gallon volume they would use up. Not a bad idea, and one I had never heard before. And maybe one with some commercial appeal if packaged "For Boats" at 10 times the price of the balls.

I have thought about other options such as a small perforated canister with a reservoir at the bottom. But that would generally preclude getting the last bit out of the tank in normal operation without some failure-prone valving at the bottom even while solving the slosh problem up to that point.

Interestingly enough, the gauge in the R21 seems to give a fairly good track on how much has been consumed as long as the boat is in calm water and preferably stationary. But as you say, fuel gauges in general are not very precise, at best, and terrible sometimes.

I suspect the most sophisticated "electronic" diesels should be able to calculate fuel consumption based on the dynamics of the injector settings. However, I still prefer "simple as possible" where I can't walk home, like with boats and airplanes. I read too many posts on here about the "latest-and-greatest" failing. As a retired aerospace software engineer, I don't even like to fly in commercial airlines (TSA aside). I still prefer real steel cables going to the control surfaces. "Fly-by-wire" really means "fly-by-ones-and-zeros". Actually, I still find "high-speed-diesel" to be an oxymoron. Hopeless dinosaur I guess.

That is why I have decided to start posting the hours on the meter in the log I keep on board. Over the 72 hours we have added to the boat since acquisition we are averaging half-a-gallon/engine-hour. That should be close enough for keeping us above the half tank I propose for the future.