Red Ranger last moved in once in August 2020 and again in October 2020. Before that she last moved in October 2018. She hasn't been out of the slip in the last 8 months.
We decided to go back to Cambridge, MD, for Memorial day.
On the way… the Pride of Baltimore. This was fun to see.
Spectacular. (Snarky side note. She's under power motoring straight into the wind. We were also under power because we aren't going to try to trim sails in a river.)
While the overview (from MarineTraffic.com) looks like this, the story is nothing like a simple direct track out and back.
A big question is "why did you divert to Oxford and not continue on to Cambridge?"
Under this big question are a number of smaller questions. Like "What broke?" and "What did we do to fix it?"
The real question behind a shakedown cruise is, "Can we fix the inevitable problem ourselves?" Or "Are we self-sufficient?"
We'll start with the list of problems. It's surprisingly short.
The Light On the Piling In Our Slip. The first thing we broke was part of the dock before we left. It counts in this list because it was cockpit error. I thought we could undo our aft spring line early in the process. We pretty much can't. It must be the last line off no matter which way the wind is blowing.
Especially when we have wind from astern. In spite of banging around in the slip haphazardly for a while, we did get out and underway. So that's a problem solved without help from others.
What I mean is the Red Ranger problem of casting off the lines in the wrong order has a solution. The broken dock light is something we're not going to "solve"; instead we're going to pay the damage fee.
The Anti-Siphon Loop. The next thing that broke was the piece of the engine exhaust system that prevents the a big wave crashing over the exhaust port from starting a siphon that fills the engine with seawater.
The anti-siphon loop is mounted as high above the waterline as it can be. It has a little diaphragm acting as a one-way valve. The exhaust water, driven by the impeller is under pressure and forces the diaphragm shut. A huge wave's water, however, isn't under the same pressure as engine water, and will tend to pull the diaphragm open, breaking the siphon.
On the right, a 1″ hose brings exhaust water up from the cooling system to the loop.
On the left, a 1″ hose descends through a coupler into 1¼″ hose. And into the exhaust riser, where it is mixed with exhaust gas, and runs into the muffler.
On the top is a ⅝″ hose to try and pevent water from burping onto the engine.
The three horizontal lines are part of the steering hydraulics. They're not relevant, but in the picture anyway.
The diaphragm — inside the bronze casting — is a neoprene rubber slab mounted on a stainless steel base. With a stainless rivet. It's almost indestructible.
Which means it's not totally indestructible. The stainless steel — in an anoxic environment — isn't truly stainless. So. There's rust, which means gaps, which means the diaphragm doesn't stay closed and the damn thing burps water onto the engine.
So. In a way, that's broken.
The Raw Water Input. We knew the anti-siphon is burping water onto the engine. While stressing over this problem, the engine temperature gauge starts creeping up. It's normally at 160°F. Solidly. (It goes to 180°F briefly during warmup, and when the thermostat opens, it drops.)
In addition to a rising temperature, we have "white smoke". See this post: http://www.sailingncruising.com/boat-maintenance/white-smoke-exhaust/. There are two kinds of white smoke. The first kind: "white smoke right from start up and the smoke sits on the water without disappearing." Not what we're seeing. Ours takes a while and dissipates.
Moving on in our research: "With white smoke that quickly disappears after a couple of yards behind the boat, you're most likely looking at steam. There are two possible sources to create steam in your marine diesel engine: one is from coolant and the other is from the raw water drawn into your engine to cool the coolant."
We're not running out of coolant. So. We're looking a raw water problem. (Actually two raw water problems: the anti-siphon loop is puking water onto the engine, also.)
Things to look at:
Clogged up heat exchanger
Damaged impeller or leaky impeller housing
An obstruction clogging the raw water inlet or debris clogging your raw water filter.
Here's the impeller pump.
It's the bronze circular thing with a hose coming in the bottom and an elbow and hose coming out the top.
It's a Johnson F5B-9 pump. It's a pain in the neck to pull the impeller out. It's not too bad to mush a new one in. Turn it clockwise until the vanes mash into the body.
I have spare impellers, we can fix one of these. I don't want to try and unclog all three heat exchangers.
I have good reason to suspect that we have so much algae on the input that we're not getting all the water we want. Red Ranger hasn't moved much in almost two years.
First Day Score: 3 things broken. CA suggested we divert to Oxford and fix what we can.
Here's Oxford's shoreline on the Tred Avon.
First fix. The Impeller.
You may not be able tell if this one is old or new.
It's nearly perfect.
Zoom in on the 8 o'clock position and you'll see a vane that's bending slightly the wrong way.
Second fix. The anti-siphon loop diaphragm.
I spent hours (more than one) trying to reassemble the "Cap" to the Groco unit. It was essentially impossible to force the diaphragm back into the seat machined into the bronze. The rubber gasket around the outside of the stainless frame the holds the actual diaphragm does not go back in.
CA found me two 4′ lengths of high-temp ⅝″ hose in our spare hose cupboard. And a junction. Now the water dribbles into the bilge instead of burping onto the engine. This means the bilge pump ran 5 times in the 2 hour run from Oxford to Cambridge. It ran 12 times in the 6 hour run back to Herrington Harbour.
The "solution" is a weird hack. But. It works.
Did we pass the self-sufficient test? Kind-of.
On the way to Cambridge (and on the way back) we still had steam. The new impeller on the raw water pump changed nothing.
One bent vane (out of 12) is not enough to starve the engine of cooling water when running at higher RPM (over 1700 on the tach, which is about 1400 in reality.) I'm guessing (based on the Johnson marketing material) that this pump is geared to spew 10 gallons a minute through the heat exchanger and out the back of the boat.
A bilge pump run of 15 seconds is about a gallon of water. We're seeing about 2 gallons per hour burped in the bilge. Compared with 600 gallons per hour through the cooling system. From this, I conclude the diaphragm problem is unrelated to the cooling problem.
When we ran aground. (Yes, I cut a turn waaaay too close to the bank and hit a cliff. 30′ of depth to 3.2′ of depth in the time it takes to say "Yikes!". Full power reverse pulled us off. Steam and all. And yes, our depth meter is well below the water line and not adjusted with either a keel offset or a waterline offset.)
So. We're back to algae (and barnacles and oysters) on the outside or something in the strainer on the inside. The bottom requires a haul-out. The strainer is an easy check. The outside will wait until we paint in September.
In Cambridge, in an actual brew-pub, Rar, with actual other vaccinated people, we talked to S/V Shooting Star about the steam business. Their anti-siphon doesn't have a diaphragm or duck-bill joker valve. No. Diaphragm. Really.
Their anti-siphon has a hose. The hose goes up to a "T" fitting in one of the cockpit drain hoses. Water can run down the hose. Air can comes in from the drain on the floor of the cockpit to break a siphon. It's pretty slick and avoids the valve.
Some more reading reveals these are the two common designs. Diaphragm valve and overboard vent. (Or. Hybrid not-seating right valve and bilge vent in the Red Ranger case.)
I could install another Groco. In principle, they sell caps as a stand-alone replaceable part, but they're hard to find using ordinary Google search. Instead, I'm going to try the Vetus anti-siphon. It looks like it's easier to clean the diaphragm and reassemble the loop.