Our intention after Dry Tortugas was to take a week to regroup and provision the boat for the trip to the Bahamas. Preparations extended to three weeks. Here is the tale as it unfolded.....

In our last episode the Genset had quit with an overheat detected. Fortunately these protective shutdowns only cause inconvenience. In fact when we got to Marathon five hours later the food in the refrigerator was still cold.

By way of background: The Analysis of Systems Reliability begins by enumerating all possible states of the system.   Generally one starts the analysis in the fully operational state, that is: all essential parts of the system are working.  It assumes that the system changes state due to single component failures (or repairs) at as time passes.  This assumption, the so called Single Step Assumption, makes it possible to develop (and solve) a set of mathematical equations which predict probabilities of being in each state. By dividing the states of the system into two sets, Successful operational states, and Unsuccessful states one can predict the mean time to system failure, the availability of the system, AND the Reliability measures of the system.

Sorry to overwhelm you, kind reader, with these technicalities, but in my former life, (B.C. before cruising) I was a reliability analyst. It colors my thinking about failures and repairs of equipment. Because of the Single Step Assumption, I expect that repair of a system means finding the One thing that broke and fixing it. Once fixed, you start the system up and everything is OK.

Right?

WRONG!

You will recall that Ralph and I fixed the Sea Water pump in the Dry Tortugas and the Genset ran continuously for two days. One blown seal was fixed... then the system worked. The theory worked!

Next the Genset overheated at Key West.  The sea water was coming out with the exhaust in normal fashion. So the pump was working. Something else must have failed.

I called Lakewood Yacht Service in Seabrook and described my problems to Dennis Osborne the parts expert on my Genset. As a result I ordered a kit for rebuilding the sea water pump and a Thermostat.

After three days the parts had not arrived. Dennis put a trace on the shipment and found they had been mistakenly been shipped by Surface instead of Air. It would be a week before they arrived. Meanwhile there were other things to keep us busy:

    Catalog all of the audio CD's on Lotus 1-2-3 and make a directory for the CD carrousel.

    Printout all of the Great Loop Adventures and file in the Remedy Scrapbook.

    Go to Office Depot and buy another ream of paper and 2 Color, and 2 Black Inkjet Cartridges.

    Buy a CD Reader/Writer for the Laptop, install software and learn how to make CD's.

    Offload Un-needed Navigational charts from the Laptop and reorganize the photo files.

    We also visited the Crane Point Hammock Museum where I photographed Genny the Iguana.

The parts arrived and I put the thermostat on first. Test showed no improvement. Somehow I had lost coolant so I refilled the coolant. Operating on the assumption that the coolant pump was not circulating water, I turned the fan by hand. It moved easily; it should not have moved at all.. The fan belt was so loose that coolant was probably not circulating.

I was ready to tackle the difficult task of tightening the fan belt when I discovered water flowing into the boat. The ancient water hose which carries the Air Conditioner cooling water from the forward AC unit was leaking profusely at the overboard fitting.  A sinking boat takes priority over genset repairs so I called in the Air Conditioning repair company and told them to bring enough hose to completely replace the overboard line.  Frustration is mounting... Six or Eight wraps of Duct Tape cut the leak back to a manageable level.  The AC is back on and it's time to relax and have a beer and wait.

Steve, the AC repair man worked quickly and in less than an hour we had 25 feet of hose run. He is a younger and more agile man than I.

"Steve," I asked, "How are you at Genset repair?"

"We don't do them," he said, "But what's the problem?"

"I was just getting ready to tighten the fan belt but I am afraid I can't squeeze back into that corner. How about you tackling that chore before you leave?"

"Sure.. No Problem... I can handle that."

It took him less than five minutes. After he left, I immediately called Lakewood and had Dennis send two fan belts. We would not be leaving for several days because Marion was suffering from a bladder infection, had seen a doctor, was on medication,  and she needed to check out A OK before we would consider traveling.
 

"Why don't you quit for the day?" urged Marion. "Great idea, I've done enough." I agreed, "I will test the Genny tomorrow." Next day the BIG Test....  Genny again overheated...  Then I overheated... What could it be now?

As I went below to check the cooling system I noticed a bright green color in the Sea water strainer. If that is coolant then I must have a leak in the heat exchanger which allows the coolant to drain out. Sure enough  it was. I found a local mechanic who does Westerbeke Diesels and he conformed the diagnosis. A new Heat exchanger would be ordered. It came the next day and was installed that afternoon. The pump was rebuilt and reinstalled and everything finally checked out.

Here is my final analysis of the MULTIPLE failures that occurred.

1. Original Fan belt finally wore out enough that the coolant pump did not circulate enough to be effective.

2. Engine shuts down due to temperature rise. Pressure built up and blew a small hole in the heat exchanger.

3. Pressure on the sea water pump blows out a deteriorated seal.  The initial seal repair miraculously holds for two days of running.

4. Hole in the heat exchanger gets larger with each stress test until it finally leaks most of the coolant into the Shearwater side.

Restoration of normal running required replacement of the Heat Exchanger, rebuild of the sea water pump, tightening the fan belt and numerous refills of the system with coolant. The thermostat replacement was not needed.

The Theoretical Foundations of Reliability Analysis have been shaken to the core. The chain of events produced multiple near simultaneous failures. The lesson: Don't Assume single component failures.

Sombrero Reef Revisited

Two days before we headed of the the Bahamas we got together with Ralph and Mary Ann Close for Lunch at Don Pedro's Cuban Cafe and a Cruise to Sombrero Reef.

Cuban style Roast Pork has become one of my favorites. They serve it with black beans over rice and usually with fried plantain (banana) as a side. They have some special spice on the pork that I can't identify. I love it. Lunch at Don Pedro's Rating ***$$.

After lunch we took Remedy out to the Reef for her trial run and ran the Genset all the time. Hooray, no overheating. We had a great time diving on the Reef.

 

There were lot's of fish we had not seen before.   These are the Blue Tang. They swim together and run away when you try to get near.

Here is my first photo of a Manta. He swam by twice below me. I think he wanted me to get his picture. Actually, this is Spotted Eagle Ray. About 6 feet wing span. He was dragging a hook and line, his natural tail barb is missing. I will show you a Giant Manta Ray later.

Finally We Depart

We did provisioning  on our last two days and with our returned confidence in the Genset repairs we set out for the Bahamas.

The first night would be at Rodrigues Key. That's just south of Key Largo. Then at first light we pulled anchor and Started our crossing of the Gulf Stream.

Stay Tuned.