SOMETIMES THE THIRD TIME IS NOT THE CHARM
April 29, 2019
This is a good news/bad news update.
We attempted to Leave Charleston with our newly conditioned propellers on Sunday, April 19th. We had been in Charleston for a week and were ready to shove off the dock. Unfortunately, the boat vibrated tremendously when the throttles were pushed up. Vibration high enough that I had blurred vision. So we throttled back, made a U-turn to the boat yard, and tied up in the marina. It was Easter weekend and the boatyard was closed until Monday.
I was at the office bright and early Monday morning and reported the problem. The yard was great. They hauled out the boat, removed the props, and returned them to the prop shop. They determined that the props were not balanced properly and gave us a 24 hour turn time to fix the problem and return the props. We launched on Tuesday April 23rd. The mechanics from the yard and I went for a ride. The original problem of gray some seemed to be gone. My tooth fillings were no longer in jeopardy, but the boat still shook. Another U-turn back to the yard.
We checked the engine alignment and made it better. We went for another ride and had the same results. The boat was hauled out for a third time on Wednesday. The props were pulled and sent back to the shop. The shafts were inspected and found to be straight as an arrow. The struts and rudders were good.
Our props came back on Thursday April 24th. We knew they would be there soon when the travel lift arrived and started to lift the boat. We rolled over to the launch area, the props arrived and were reinstalled, and we splashed. I think the yard was anxious to get rid of us. Surely these are now the best, most perfectly balanced, straight, perfect props ever!
Half the crew from the yard and I went for a ride. We pushed the throttles forward, and ……. still shaking. The vibration now is harmonic; it vibrates for about a second then drops off for about a second. And repeats indefinitely.
The theory from the yard now if that the new prop geometry is creating cavitation. My theory is the prop shop did something wrong. But we have to move on. Charleston was great and we could not have asked for better Southern hospitality from our friends John and Brandy. But we have a loop to complete. Another 5500 miles to go. We don’t think the vibration level is hurting the boat so we are casting off the dock lines.
We will determine our next step on the way to Chesapeake Bay. I have a feeling the bottom of the boat will be seeing either Maryland or Virginia sunshine and the props will be off for the fourth time.
WHEN THINGS DON’T WORK
Friday, April 19, 2019:
As I write this we are in Charleston, SC, a little over 500 miles into our 6,000-mile journey. Nautilus has been safe, comfortable, and reliable but we took the opportunity while here to address a couple problems.
Just before we left North Palm Beach, we had an AIS (Automatic Information System) transceiver installed on our boat. AIS transmits the boat name, length, beam, current position, direction of travel, and current latitude and longitude position of the vessel to other boats having it installed. We can also see the same information for boats which have AIS installed. All commercial vessels and some recreational vessels have it. We thought it would be handy to see barges, tugs, and other vessels hidden around curves towards us. There are portions of the Intracoastal Waterway that are too narrow to pass a large boat or barge and it’s a great way to ensure nothing large is coming our way.
The AIS worked great. It was like a new toy to play with. We could call other boats on the VHF radio by name without seeing them first. We knew their closest point of approach to us and when we would pass them. We had knowledge that we never had before. That lasted two days. Our new toy stopped working on day three. We troubleshot it underway and determined the problem was not related to the power or the antenna system. It was infant mortality of our brand new unit. Fortunately, we bought it from a reputable company in Stuart and they programmed a new unit and shipped it overnight to us in Charleston. We are back up and running.
The other issue was an old one. We have always had a problem with excess gray smoke and soot coming out of our engine exhausts. Gray smoke is unburnt diesel fuel so we were wasting money. Nautilus only gets about one mile per gallon and we don’t want to make it worse. Over the last year we tackled every potential reason on the engines. We cleaned the turbochargers, replaced filters, rebuilt the injectors, ultra-sonic cleaned the turbo air coolers, and tried various fuel additives. We thought the smoking gun was the aftercoolers for the turbochargers. These cool the air used for combustion to provide the proper fuel/air ratio. Ours were clogged with an oily residue. The smoke problem was reduced but was still there.
Our new dinghy hangs off the transom and it was turning black from the engine exhaust. The dinghy will be our shore access when we are anchored and vessel for exploring and we cannot be taking the time to clean it every time we want to use it. We decided once we got to Charleston that we would stop at a boat yard and have them take a look. John and Brandy Keener, our boat neighbors at Old Port Cove Marina, live in Charleston and recommended Ross Marine. John should be mayor of Charleston because he seems to know everyone. They were expecting us when we arrived.
We took a mechanic for a sea trail. The consensus was that everything done to the engines was correct and that the engines were not the problem. We recently learned that the propellers on Nautilus were not the ones installed by the factory. We don’t know why or when they were changed or the reason for the change. We found that the full throttle RPM was below the recommended minimum which meant that the boat was “over propped”. Basically that means that the props were trying to take too much of a bite out of the water with each revolution causing the engines to run in an overload condition.
We had the boat hauled out on Monday April 15th and the props were sent to the local prop shop. Nautilus looked lonesome without props installed.
It’s not an exact science, but the prop shop calculated what the “pitch” of the props should be based on the speed we were getting vs. the target speed. They determined the pitch should be changed from 22.5” to 21”. That means for every revolution the boat will move forward 21”. I don’t know how they bend the blades but somehow they do and the boat was launched with the modified props on Thursday April 18th. My Admiral Jill was certainly happy that our home was going back into the water.
We originally planned to stay in Charleston a couple days. Maybe a couple longer with the boat work. We experienced true Southern Hospitality by staying at John and Brandy’s. They were incredibly generous allowing us to stay with them and showing us a fantastic time here but we’ve been here a week and we are ready to move on.
I’ll let you know if the propeller modification was the final piece of the puzzle.