Mississippi Harvest a 28' Tall Bronze by Erik Blome in Celebration of Muscatine's River Heritage
Lock 16, one mile above the Muscatine Marina, was closed for repairs yesterday. Today there's a traffic jam trying to get through. We call the lock expecting bad news. Instead we're told to "hurry up" as they're about to pass rec (recreation) boats through.
We quickly cast off and get underway. There's a good head of stream on when, all of a sudden, Nellie burps and emits a cloud of black exhaust. Bicki and I exchange a brief, quizzical, and anxious look before Bicki throttles Nellie down and I dive into the engine room.
Duckweed Can Easily Clog Raw Water Strainers So It's Best to Check Strainers Often
Yesterday's project list included cleaning the raw water strainer. To do so, its thruhull must be closed. Of course a competent mechanic opens the thruhull right after the job is done; lest he forget...
We dodged a bullet. When the valve was opened the raw water flowed. Amazingly, the rubber impeller hadn't been destroyed and indeed saw us safely through the remainder of today's trip.
Two Towboats in Front and One Oncoming
Having done its duty the impeller will be retired, with honors, tomorrow morning. The first step in replacing the impeller is to close the strainer's thruhull. Now if I can only remember to open the thruhull when I'm done...
The burp and black smoke were fortuitous for they alerted us to the closed thruhull. But, what caused the burp and smoke? To discover the answer we need to know how the muffler was made.
The fiberglass muffler, which was fabricated in the same yard as Nellie, has some small lengths of PVC pipe inside it. The PVC was a temporary form over which wet fiberglass was laid. The PVC probably sould have been removed after the muffler was built, but it wasn't.
When the uncooled exhaust gas entered the muffler it curdled the PVC pipes and they partially peeled away from the fiberglass. This restricted the exhaust's flow and built-up
back pressure. The burp we heard was the pressure clearing the PVC obstruction. The black smoke was a result of poor combustion due to the high back pressure.
After changing the impeller I'll be probing the exhaust hose for PVC kidney stones.
Muscatine, Iowa to Rock Island, Illinois
It was an exciting 25 miles to the Sunset Marina in Rock Island, Illinois. The flood waters peaked today so hopefully future speeds will be greater than the 4.8 mph we managed today. Total under the keel is now 3,864 miles. DBH
