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Overhaul long overdue done

Finally we were able to overhaul the ship. After having been decommissioned in 1991, had only been in dry dock once while being converted into a discotheque. The usual frequency for taking ships out of the water for inspection and maintenance is 5 years.

In Holland, as probably in every European country, ships can be “classified”. A ship can be registered in a certain “class”’ when a so called “class-bureau” issues a certificate of a certain level. The relevant levels for the Jenni Baynton are the “Sea-class” and the “Inland sea and canal/river class”. If you want your ship to be registered in a certain class, a lot of things (mostly safety related) need to be up to standard. It will be no surprise a recent report on the state of the hull is one of the first things a surveyor will ask for. The hull was 12 to 14 mm thick. Considering the ship was built 60 years out of 15 mm plates she hadn’t been doing too bad. However it wasn’t all positive. Even though we thought we had nothing to fear from “Electro corrosion”  because we don’t have a bronze propeller we were in for a surprise.

By the way Electro Corrosion is a phenomenon caused by the difference in electric tension between metal of different nobility. When various different metals are connected an electric current is created causing the “less” noble metal to sacrifice itself to the “more” noble metal. Factually this leads to the less noble metal to literally vaporize. This is why different metals (even two different alloys of steel) need to be connected with insulation when bolted together. However, when in (salt) water insulation is useless as the water works as a conductor. So having a bronze propeller and a steel ship, the propeller will “eat” the ship completely when given time. This is what most likely caused the sinking of the Mi Amigo.

Holes just appear for no reason as the metal is eaten and eaten until there is nothing left or the remains are so weakened the slightest impact causes leaks.

Is there no cure? Yes there is. By offering the “more” noble metal a pray that is even lesser noble than the “less noble metal” it will eat the lowest of value first. This is why ships always have zinc anodes welded onto the hull or rudder, close to where the bronze, brass or whatever noble parts are. Alternatively to welded anodes you can try to connect sink blocks to the railing with electric wire and to hang it over the side, but this doesn’t work as well (if at all) as welded on anodes. 

Alright, back to the Jenni Baynton. Having no propeller we thought we needn’t fear the Electro corrosion much. Fair enough, when a ship moors up along side our ship and that ship would not have proper anodes, the propeller of that ship can damage ours as well. Also when our ship would be moored alongside a sheet pile wall the current may be established, but all in  all we weren’t too worried.   After the ship had been lifted out of the water, which is a happening in itself, it turned out to be covered with shells. Massive Japanese oysters and all sorts of weeds. After that had been blasted off  the bare skin showed and indeed she looked alright. However there turned out to be eight bronze plugs alongside the keel. These plugs are used to empty the bilge every time the ship is in dry dock. However, being made of bronze the risk of corrosion is all but imaginary. Which proved to be true as  the measured steel around the plugs was only 8 mm. Not a problem for the surveyor as 7 mm is the minimum but nevertheless a point of attention. The plugs were removed and replaced by small steel plates, welded on top of the holes. 

After inspection the underwater ship was painted a few times so we should be safe for the next few years. Of course the underwater part of the ship is not the only part that is subject to the survey. Also escape hatches, fire distinguishers, life rafts, life boats, emergency lighting, a proper electric system around the ship, bilge pumps and last but not least the galley had to be brought up to standard. The ship is in excellent condition and will most likely outlive us all. 

 

 






 

 

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