Monday, October 27, 2008

Italian TV Film Crew

Feeling that it was just the right time to visit Maine with the gorgeous foliage and lack of tourists, Cristina Borgogna Di Capriasco gently requested to have multiple shipwrights pose in front of the 275 gallon oil sign with tools of their trade. They kindly posed one at a time with a variety of tools such as a chain saw, trunnel hammer, welding gear, laptop computer and about nine others.

Boothbay and Boothbay Harbor Shipyard had a team of six Italian TV crew here last week filming for the European show "Classic Boat". In addition to the still images of the shipwrights, they conducted interviews on two large projects in process here at the shipyard: Ernestina and Belle Aventure.

Each show is broadcasted in 4 languages: Italian, French, English and German. It is a 1
2 months program, with 24 episodes of 24 minutes each, which began in 2004.

Classic Boat's goal is to pass on the passion and the complicity of sailors, owners, and artisans who dedicated their whole life and their energy to the restoration of boats and ships. The show tours shipyards, showing the ancestral knowledge laying at the base of
a restoration project.

Hosted by Michel Dejoie and produced by M & N Yacht, Classic Boat is a television program totally dedicated to classic and vintage boats, as well as to sailors, skippers, owners… but also to artisans and sea carpenters.

Thursday, October 23, 2008

New Service Provided: Cathodic Protection

Cathodic protection is one of the most effective ways of reducing or eliminating the corrosion damage that invariably affects metals that are in contact with sea water.

Metal hulls, rudders, propellers, stabiliser fins, ballast tanks, water tanks are all areas that need protection. Paint provides only minimal protection from the corrosion of metal.

On the right is the famous ship the Cutty Sark. Below the ship is one example of corrosion damage, rust flaking off a stringer plate behind the figureheads on the Cutty Sark.

Boothbay Harbor Shipyard has expanded the scope of services to our customers to include the ability to perform an electrical signature analysis of metal hulls. This tool helps identify the risks of structural and mechanical corrosion.

This pier side activity begins with all onboard systems shut down and the placement of a submerged device adjacent to the hull. Starting with quality issues related to shore power, a multi-input data logging system documents the results of activating the entire range of onboard systems.

The analysis and interpretation of these results allows for a cathodic protection plan to be customized for each vessel. Correcting these risks not only protects the longevity of the hull but can extend the life of mechanical and electrical components.

It is recommended that a new analysis be performed at the conclusion of any major change in electrical related components. New equipment has the potential to create additional cathodic risks.

When the yacht is going to be harbored for an extended period of time, additional data logging can provide indication of risks based on the electrical signature found in that particular location.

An inventory and specifications of onboard systems and equipment is required to be able to provide a price quotation for this service.

Tuesday, October 14, 2008

Shipworm Not a Worm

Not only do shipwrights need to be concerned with gribbles but they also worry about the shipworm. The shipworm, which is not a worm at all, is actually related to the clam and mussel, therefore it is a mollusk.

These "termites of the sea" are able to digest the wood due to a symbiotic relationship with a bacteria that is stored in a special organ in their body. This relationship is much like the termite, which also needs a bacteria to allow it to digest the cellulose in the wood and turn it into glucose for
The larva of the shipworm uses its small sharp shell to drill into wood. As they grow, the tunnels get larger and larger. Often, wood may have a tiny hole on the outside but the inside will be a maze of larger tunnels. The shipworm (teredo navalis) or sometimes known as the teredo worm, uses the shells near its head or siphon to burrow. Their ridged and rough surfaces rub the wood away as the mollusk turns its head one way and then another. It leaves behind a circular tube that is a bit larger than the shell. The shipworm eats the wood and the soft body's mantle leaves behind a white calcareous substance like chalk to line the burrow for protection and strength.

Shipworms have long been a global scourge of maritime activities. In 1502, during Columbus' 4th voyage to the Caribbean Sea, his ships survived a water spout, a hurricane, high seas, lightning and rocky reefs. However, luck ran out when two of his four ships had to be abandoned in the Hispanolas and Jamaica because of shipworm rot. He later used copper on the hull to protect it from shipworms.

Pier owners in San Francisco Bay saw an estimated $1.3 billion (today’s dollars) in shipworm damage in the early 1920s. In the last decade, the city of New York has spent well over $100 million to protect and replace worm-damaged structures.

One good way to decrease shipworms attaching and living on marine wood is to inhibit the symbiotic bacteria it needs to live. Some wood that inhibits the growth of the symbiotic bacteria is Douglas-fir, ebony, jarrah, koa, lignum vitae, narra, Osage orange, paduccah, purple heart, red alder, red oak, teak, verawood, and western red cedar. That is why Boothbay Harbor Shipyard spends much time and care choosing the right wood for each section of a ship for a new build or rebuild.

Tuesday, October 7, 2008

Attack of the Gribbles

Sounds like a science fiction title doesn't it? But the attack of the gribbles could be in most any shipyard, dock or under any wooden boat. These are one of the two animals that cause the most damage in wooden boats.

Gribbles are related to the lobster and crab. They are mostly a pale, white, small crustacean from one of the 56 species of marine isopods from the Limnoriidae family.

For a long time the gribble diet was a mystery; gribbles lack the nitrogen-fixing bacteria in their bellies that symbiotically allow termites and shipworms to survive on the carbon riches of wood. In other words, they were endlessly gnawing through wood that provided little nutrition or energy to them.

The secret is the wood in seawater, like our harbor estuary, has a slimy surface. That slimy surface, scientists have discovered, is the true diet of a gribble. And by tunneling through wood, and having succeeding generations of gribbles widen those protected tunnels, gribbles dramatically increase the surface area on which the nitrogen-rich microbial slimes can grow.

Gribbles and shipworms, another wood borer, were absent from many harbors for generations because pollution levels were too high, and oxygen levels too low, for them to survive. Strangely enough, the very polluted harbors were often known as "clean harbors" because they had local waters that were so toxic that the unwanted organisms would die off of ships. Luckily, many of these harbors are healthier and the gribbles are back.

At the shipyard, we have classic wooden ships and yachts. Careful maintenance of making sure the bottoms are painted and all the seams are sealed, prevents gribbles from damaging these ships and yachts.