"...It has been estimated that one in three Kiwis owns or has a
share in a boat. Obviously a great many of these will be trailer boats and
dinghies where the use of antifouling is of little importance, but as New Zealand
coatings chemists this topic should have great historical, cultural and
commercial interest to us.
I have always been fascinated by James Burkes’ Connections
series, and I’ll try to paraphrase his take on the importance of antifouling
coatings here, before you go on to read another historic perspective in Peter
Walters’ ‘Painted Memories’. James’ sequence goes something like this: Wooden
ships were hugely important to European nations of the 15th & 16th
Centuries as they expanded their horizons and trade gathered momentum. Ships became
larger and larger as they carried more armaments, men and cargo, with some of
the galleons tipping the scales at 1000 tonnes. In almost all countries except Holland , the Navy designed and built all ships, but in Holland the merchant
ships were designed and built by traders, and the fluyt changed the face of maritime trade. These were narrow, long
vessels with an almost flat bottom , much easier to fill effectively with
cargo, and which used blocks and pulleys extensively so as to reduce the crew
required. This design was soon copied across Europe
with the result that seldom did vessels exceed 500 tonnes, and costs reduced
with the use of pine rather than oak in the upper works.
So with reduced initial costs, and lower running costs due
to smaller crews the incentive to build fleets and sail the vessels more
frequently grew. For a nation like England with colonies spread across
the globe, this was truly a bonanza, and with a population of 5.5 million at
the time, 50,000 were at sea. This boom has two parts to play in this story,
the first being the drive to obtain capital to deal with financing all these
voyages and the second the delayed maintenance that this drive for more voyages
created, along with new marine organisms encountered in differing water temperatures.
By the end of the seventeenth century the limit for what
most single investors could finance had been reached, and the stimulus for continued
growth came through the registration of title to land, which came into effect
at this time. So with security of title, landowners could then borrow
confidently against their holdings. These loans were arranged through places
that had recently opened, called coffee houses, where people gathered to
exchange gossip, information on the latest imports, disasters at sea or job
opportunities and well as lend money, borrow it, invest it or just spend it.
One of these, The Nags Head in Cateaten
Street , in 1694 became the Bank of England. Nearby
in the coffee shop opened in 1688 by Edward Lloyd insurance was bought and sold
– there was no point investing in a voyage if a ship went down and all the
money was lost – and shipping news was read to the assembled customers. By 1700
Lloyd was publishing a list of all vessels and rating them according to their
hull and equipment. He used the letters A, E, I, O, & U to indicate the
soundness of the hull, and G (good), M (middling) and B (bad) to describe the
equipment. Thus a ship rated AG was the best risk and UB the worst.
The reason for so many dodgy hulls was a mollusc called teredo navalis which lives in tropical
waters and devastated the wooden hulls. The search for protection from this
directly relates to the topic of this magazine. As mentioned in ‘Painted
Memories’, the use of pitch and tar for the protection of ships hulls goes back
to antiquity. By the eighteenth century most of this came from Scandinavia as
the forests of England , France , Spain
and Portugal
had all become depleted for use in shipbuilding. In 1700 though, Russia went to
war with Sweden-Finland and supplies dried up. All looked fine for England
though, as they owned a colony that could produce as much pitch and tar as
required and by the time the Baltic war ended in 1725 80% of all of England’s
requirement was supplied by the American colonies. This did eventually prove
unfortunate as in 1776 those colonies revolted and once again the supplies of
pitch and tar dried up.
Making turpentine, a solvent for pitch & tar Source: lphsdepotmuseum.org/
Now it time to introduce one of my favourite anti-heroes.
Archibald Dundonald, the ninth Earl of Dundonald was a researcher into coal. He
attempted to produce pitch and tar from coal through destructive distillation,
which involved cooking the coal and condensing the tarry substances from the
vapours produced. He poured a fortune into the venture, taking out a patent in
1781 and building a tar works in the grounds of his home with 4 kilns capable
of processing 14 tonnes of coal at a time. He had to borrow heavily to finance
all of this, and was happily turning out pitch and tar in large volumes when
the English Admiralty made the decision to begin sheathing ships bottoms with
copper. Archibald ended up dying in poverty in a Paris slum but will remain the father of coal
tar chemistry and is worthy of an editorial in his own right – and I am sure
that we will come across him again in a subsequent issue of ‘Brushstrokes’…
Archibald Cochrane, 9th Earl of Dundonald Source: en.wikipedia.org/wiki/Archibald_Cochrane,_9th_Earl_of_Dundonald
The issue with copper sheathing is dealt with elsewhere in
the magazine but the use of copper in various forms remains a key part of
antifoulings to this day.
Indeed, the historical aspects of antifouling continues with
our own Captain Cook pulling into Dusky Sound in 1773 to scrape and repair the
hull of the Endeavour, and whilst
there finding time to brew the first beer made on New Zealand soil. So if you
are one of those Kiwis with either an interest in a boat, or a chemist involved
with the formulation of coatings, at the end of a day antifouling or on the
development bench, do raise a glass of the amber liquid and celebrate the
completion of the circle linking us to the water and the past – boating, beer
and antifouling..."
Source: blackcreekbrewery.files.wordpress.com
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