I was surprised to find that this article was written in 1997, but
seems to be pretty relevant today as the American shipowners still buy and
build to catch up with the Europeans. They are making up for 20 years of
lack of development. This was my view on 1997. Lets have a view from
simple stupid! The first principle of American supply vessel construction
is under threat. Even more revolutionary, the old principles relating to
the minimising of gross tonnage have been discarded.
unaware of these principles will obviously be underwhelmed, but like other
changes taking place in the supply vessel industry world wide, they will
have far reaching effects.
KISS principle, is a means of construction which ensures that a supply
vessel built in the Southern States of America can be maintained with only
a modicum of effort and expertise, and virtually without backup, anywhere
in the world. One hundred and eighty foot anchor handlers built in the
late seventies and early eighties still service rigs in some of the most
inhospitable ports known to the oil industry. And that is saying
technique well know in Morgan City and in various lesser ports in the Gulf
of Mexico, might be known as the gross tonnage scam. It will be most
easily understood by old seafarers who used to travel on ships which
passed regularly through the Suez Canal and were measured in terms of what
was known as “Suez Canal Tonnage”. No-one seemed to really know what
spaces were actually involved in the measurement, but what they did know
was that the forecastle was exempt.
result, in the day or two immediately before the ship arrived at Suez, or
Port Said, depending on the direction of the voyage, the crew would be
employed emptying everything out of the forecastle. The foredeck would be
piled high with ropes of every type and size from, point line to mooring
rope, as well as paint, tallow, stockholm tar, lamp oil, tools, ratguards
and much other nautical paraphenalia whose uses, even then, were a mystery
to all but the most ancient mariners.
here is that everybody could see that there was no way this stuff lived on
the foredeck, it would have been washed away in the first storm, but since
it was not actually in the forecastle during the canal transit the space
the gross tonnage of the traditional American Gulf supply vessel was
“adjusted” by structural alteration. This was achieved by putting large
plates in the bulkheads of all the cabins on the upper deck, and at the
time of measurement they would be removed so that this space would be
effectively a meaningless jumble of holes and doors. Everybody knew that
once the measuring had been done the plates would be bolted on and there
would be half a dozen cabins for a good sized crew if it was required.
Quite large vessels, relatively speaking, came out at under 150 gross
tons and as such could go to sea with only three crew on board.
all very well when the ships were working jack-ups within a few hours of
the coast of Louisiana, but the shift into deep water has caused the
supply vessel operators to shovel the old rules into the dustbin and start
again. Builders like Halter Marine are manfully trying to maintain the
KISS principle while at the same time building vessels of major
Marine’s HLX 2255 is an two hundred and fifty five foot anchor handler.
The American way of designating ship types is much easier to understand
than the Norwegian system of obsure model numbers. They also have an HLX
2225 which is of course two hundred and twenty five feet long.
2255 is a formidable vessel advertised as being under 3,200 gross tons, so
there goes the minimum manning, as for the KISS principle, well time will
certainly been difficult for them to maintain even a pretence of
simplicity, and one of the biggest changes is in the winch, the heart of
any anchor handler. The 180 foot Halter Marine anchor handlers were
provided with a Smatco winch powered by a Detroit Diesel of the same size
as the generator engines and the bowthrust engine. These winches offered
something like 135 tonnes pull on the first wrap.
2255 has a Smatco electric winch which claims 500 tonnes pull. Halter
acknowledge that the most effective winches are powered by low pressure
hydraulics but the patents are held by some selfish Norwegians who are
unwilling to share this technology with the world, hence other designers
look for other methodologies. When lowering heavy weights to the seabed
low pressure hydraulic winches really come into their own, its just like
heaving in but in reverse. Electric winches are a different case entirely.
There is a tendency for the weight to take charge, turning the motors into
generators with resulting dire effects on the ship’s electrical systems.
As a result such winches have to be fitted with some alternative means of
breaking sometimes disc brakes, sometimes, as in the case of the HLX 2255,
Additionally one of the components of the Smatco model 140E is a tension
winch. This may well be the first tension winch fitted to a supply vessel,
although a number have been fitted to semi-submersibles for deep water
mooring. The purpose of these tension winches is to always have the first
wrap available, and therefore the greatest pulling power. The laws of
mechanical advantage result in less pulling power being available at the
winch as the drum fills up with wire, as more chain is suspended above the
seabed ,and therefore as more weight is put on the system.
tension winch is made up of two drums, the first doing the pulling and the
second doing to storing. But, to get back to the kiss principle.
is powerd by 4 EMDs producing a total of 14,000 BHP. The engines are set
reassuringly in the after part of the vessel, in direct contrast to the
recently reviewed UT720 whose engines are shoehorned almost as an
afterthought into the not very useful space underneath the accommodation.
Additionally the exhausts still emerge through the deck just aft of
midships, in just the position of the funnels of the early American supply
vessels, they are then trunked along the deck, over the top of the stores
and then vertically into what the Americans call “North Sea Stacks”.
Anyone who has sailed on a gulf supply vessel will recognise the style.
North Sea Stacks are not popular in the Gulf of Mexico because they are
too noisy. The Europeans of course do not know any better.
propellers have been part of the standard equipment in Europe for almost
twenty years, so perhaps they can now be considered to be reliable, as can
tunnel thusters. The HLX2255 is provided with two of the former and three
of the latter giving 2400BHP of thruster power, and in addition to two
2000 Kw shaft generators, a 400Kw and a 190 Kw Caterpillar are fitted.
motive power may be controlled by a Simrad joystick which indicates some
thought towards the move into deep water, and seems likely to consign to
the bin any designs in the US Gulf for deep water supply vessel moorings.
Once more, such thinking was part of the North Sea philosophy fifteen
years ago witnessed by the presence on the forecastle of two Farstad
ME202s a couple of anchors attached to 2000 feet of wire, and never used
complications on board the HLX 2255 are three Triplex Sharks Jaws,
possibly the most comprehensive but certainly the most compex of the
available wire and chain securing devices currently fitted to the sterns
of anchor handlers.
regardless of specification, the most important aspect of supply vessel
activity is their ability to do the job, and since these anchor-handlers
are built to work in deep water, their ability to carry out that
particular task. At the present moment numbers of very large vessels
designed in Norway are making their way towards long term charters in the
southern ocean. In UK, rigs are about to venture out into the Atlantic. If
vessel such as the HLX2255 prove themselves in the 5000 to 6000 feet in
the Gulf of Mexico we might even see them in the Atlantic in the
comparative shallows of 4500 ft.
Vic Gibson - The Return to Features Click Here.