What defines an Expedition Yacht?

Your 48.22 is very close to the published speed of 47.2 km/h

There is a slight difference betweem knots (25.5) and kilometers/hour (47.2).

P.S.- For those who like to think in mph, the speed is 29.3 mph.

Emma Mærsk - Wikipedia, the free encyclopedia

Hi,

For the curious.

1 Nautical Mile is equal to 1852 Metres

1 Statute Mile is equal to 1609.34 Metres

Sorry Sir, but there is nothing wrong with my statement. 48,22 Kts (89,3 Km/h) is the calculated theoretical hull speed of the ship based on its LWL. A speed which will never be reached in practice, because of the power required, whereas 25,5 Kts (47,2 km/h) is the service speed (not the top speed) of the ship. The service speed of a commercial ship is the maximum continous speed which cleared by the engine manufacturer (and the ship is still economic). During sea trails, Emma Maersk has achieved higher speeds. I just wanted to explain the relation of LWL and Hullspeed of an FD Hull. I just took Emma Maersk as an example, because she is at the moment one of the most economical cargo ships in the world, this from the specific fuel consumption point of view and the fuel used per ton of cargo (because of her size).

Even 25 Kts is not the normal cruising speed of some of the big container ships at the moment. Many companies have reduced the cruising speeds of their ships down to 18 Kts or even down to 12 Kts to cut down fuel costs.

Cheers

So what does it take to get a pig to fly? Enough horsepower?

The chief designer of McDonald Douglas was blamed for the design of the
famous F-4 Phantom II one day. Because someone was wondering whether this thing could fly at all.
He said, just give me the right engine and and I will get a barn door flying.
He got two GE J-79 and that thing performed like hell (and still does).

Cheers

In the early 70's - I worked a flight line of 40 F4's - absolutely awesome! More to the point - he said a barn door, not a barn.

Still, the thread was interesting and informative, particularly when some of the forum dinosaurs disagreed with each other. Amazing how JWY's simple, astute observation generated such passion.

It really depends on the size of the Expedition yacht. Obviously on the smaller ones many of these items are impossible to fit or just far too costly. Hull could be made of any of the popular metals. Steel would be ideal for most Expedition yachts due to it's strength and ease of repair worldwide. But on the smaller ones Fiberglass would be just fine and has been popular as well with Nordhavn, Northern Marine and others. An engine(s) (usually detuned) and rated to go long hours.....If a single engine, a get home engine or means to get home. Redundant steering would be nice, but again on the smaller ones you could carry enough spare parts to fix underway. Exhaust doesn't matter too much dry or wet. I prefer wet because every dry exhaust boat I worked on, we got soot on the paint or top deck while at anchor and on generator or underway if the wind was just right......Same with exhaust gas cleaning and wastewater treatment, unless the owner's travel plans have them going to a place where it's necessary by law, it doesn't matter. Redundant systems are great and having as many as possible is nice. For example (Hatteras builds no Expedition yachts) but on many of their motoryachts they have a second water pump and air conditioning pump where you just flip a switch and a valve/lever and you can fix the broken one at a convenient time/place. However all of the steering, mechanics, and such should be built to last, with quality parts, and not overly complicated.

For example, on an old Detroit Diesel, as crude as they are. You can almost always get them running anywhere in the world. As long as you put fuel and air to them, and they have compression, they're a pretty simple engine to fix most items on......So sometimes the latest technical innovation is best left for the shiny European MY's.

So, if I understand You correctly, unless you are going for ice class, GRP hull is good due to maintenance. Unless you are going into sensitive areas, standard heat exchanger cooling and wet exhaust is the choice. Diesel engines at maximum continuous rating, when single engine plus get me home device (like Nordhavn boats). All system either of rugged design or redundant.

How about the setup of the electrical system, generators, batteries, etc.?

This B & B 74' yacht is a mix of many of the things you would look for in an Expedition small yacht, but all done differently. With a range of 5500 miles, a strong simple engine (Kelvin, an institution in commercial fishing) and the large tenders up forward.

On the other hand, she is all aluminum in construction, has forward facing galley windows and is very elegant.

She's also my Lotto boat.

Yachts for sale

index.Kelvin

I have seen Griffeon in Makkum a few years ago and been on her. A very well build boat and a true classic. But she is for sale for quiete a long time now. Go for her, her proprietor is very motivated to sell.

Cheers

While wet exhaust is convenient for pretty making, it's fairly complicated compared to dry exhaust. I think that it's optional at best. No fisherman that I've talked to have thought it a very important system, even those who have wet exhaust. For a yacht, if you are out on an expedition you don't have to worry quite as much about looking pretty for the neighbors.

Yep

I looked for Expedition - and not for Expedition Yacht

Hi,

Wet Exhaust comes in many different forms.

There are some that just spray salt water into the exhaust as it travels out of the boat, some that introduce it close after the turbo or exhaust outlet from the engine, others that introduce it into a chamber that uses the exhaust gas to throw the water out. others that introduce it into a cyclonic separator and drop the water and soot out the bottom and the cooled gas out the side.

Dry Exhaust is also available in various configurations

Straight up the mast like it was a truck, through an electrically heated scrubber, through a diesel burner. Some also use a LT Soot Release powder to burn the pipes off at regular intervals. Moisture can get in when left idle and cause major eruptions when restarted throwing out rust and sticky wet black stuff.

I have worked on vessels with the majority of the arrangements, none are perfect by any means/ There is always something that gets out now and again.

Drystacks not only detract from the appearance when the soot plumes erupt, the soot that comes out causes damage as it often contains a sulphur residue which when wet is sulphuric acid. This can damage the finish, teak decks,tenders, covers, cushions and clothes.

They also take space from the interior and are often extremely expensive to maintain.

Yes, if you've got a beautiful high gloss finish or beautiful woodwork it's absolutely going to do damage. Same thing to seat covers and canvas. Fine wool carpets and textiles inside the boat probably see decreased service life from soot tracked in as well.

That having been said, I think that the folks who are looking to spend a great deal of time on expeditions tend to be less focused on those fine luxury finishes.

The black belching smoke certainly is a put off for me, but I've been told off at parties for being a sissy about it.

My understanding is that, if the components of a dry exhaust system fail, you simply keep going and are dirtier until you fix them, but if your wet exhaust has something go wrong it can be more serious, and leave you limping; this would not be an advantage on an expedition. On space requirements, I would imagine that that increases linearly, so if you've got a very tall wedding cake vessel it's going to take more room for the stack than if you've got a two deck trawler type vessel: but I can certainly see your point that it takes more internal space to run a stack up the inside of the boat.

I would like to show you one of my favorite explorer / expedition / retirement
yachts. I took that picture on the weser river at the Fassmer yard.

This boat is a single engine (medium speed MAK engine), variable pitch prop
version with emergency propulsion via PTO / PTI and shaft gen / motor,
unfaired hull, ice classed, long range, 4 double cabins plus owner and crew.
The boat is full SOLAS commerial classed. It fulfills all "green" requirements
for going into sensitive areas, like arctic waters, has dry exhaust stacks and
is equipped for worldwide cruising, both in very cold and tropic enviroments.

Things I would change are:

Make her a bit larger (180 to 200 feet). Main engine power about just under
3000 KW, not by means of a heavy MAK engine (to much height), but with
two MTU 16V 4000 M53R Ironman geared through a Reintje 2 in one, 2-speed
gear on a single shaft with VP Prop, but still with shaft gen plus 2 diesel Gen.
By this setup the boat could cruise single engine without creating asymetrical
thrust. The boat should be DP-2 capable by means of a Schottel pumpjet or
retractable and steerable thruster. Besides the strakes I would add 2 B&V
retractable, zero speed stabilizers. No bulbous bow, I would go from ice
classed to ice going, therefore icebreaker type bow, like on the picture. The
extended length would be used to create a landing spot for a light helicopter
(Robinson R-66, whenever he gets EASA certified) or to accomodate a single
engine (Soloy-turbine) float plane. If the landing spot could not be certified
under LY3 or IMO/SOLAS regs, the heli could land on floats and be
hoisted on to the deck. Flexible setup for tender and toys, according to the
planned route.

Cheers

Why would you want an ice breaker bow? All the sea keeping abilities of a goldfish bowl. Unless you are going to be actively icebreaking or spend all your time in some very sheltered harbors you don't want an icebreaker bow. There are even icebreakers who put their icebreaker bow on the stern and break ice backwards just so they can have a real bow on the front when they are en route through open ocean.

It's his boat.

Let him have it his way.

You build yours with the icebreaker stern.

Just curious HTM09, ever give any thought to this style?

http://www.yachtforums.com/forums/a...ernational-boat-show-2012-flibs-copasetic-jpg

http://www.yachtforums.com/forums/a...ternational-boat-show-2012-flibs-img_5162-jpg

http://www.yachtforums.com/forums/a...ernational-boat-show-2012-flibs-copasetic-jpg

http://www.mvcopasetic.com/index.htm

You are correct. I do mean a mild version of an ice breaking capable bow, like
shown on that picture. I am familiar with the seakeeping disadvantages of a full
icebreaking hull, as far as comfortable cruising is concerned. The big guys
compensate that with their heavy mass. I am just dreaming of the nordwest
passage or going around Jan Mayen or Greenland. A bulbous bow would be
counterproductive for that purpose.

Cheers