Discussion in 'Popular Yacht Topics' started by Pelagic Dreams, Sep 23, 2010.
Depends who and how well there both made really
Regarding Steel vs Fiberglass:
If I compare two modern 90ft expedition-type trawlers:
Nordhavn 86 (fiberglass) and Northwest 90 (steel hull) I find them to have the same deplacement!! ~180t even though the Northwest is slightly larger!?
Is this because Norhavn uses medieval manufacturing methods where they use to much to often in those handlaid hulls. Or is the Northwest using less steel in theirs compared to other ships?
Every article i read about steel vs fiberglass tells me the steelhull is always much heavier because steel is heavier than fiberglass...
Northwest Yachts – Trawlers, Expedition and Motor Yachts
Welcome to Nordhavn.com - Power Thats Oceans Apart
Most likely the Nordhavn makes up the difference in ballast, while the Northwest Yacht has more weight in the overall structure, and possibly some ballast, but I would assume very little.
In addition to steel being heavier, the yield, tensile, compression, and shear strengths (as measured in psi's) are all greater as is the modulus of elasticity and hardness.
"PacBlue", you have part of the weight differential correct as the steel hull vessel uses its steel as "ballast" or to put it more correctly, the required vertical, and longitudinal center of gravity of the steel aboard is manipulated to achieve the proper centers, thus not requiring much if any ballast. Now for those of you who really READ the specs at the NW site you will see that they published the displacement at HALF LOAD. Do the math and you will see the NW boat really is heavier than a similar Nordhavn. You are also correct that the Nordhavn's are overbuilt and I have done exactly the same these 43 years of building FRP boats. Whoever used the words "Medieval" is also correct but having been at sea in the middle of the Pacific Ocean during a full blown hurricane in a 63 foot design of mine I really like "Medieval" construction, steel or FRP. One additional fact to think of.....maybe the NW design has a "lighter interior", maybe the specs are not really as they seem to be (few published specs are true as there is so much room to maneuver the facts and still be "truthful", think about that. For the record the NW specs are spot on.) As a designer I read and collect all the data I can get my hands on, per teaching of my old boss - Bill Garden and Ed Monk, SR) and when I run the numbers myself, with or without covert data, I find much is different than the "published" data.
So much for this topic as I got to send out new specs of a new design of mine as I write this, hope this helps. Thanks "PacBlue" for really thinking. Too many people who really love boats just do not dig deep into the subject, as an old Boson's Mate in the Navy told me (also during a day of 30 foot seas) "study son, study the sea, it can be a &%^#@ scary place for the ignorant sailor" Stephen Seaton
Thanks for the comments Mr. Seaton, I envy the fact you are able to trace your roots back to the Bill Garden / Ed Monk Sr, days. I did have some correspondence with Mr. Garden in the late 80's and still have his response, written of course on the back of my original letter and in pencil, being the conservationist/minimalist he was. Never got to meet Ed Sr. but have worked with Ed Jr. and the Monk family has such a special place in Northwest boating history. I imagine he was a man of few words as is Jr? Their vessels have plenty to say anyways. Since you have the Northwest in your blood, I would venture you could replace "Medieval" with "Skookum" and be done with it!
I do recall a special boat of yours, built of FRP. I met a retired couple from the Midwest in the early 90's, I believe they were retired home builders / true crafstman, and I recall they were finishing a one-off design of yours in the do-it-yourself yard in the back of Huntington Harbor. I believe she was powered by a rebuilt single 8V-71 natural. The interior craftsmanship was truly remarkable with book-matched (Appalachian?) cherry throughout, and exposed laminated (Hi-gloss) wood beams overhead. The wife was in charge of all the finish work, and their combined efforts were amazing, I think so many people from the Southern California area took a look at there work (probably hampering their progress) and came away amazed at the results. I have been on plenty of small and big yachts since, and that Interior work in particular still stands out the most. I hope she has found a good berth somewhere!
good to see and read your post's i have been to sea in one of your designs we have met in person before on a couple of occasions and had some great conversation about boats and sailing glad to see you are still busy and doing well
This doesn't sound right...you mean by volume I guess.
If you instead compare the materials pound for pound (a more useful comparison), an E glass epoxy composite is MUCH stronger than a mild steel (for example).
It isn't quite as stiff (still talking relative to mass), but it's not far behind (approx 80%).
Steel's main positives are its low price and far superior ductility.
No matter how large the yacht gets there are two little words in your statement that ring true to all Owners.
True statement. With steel, any yard can produce large and sturdy hulls for remarkable low price in very short time. Old saying of shipbuilders: "Empty steel does not cost much". Computer aided manufacturing with CAD data directly transfered to the plasma cutting machine, semi automatic welding and computer controlled robots used for painting, will produce large hulls in no time. Simultaneous production of segments reduces building time even more.
But if the owner only has cheep building of his new ship on his priority list, he will end up with a vessel like this (This RoRo vessel is only a few years old). I would feel ashamed, to own a vessel like this with my funnel markings on it.
If you look for a yachtbuilder only under the premise of who is the cheepest, this low quality skin of your yacht will just be hidden under LOTS of filler and paint.
As one said before, if you want northern European quality, you have to pay a northern European price.
You would get an unpleasant surprise if you knew how much filler and paint was used in most if not all yards building steel/alu yachts to obtain the high gloss mirror finish desired by all.
It is this part of the yacht that often causes the most work and anguish during the warranty period as the Owner and Yard try to come to terms with a solution they both feel is fair and reasonable.
I have made very similar statement right here on YF and been put in my pace by another member.
You might or might not be aware at the lengths some brokers will go to to sell a yacht to a client. The have less interest in where it is built or how it turns out than they have in collecting their commission.
I know of an incidence where the Owner of a yacht wanted a bigger one, he was making some discreet enquiries when his existing Captain receives an e mail from a yacht captain he knows turned Broker telling him that he could do the Owners new yacht in 1/2 the time quoted elsewhere and using all the same sub contractors and equipment as Nthn European yards at 25% of the cheapest price to date.
The e mail contained quite a lengthy bio of the author, some of which I know to be blatantly untrue.
More easily swayed or impressed Owners would probably jump at this great saving in time and quality and then have to accept when what he got did not live up to the promised standards that the build team he engaged were useless, the Captain and Crew were useless, etc till he got so disappointed with the business that he sold it and left the business.
There is no such thing as a free lunch even in this game, if the deal sounds too good to be true there is a way better than average chance that this is the case.
Whilst a person might have been absolutely ruthless in business, hiring, firing , closing business and cutting costs to maximise his returns there is something that happens to a lot of them when it comes to yachts.
That drive and ruthless determination that made them who and where they are today seems to disappear. It would seem that a yacht can have the same effect on some of these people ( predominately male) as a woman less than half their age after they have had 30 yrs of marriage to the one lady.
I remember my owner briefing for my latest sailboat in this northern European yard. After we had settled the hull material and construction method of the hull, the naval architect asked me for my choice for the colour of the hull. The design of the yacht did not excists at that point!!! As I told him my prefered colour would be dark blue, he made notes for himself about shorter frame distance and a higher number of longitudonal stringers. I must say, I felt well treated and during the whole building process, whe had no arguments about quality at all. And I must say, my demand, as far as quality was concerned, made them transpire. But we still enjoy the boat without major issues.
Making of ALITHIA - YouTube
I wonder how many serious shoulder injury disability workers compensation claims ensue... too. You notice its the younger group rubbing it off in the video!
Lots of "smearing on the sploge and rubbing it off" to get those fair hulls...
Comes from a comment from a very famous builder in metal made to me long ago! And, when I was running my hand down a surface to "feel" the imperfections... finding one and pointing it out to him... he said "no problem we'll just smear on some more sploge and rub it off again". Which just struck me funny... had me rolling on the floor laughing.
Why I found it funny was it was sort of the opposite of what is naturally normal.
When did it start?
When did "Yachts" as in pleasure craft under 100' begin being fabricated in steel? It was usually reserved for larger ships and commercial vessels but now you can find many yachts as small as 18m being made from steel. I ask because Yacht quality finish is much different than a commercial fishing boat hence the amount of work in fairing....which would not be necessary in a work boat. Maybe the qualities and advantages of a steel hull don't really work well to the "smooth as glass" finish most yacht owners require.
Just a thought.
I remember getting onboard the 67m Golden Shadow built by the now defunct Campbell Shipyards in San Diego, launched in 1994. They typically built Tuna Seiners, but the level/skill of steel work on this hull was amazing. It was so fair even with complex bow/bulb/stern shapes, they were able to paint without the typical layer of marine bondo. They left the weld seams proud and not ground down, and she looked fantastic. I was working on a custom FRP 130' at the time, ordering Awl-Fair by the cases, and wondering who was getting the better deal at the time.
Too bad they sat on such valuable CA waterfront, the quality of steel/aluminum work was exceptional.
The Golden Shadow
This is a nice video... it may be aluminum but same for steel...
Professionals at work...
These are in no particular order because there is no best just what works well for where you plan to go and cost.
Since you asked,...
...,its not just for Soviet Sierra-class subs no more:
U.S. Navy: The Business Case for a Titanium
"Participants at a workshop exploring the use of titanium structure for ships found that it is not only possible to construct a ship hull from titanium—or Ti, it could be cost effective."
Me, I'll stick with my 5086 AL hull 'till then.
They've been making pleasure craft out of steel since at least the 1940's and such. Long before fiberglass. Wood was much more popular back then, but steel pleasure yachts were made as well. Depending on the purpose and the builder.
I worked on a 97' displacement motoryacht that was steel back around 2003. Hinckley in Stuart had repainted the boat right before I started working on it......The fairing and paint job was flawless and was like a mirror. You couldn't tell if it was a steel boat (which it was) or fiberglass.