Steel Hull Construction

[Jeff_H]

This is a copy of an earlier post of mine on this subject.

As I have said before, I am not a fan of metal boats. Compared to wood or glass I think they are way too heavy for the strength achieved and too difficult to maintain. They are noisy and prone to have problems that are not easy to get to and repair. For the distance cruiser any bonehead can carry and use glass or wood to repair wood or glass boats anywhere in the world. Welding a metal boat in some atoll on the backside of no-where is another story.

There is a relatively small and specialized market in this country (US) for metal boats; a bit out of ignorance and a bit because metal boats really do not make sense for the venues that most of us sail in. While cruising people are a bit more open minded toward metal boats, I think metal boats will be a hard sell in this country for a long time making resale a bit difficult. Many of the metal boats that we see over here are crudely built hardchine affairs. The chines are often laid out without care for their visual impact. Cabin and deck structures are often rather primitive. Hardware is often painted galvanized steel. As they age they develop areas that have been dented in between ribs and other framing. It is not to say that there are not well built metal boats, but the perception of metal boats comes from the poor examples.

Amongst the proponents of Metal boats, much has been made of the ability of metal boats to bend rather than puncture. I think this is a little bit bogus. That may be true of the extremely heavy boats designed to workboat standards, but not really true of boats built to meet yacht standards which tend to be much lighter. These lighter weight metal boats use lighter weight skins spanning between a more closely spaced frame and stringer system. If the impact is on a frame you are more likely to bend the boat than puncture the skin but an impact next to a frame or between a frame is more likely to sheer the skin than bend it in any impact that would be hard enough to puncture the average fiberglass boat.

The one advantage of steel is a higher abrasion resistance. In the unlikely event that you end up rubbing against a rock for hours on end without puncturing the skin, a steel skin can withstand abrasion better than glass. If you sail in an area where abrading against rocks is a serious problem then steel may make sense. I doesn't for me.

Metal boats are seen as being very durable, but again in the weights of materials used in yachts I seriously question that idea. All boats flex; it is only a mater of degrees. Over time this flexing work hardens and fatigues the steel especially where the skin meets at frames and other hard spots. Rust, mostly from the interior makes the skin thinner. Like any other material each boat has a real lifespan. It may exceed our own but it may not. It is true that fiberglass will also fatigue and weaken over time especially non-cored hulls which tend to flex more. It is true that cored f.g. hulls may eventually delaminate from the core or the core itself may sheer but in well-built boats this is a very long-term process, but properly maintained glass or cold-molded wooden boat will last for 40- 50 years. The same cannot be said for steel.

In a number of studies that I have seen over the years, steel is generally seen as being the most maintenance prone material out there, both long and short term. This is slightly offset by some of the exotic steels being used in the last couple years but for the most part, just like wood you need to keep the actual hull and framing protected from water and air. Unlike wood this means both inside and out. On most steel boats there are areas on a steel hull that are inaccessible and just because you can’t see them that does not mean that they aren’t deteriorating. Rust never sleeps and metal boats actually deterioate mostly from the interior out.

Then there is electrolysis. This used to be the kind of problem that was a compelling reason not to own a steel boat. In the early 1970’s I worked in a boat yard that had to do an emergency hauling of a steel power boat to prevent it from sinking. This boat which had been launched weeks earlier in perfect shape had changed slips and was tied up next to a boat with an improperly grounded 110 electrical system and in a mater of days the bottom of the power boat in question had lost sufficient thickness and was covered with small pin holes that the boat needed replacement of her entire bottom plating. This kind of loss was not covered by insurance. Today, there are ways to combat the electrolysis problem but, in my mind, they are bandaides treating symptoms rather than real cures to the problem.

My biggest gripe comes down to compromised sailing ability and seaworthiness, poor motion comfort, and how this issue affects deck and cabin materials. Some of this goes away as the boat gets to be 45 feet or bigger. In boats under 45 feet, steel hulls are just plain heavier for a given strength than any other material except perhaps ferrocement. Weight in and of itself has no advantage at all. More weight means that you need to have more sail area for a given speed and a given sailing ability. More sail area means that a boat needs more stability to be able to stand to this bigger rig which means more ballast which means more weight which means more sailarea. As a result steel boats tend to be a very poor choice for the US Atlantic coast which tends to have lighter winds throughout the prime sailing seasons.

The problem gets worse because steel boats often have steel topsides, steel decks and steel deckhouses. This is weight high above the center of buoyancy and as such reduces stability further making it hard to carry a decent sail area to weight ratio. In the ultimate bad sailing day, it also means that once inverted you are more likely to remain inverted longer. This problem is often addressed by the use of wooden deck and cabin structures. Deck and cabin structures are the area of greatest maintenance in a wooden boat and so you are just upping the amount of manitenance even further. The heavy weight of the topsides and deck structure results in a boat that tends to roll and pitch through noticeably larger angles making for a wearing ride for crew.

Of course, like many subjects this is one that frankly does not have one universal always-right answer. The right answer is the one that works for you and while my opinions are based on the physical properties of the materials involved, in fairness, I must point out that puncture resistance has never been a criterion by which I select a boat. I should also note that my personal taste leans toward lighter boats. My prior boat was a 4,100-lb. 28 footer made of kevlar over high density closed cell foam. She was one tough little boat. I have always been a proponent of buying a boat suited to your anticipated sailing conditions and in my case my sailing conditions are strictly coastal and do not include passages to remote areas, and she worked well for that purpose. If you are looking at passages to the remote areas of the Pacific Southern Ocean, then puncture resistance becomes more critical and the ability to make repairs in a remote area becomes even more critical still. You may also sail in a windier environment that I and maybe able to tolerate a heavier boat.

But also, to further explain my point of view, I am fan of truly traditional boats and also, although seemingly contradictory, fast lightweight modern boats. By traditional boats I mean boats that authentically draw off of the principles of actual historic craft with a high degree of integrity. I do not like quasi- traditional boats that wear their sense of tradition like tail fins on a 58 Caddy. I also like fast/ modern designs that have their own sense of integrity. I find both types of boats fun to sail but for very different reasons. I have owned both types. For my current life style I cannot imagine owning a traditional boat again but I truly do love them. It is hard and expensive to do a truly accurate traditional boat in metal and it is impossible to do the kind of small high performance boat that I love in Steel.

No matter what material you use, workmanship and quality materials will be critical. I do not believe that steel tolerates poor quality any better than any other material and since so much depends on the welds the welding needs to be top notch. Steel is not just one material but a family of iron based materials. How the metal is made, purified and alloyed affects initial strength, fatigue qualities and its resistance to corrosion.

You often hear that steel boats can be built cheaply. Quality metal construction never was cheap. You could build a quality boat in almost any other material as cheaply or for less. With advent of computer driven cutters and the more common availability of some of the newer (last 15 years) welding techniques steel has come down in price to the point that custom simplified steel boats maybe less expensive than custom boats in some other materials. The problem with the court of public opinion saying steel is cheap is that simple hard chine steel boats with workboat levels of finish are often compared to yacht quality boats of other finishes. Probably a properly comparable and way less expensive construction is glass over sheet plywood. Properly done, for its weight, this can actually be a far stronger and less puncture resistant material than steel. Glassed inside and out with quality laminates and epoxy resins, the plywood boat would have far and away less maintenance costs and would have a much lighter hull weight than steel, thereby having considerably better sailing characteristics in all ways.

I think much of the answer in picking a metal boat comes from picking the right designer. If I had to list designers of metal boats that I like, I think that Van de Stadt from Holland does a nice job. Some of their designs seem to be IOR based, and as such, do not appeal to me as much as Van de Stadt's more straightforward cruising designs. Their design 46A is very appealing to me. Van de Stadt has a very strong reputation for quality engineering and has designed some very fast boats in their day. I think they offer some of their designs on disk so that they can be computer cut saving a lot of time and perhaps money. From what I gather they are a class act.

Yves Tanton in Newport Rhode Island does some very nice work. I think he is a very creative designer with a very nice eye for visual proportions. He is a sometimes participant on this board and I have seen his catalog and it is really an impressive body of work.

Dudley Dix from South Africa is a very interesting designer to me. I have never seen any of his boats in real life (that I know of) but he is terribly creative and seems to understand what it takes to design a nice performing boat that is also a comfortable cruiser. I like his Black Cat 38, which is a wooden boat. In metal I think the Dix 43 looks like a pretty nice piece of work. I have been drawing a blank on the name of the guy who has designed the Deerfoot series. I don't especially like his earlier designs but I think the designs have been evolving into more powerful hull forms closer in shape to my own thinking.

How could I forget Charlie Wittholz? I actually worked for Charlie Wittholz in the early 1980's. Charlie did some very nice, very interesting traditional designs in steel. Charlie was a neat guy. He actually worked for Alden and Rhodes before opening his own shop. I liked his work. His boats had a certain simplicity that was very elegant. He had a nice eye for proportion and a sweet line. Hard chine boats are actually very hard to design so that they look right. The chine forms a strong accent line that has to work with the desired hull shape, the physical properties of the plating and the other visual lines of the boat. Charlie was able to keep these sometimes-contradictory lines under control to produce attractive traditional craft. While I liked most of Charlie's work, one of my least favorite boats of his was a bilge keel cruising boat. (I drew many of the drawings for her) This was a purpose built boat for the European canals and as such was a good boat for its purpose but was not my kind of boat. Charlie and I would have lively lunch time discussions on our divergent points of view on modern lightweight boats. We both loved wood as a building material. I loved his stories of Alden and Rhodes. Rhodes was very much a patrician gentleman but Alden was a very colorful character.

Charlie made the final passage to Fiddler's Green a few years back. His family still sells his designs by mail order. I don't know if they have study plans but he used to have simple list of designs that listed the basics of each design. I believe that their phone number is 301 593 7711. Also WoodenBoat still markets some of his designs.

Bruce Roberts is popular but I am not a fan of his work. It is not so much that I do not like his work per se. I think that for the most part Roberts designs conservative simple boats, but to me they are dated. His Spray series have less than no appeal to me. Having read about the original Spray and the sailing ability of some of the so- called copies of her, I have come to believe that Josh Slocum made it around the world despite the short comings of Spray rather than because of her sterling virtues. Josh Slocum was the consummate seaman. Spray was a coastal oyster boat. Why anyone in this day and age would want to use her as a model for a whole line of boats is completely beyond me. But I emphasize this is only my opinion and Roberts has sold a bunch of these things so my opinion is not shared by everyone on this.

Roberts more modern designs were probably good designs in the 1970's but a lot has happened since then. To me his design ideas have not advanced as well. That said, Roberts has a boat he calls a 434 that someone built as a long range single-hander that looks like a nice boat but slightly dated to my eye. Still in all these are very heavy boats and I strongly believe that weight, in and of itself, has no inherent virtue and is a very serious liability.

At the risk of sounding like a broken record, much of the questions in sailing have no one right answer. That does not keep people like me from having strong preferences and opinions. My opinion suits me, and the way that I choose to sail, very well. It may not suit you at all. It is easy for someone to refute my opinion on some other criteria than my own. As I have said before on this forum, ultimately that debate can have no more substance than a trying to prove that Vanilla ice cream is inherently superior tasting than strawberry ice cream, (which is why these are called 'opinions').

Good luck
Jeff

[cockeyedbob]

Aye Jeff, and it is the sea's duty to return ALL things from whence they came.

[chucklesR]

I still don't know - of course my boat is FG, but for 22 years I motored around on US Navy steel and aluminum ships - with basically unlimited manpower to do preventative maintenance, chip, paint etc - and no real concern for how it looked other than 'painted'. Some of the boats I was on were more than 50 years old (Tenders from wwii) and still are going strong 10 years later.
Mild steel can deform and bend - Gringo was obviously not built from 1/8 inch cheap steel, I think any other boat would have maybe bounced, but been punctured by a blow that can bend steel that much.

Anyone build a steel catamaran?

[Jeff_H]

Chuckles its all in how you look at it. Corrosion moves at a constant rate of speed, so when you look at a big ship which may be plated with 1 1/2 to 2" plating, loosing an 1/8" of steel in a couple decades is no big thing, but when you compare that to loosing an 1/8" out of 1/4" or 5/16" steel plating (which is more typical for a 40-45 footer) you can quickly see why a steel yacht has a shorter lifespan than a steel ship.

Again its about how much weight you are willing to carry around with you. when you realize that the equivillent weight hull to the 1/4" to 5/16"steel hull probably used on Gringo would be fiberglass 2 1/2" to 3" thick or cold molded wood 10" to 11" thick, I seriously question whether those hulls would have been breeched either.

As to steel catamaran's there was a guy on one of the metal boat websites who was building one. I don't know what happened to him but he did get her built and sailing. There were some performance issues early on but I don't know how experienced a sailor he was.
Jeff

[cockeyedbob]

Wow, a steel multihull! Now there's a fella with two reasons to be a bit defensive. Hell fellas, life's just too short to be quibblin' over details. How long ya plannin' to last anyway?

[Jeff_H]

"Hell fellas, life's just too short to be quibblin' over details. How long ya plannin' to last anyway?"

From my perspective we're not 'quibbling'; we're just explaining where we are coming from.

To me the question of durability is a valid one. I tend to buy used boats and keep them for a while. When I worked for Charlie Wittholz, I worked on drawings for a 55 foot motor yacht. We did everything that we knew how to do to protect the steel on that boat. Roughly 20 years later I was called by a potential buyer of that boat and I went to look at the boat. What we found was less than half the plating thickness left at the stringers. That boat had already had part of its bottom replated and the cost to replate the remaining areas in question was more than half the value of that boat in perfect shape, and that number did not include the costs to replace the interior finishes, wiring and plumbing that would need to be removed in these areas. My current boat is 25 years old and I plan to keep her for at least a decade longer. So if she's been steel, she'd be shot instead of going strong.

Respectfully,
Jeff

[cockeyedbob]

I hear ya.

[steelboat]

Jeff, having built a 50' steel boat, it's hard for me not to jump in here and point out that today's epoxies have made a large difference in the longevity of steel hulls. Where a steel hull built in the 70's say, and coated with enamels, may very well have an internal rust problem today, had she been properly blasted inside and out and then coated with epoxy, there's no reason to suppose that she will have lost 1/2 her plating thickness in 25 years, provided there are no water traps in the interior, and that she has had normal maintenance. Obviously if the metal is abraded it must be recoated... that's normal maintenance. My own hull is cor-10, with mill certs, has no internal water traps, and was blasted twice (once before plating, one side of all the plates, and the whole frame, and then again inside and out after final welding) before getting 7 coats of epoxy. I'm sure she will outlive me. Not all 25 year old steel boats are shot; there are literally hundreds of them in Holland right now. And incidentally, my boat weighs about 11-12% more than the equivalent fibre glass boat, has correspondingly slightly more sail area and a little more horse power, and is, in my opinion, significantly stronger, Gringo being a case in point. Different strokes, is all. Regards, Bob

[cockeyedbob]

Nice site steelboat ...

A lot of steel boat folks gonna be surprised to find the boat they're sailin' today should have rusted away years ago.

Now, 'bout Slocum and his oyster boat ... just can't figure out why folks keep buyin' and readin' that ol' fools book. Bet a lot of Sailnetters got lost among the pages of Sailing Alone ... a lot of dreams were born 'tween its pages.

[steelboat]

Thanks, cockeyedbob... the site was a lot of work, since we didn't really know how, but still fun to do. By the way, I agree with you about Slocum, but I still liked his tack trick. And no, that doesn't look quite straight to me, but then not much does anymore. Bob