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Roberts Ketch

11K views 13 replies 3 participants last post by  Jeff_H  
#1 ·
We''re planning on buying a boat in the 40 to 45 ft. range next year and have been looking at a number of different boats. We want something that two moderately experienced sailors can handle and live aboard comfortably. We plan on spending a year or two in the Carribean and then heading out to wherever the spirit takes us. I''d like to buy a boat and get it ready for cruising for under $250,000. Recently I''ve seen a couple of used boats made by Roberts that appear to offer quite a lot of boat at a reasonable cost. Could anyone tell me more about the 45 ft Roberts Ketch.

Thanks
 
#2 ·
Most of Bruce Roberts boats are owner built or at least owner finished. Because of that build and finish quality can vary between extremely high quality to dangerously inadequate depending on who did the building and finishing work. Beyond that amatuer builders will often have varying degrees of skill in the diverse areas of skill needed to finish a boat, so for example you might see beautiful woodwork on a boat in which the electrical and plumbing work does not meet any established standards.

As with most home built boats there is also more of a chance that the owner ''adlibbed'' with the specifications. For example, my stepfather considered building a Seamaster 45, which was a Bruce Roberts designed 45 footer. He planned to use lead bricks held with reinforced resin for ballast. Seamaster used steel punchings held with resin, and we met a fellow who had used simply concrete with a little bit of reinforcing rod. Obviously there would be big differences in the lifespans, stability and sailing ability of these three boats.

Bruce Roberts is popular with owner builders 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 very 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 though still dated to my eye. All of his designs are very heavy boats and I strongly believe that weight, in and of itself, has no inherent virtue and is a very serious liability.

Jeff
 
#3 ·
Roberts boats are made out of steel. Steel is an excellant choice if you can keep the boat dry inside and are not 100% certain that you will ever ram anything, or that anything will ever ram you.

Yea they are heavy, and rust never sleeps but you can hit stuff and keep going.

Read the Steven Calahan and Dougal Robertson stories to help you make a decision.
 
#4 ·
Back in the late 70''s or early 80''s, Robert Perry gave Robert''s design his seal of approval. Many sailors like the designs of the 70''s over more modern designs - see Ted Brewer''s article in the recent good old boat about some interesting perspectives on design.

I think Jeff has a very good point about things that home builders might have done. There are, however, a couple of points to think about with this argument:

1. We see some very reputable commercial builders who do some strange things, too. For example, Caliber, I have been told by one owner, has used concrete to fill space in their encapsulated keels. Concrete holds moisture = problems.

2. A Roberts could be a great deal. Because they were owner built, that may lower their value. If one can feel confident about an owner''s attention to detail, one might find a very well built boat at a good price.
 
#5 ·
Actually a comparatively small proportion of the Roberts 45''s have been built in steel. Most have been built in glass. And when you read Steve Calahan''s story remember he is sailing a race boat designed 20 years ago.

Jeff
 
#7 ·
And when you read Steve Calahan''s story, think about what might have happened had the hull been made of steel???

Instead of sinking (because of the collision) he would have bounced off, done the trip, never written a book and would be just another obscure sailor out there doing his thing.

I’m still searching for books written by steel-sailboat-owning-shipwrecked sailors, where the boat was hole in a collision at sea, but just can’t find any.
 
#8 ·
See if you can find a copy of the local Savannah, Georgia or Charleston papers from early spring approximately 1979 or so. There was a well covered case of a couple who struck a submerged object with the nearly new steel ketch and sank. Also check the Miami papers from the early 1970''s probably around 1974 or so. Also a steel hulled boat that piled up and went down quick.

Pound for pound, both cold molded wood and fiberglass hulls are actually stronger than steel. So if you compared a steel boat of the same weight as Steve Calahan''s boat, I doubt the results would have been any different. The fact that few steel vessels sink due to hitting objects reflects the fact that most steel boats have heavier hulls and the fact that there are just plain fewer steel boats out there. Steel commercial vessels are lost with no lesser frequency than composite commercial vessels are lost.

Jeff
 
#9 ·
So what you are saying is that in the sailboat demolition derby, you could take a Hunter, a well built cold molded wood boat and a steel boat, all of equal displacement (equal weight, pound for pound), let them go at each other, and the steel boat has no better chance at surviving than the other 2 boats???
 
#10 ·
Close- All other things being equal, I am saying that I would take an equal weight properly engineered cold-molded boat over an equal weight properly engineered FRP boat and both over an equal weight steel boat in a demolition durby where the impacts match the hazzards likely to match those encountered at sea.

Jeff
 
#12 ·
Its not that a steel as a material is inherently bad for the Southern Ocean or other areas where icebergs are common. The issue is more about how steel is engineered. Our image of steel as this very rugged material that can withstand any assault that nature might hit it with comes from heavy duty commercial craft. The reality is that steel yachts are generally plated with much thinner playing in an effort to keep the boat''s weight in a range that is closer to that of other materials. Since a Pound for pound a properly constructed cold molded boat is sturdier and more punture resistant than a steel boat. I think that I would certainly take a similar weight cold-molded boat over a steel boat if I were going into a harsh venue. That said, few cold molded yachts (or steel boats for that matter) are really intended for those kinds of harsh conditions.

Jeff
 
#13 ·
I found some interesting stuff on this web site; http://www.kilim.com.tr/ardali/boatbuilder.htm



Without doubt, steel is the strongest of all boatbuilding materials, and in a stregth/weigth basis is superior to wood, grp, or aluminum.

Ordinary mild steels have typical tensile strengths of 3,500 to 4,200 kg/cm2 (50,000 to 60,000 psi) and typical yield strengths of 2,100 to 2,800 kg/cm2 (30,000 to 40,000 psi),which is to say they will sustain loads in that order before beginning to stretch or yield without returning to their original position. At the same time, they are very ductile and will elongate 30 to 40 percent before failure. Thus, a steel boat in a collision or cast ashore on rocks may sustain repeated loads or blows that would irretrievably shatter wood, fiberglass, or ferro-cement boats, and yet still be in floating condition when hauled off, though possibly with some bad dents. The high tensile steels are even stronger with typical yield points of 3,500 kg/cm2 (50,000 psi) or more, and ultimate tensile strengths of 5,000 kg/cm2 (70,000 psi) or better. Ductility, of course is less, but still greater than other materials.

There are other measures of strength besides tensile strength. They are: (1) resistance to impact, (2) stiffness, (3) resistance to abrasion, and (4) fatigue. In all of these categories, steel is in the first rank. As already noted, a steel hull will survive grinding and collisions that would be fatal to other materials. Any vessel that is subject to the repetitive flexions of the sea, is subject to fatigue. Fatigue failure generally starts as a small crack, which can then progress rapidly. The fatigue strength of most materials is usually in direct proportion to their ultimate tensile strength. Wood is not particularly prone to fatigue but its fastenings are. Some of the disastrous cracks and splits that occur in fiberglass hulls are in fact fatigue failures.

Weight
 
#14 ·
This is an interesting site and they are right that steel really looks good on a PSI (Per Square Inch) basis. Glass fibers only have about 80% of the tensile strength of steel and Wood only have about 10% of the tensile strength of steel when taken on a PSI basis.

BUT when you factor in the relative weights so that you are comparing materials on a pound for pound basis, fiberglass has 4 times greater bending strength and Cored fiberglass has 7 times the bending strength and a fir/cedar cold molded section has a 16 times greater bending strength. If you add a couple laminations epoxy/kevlar to the outlayups, you far exceed the sheer and abrasion resistance of a typical steel section and you end up with a much stiffer, stronger in bending and slightly greater sheer resistant section than a steel section of the same weight. I think that they have spouted the usual "Steel if tougher" mantra without actually running the numbers on a pound by pound basis. They have also glossed over the loss of strength in steel once it has exceeded its yield point. (i.e. been bent)


They are correct that wood has tremendous fatigue resistance but the conventional means of building with wood can result in fatique failures of the fastenings. One of the biggest advantages of cold molded construction is that it pretty much eliminates fastenings and flexure in areas where fatique is possible. They are also correct that fatigue can be a real problem in fiberglass boats and that fatigue is particularly a problem in early fiberglass boats where there is a much higher degree of flexure and there was a poorer handling of resins and fabrics.

Jeff