Thoughts on Gunga Din
I have been thinking a lot about the loss of two boats during the 2024 Newport Bermuda race and the excellent report by experts who can only be described as making up a blue-ribbon panel.
As usual, I strongly recommend reading the actual report, it’s excellent, but here are a few things that jumped out at me about the loss of Gunga Din, a well-built, but older Sweden Yachts 41.
Yikes! Well that pricks a few bubbles. One of the world’s best built boats and one of the world’s best naval architects likely brought undone by an idiot in a boatyard with a reciprocating saw.
But there is another interesting element that the report raises, that of easy access (within minutes) to critical structural elements of the boat. Had the keel bolts been easily accessible, maybe the reciprocating saw would not have been used. Who knows?
But the issue remains that we have all been in the situation of having to dismantle half the boat to get at something that really matters because some aesthete at some stage wanted something pretty there or some pragmatist installed another device over it. Everything has its price. But it’s awfully difficult to make a decision if we don’t understand the price we may have to pay for some “improvement” that makes it very difficult to fix or even save the boat at some later stage.
Hi Paul,
I agree, access to these structural areas is vital, and get sadly lacking on many otherwise good boats.
A good manufacturing engineer will design a thing to go together easily in a factory. (Production boats are built in segments – the underside of the deck is populated with wires and hardware before the cabin overhead is added, and only once that’s complete is the deck joined to the hull.)
An *excellent* manufacturing engineer will design a thing to come apart easily 40 years later.
You see the same thing with cars. Audi has good manufacturing engineers. “Please put the Audi in the service position” is a horrifying thing to hear; you’ll be removing bodywork at the very least, and might come back to find the entire front end of the car missing and the engine on a stand to do a repair that might have been $700 on a Mazda. Toyota has excellent manufacturing engineers. They test-fit a socket wrench to every bolt you could conceivably need to touch in the car’s life before they finalize the design.
We poked around the yachts at the last Annapolis show quite a bit, and found a similarly stark dichotomy. Some builders (e.g. Beneteau, Seawind) had made a point of leaving tool clearance around every conceivable service point and planning removal/reinstall paths for every piece of equipment; I think I’d be able to completely repower a 2024 Oceanis in three days in 2054 with just basic hand tools and no outside equipment. Others (e.g. Catalina, Bavaria) had tucked stuff away in a way that made total sense at the factory, and would be utterly painful to fix.
Hi Matt,
Good to hear that there are builders who are thinking about this. That said, one other issue is that many of the same builders (I think Beneteau are one) use fibreglass cabin liners as well as drop in webs in the bilge that extend a long way out and have a lot of furniture bonded to them, both of which can deny critical access to the hull in an emergency.
The other issue is most of these French boats use interiors that are glued together, which makes any repair that requires removal a total destruction and rebuild game.
Yes. The full fibreglass liner and bonded furniture technique looks beautiful, and is easy (and affordable) to build. But woe betide you if you ever have to dismantle those parts. That’s not exactly a new problem, though – our 1974 C&C, and many friends’ 1970s and 1980s boats, have similarly limited access to the hull itself without totally destroying the interior.
Hi Matt and John,
Sort of related to Matt’s comment, one of my observations of looking at boats is that the designs are not complete usually. I am not an insider in this industry so can’t speak to the specifics but I can tell it is going on both by speaking with friends and acquaintances who work in the industry. By this I mean that if you took the documentation package to 2 different builders, you would end up with 2 substantially different boats and the builders would have had to do a lot of figuring out along the way. One of the silliest things that would be different would be that the fasteners used between the boats would be different even if just by length. If this part of the design is not done, everytime you put a piece of deck hardware in, you have to measure the diameter of the hole in the hardware, drill the deck (they may have to figure out the location each time if there isn’t a template or CNC program), then measure for bolt length, then climb down a ladder, go to the bolts bin, grab the right bolt, climb back up the ladder, then install the hardware. At the same time, someone would need to be constantly checking that bolt inventory and re-ordering in a guesswork fashion. For a design that is complete, ideally you get assigned to install that piece of deck hardware and there is a bin with everything you need that someone (maybe you) has kitted, sometimes including tools, and you just go do it without measuring or getting off the boat. And instead of taking inventory daily, someone takes inventory quarterly and orders the bolts based on the predicted demand from the bill of materials (BOM).
I am not surprised that the higher volume builders are better at this stuff, you have to be to survive. I would bet that even a very low volume run would have it make more sense financially for the designer to take a few hours, put all the hardware in the CAD model and then have it automatically populate in the BOM as the build will go so much faster. For the high volume runs, the design cost is completely trivial compared to the time savings of workers trying to figure it out as they go. Sure, you need more formal design changes as hardware goes obsolete, you change to a cheaper supplier, etc. but those are not enormous burdens. By the way, this also translates to service as well, if you have a good BOM, the service guy knows what to bring with them including the tools and doesn’t have to go to the hardware store pray they can find a sort of appropriate fastener.
This is all a long way of saying, I would bet that the designs of the high volume boats are more complete even if the boats are designed to be cheap. After all, complete designs make for smooth production which is cheap.
Eric
Great post. Over the last 10 years of sailing something that has really had hit me hard in the face is that even if I in some cases could afford to pay for help I more often that not find it hard to find competent help! Maybe it is easier in some countries, but in Denmark I would not know where to find a naval engineer that would help and the shipyards make so many sloppy mistakes, sailmakers that just hurry the production of sails, the rigger that says all is good when you know it’s not and the mechanic that has no clue what is the problem with the engine. It’s not that I don’t love the process of learning myself and I sure take a lot of wisdom from this site as to critical thinking, but it’s hard to be an expert on every thing. I just dreamed of sailing and look where it ended up 😂
Perhaps this has always been a problem and I’m just more aware of it now, but I get the distinct impression that in the last decade or so, the overall level of competence of trades in general has slipped significantly. At various points, I’ve had to deal with the aftermath of concrete finishers who made the surface slope up toward the drain, paving crews who didn’t know how to screed gravel or use a laser level, plumbers who didn’t understand how to prime a pump from a tank by gravity, an architect who thought single-ply flat roof membranes couldn’t leak, mechanical engineers who just copied stuff from catalogs without checking if it’d meet the specs, roofers who thought that ice/water shield membrane and drip edges were unnecessary, crane operators who banged up the side of their own crane with its own hook for two hours trying to figure out how to rig the straps, mechanics who just poke at a misfiring engine for four hours and come back with a shrug and a $600 invoice….
While there are still exceptional good tradespeople around, the overhead, time, and effort spent in finding them, qualifying them, and supervising them at near 100% coverage for the first few days until I know they aren’t total jokers is often more costly than just doing it myself.
It is hard to become an expert on every thing. But it is surprisingly easy to be better than the average modern “professional” at almost every thing.
Hi Matt,
Sadly, my experience has been the same. A friend of mine who is a Mechanical Engineer is want to say that the only difference between us amateur mechanics and the pros is that the pros have the tools. I would not go that far but would say that the primary difference in many cases is that we give a shit.
Hi John,
Yes, the diagrams of the cutouts are quite alarming.
If working on something like a modification with an engineer, I think it is important that you tell them how you want the design/analysis optimized. For example, the compressors I designed were all about thermal efficiency, reliability and to a lesser extent cost with no real bounds on size and weight while what I am working on right now is all about stiffness to weight ratio. Lets say you were asking for them to advise on rebuilding a bonded-in liner post grounding. If you just asked them how to repair it, you would get something that reflected their preferences like it might be super lightweight but hard to execute (racer) or super cheap and just equivalent strength to the original design (cheap). If I had a cruising boat which was in this situation of needing repairs, I would probably ask for something like “Repair needs to be easy to execute skill-wise for a novice working with composites, needs to be structurally insensitive to small mistakes made in repairing, should be strong enough to make 50 US east coast to Bermuda passages or take a hard grounding at 7 knots with no damage and we should chat if the total additional weight will exceed 100 lbs.” Then when I got the initial design back, I would look and make sure that it seemed right including things like cost of materials. On high budget projects, you can make requirements of all that stuff up front but on a simpler one like this, I would only specify the critical things and then ask them for an iteration if the design is way off on something not as critical.
By the way, mechanical engineers can’t eyeball a lot of stuff either unless the geometry is very simple but all should very quickly recognize things like a cut creating a stress concentration. We use tools like finite element analysis (FEA) and do many iterations of optimization to end up at the final result we want. Once optimized, it is usually easy to explain why it ended up that way but you wouldn’t have gotten to that exact design without the optimization.
It is also worth noting that engineering has a ton of sub-specialties and mechanical engineering has a number of them as well. The number of mechanical engineers who are really qualified to specify composites is pretty low as they are anisotropic materials and not used a whole lot. If you get into really complex geometries or low safety factors, the number of people qualified to do the FEA will be even lower. If needing advise on something composite, I would ask for composites experience upfront when finding someone to do the job.
Eric
Hi Eric,
Thanks for the fill on that, particularly the part on prioritizing the most important goals in a repair. Makes total sense.
And yes on eye balling: Despite being a racing sailor himself and a specialist in marine work, the engineer I hired just shrugged when eye balling the mast damage and I asked him for an estimate of the strength reduction. However, after doing an FEA he was confident that the mast was toast, but even then he made clear that an exact strength reduction number would require a NASA sized budget, but given that the strength reduction was substantial in the highest loaded area, he would also find it impossible to certify the mast as fit for use so it really didn’t matter. The insurance company agreed.