Aerospace vs. Marine

Generally the precision end of the marine game is the high performance realm. Which is not all pro race boats. Lots of well healed play racers out there too. Aerospace may well be an excellent fit. Dunno how you would break into that sector however.

Kelly Cook

There are indeed many similarities between the marine industries and the aerospace industries, particularly when it comes to aerodynamics, hydrodynamics, and structures. Aerospace benefits from the simplicity of a vehicle travelling in a single medium (air) that is only 1/800th the density of water, where marine craft travel. Marine surface craft must travel at the interface between air and water (the ancient interface, as it is known), and, as in sailboats for example, must derive power from one medium (air) in order to travel through the other medium (water). This complicates the loading on marine craft exponentially over that of aircraft.

The aircraft industry generally runs at levels of cost and precision that are many times greater than the marine industry. Composite tooling is much more expensive, the processes are more complicated and expensive. It is only at the very upper Grand Prix level such as in the America's Cup or in the current Volvo Round the World Race where the level of investment and engineering begins to approach that of the aerospace industry. And if you have tracked the Volvo Race lately, now in its second leg to Australia, you will see that the designers and crews are not doing a very good job--boats are breaking apart with alarming frequency.

From my own point of view, designing marine craft for over 30 years, I can say that customers in the marine field generally are insanely conservative, and making technological progress drags at a snail's pace at best. You can get a sense of this when you realize that the aircraft industry got rid of wires holding the wings on airplanes back in the 1920s, but we in the marine industry cannot break out of that thinking--why should sailboat masts be held up by wires.

the IT side of things

As you would imagine the IT side of the business is in line with what Eric says,

I work with software which is depoloyed in all major aircraft contructors, the level of investment for new designs and engineering is a factor of 1000s more than any Maritime entity, only the UN Navy come close with their warship programmes.

As a result the methods and practices the aerospace industry use are far advanced from those we use in the marine industry.

The recent trend has been towards copying what the aerospace industry does, with many of the larger production boat builders looking towards aerospace practices for inspiration, lean engineering collaboration with suppliers, turn key etc..

Any questions about this side of the business Ill do my best to answer.

DT

I'm probably not the best qualified to answer this but, it depend on what you are manufacturing...

When we are talking about pipe spools, or Structural assemblies then nearest 5 mm is OK, sometime more when double curvature panels are considered, as it hand work.. hence the old expression the 'persuader' referring to a sledge hammer used when banging something into shape. (Good argument for a powerful CAD system)

For Valves and components it depends once more, on the usage, I'd say most components are non-critical so the tolerances are not strict , but when ever high pressure steam , or safety systems etc, are in question the standards are much higher. I have some friends working in ABS (Classification) with yachts , they would know the details for quality requirements.

Quality and tolerance, of course, are two different things. The marine industry does have its standards, but it is no where nearly as highly regulated as the aircraft and aerospace industry. Whereas an airplane has to go through annual inspections at the minimum, and 100 hour inspections if it operates commercially, and with everything documented in log books by certified aircraft mechanics, the marine industry is nowhere near that rigorous.

Recreational craft have to meet a few federal standards, and there are voluntary industry standards to meet (American Boat and Yacht Council, for example.) Larger motoryachts (over 79' Loa) may meet classification society rules to varying degrees, depending on the desire and budget of the owner. If classed by the classification society, then the yacht must undergo annual haulouts for inspections. Also, if classed, the yacht must be inspected by classification society surveyors during construction.

An owner can also ask to meet MCA standards (English) and European Community (EC) standards, which themselves comprise many of the ISO standards that are becoming very prevalent. For example, you cannot sell a yacht in Europe unless the entire vessel, and that includes every piece of equipment down to the last screw, is certified by paperwork to meet all applicable ISO standards (of which there are over 220).

The construction standards such as the classification society rules (American Bureau of Shipping, Lloyds Register, Bureau Veritas (France), Det Norske Veritas (Norway), Germanischer Lloyd (Germany), etc.) set structural and equipment minimums which the builder elects to meet or exceed. If a yacht is to be made out of composite materials, which the builder himself molds and puts together, then the classification society rules stipulate that some testing be done to verify the quality, strength, and stiffness of the laminates. For metal yachts, welding must be inspected, and welders have to be certified to the classification society standards, verified by welding tests.

Overall, I think there is probably a sufficient level of construction standards to assure the quality is built into the vessels. It is getting more onerous, however, with the movement, particularly in Europe, to increase the level of standards, I think, almost exponentially. I have to confess that I sometimes wonder if we are not standardizing ourselves out of existence. The cost and time involved just for certification is becoming a major construction expense.

The quality really depends on the builder--who do you trust, and what does the market bear? It's a case of caveat emptor, certainly, but also, the free market usually sorts out the good from the bad by itself--the good stay in business, the bad don't.

Eric

I think the post above defined the differences between aerospace and the marine industry very well; it comes down to regulation and the tolerances that are mandated by governing protocols. As different as the two arenas are, I believe there are great similarities between aerospace & marine.

Both have benefited from advancements in computer technology, CAD systems and the automated tools these technologies control. But there are many more similarities when you look beneath the surface. Take for example, virtual rendering and scale model testing. While aircraft development has benefited from wind tunnels, hulls have benefited from flow channels. Each is seeking optimum efficiency through a designated medium. Both industries have utilized computers and various software programs to gather data and further refine designs. Although the aerospace industry pioneered much of this work, the boat building industry has adapted this too.

The construction techniques of the fuselage/wings of an aircraft or the hull/superstructure of a yacht are not that different. In alloy-type construction, both are beginning with a skeleton that is eventually skinned. The most pronounced difference in building procedures would be initial attention to detail that an aircraft manufacture must maintain, as it will closely resemble the final product. In contrast, it is the finishing stages of building a yacht where the attention to detail will be most prevalent. In recent years, the final finish of many custom yachts has approached the same level of detail (and in some cases tolerance) as you would find in aerospace.

Although composite lay-ups vary on aircraft applications, such as filament wound carbon for military aircraft (and now commercial) fuselages and wings, there are definite similarities in construction between composite boats and light, private aircraft. Both are utilizing molds to extract parts from. These molds are typically taken from plugs that were originally machined by 5-axis mills, accurate to 1000’s of inch. That’s Mil-Spec.

In composites, because weight is not a critical issue for yachts, attention to lay-up schedules doesn’t need to be as stringent. The additional weight can also add strength, where as weight is a very critical issue with aircraft. Much like aircraft, yachts must be built to withstand forces that are generated by their operational environment. Although Mil-Spec construction is not a pre-requisite in yacht building, some builders have achieved ISO 9000 certification and/or have adapted vacuum bagging techniques. Again, much like aerospace. Granted, aerospace tolerance is more critical, but it has to be for many reasons, from reliability, to weight, to space limitations and of course... regulation. The number of redundant systems onboard an aircraft further compounds this scenario.

From a manufacturing standpoint, I think there are clear similarities. But this also carries over to onboard systems and equipment. Out of a comparative curiosity, I began jotting down a list. Add or subtract from this list as you like…

Aerospace AND Marine: Equipment

1. Hull Stabilizers vs. Flight Control Surfaces: Piezo or gyroscopic sensors: same technology, whether they activate servos or hydraulics.

2. Fly-By-Wire Technology: In some cases, fly-by-wire is utilized for yachts, such as servo’s for controlling rudders or stabilizers. Another fly-by-wire example is electronic throttle control.

3. Variable Pitch Propellers: On planes or yachts, same purpose/concept, different application.

4. Thrust vectoring: Azipod Drives or the YF-22 Raptor. Different needs, same concept, each with their own purposes and engineering hurdles.

5. Radar, Auto Pilots, Navigation Equipment, etc: Basically the technology, and sometimes the same suppliers!

6. Wiring: Many of the same servicing, anti-chafing and insulation protocols are applied to both industries.

7. Engines: Diesel or turbine, aerospace app or marine app… they’re the same power plants.

8. Transmissions & Drives: Different applications and mechanical engineering, but much of the same purpose and need. Yes, aerospace protocols are rigid… but they don’t have to survive being submerged!

9. Deployment mechanisms: Tender garages, cranes or doors for yachts. The engineering is not so different from the landing gear for aircraft. They both utilize pneumatics or hydraulics. Admittedly, the aerospace doors probably fit a little tighter.

10. Onboard systems: From the kitchen sink, to HVAC… often, they both use commercial suppliers.

When you add in the level of artistry and craftsmanship found on today’s yachts, as well as having to hold the hand of buyers who know-knot what they want… I think the marine industry (custom yacht builders specifically) have equal or greater challenges than meeting the regulatory protocols of the aerospace industry. In that respect, aerospace has it pretty easy, as they typically work with educated buyers, such as reps from major airlines, the military, etc.

I have to give the nod to yacht builders. Making customers happy is much harder than meeting Mil-Spec.

I didn't realize I wrote a book until I hit the submit button. Sorry!

Just consider it a test of the latest software transition

I hate it when a site drops my connection just as I try to submit a long post.
Kelly Cook