Chris Museler's Race Prep Diary #4 - On Keels and Peace of Mind
By Chris Museler
The last thing my wife wants to hear before I go racing is a story about professional offshore sailors being rescued after the keel falls off their speedster. Unfortunately, this is not completely unusual as last year’s Fastnet Race illustrated when Rambler 100 lost her keel.
Fortunately for me, I am sailing aboard a Class40 where preventing such a catastrophe is part of the maintenance cycle. Owner Michael Hennessy had Dragon’s keel inspected 10,000 miles ago, in 2010, and it was due this spring for another look-see before the Atlantic Cup and Bermuda Race.
Non-Destructive Keel Testing (NDT) is not often done, even for the grand prix racers sailing in this year’s Bermuda Race. It is a scary thought that in the eventual obsolescence of racing boats, they are often bought inexpensively and passed along as such to owners without the means to maintain them properly. The boats are built to tight tolerances, as light as possible. This leads to many little time bombs on boats being raced locally and sometimes offshore with modern shaft keels having potential weld or bolt failures.
For now, this isn’t the case with Dragon and I will endeavor to explain the extensive process used to examine the keel before I sailed with Rob Windsor to Charleston last month.
Dragon’s slender, short cord-length keel is a steel box section, like an I beam, with vertical plates that make up the leading and trailing edges. A sheet of 3/8” steel is wrapped around a steel grid on either side to make the foil shape with all contact points welded including long welds along the leading and trailing edges. The keel is hollow and there several different tools are used to inspect the different types of welds.
After the thick fairing compounds at both ends of the keel were chiseled away, Mistras Group was hired to perform inspection. The company, with an office in Connecticut performs NDT on pipelines, nuclear power plants, tank farms, offshore drilling rigs and in the aerospace industry.
Mistras Group performs non-destructive testing (file photo)
Mistras used Magnetic Particle Inspection, radiography (x-ray), Ultrasonic inspection and dye-penetrate testing. To avoid getting too techy, the top and bottom plates of the keel, where it attaches to the boat and the lead bulb, were both inspected by Ultrasonic and dye testing. The inner web, which included 96 slot welds, was inspected with MPI, x-ray and ultrasonic testing.
The same week Dragon was undergoing her ultrasound, so was my wife. And though it’s difficult to compare emotions on the subject, Michael seemed as apprehensive as I was for my pregnant spouse. He even broke out in a cold sweat when the testing found some anomalies in the top keel plate joint. The thought that he had cheated a catastrophe last season sent chills through his spine. It turned out that a thick section of fairing lead to a false reading and Dragon’s keel (and my unborn child) passed with flying colors. Phew!
If you could ever buy peace-of-mind, this is the way to do it. The process seems extreme and though Michael would not tell me the cost, it’s not inexpensive. But this is not unusual in the world of shorthanded sailing where not only do the boats annually sail more miles then most racing boats sail in a lifetime, the exercise is a necessity. It starts to make sense that when the shortest race you do in a given year is 600 miles, there is no waiting till tomorrow to repair and sail a few more races.
Gear failure means your event is over, and this reality forces Class40 teams to truly cover all their bases. Excessive as it may seem, some owners of offshore boats may want to think about investing in an inspection like Dragon received. Isn’t peace-of-mind priceless?