Last update, March 26, 2000
Mid January 2000...
Day of Reckoning
This section is primarily devoted to the weight and measures of your effort. The boat will go into the tank with all its gear less the final gluing of the ballast and deck. A weight "pig" to simulate the rig and final glue will be added in the process. Here is when you need to slow down, consider the options and methodically move forward in trimming the boat to your liking while within the LWL limits specified by the class. We approached this day with excitement and ended it in confusion and frustration. There was still more to learn that was not obvious in our reading.
'95 Standard EC12 Hull Displacement
As the new guys on the block, we figured that "standard" meant all the hulls were the same. Wrong! That if we took several '95 standard boats and loaded them all to produce a 43" LWL, they would all weight the same less some minor variations in trim angle and beam settings. Wrong! After burning the ether with emails for a couple of days, this is what surfaced.
Despite the boats being build from daughter molds the keel widths could vary but not to exceed 2.1 inches. It was guessed that this variance could produce as much as 12 ounces in weight for a static LWL. That is a lot! The variance in beam is known by class specifications. However, the legal variance of .25 inches could place one boat almost a half inch different from another boat. This could mean a swing of as much as 8 ounces. That is a lot!
When you work hard at weight control while building, not knowing the above can be shocking. However, as was pointed out, the '95 standard may not have produced a level playing field but it is better than the rough one before. So, it gives you something else to consider in the planning of a new boat. These were the positive results of this illumination:
1. A boat that has been built close to 4.7 pounds (less the rig pig) and with concentration on keeping the weight low, you will be very stiff at any LWL. This is good.
2. If the boat is approaching 24.5 pounds and 42.5" in LWL, stop. Make sure the trim angle is positive.
Note: At the moment we can see no reason to push the multiple ballasting procedure throughout the full one inch of waterline allowed by the class specifications if it will put you over 24.5 pounds total weight. Higher weights and deeper waterlines would only be desired for high winds and rough seas. It would be thought that such days would be at a minimum.
3. Multiple ballast to 42.06" LWL with a zero trim angle or slightly negative..
Remember, you are only so tall. If you are fat, you carry more weight. If you are thin, you carry less. Simple enough...now go have fun.
This is the boat from which illumination came. This boat was built ahead of and outside of our testing. It was know to be heavily built and with little understanding of multiple ballasting and trim angles. The numbers on this boat are not horrible but nothing we had expected. There was a whirlwind of thought until the above information became clear.
At her heaviest weight, 24.38 pounds, she could only muster 42.5 inches at a trim angle of +1.07 degrees. She was below 42 inches with only the primary ballast. The lightest we could get her was 23.4 pounds and .716 degrees and this was with little foot permanently installed. This all can be seen in her lines in the tank.
Mid February 2000
The yellow and orange boats have now been tanked, measured and weighed with results that produced great relief in this group. As opposed to the swing arm sail control boat above, these are drum winch set ups on the ballast. They covered the multiple ballasting spectrum and trim angles we were expecting. They were built side by side and the numbers differ only by what we have learned above. The documentation for each boat was two printed pages long. Everything was checked to establish a good baseline.
Four ballast sets:
Orange boat LWLs: 42-1/8, 42-3/8, 42-5/8, 42-13/16. Yellow boat: 42-1/16, 42-5/16, 42-5/8, 42-7/8.
Orange boat weights: 23.11, 23.56, 23.95, 24.41. Yellow boat: 22.78, 23.26, 23.86, 24.34.
Orange boat trim: Zero, +.179, +.313, +.446. Yellow boat: Zero, +.134, +.403, +.537.
Is this good? Don't know yet. Never been here. We are happy with all the numbers, however, the trim angles are a question because we have no experience. To cover our butts if the sailing test fails, there is a means of moving the trim angles by .250 degrees +/- .075 at the various weights. While dummies, we are not so dumb to say how just yet!
Tank Test Procedure and Documentations
1. The boat with all the gear it will ever carry, less the ballast, is weighed and recorded.
2. The estimated rig and final glue weights are recorded and a pig for the mast step is prepared. This will produce a dry weight, which is also recorded.
3. The primary ballast and the two shoes are weighed and recorded.
4. List and recorded any additional ballast that is thought to be needed and where on the boat it will be.
5. Put everything in the boat, where it will live and function, and weight the whole thing. This will be the total ballast weight of the boat and the heaviest it will ever be, less leaking water, lost screws and dust.
6. Place the boat in the tank and set the pig on the mast step. Carefully measure the waterline. Fiddle with it till everyone present agrees with the reading. Calibrate the trim angle device. Pick a place on the deck to make the measurement and use the same spot each time. We set ours just touching the rig pig. Record all this information and the weight from above. After measuring the waterline, we found it safe to back off the T-square from the stern so the boat will float freely during the trim measurement.
Follow the same steps for the other ballast set ups.
7. Remove little foot ballast and record the readings.
8. Remove big foot ballast and insert little foot and record the readings.
9. Remove little foot ballast and record your lightest weight readings.
Ponder the results and plan the changes that need to be done. We were fortunate and did not have to remove any ballast. We were armed with some tire wheel balancing 1/4 ounce lead weights and used a couple here and there. However, we will bring the boats back to the tank when they are complete and fully rigged. Then final trim decisions will be made for the primary ballast will have been set forever. Those pictures will be presented here at the time; probably mid April.