Performance Tips for the EXPRESS 30 – by Steve Killing (yacht designer)
The following is an article published by Steve Killing, designer of the Express 30, presumably early 80s when the yacht was manufactured. This was scanned from original that came with 74209 Thumper / Sir Nautalot
If you don’t feel like reading any further, here it is.
1./ Rake the mast.
2./ Bend the mast.
3./ Don’t use the babystay unless it is really blowing.
4./ Don’t heel over 28 degrees.
5./ Gybe downwind.
If you’re still with us and want more detail read on.
The 30 was designed to sail with 8-12″ of rake and in practice this seems to work pretty well. Have a check at the dock early next season. Get the boat floating level with a man standing on deck at the mast and check the rake by hanging a winch handle, coil of rope, or an old boot on the end of the main halyard. If you need more rake (I doubt that you will have too much) then back off the headstay and take up on the backstay. This raking procedure will also increase the bend of the spar, if the mast step is not moved. I would recommend both rake and bend. I have yet to see a boat with too much of either. This procedure will set up the boat with a nice weather helm and good mast bend in heavy air.
The other controlling factor in mast bend is the babystay. Its purpose is to increase mast bend or stabilize the spar in heavy air. The detriment of the stay is its interference with the genoa in a tack. So sail without it whenever you can. Only in heavy air is it necessary for mast controi; if you notice the spar starting to pump fore and aft when going through waves then it is time to put it on. When not in use it can be clipped to the mast collar. In very light air when the backstay is eased, you may need some babystay on to take the fullness out of the leading edge of the mainsail. But have a look first; don’t use it if you don’t need it.
The next two items deal with sailing performance and we can learn something here from the computer performance prediction. It has done an analysis which is often hard to judge out on the water, that of deciding whether it is better to reef and heel less or to keep the power on. It suggests the following set-ups for 14 and 20 knots.
True Wind Speed 14.0 | 20.0
Apparent Wind Sp 18.7 | 24.5
Apparent Wind Ang 28.3 | 27.7
Boat Speed 5.88 | 6.11
Heel’ Angle 21.0 | 24.7
Reefed No | Yes
Flattened Sails Yes | Yes
I would suggest that the heel angle should be kept below 25 degrees upwind and 28 degrees on a reach.
Let’s deal lastly with gybing angles downwind. It is always hard to force yourself to gybe as widely as you should when the course is directly downwind. Sometimes there are tactical reasons not to sail where these figures will tell you, but if the breeze is just as good on the gybing course as it is closer to dead downwind then go off on the gybe it pays off.
Take a look at the compass gybing angle. It is greatest in light airs. Over 70 degrees on the compass. However, if you are sailing in a shifting breeze that compass angle won’t help you. The one you want to watch is the apparent wind angle. Even if you only have a Windex at the mast head, you can estimate the apparent wind angle quite well. Picking a few points off that graph gives:
True wind speed 5 | 10 | 15
Apparent Wind Angle 110 | 124 | 165
These are the optimum apparent wind angles for maximum downwind speed, measured in degrees from the bow of the boat. Notice in very light air, the wind is just aft of the beam. Keep that in mind next time you have got a long
downwind leg.
No doubt you too have learned a few things about the performance of your Express 30, perhaps a lot more than mentioned here. I know the people at Express Yachting would like to hear from you with your secrets, so why not drop them a line?
~ Steve Killing
