Folded Stability

TAKE CARE! – folded stability can be very good, BUT it is limited on larger designs

Folded stability was one of the first things to be checked when the original 18′ prototype was launched in Australia, and this was found to be remarkably good. Consequently I motored and even sailed it many times into the ramp while folded.

In fact, a few years later, it surprisingly took six people standing on the float of the 19′ folded TRAMP to deliberately roll it over (without mast) for capsize and righting tests. We found that if we did not hang on until the last possible moment, it would immediately right itself again! Worst part of the whole exercise in fact, as the beams on the opposite side came over like pile drivers once it finally went.

Hiking out on the original Trailertri 18, to test folded stability

The F-22 is also very stable while folded, with the standard mast, due to its much larger floats.

But care should always be taken with the taller aluminum R mast. We will also soon be implementing a variable folded beam that allows the boat to be set at the maximum legal trailering beam in any area, or wider for when needed. Makes it as stable as it can be while folded, and this can be an important factor with the taller F-22R rig. Will become available in 2017 HOWEVER, care MUST always be taken with larger designs, particularly those with an aluminum ‘R’ mast, as the boat has a much higher center of gravity, with a much taller heavier mast, while the folded beam/stability stays virtually the same. Thus care MUST be taken when folded in strong wind conditions, and never do a tight fast turn while folded, as this has rolled boats over in the past.

The F-9AX and F-32AX are more stable due to their wider folded beam, while F-9/F-31s and F-32s have a secondary wider folded position which also helps to minimize the risk. However, this only reduces the risk and does not eliminate it. So when launching or retrieving in cross winds of over 15 knots, always unfold one side as soon as you can, or only fully fold the remaining side at the last minute, just before going on the trailer, to be safe.

The F-32 design series is shown above, but F-9 and F-31 are very similar. Overall, and to keep this in perspective, the risk is generally low, and I have motored many miles while folded. But always be aware that a risk is there, and if any doubts exist then partially extend floats (even a simple prop between beam and main hull will do), or just unfold one side.

We found it possible to even sail the F-27 folded, but it was tricky, and definitely not recommended

Also be aware that stability while folded in a marina berth is similarly limited, and extra precautions should be taken should strong cross winds be forecast. Simply taking a halyard down to the dock on each side is probably enough to take care of this, and looping the halyard under or around a lower spreader will also increase the effectiveness.

Folded stability is not really a problem with the F-39, where folded beam is 15′ 9″ (4.8m), but reasonable care should still be taken in very strong cross winds

The lower stability while folded can also have some benefits, as I have pulled a Tramp on its side while on a beach, using a halyard from masthead, in order to reach the centerboard slot underneath and free up a sticking centerboard. Worked well, and proved to be a very quick fix – Ian Farrier