I often write about amazing scenery, wildlife, nature, people and experiences during this cruise. There’s a darker side to cruising, however. When critical equipment fails, it can be very disruptive. I mentioned our friends who’ve been stranded on an island for weeks waiting for a new rudder.
We haven’t had anything that dramatic happen but we did have a series of mishaps over the last two days.
WARNING: This post is a little technical.
Cruising sailboats have engines to travel when there’s insufficient wind, or for tricky port manoevers that can’t be done under sail. When sailing, the water flowing over the propeller can make it spin because of the same physics that allow it to propel the boat when the engine is on. This can cause noise, vibration, and wear on other mechanical parts along the drive train, such as the cutlass bearing, shaft seal and transmission.
To avoid this, Amel designed in a shaft brake, depicted in the introduction. It’s a disk with calipers. When sailing, the calipers squeeze the disk, stopping the shaft rotation. When motoring, the brake releases, allowing the motor to drive the propeller. This is achieved by using the fluid pressure in the engine’s transmission to engage or disengage the brake.
Those who followed our blog last year will remember that it never effectively stopped the propeller from spinning. We had it repaired of the winter. It worked well for a month. Then, when leaving Boothbay Harbor Monday in a thick fog, we smelled smoke. The calipers engaged when they shouldn’t have (the greater evil vs. not engaging when they should) and siezed the disk, leading to the caliper pads burning from the friction.
Once we cleared the smoke out of the engine room, I made adjustments to disengage the brake. There was not enough brake pad thickness left, so the propeller is once again spinning under sail.
Many other Amel owners have had similar problems with the shaft brake. Some have removed it altogether and replaced the propeller with one that feathers under sail so that it doesn’t spin. Amel has adopted a feathering propeller on newer models and discontinued the shaft brake.
After fighting with it for two seasons, I’ve decided to eliminate it, and replace the propeller with a feathering one. Smoke on the water is scary!
14 Responses
Sandy and Dan
Nice pictures of scenery. Also enjoyed seeing and hearing the bird life. Seems like you are having a great sailing summer. Good thing you have an Admiral on board to handle all the technical issues that arise. 😂
We all need a good admiral!
Great photos. Sorry for the problems but great to have the know how
Thanks, Tom. Necessity is the mother of invention!
Oh no! Very glad though that you figured out a work around to avoid future issues!
Someone told me on our trip, if there is nothing broken on your boat, you just don’t know it yet. So sorry this happened to you. I can attest to the value of a feathering prop. We have one and glad we do. Looks like you’re having a great summer. So happy for you both. Great job with the diving gear. Impressive.
Or, it is yet to brake (and it will). The bright side is that we really learn a lot when we have to roll up our sleeves and fix something. Looks like you finally escaped Drummond Island. Hope it didn’t completely mess up the summer.
Can’t you stop the prop from spinning by putting the engine in gear? That’s what I do. Also, with the transmission stopped, the feathering prop feathers. Otherwise, even a feathering prop stays unfeathered if the the transmission isn’t put in gear.
Moby, It’s tricky with hydrolic transmission. You can’t change gear when the engine is off. What Amel owners with feathering props do is, before shutting down the engine, they put it in reverse for a few seconds to feather the prop, then back to neutral to shut down the engine.
Courage, la solution existe
C’est sans aucun doute la meilleure décision. Personnellement, je ne peux que recommander l’hélice JProp : elle est très efficace, aussi bien en marche avant qu’en marche arrière, et son pas est réglable facilement même sous l’eau ! Un système vraiment ingénieux, avec une faible consommation. Car ce réglage fin permet vraiment d’optimiser le rapport T/min-vitesse
Il suffit simplement d’embrayer l’arbre une fois le moteur arrêté, pour forcer la mise en drapeau immédiate.
Et il faut être un peu “simple” pour croire qu’un bateau à voile ira aussi vite avec une hélice bloquée qu’avec une hélice en drapeau….C’est l’héritage de Monsieur Amel, conçu à une époque où les hélices sans traînée n’existaient pas, et qu’il paraissait intelligent d’utiliser la rotation passive pour produire de l’électricité via un alternateur…ou de bloquer pour ne pas être importuné par le bruit (certain).
J’imagine que le coût du montage du frein à disque compenserait largement le surcoût d’une bonne hélice moderne, cependant. Cela laisse songeur sur la force d’une hélice bloquée à huit neouds et on comprend mieux la recommandation de ne pas bloquer l’arbre avec l’inverseur !
When first seeing smoke on water, I assumed you were referring to the Canadian forest fires drifting down over Maine. Obviously, not! Once again all your research and training has proved beneficial to get you out of a tight spot. It must be a relief to finally not have to deal with the brake process on your propeller, and now have the feathering down type, which we have on our Vintage freedom 40.
The pics from Arcadia are amazing and especially enjoyed looking down at the busy harbor and Fregata from above.
There’s that kind of smoke too, making for some very red sunsets. Learned a lot but still a lot to learn. As intimidating as technical problems sometimes are, it’s a great learning opportunity and facing into them helps get over the fear of the unknown. I still struggle with certain electrical issues, but mechanical, rigging, and plumbing are coming along.
We loved our Max Prop! 15 years no problems!
Right. Had a Variprop on an old Hunter and it was very good too. I’ll miss the superior performance of the Autoprop, but life is full of compromises.