My prop fell off... f.ck f.ck f.ck.

[hoppy]

I had a hard sail in heavy winds today and got to an anchorage and it was blowing 30+ and even got to 42. First drop resulted in me being too close to another yacht, so I brought up the anchor and move. Second drop was fine and I was happy.

A couple of hours later I dived in to check the anchor set and as I was surfacing in the bubbles I could see something wrong, a bare prop shaft.

F.ck!!!!!!!

I went for a snorkel in the area I was swinging and spotted my flexofold laying in 10m

At the start of the seas I brought my dive gear to the boat and bought a tank, but had not used them. The sun just dropped below the hill, so in a mad rush I set up my gear for the first time in 6 years and jumped in.

I had some floating line and tied it around the prop and after first trying to surface with it, found it better to surface, fill the BCD and pull it up.



I'm not far from Athens and a 5nm sail or 8km taxi ride from the marina I was planning to go to.

I am thinking of fitting the original prop, but I first need a "key". So I might take the dinghy to a nearby hotel and call a taxi to take me to the marina. They have a lot of engineering work so I hope they can supply me with a replacement key. Then I need to dive and fit the prop. It's going to be windy so this wont be an easy job....

[Zanshin]

That is too bad - although you were incredibly lucky to have noticed while still at anchor and not after having weighed anchor and discovered that you had no forward or reverse thrust!

Can you see why the prop fell off from either the shaft or the prop itself?

p.s. you were lucky to find the prop as well - I dropped my dive ladder overboard earlier this year in murky 20 foot deep water and spent many tanks of air diving for my missing ladder before finally finding it!

[vasko]

Hoppy,

you are very VERY lucky ! I had similar experience with fell off prop in a lot worse conditions in the busy Portsmouth channel and inside the PortSolent lock in UK... after this I do not trust engineers anymore and do everything myself! 

btw: you look very close to Lavrion and Olympic marina you should be able to find anything that you may need in both places 

if you cannot find the exact key you sure can find a metal workshop in Lavrion that can cut for you a temporary key from regular steel to get you to better service place - personally I find best boat yard in the area to be on Agina , in Lavrion you can get the boat out and fix the propeller properly , Olympic marina has always been expensive for my taste... 

best strategy for transport - hire a scooter from somewhere close

[vasko]

btw: Lavrion is quite big and very safe harbour (quite noisy overnight) if the wind is light you may be able to get there only on sales and drop anchor in the harbour and find someone to help you there - plenty of charter boats and companies there

[Damir]

Hi Hoppy

I have similar prop but other builder, what i reason for falling of prop that i have in mind for future to avoid this problem.

[hoppy]

I have not had a look at the flexofold to see what happened. It's a bit stressful at the moment and as I am focusing on fitting the old prop, my mental energy is not so interested in the flexofold. I did have a quick look at the shaft last night and it looked fine, so I'm guessing that the pin that secures the nut came loose allowing the nut to loosen. #5 in the diagram



It was lucky I found it, but most of all I was lucky that it fell off after I was securely anchored and that I took the swim.

I will take another swim in a minute just to be 100% sure that the key did fall off the shaft.

I also need to figure out how the prop nut is secured. There is a hole in the end and I just wonder if there should be a screw hole at the end of the shaft?



Theres a hotel nearby and the dinghy is ready to get me to shore. I'll get them to call me a taxi and go to Olympic Marina as that was supposed to be todays destination.



I must say I was happy with the dive. First time I set my gear up in 6 years. I rigged up a line with a carbineer and had it in the water for me to hook the BCD to so I could take it off in the water and climb out. That all worked well.

[Damir]

Hoppy

Thanks and good luck

[vasko]

You have a plan just get cracking that's the important part  ....

the original prop nut is secured by bending the washer 

about why the old prop fell off - most likley as you said the locking screw has come loose or it was touching the nut not at the rounded part but on the hexa part - you need to check when you mount it again and if needed put some washers to adjust - other reason may be the locktight type that has been used (or not used) personally I put locktight on all locking screws + on the shaft nut itself too

[hoppy]

Found a machine shop who will make me a couple of keys incase I drop them. They have my old prop so hopefully it will fit although the groove in the shaft has rounded corners and maybe I'll have to cut them to fit. All I need it to do is to survive minimal motoring, hopefully later today.

[hoppy]

I was given two lengths and one was perfect. I cleaned up the inside of the prop and then used some marine grease just to make sure it slides on. I did a test fitting of the prop without the key. I was going to wait for the wind died down a bit but then decided f.ck it. I decided to do it by snorkel and to simplify things I put the prop on first and tied it on loosely. I then went back down with the key, slid the prop off and then back on once the key was in and tightened up the rope. Then I could get the nut and washer and fit them. While I was waiting in town for the key to be made, I found a hardware store and bought a 32mm spanner for the nut. I have half an old wooden oar handle that is used in the chain locker and used that to hold the prop when tightening.

I did a quick run in forward and reverse and then went back down to check the nut. So far so good.

BTW I took a look at my flexofold and found that it was missing the shaft nut locking screw.


I can be on the move again

[hoppy]

Will probably order a full set of replacement screws from Flexofold and will get them sent to Sweden as I'll be there on the weekend.

Also looking at ordering some spare keys, but I don't get the key sizing... I found them in a store in Stockholm I know, but for a 30mm shaft the size is 8x7x40mm. The 8x7makes sense but the 40mm is a lot shorter than what seems right for my shaft which seem to fit well with the 53.6mm.

www.capella.se/produkter/axlar/propelleraxelkil/

[MalcolmP]

Well done Hoppy. You did a great job getting that sorted so simply, by having all the right gear. Glad you are seaworthy again.

[hoppy]

I have never ever ever ever ever ever ever been so relieved to be tied up in a marina as i am right now

Because it has been so windy and the marina was all the way up wind, even if it was on 5 nm, I decided to wait at anchor for the predicted easing of the winds and headed off a little under an hour before sunset. If I hadn't had the prop issues I perhaps would have motored hugging the coast to get shelter from the chop. But not exactly trusting my installation and having nothing more than the nut holding on the prop (on where for cottle pin but the tip of the nut had thread) so I sailed. I normally never sail with just the headsail, but I did tonight. Tacking up between an island and the mainland in what became pitch black and then arriving at a totally unfamiliar marina solo.

When sailing I put the tranny in reverse which was then really hard to put back into neutral (I wonder what is recommended? Never sailed with the fix prop before). As I approached the marina under sail I was felling a bit nervous about the prop, so I prepared the anchor so it could be dropped and have the remote in my pocket just incase. I started motoring and rolled in the sail at anchoring depth which I knew would be just near the marina.

Conveniently they have put me 50m from the haul out area. I'll be booking a time there for when I'm back with the flexofold parts......

I must admit that in the days leading up to the prop loss a couple of times I heard strange noises when engaging gear. I put it down to ham fisted handling of the throttle.

In the future, I think I will try to make a habit of occasionally checking the prop when I swim


So f.cking relieved....

[vasko]

Good that you are safe in the marina you know now why I do everything related to props tightening myself after two times on a boat when a prop fell off 

btw:) generally the propps should be designed to tighten when on forward e.g the safest way with non trustworthy fixing is to keep the engine on forward and running ... both times i have lost a prop was when reversing... 

use locktite 270 on the 3 locking bolts and on the main nut on the shaft... generally the suggestion is to use the lower grade but I fell safer with 270


www.loctite.co.uk/loctite-4087.htm?nodeid=8802623619073

[Damir]

Fortunately came to the marina. It was a hard school with nerve and physical strength to the limit.

In life you have to have some luck.

[hoppy]

Aug 26, 2015 5:16:46 GMT hoppy said:

I have now heard that with French boats, the cone shaped nut and washer displayed here is the way they like securing props. Something I did not know until now is that to stop it coming loose, I should bend the edge of the washer on to one of the flat surfaces of the nut. If I knew that at the time I fitted the prop, yesterday nighttime sail could have just been a dusk straight line motor

Looking at the washer in the pic, it's obvious as to where it was originally bent over.

[sitara]

Hi Hoppy,
The hole at the end of the nut is threaded and designed to hold a small cone shaped anode at the very end of the prop shaft.
Rob

[Damir]

Yes you are right washer must come in line with security pin, nut tight asnd washer bent over to not lose. But on your flexofold prop you can't put it because i think is diep inside and can't bend maybe is fix with pin thru nut and shaft but eaten by gasvanic el. Problem come if is different materijal there is shaft SS , Prop brons and pin materijal?

[hoppy]

Aug 27, 2015 5:45:08 GMT Damir said:

But on your flexofold prop you can't put it because i think is diep inside and can't bend maybe is fix with pin thru nut and shaft but eaten by gasvanic el. Problem come if is different materijal there is shaft SS , Prop brons and pin materijal?

Yes I realise, the washer is only for the fixed prop.

There must not be an issue with bronze and SS as the shaft is SS and the props are bronze

[sailbleu]

Aug 27, 2015 6:39:43 GMT hoppy said:

Aug 27, 2015 5:45:08 GMT Damir said:

But on your flexofold prop you can't put it because i think is diep inside and can't bend maybe is fix with pin thru nut and shaft but eaten by gasvanic el. Problem come if is different materijal there is shaft SS , Prop brons and pin materijal?

Yes I realise, the washer is only for the fixed prop.

There must not be an issue with bronze and SS as the shaft is SS and the props are bronze

There is , that's why we use zincs on the shaft's end and/or around it .

Regards

[hoppy]

The flexofold is now cleaned and disassembled and as it seems complete. The shaft nut retainer screw was still in there, but deep so I could not see it earlier. I disassembled without touching the screw and found that it only just came out the hole where the nut is.

One thing I noticed is that the shaft was only half way through the nut based on the barnacle growth inside. I will be interested to see how it looks when I refit it.

I did see signs of loctite red on 3 screws but nothing on any other. The locking screw was easy to turn so maybe there was no loctite on it?

[vasko]

me personally I put locktite 270 the green one on No.8 ( 3 of them) No.5 and No.4 on you schematics


for your exact problem my guess is that the locking screw has not locked the rounded part of the shaft nut but  has been on the part where you wrench goes - on the latest models folding propellers (from Volvo and Elice at least) the locking nut is now longer and imbus type to prevent exactly this problem and outside it is rounded on its full length   

[rc sail]

Hoppy,
thanks for sharing your adventures. Good lessons to be prepared with
dive/snorkel gear and spares when cruising. Hope all continues with
favorable repair and relaunch.
Wonder if possible to engineer additional lock tab, washer, or
some sort of lock key for the #4 shaft nut. Such to provide
additional mental security of a lost prop.
kind regards

[rene460]

Hi hoppy,

You did well to retrieve your prop and get to a port suitable for arranging repairs.

Your comment that the nut may have been only half on is telling.  I would expect that the nut would be fully on the shaft and the locking screw would make a deep circular mark where it sets against the outside of the cylindrical portion of the nut.  The end of these grub screws is usually a cup shape that digs in deep when it is properly set.  Is it possible that instead, your set screw was inserted before the nut, and the back of the nut screwed up against the screw?  In this case I would expect there might be marks on the back of the nut.  If so, this would be a more than adequate explanation for the prop falling off.  The only surprise would be that it lasted so long.

At least if there is adequate evidence of why it fell off, when you have properly reinstalled it with the right torque to set the nut, the right location on all the screws and the anode reattached with its screw in the end of the shaft, you will be able to sail on in confidence that it will stay where it belongs.

The manufacturer should be able to advise you on the proper torque for the nut, and I suggest that you beg borrow or buy a torque wrench for the purpose.

We all look forward to the day when you have it all fixed and can sail on.  Thank you for writing about it in such detail.

rene460

[hoppy]

After a couple of stressful days, ive had a chance to chill out for a couple of nights in a 5 star hotel in Stockholm, so now the adventures seem a distant memory

I have a haul out booked for Wednesday morning. I will be certainly very interested to see if the prop nut goes fully unto the shaft. I would be shocked if the nut does not go fully on leaving space for growth inside. I do think it may have been loose for perhaps a few weeks.

I will plan in the future to occasionally inspect the prop. I suspect that if the nut gets loose enough I should be able to feel the play if I inspect it after giving a blast in reverse to set the anchor. In the event that it does get loose again, at least now I know what it will take to remove the blades so that I can tighten the nut.

Tomorrow I should receive the spare screws and nut from Flexofold and will buy several spare keys. Need to track down some loctite 248