Going to be windy - safe to disconnect lowers for chainplate repairs?

[Refueler]

WOW ....

I've read some posts - but this thread just about does it !!

Put simply : If the weather / wind etc is OK for the guys to work on the chainplates - then it would be reasonable to assume that the weather / wind is not hurricane force....

If a mast cannot survive main stays and shrouds (as I mentioned before - relieve any bending moment from backstays that may be ... ) - then it must be a pretty weak mast. Basically use the mains set at a reasonable tension to keep mast upright - which may mean slacking each a touch.

If I read some above correctly - and followed their posts - I would never raise or lower a mast again !! Only on taller masts (over 8m or so) have I used mid height and masthead lines for raising / lowering ... to carry weight and prevent mast flexing.
Many times I have helped others as well as on my own boat - released lowers for servicing turnbuckles, fittings .. replaced stays etc etc.

 

[lonederanger]

It would be good if refueler could keep his opinions to himself as I do not believe they are in anyway beneficial to the webcrafts post. Talking from experience of removing ones lowers to have them measured on a 40ft large selden sectioned mast. Having secured lines round the spreaders and back to the toe rail (steel hulled boat) I thought i would be good for a couple of days. The wind picked up one night, and not a hurricane, the amount of flex in the centre section of the mast was quite horrific as well as the noise it makes. I spent the rest of the night adding dynema lines and trying to tension them adequately to stop the flex. Webcraft is quite right to ask the question. It was something that I did not overly think of, I was more worried about sourcing a new set of lowers in a foreign country before I embarked on a thousand mile ocean passage to Bermuda. It shows webcraft is actively thinking of problems ahead and trying to mitigate them, a true sailor

 

[Refueler]

Can't be ''serious'' on forum, I just suggest you check figures by yourself: compute the bending moment at the spreaders with a. only the lowers (the upper part of mast self standing), then b. only the upper shrouds bearing the whole mast load= spreaders compression load without lowers. Same mast section, uniform load, etc, which mast collapses first?
Then of course do whatever you like

We are talking about a guy releasing his lowers to work on the chainplates. We are not talking about loading up the mast such as under sail or such.

What happens when you release lowers to lower your mast ? Does your mast collapse ?

 

[Refueler]

It would be good if refueler could keep his opinions to himself as I do not believe they are in anyway beneficial to the webcrafts post. Talking from experience of removing ones lowers to have them measured on a 40ft large selden sectioned mast. Having secured lines round the spreaders and back to the toe rail (steel hulled boat) I thought i would be good for a couple of days. The wind picked up one night, and not a hurricane, the amount of flex in the centre section of the mast was quite horrific as well as the noise it makes. I spent the rest of the night adding dynema lines and trying to tension them adequately to stop the flex. Webcraft is quite right to ask the question. It was something that I did not overly think of, I was more worried about sourcing a new set of lowers in a foreign country before I embarked on a thousand mile ocean passage to Bermuda. It shows webcraft is actively thinking of problems ahead and trying to mitigate them, a true sailor

My 'opinions' .... ?? My posts here are based on not only personal experience - but also many hours assisting in boat yards as well as having had a successful Yacht Survey business in the UK.

I would suggest that your mast flexing may have been due to your not adjusting the main stays / shrouds to only maintain mast vertical ... if you still had 'rig tension' on fore and backstays - then of course you will see mast flexing in strong winds ...

I too applaud Webcraft for asking ... in fact if I was anywhere near his location - I would be more than happy to assist him in the work FOC ... without fuss or palaver.

 

[Chiara’s slave]

We are talking about a guy releasing his lowers to work on the chainplates. We are not talking about loading up the mast such as under sail or such.

What happens when you release lowers to lower your mast ? Does your mast collapse ?

Madness, innit. We can raise and lower our mast ourselves using the boom as a lever. It does’t break. The loads on the mast without sails ate trivial compared to those that every mast has to endure whilst sailing. Masts gail if a lower fails with pressure in the sails, of course. But never, without sails unless something totally extraordinary happens.

 

[Refueler]

Madness, innit. We can raise and lower our mast ourselves using the boom as a lever. It does’t break. The loads on the mast without sails ate trivial compared to those that every mast has to endure whilst sailing. Masts gail if a lower fails with pressure in the sails, of course. But never, without sails unless something totally extraordinary happens.

One time lowering my mast (9m length) - the mast foot snapped due to it being frozen ... and mast fell onto the pushpit aft ... the part of mast that hit was just about spreader location.

Mastfoot snapped when mast was about 30 deg from horizontal ... so it was a hard hit onto the rail ... I expected to see a crease or evidence of a bend ... NOTHING.

I forgot to check the foot as it was completely frozen to the blade mount. Luckily I have a pal who owns a specilaist Metals Fabrication business - he put his guy onto cleaning up and welding / grinding the foot ...

 

[Chiara’s slave]

It is true that if there is a lot of tension on the caps, the mast might go out of column. But as it does this, the tension will lessen in the caps, until the forces balance. This might be a few cm. The mast will still be standing, just a slight curve.

 

[Muddy32]

I prefer to put my trust in the Mast manufacturer who designed the section.
Look at Selden's range and trust them. Borne out by more than a few year's experience.

 

[Refueler]

I prefer to put my trust in the Mast manufacturer who designed the section.
Look at Selden's range and trust them. Borne out by more than a few year's experience.

Of course ... but posts above are taking mast construction form to a level that is uncalled for in the job asked about here.

 

[Refueler]

It is true that if there is a lot of tension on the caps, the mast might go out of column. But as it does this, the tension will lessen in the caps, until the forces balance. This might be a few cm. The mast will still be standing, just a slight curve.

In each yard I did jobs in - when involving masts - ALL stays / shrouds were adjusted reducing the tension applied for sailing. This then meant the stays etc were maintaining the mast upright without stressing or bending ...
We could then remove any one or two stays / shrouds keeping in mind 'balance' of remaining to keep mast up.

No need for fancy science ... just straight common sense.

I've even seen experienced riggers step a keel stepped mast and not connect stays / shrouds for a period while working on them. Not something I would do - but worth noting.

 

[alahol2]

WOW ....

I've read some posts - but this thread just about does it !!
...
Basically use the mains set at a reasonable tension to keep mast upright - which may mean slacking each a touch.
...

That's precisely what I said in my original post.

 

[alahol2]

So the function of the lowers is to stop the other stays/shrouds from pulling the mast down?

Seems unlikely, but I may have misunderstood you?

— W

The function of the lowers, amongst other things, is to prevent the middle of the mast going too far out of column.
ie to prevent it bending too much.

 

[Chiara’s slave]

That's precisely what I said in my original post.

The consequences of not slackening them might be as bad as a slight curve in the mast, til the lowers are put back on. I guess the lowers would be easier to reconnect if you slack off.
The lowers certainly do prevent the mast going too far out of column. When sailing. It just won’t go too far out when not sailing. OK, maybe some extreme racing rigs might need a more cautious approach, but Webcraft’s boat is not one of those. It’ll be over engineered by about 100%, as befits a cruiser set up first and foremost to arrive at it’s destination. Not death or glory arrive there first.

 

[Refueler]

The function of the lowers, amongst other things, is to prevent the middle of the mast going too far out of column.
ie to prevent it bending too much.

Plus you use them to control the amount of bend not only longitudinally - but prevent transverse as well .. that backstays are producing along with rake.

 

[Refueler]

That's precisely what I said in my original post.

Don't think I was getting at you ...

 

[webcraft]

So - I will slacken the caps a tad. Remember, I will be using the bottlescrews to attach the lowers to the toerail, they will still be under reasoable tension.

Thanks everyone, as so often here a simple yes or no was all that was looked for, but I have certainly learned a good bit in the meantime.

- W

 

[Chiara’s slave]

So - I will slacken the caps a tad. Remember, I will be using the bottlescrews to attach the lowers to the toerail, they will still be under reasoable tension.

Thanks everyone, as so often here a simple yes or no was all that was looked for, but I have certainly learned a good bit in the meantime.

- W

There’ll be a lot less drama than this thread Hope the work goes well. You can relax about your mast.

 

[Refueler]

So - I will slacken the caps a tad. Remember, I will be using the bottlescrews to attach the lowers to the toerail, they will still be under reasoable tension.

Thanks everyone, as so often here a simple yes or no was all that was looked for, but I have certainly learned a good bit in the meantime.

- W

Good luck and look fwd to hearing all completed ..

Caps should be OK - its forestay and backstays that should be adjusted to make sure they are not 'bending' the mast ...