Ok to go up mast whilst in cradle ?

NigelFortune

New member
Joined
12 Feb 2008
Messages
71
Location
North Wales
Visit site
Lost main genny halyard this afternoon at top of mast. Was measuring length of forestay to fit Plastimo furling. Had a cord tied to the a small shackle round the forestay which was shackled to the halyard. Pulled the halyard to take shackle and cord to the top of the forestay so could measure length of cord down to furling drum. Halyard jammed at top, no up or down movement at all. Then cord broke!!. Think top pulley twisted and jammed with other 2 halyards. Have had No.1 son up mast in past but boat was in water at time. Is it ok to go up the mast when in the cradle ? Usual safety precautions still have main halyard and one other that works amd using ascender and climbing harness. Boat is Sigma 33C. Any ideas gratefully received.
Nigel
 

Norman_E

Well-known member
Joined
15 Mar 2005
Messages
24,609
Location
East Sussex.
Visit site
Very much frowned upon in our marina in Turkey. Advice is always to wait until the boat is in the water. Nobody has actually explained to me why it is considered so much more dangerous that the professional riggers won't do it.
 

Leighb

Well-known member
Joined
8 Aug 2007
Messages
6,785
Location
Suffolk
Visit site
I have certainly seen professional riggers up a mast on a boat ashore in this locality.

It might depend on the size of the boat and support given by the cradle I guess?
 

Dipper

Well-known member
Joined
30 May 2001
Messages
5,061
Location
Dorset
Visit site
People do it all the time in our club. As long as the cradle holds the boat securely you will be fine. If you are worried, put a few extras props under the hull.
 

VicS

Well-known member
Joined
13 Jul 2002
Messages
48,334
Visit site
If the boat is ashore in boat yard or marina they may not permit it.

In a club compound it would be wise to check with the club.
 

srm

Well-known member
Joined
16 May 2004
Messages
2,924
Location
Azores, Terceira.
Visit site
I replaced all the standing rigging with the mast up and in the cradle at a yard in Plymouth, 2009. Pro riggers were also up and down masts while I was there.
35 ft yacht displacing about 9 tons, double spreader cutter rig so a lot of wires to remove and replace, but also plenty of support even with some wires removed.
Didn't think to ask for permission as had seen riggers up the mast on another boat and no comments from the yard staff except one of the lads who jokingly said he couldn't watch when he first saw me up there!
 

Lakesailor

New member
Joined
15 Feb 2005
Messages
35,237
Location
Near Here
Visit site
When a boat is in a cradle the ballast has a very damping effect on movement.
I have experience of a fin keel 18ft boat losing support on it's road trailer when an arm broke away (don't ask, not my trailer).
Although the boat was laid over at nearly 20° two of us easily pushed it back to the vertical whilst a third guy replaced the arm.
Whilst the boat is vertical it will take quite a bit of force to move it past the point of stability.
Dangling from the mast isn't going to do that.
As long as the cradle is stable it should be quite secure.

If you are dubious rig a couple of stays using halyards or simply lines to fixed points (could be simply a vehicle) either side.
 
Last edited:

Scotty_Tradewind

Active member
Joined
31 Oct 2005
Messages
4,651
Location
Me: South Oxfordshire. Boat, Galicia NW Spain
Visit site
In my yard it's frowned upon although I have mast steps and I'm sorely tempted to go up and check things out whilst ashore..
In a cradle you will poss' find that it will move a little and be more forgiving than shores/props with wedges and the whole thing will move a little.
I agree with Lakesailer that a couple of halyards taken off sideways to something really immoveable would give you better security and very similar to holding the boat against a wall when drying out. With a couple of shores each side it would be safer still.
 

Strathglass

New member
Joined
16 May 2001
Messages
2,197
Location
Fife
Visit site
Quite possible with a good cradle but not very safe with props.

I will be going up shortly to replace some running rigging.

This was replacing the cups on a well known wind speed fitting.

Anstrutherchrisextentionets034.jpg


The mast is quite vertical the camera isn't.

I am at the foot of the mast on this occasion although I have been up it.

I now use a bosuns chair with a pulley system plus a seperate harness for safety.

I used to use a get up quick mast ladder when I was younger but my legs no longer have the strength to get up easily or to stay up for very long. I find the bosuns chair much more comfortable and easier to use (with some help)
 
Last edited:

savageseadog

Well-known member
Joined
19 Jun 2005
Messages
23,300
Visit site
If the cradle or shoring is good then not a problem. A yacht onshore has to, or should withstand storm force winds which will exert forces far in excess of what a man aloft will.
As with all these things if you aren't happy doing it then don't. I recently went up a 60ft mast in a yard.
 
Last edited:

ghostlymoron

Well-known member
Joined
9 Apr 2005
Messages
9,889
Location
Shropshire
Visit site
There's technically no reason why the boat will be more unstable with a man aloft unless he is wildly swinging from a halyard which would put some sideways force on. If you were to climb vertically (as you are bound to do) your weight will always be transmitted down through the mast and hence to the deck. Theoretically the boat would be more stable that way than if you were to stand by the rail.
 

mattnj

Well-known member
Joined
26 Jul 2007
Messages
1,351
www.red-data.co.uk
you need to find a small child to go up there, my 10year is super handy, pops up the mast all the time, easy to winch up and much less stress on everything.
 

Scotty_Tradewind

Active member
Joined
31 Oct 2005
Messages
4,651
Location
Me: South Oxfordshire. Boat, Galicia NW Spain
Visit site
If you are only doing it once I wouldn't check with the yard or club.
It's not much good them telling you off after the event.

It could be that you'r contravening something in the yard or marina rules or even your insurance policy.

If you put 12stone at the top of a 30+ft mast you would be surprised at the 'turning force' that horizontal movement imparts on the boat down below.

You will find that some riggers are not covered by their insurance to go up a mast ashore... Paul Cochrane (XW Rigging Haslar marina, Gosport) confirms that he is not.

You can imagine what a 'pack of cards collapse' one boat in a yard may cause.
 
Last edited:

prv

Well-known member
Joined
29 Nov 2009
Messages
37,361
Location
Southampton
Visit site
If you put 12stone at the top of a 30+ft mast you would be surprised at the 'turning force' that that imparts on the boat down below.

...exactly the same as it does if you hang from the halyard with your feet an inch off the deck.

Certainly if the boat is already leaning over then you have quite a turning moment (again, whether you're at the masthead or hanging an inch above the tarmac is immaterial) so it depends how solidly the boat is supported and hence how likely it is to acquire that initial lean.

Pete
 

Scotty_Tradewind

Active member
Joined
31 Oct 2005
Messages
4,651
Location
Me: South Oxfordshire. Boat, Galicia NW Spain
Visit site
...exactly the same as it does if you hang from the halyard with your feet an inch off the deck.

Certainly if the boat is already leaning over then you have quite a turning moment (again, whether you're at the masthead or hanging an inch above the tarmac is immaterial) so it depends how solidly the boat is supported and hence how likely it is to acquire that initial lean.

Pete
Only if the force(weight of person) is acting vertically.
Imagine the mast as a lever.
If the force is applied horizontally (weight of a person shaking from side to side at the top)then that force is multiplied by the length of the mast.
Similarly the righting curve of a boat can be drastically altered by sticking a gantry with solar panels, a wind generator and a radar on top of it. In fact a coded boat has to be re coded if such things are added to make sure it is safe.
 
Last edited:

prv

Well-known member
Joined
29 Nov 2009
Messages
37,361
Location
Southampton
Visit site
Only if the force(weight of person) is acting vertically.

Statically, it can't do anything other than act vertically downwards due to gravity. Unless you give your masthead man a long pole, or a rope tied to a nearby lamp-post, to push or pull on.

You are right that he can apply some dynamic forces by throwing his weight (ok, mass :) ) around, and I neglected to consider that. The answer to which, I guess, is "don't do that then" :).

Similarly the righting curve of a boat can be drastically altered by sticking a gantry with solar panels, a wind generator and a radar on top of it

Indeed - and a man at the masthead will have even more effect. But for both man and gantry, a turning moment is only applied once the boat is already heeling. Important for the gantry, but most people (hardcore racers excepted) don't pull people up the mast whilst dipping the lee rail under.

Pete
 

Scotty_Tradewind

Active member
Joined
31 Oct 2005
Messages
4,651
Location
Me: South Oxfordshire. Boat, Galicia NW Spain
Visit site
Statically, it can't do anything other than act vertically downwards due to gravity. Unless you give your masthead man a long pole, or a rope tied to a nearby lamp-post, to push or pull on.

You are right that he can apply some dynamic forces by throwing his weight (ok, mass :) ) around, and I neglected to consider that. The answer to which, I guess, is "don't do that then" :).



Indeed - and a man at the masthead will have even more effect. But for both man and gantry, a turning moment is only applied once the boat is already heeling. Important for the gantry, but most people (hardcore racers excepted) don't pull people up the mast whilst dipping the lee rail under.

Pete

Makes me wonder sometimes how many people have been up the top of their mast to experience those 'dynamic forces'. They are very easy to impart and some lightweight boats with nothing but a bolt on lolly-pop, do respond very well even if they're in the water. :)
 

Lakesailor

New member
Joined
15 Feb 2005
Messages
35,237
Location
Near Here
Visit site
I'd give up on this one. I've described how easy a boat is to move around the vertical axis, even without any propping. That means it is in balance. The weight of the ballast is not lending anything to the boat's propensity to fall over.
I've been up the mast of a 19 foot boat on the water and there is very little turning moment. I had a mate ready to apply his weight to the side decks to counteract any heeling, but there was none.
To get the boat moving and overcome the strength and stability of the cradle you'll need the mast top man to get his weight outside of the cradle base (ie: the mast tip well over). Even then he will be trying to lift the ballasted keel to get the cradle to tip over.
It's just not going to happen.


Perhaps it's another test for the YBM Crash Test Boat
 
Top