How heavy is a mast, stepping by hand - how hard can it be..

[GHA]

Carrying on with the never ending refit......
Leaks under the mast and nasty rust, can't have that now can we

So over a dust buster beer the next cunning plan in the quest for no holes anywhere is more plate with studs welded to the deck which the mast foot will attach to, but why not go further!
What about 2 plates hinged then if there's ever a need to drop the mast it can be done easy enough.

Means dropping the mast first to get at the deck, looks like there shouldn't be any major hoops to jump through, load of dyneema onboard to make up tiebacks & guys plus day job used to be lifting things an awful lot heavier so what could possibly go wrong...

Very vague plan - use whisker pole as compression member either attached to bottom of track on mast or maybe weld a bracket onto the deck.
Use windlass as a hoist, maybe double reeved to keep the speed down.
Looks like it will hit the boom gallows first so maybe a temp something above the radar arch or on the mast so both touch together. With a laser & CAD this can be plenty accurate.
Very rough sketch just to get started below.

So the questions:

How heavy is a 12m single spreader mast? Guessing somewhere between 80Kg & 120Kg but instinctively prob less, best to guess high.

For those who have done it - was there a "Ohh, didn't think of that" bite on the bum moment? Or tips for an easy and happy mast lower experience?

Big TIA as always

 

[Yellow Ballad]

I would guess my beefy 70's 12m mast is around 250kg but thats just a guess I struggle to lift it a few inches off the stands when it's down. I have helped move a similar mast at the club and there was 7-8 of us.

I would not consider trying to raise or lower anything this size without a crane.

 

[Hoolie]

Our mast is a bit bigger at 14.5m and weighs maybe 350kg with the rigging. It takes a crane + three people to manhandle it ... ...

 

[Thistle]

See http://www.seldenmast.com/en/products/masts/aluminium_mast_sections.html for some examples.

 

[Tranona]

Far too big and heavy to drop and lift hinged on the mast step. my eventide mast is around 10m and needs two to lift comfortably and is just on the limit of DIY. The danger point is where it gets past the point of balance and wants to come crashing down. With your size mast it will do that when the point at which you can "catch it" is behind the stern of the boat so you need a high structure to stand on to ease it down. The other thing is any wind could set up sideways movement which can quickly get out of control.

 

[PetiteFleur]

My mast, 12.4 metres long, can just about be moved with two people, moving gently on trestles and rotating. The yard crane lifted it down and onto the trestles for fitting new rigging this spring. 1979 Moody 33.
Previous boats, a Vivacity 20 and Halcyon 23 could be raised and lowered using your method.

 

[steveeasy]

Used to raise and lower a 10 mtr mast on a smaller boat. Allways thought it was bordering on too much weight. 12 meter mast is way too heavy. What is going to stop the base of the mast moving forward. Anyone helping will be in danger as well. Seriously forget it before you regret it.

Steveeasy

 

[prv]

One issue is if any sideways force develops, for example from the boat not being level, it will put a powerful twist on the foot arrangements. Setting up temporary shrouds such that their geometry will work all the way down is not easy.

The actual shrouds getting caught on stuff on the way up can be a problem - you really need a person dedicated to watching the loose rigging and ensuring it all moves freely. Even then they can miss things; we bent a bottle screw this way.

I think there was only one year that we didn’t forget something like the burgee halyard and have to bring the mast back down to fit it

Don’t underestimate the manhandling needed to get the mast from its fully lowered position (on the radar arch in your case) but still secured at the foot, to the actual stowage configuration.

We were only lifting the masts on a 24 footer; bigger is still possible with the right gear but it’s a serious undertaking.

Pete

 

[Yellow Ballad]

Here's a vega mast being dropped on a hinge for reference, guessing it'll be about 8m (?)

https://youtu.be/4s1aS6T0Rs0

 

[LadyInBed]

Having done it several times on a 22 footer, the problems I had were
Keeping mast on the center line as it was lowered
Keeping the forward fulcrum spar on the center line as the mast was lowered - an A frame works better
Stopping stays snagging
Getting a pivot point far enough back so that the bottom of the mast doesn't head skyward
Not to mention trying to control the weight of the mast

 

[earlybird]

I'd say your task is do-able with great care and preparation. As said, an A-frame is a better, more stable alternative to a whisker-pole, angle iron hinged at the chain-plates.
Fraught moments can occur when the mast has lost all sideways support from the shrouds, when it can start to sway alarmingly from side to side. Helpers with steadying ropes to the mast-head are useful. Also plenty of help for the man-handling when it is near/at horizontal. A strong and reliable winching set-up is also a must for that size of mast.
Should point out that this type of operation is much more secure if the boat is not afloat or, at very least, firmly between 2 pontoons. I wouldn't try on a mast of this size if that wasn't the case.

 

[PabloPicasso]

Hmmmm. Lots to go wrong with this, bending breaking stuff like the mast, and injuring people helping. Not good. Another way to lift a mast is between two other (preferably bigger) boats. Use their main halyards to make a bridle. Probably need six to eight willing and obedient blokes with clear leadership. But very doable. Charter companies do this a lot, having the means (spare boats), the motivation, to save money on craning, and crew around to help.

 

[steveeasy]

I'd say your task is do-able with great care and preparation. As said, an A-frame is a better, more stable alternative to a whisker-pole, angle iron hinged at the chain-plates.
Fraught moments can occur when the mast has lost all sideways support from the shrouds, when it can start to sway alarmingly from side to side. Helpers with steadying ropes to the mast-head are useful. Also plenty of help for the man-handling when it is near/at horizontal. A strong and reliable winching set-up is also a must for that size of mast.

Fraught moments!. If the op has done this before with a smaller mast, hed appreciate how mad and dangerous the plan is. If he has not done it before, he should not even consider for a moment trying it with such a large mast. when it starts to go wrong there will be no fraught moments, it could easily kill someone in the blink of an eye.

Steveeasy

 

[William_H]

OP is not clear on the style of mast base existing. It is essential that this is suitable for tilt down. If not he will need a crane to lift mast up then lay it down. (on the cabin top). If the base is suitable then it may be doable. If the boat is on dry land then perhaps easier. You need a crutch as far aft as possible. Beware if this is closer to the base than balance point then there will be a huge lifting force at the base. Once mast is down to the crutch it can still be difficult to work on the mast or as you indicate work on or under the base.
As said sideways control of the mast as it traverses down is vital. The hinge can easily be wrecked by any side swing.
Yes it can be done. I and others have posted a lot of detail on this forum. However mainly for smaller masts. Certainly many much larger boats around here that lower there mast in this way while under way. (for getting under bridges) However they do it with a lot of experience and even then things go wrong. Usually in the sideways wing of the mast when a mobo goes past. So best get a crane once off and once back on. ol'will

 

[prv]

OP is not clear on the style of mast base existing.

I believe he's planning to replace the existing one with a new one, made with lifting and lowering in mind.

Pete

 

[AndrewB]

The mast tabernacle and a rigid A frame is the conventional method. In the past this was used with quite heavy masts, e.g. on the Norfolk Broads. The A frame's feet are bolted to the toerail either side of the mast and point is as far forward as possible, controlled from the anchor windlass.

Many years ago I used a bridge to lower the mast on a 26' yacht without an A frame (on the Rance near Dinan).

 

[bluerm166]

Whereas with such a long,possibly older mast ( as previously said 70's masts might be 50 % heavier than those with modern thin wall sections) it is probably undesirable to attempt the lift without a crane, for those with shorter masts considering pulley assisted methods and concerned about lateral stability I re-offer my previous post showing a simple control method. This provides temporary stays that don't require an anchor point in line with the mast pivot ,gives the co-ordination that 'two strong men' might lack,and allow the operation to be stopped and held at any point.
http://youtu.be/4yrOQkVaFKA

 

[Flica]

I would guess my beefy 70's 12m mast is around 250kg but thats just a guess I struggle to lift it a few inches off the stands when it's down. I have helped move a similar mast at the club and there was 7-8 of us.

I would not consider trying to raise or lower anything this size without a crane.

My mast is a 2 panel rig, of 13.68m, it's possible to manhandle it alone, but not raise or lower it - I guess about 280kg.
As it has to thread through the deck to locate on the keel raising or lowering by hand is just not feasible.

 

[GHA]

OP is not clear on the style of mast base existing.

Well done, first person to actually focus on where all the opposing forces meet.
And which might well scupper the whole idea, looks like it could be a bit complex to sort.

Just pivoting on the base would very likely go bang as it broke with all the force concentrated at the leading edge but doesn't matter as the mast heel plug looks like it just sits in the base anyway. Looks like it could be a show stopper, which is a pity - a lot of the idea was to be completely self sufficient in the future when somewhere without a crane.

 

[GHA]

Whereas with such a long,possibly older mast ( as previously said 70's masts might be 50 % heavier than those with modern thin wall sections) it is probably undesirable to attempt the lift without a crane, for those with shorter masts considering pulley assisted methods and concerned about lateral stability I re-offer my previous post showing a simple control method. This provides temporary stays that don't require an anchor point in line with the mast pivot ,gives the co-ordination that 'two strong men' might lack,and allow the operation to be stopped and held at any point.
http://youtu.be/4yrOQkVaFKA

Ta. Lots people getting freaked out about lateral movement, it's not really rocket science. With some guys near to top to to an anchor point each side at the same height as the pivot then it's not a problem. Though dyneema is wonderful in so many ways the non stretch can be a hindrance, you need to be very accurate with the height of the anchor points.

I've actually done dozens of these, next big outdoor event you're at have a look at the PA delay masts dotted around, they're raised/lowered in exactly the same way using the chainhoist which lifts the PA round a short A-frame compression member. Usually 10m - 15m & a fair weight with a big headblock up top. Simple operation but they have the benefit of a big hinged fulcrum at the base.

Thames barges have been at it for donkeys
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