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

[Praxinoscope]

We have been succesfully dropping th mast on my previous boat, Invicta26 which has a 10m mast each winter for the last 10 years using an A frame purchased from the now defunct Compass Marine, which had a SWL of 120kg.
I never weighed the mast but my guess is that is was getting close to the SWL.
My new boat has roughly the same mast, but have decided not to use the A frame for this mast as for some reason it ‘feels’ heavier.
Obviously if in a boatyard the boatyard crane is an obvious answer, but we also use a couple of other options as we are not in a yard and getting a crane in is ‘b****y’ expensive, one is our local boat transporter guy who uses a ‘Hi-Ab’ on his artic’ tractor, or a our local JCB guy with his lifting gear. Both know what they are doing and only a fraction of the cost of a crane, £60 for dropping or raising a mast.

 

[zoidberg]

I won't gainsay any of the above sound guidance. However, having lowered a similar mast ( afloat alongside ) in Dover Marina - saving £120 + vat , while the yardies ran a book on me dropping it - I used a pair of 16' alloy sailboat masts as sheer legs, with a proper 'sheer lashing' at the top ( used for many hundreds of years for masts ) and the heels inserted into 'shoes' of old rubber exhaust hose, against the toe rails and well roped laterally to prevent movement. As shown above, that's one way it was done worldwide, for centuries.

The 'apex' rested initially on the pulpit frame, with a stout halyard through a sheave-block secured to the stemhead and back to shorewide cleat, for surging.
The mast base was similarly roped left and right, fore and aft, to prevent 'going walkabout'.
Assistants to left and right held halyards secured to the masthead, preventing sideways leans and twists.
A temporary wooden A-frame gantry secured to the pushpit received the mast, temporarily, before the struggle began to lift the thing forward, for balanced stowage.

That worked.

 

[lw395]

I've done this with small boats.
It is fraught.
I won't get involved unless there's enough of the right people around. You need people to tend each shroud, backstay, forestay etc.
The beer bill soon racks up towards the cost of a HIAB on the quay at LW.

As drawn, the compression forces the gin pole is putting on the mast are not small when the mast is at a low angle.

 

[steveeasy]

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.

Hi,
Please read post 7.

What is going to stop the base of the mast moving forward. Don't think anyone is freaking out actually. More people think it doable than not. your plan for the future is a good one with a mast step designed to allow the mast to pivot. Gin pole needs to be strong enough not to buckle or move sideways. the forces on this part are immense. your windlass could be ripped from the deck with the weight pulling directly upwards.

However without a suitable mast step to allow the mast to pivot, the potential outcome could be horrendous. all the forces on the gin pole will transfer through the mast and either destroy your deck or propel itself forward in to the person at the windlass and or at the same time coming down on the idiots who have chosen to catch your mast as it falls at great speed.

In a well designed system the whole thing can be done single handed easily and is probably safer than with people running around with arms in the air to catch a mast weighing 250 kg.

Steveeasy

 

[Praxinoscope]

I've done this with small boats.
It is fraught.
I won't get involved unless there's enough of the right people around. You need people to tend each shroud, backstay, forestay etc.
The beer bill soon racks up towards the cost of a HIAB on the quay at LW.

As drawn, the compression forces the gin pole is putting on the mast are not small when the mast is at a low angle.

If there isn’t a furling genoa tackle then the job is fairly straight forward with an A frame, I have dropped my 10 m mast successfully single handed several times, but raising it is certainly a lot easier with at least one other as you need to line the base of the mast up with the mast step. The shrouds, forward and backstay tend to look after themselves.
If fitted with furling genoa kit then additional help is certainly needed to avoid damaging it, both when dropping and raising the mast.

 

[GHA]

Hi,
Please read post 7.

What is going to stop the base of the mast moving forward. Don't think anyone is freaking out actually. More people think it doable than not. your plan for the future is a good one with a mast step designed to allow the mast to pivot. Gin pole needs to be strong enough not to buckle or move sideways. the forces on this part are immense. your windlass could be ripped from the deck with the weight pulling directly upwards.

However without a suitable mast step to allow the mast to pivot, the potential outcome could be horrendous. all the forces on the gin pole will transfer through the mast and either destroy your deck or propel itself forward in to the person at the windlass and or at the same time coming down on the idiots who have chosen to catch your mast as it falls at great speed.

In a well designed system the whole thing can be done single handed easily and is probably safer than with people running around with arms in the air to catch a mast weighing 250 kg.

Steveeasy

From post 1 -

load of dyneema onboard to make up tiebacks & guys

Tiebacks & guys aren't a problem, trivial mechanically but a bit time consuming though dyneema is quick & easy to splice.

Archimedes had it - "Give me a place to stand and with a lever I will move the whole world.". Levers aren't a problem, quadruple reeve the windlass with a shunt back up and the force there won't be horrific, some rough vector sketches assuming a 200Kg mast coming out at about 450Kg which feels about right so basically a big fat bloke off the windlass with a max of 1250Kg & WLL of 170Kgf.

Somewhere to stand is the tricky one, getting a decent fulcrum, stopping unwanted lateral movement isn't really all that hard.

 

[oldharry]

Its a job I have done many times on boats up to 30ft, so its perfectly doable IF you know what you are doing and have done it regularly before. If you havent done it before, then my advice would be dont try 1st time with such a big heavy spar. There is so much to go wrong, and huge consequences including killing someone, destroying the mast, serious damage to the boat or its fittings etc. Once the mast is off vertical and the stays released, it is about as safe and as destructive as a tree falling down if anything fails. You MUST know how to control it properly. Guessing just isnt safe enough because like the sea, it will have tricks up its sleeve.

Firstly as has already been pointed out: what is to secure the base of the mast for it to hinge on? On traditional working boats and many smaller modern ones they used a tabernacle which kept the foot of the mast under complete control. There is no real substitute. Some spars have a hinge pin arrangement, but unless the spar is perfectly in line all the way down, this will (and frequently has!) twisted, and broken, allowing the mast to drop suddenly, totally out of control.

If you can invent and construct some means of holding the foot of the mast safely, then its safe to try the rest as above. But if it fails, you lose your mast, damage your boat, dent your pride, and if someone is standing in the wrong place,.....

The next issue from your diagram, is that you do not have space for it to come down backwards. If it fouls the radar arch in your diagram, it will destroy it. If it survives, you will have great difficulty manouvering the mast down from there. The problem is that until its down you do not know where the balance point is. If you cannot support it at or beyond the balance point, then as soon as you release the foot, it will kick up on release, which is dnagerous, then fall off over the back of the boat.

Possible solution:: if you are inventing a mast foot hinge for the job, consider taking it down FORWARD. If you have a jib roller spar, this makes it a lot more difficult, and you will need at least one hand whose sole job it is to guide that down safely. Not a bad thing anyway even dropping it aft to have someone to look after it.

Whichever way, use a jib halyard with a rope at least as long again out forward of the boat to control the rate of descent. Once it gets below around 35 -40degrees the angle becomes too acute, and the deck crew need to start taking the weight as it comes. I have had a spar (it needed 2 people to lift it) off a 26footer doing it this way with just 2 people who knew exactly what they were doing. Normally it takes 4. More than that there is a limit to the space on deck for them to work safely. Its not just weight, its finding the point of balance, and controlling 6m of spar either side of it! Virtually impossible to lift or control it single handed even if it is light enough. try it with a length of heavy timber!

The mast must stay in line with the boat. If the boat is more than a few degrees off horizontal across the beam, the mast will want to run away in that direction, even using a tabernacle arrangement. Ditto if there is any strength in the wind. AVOID this at all costs, as it will go rapidly and disastrously out of control.

But I suspect, in fact would be certain, your spar is a great deal heavier with all the rigging, than you thought, so if yu are going ahead with an unassisted drop (i.e no crane) you need to be very sure that everything and everyone can take the substantial strains to keep it under control as it comes down.

Finally, if you are in a boatyard, check whether yours and their insurance has anything to say about dropping it this way. If it goes pearshaped, it will do a lot of damage to anything it hits, like neighbouring boats, and the neighbour himself, let alone you and your helpers!

Sorry if I seem to be pouring cold water on your plans, but this really is an extremely risky operation, and once you are committed with the spar off vertical, its too late to have second thoughts about your arrangements. You cant stop to adjust things for more than a few moments, unless its either vertical or horizontal, and if you lose control it will come down the quick way - very destructively! Good luck!

 

[GHA]

Just lifted another similar mast, single spreader round about the same length. Just and no more lifted the whole thing alone with a bit of a struggle so doubtful if it's over 100Kg.

Brings all the loads way down so hope yet...

So who knows what the mast heel looks like? Assuming there is some kind of plate which locates in the slot of the base?

 

[prv]

Just lifted another similar mast, single spreader round about the same length. Just and no more lifted the whole thing alone with a bit of a struggle so doubtful if it's over 100Kg.

Was that just the mast, or the mast plus standing and running rigging?

Pete

 

[GHA]

Was that just the mast, or the mast plus standing and running rigging?

Pete

Everything from when it was removed but no boom or forestay. Same as mine.

No way anywhere near quarter of a tonne, actually doubt if I could get 100Kg above the trestles as the years advance, maybe once upon a time...

 

[prv]

Everything from when it was removed but no boom or forestay. Same as mine.

Well, presumably you'll have the forestay, but fair enough that doesn't make too much difference on its own.

Pete

 

[Quandary]

We do all the larger masts at our club collectively, biggest is keel stepped about 15m.+ We do not have a crane locally any more so we use a truck with a Hiab, it has a reach higher than the tallest mast though you would never believe it when it is all folded away neatly behind the cab. We can drop 9 masts in about 2 hours of co-operative effort with pre-preparation and good planning. We do have a simple crane on the club dock but its jib height is about 8-9 metres. It could cope with the 12m. masts if deck stepped but would struggle with anything that rests on the keel.

 

[GHA]

Well, presumably you'll have the forestay, but fair enough that doesn't make too much difference on its own.

Pete

Roller reefing down already, no forestay.

It does tally up a bit better with the extrusion data which was something like 2Kg/M - so say 30Kg extrusion plus 60/70 for spreaders, rigging etc. Those high figures mentioned before just didn't sound right.

Still the fulcrum to sort so still plenty time to bail out if it starts looking iffy

 

[Elemental]

Roller reefing down already, no forestay.

It does tally up a bit better with the extrusion data which was something like 2Kg/M - so say 30Kg extrusion plus 60/70 for spreaders, rigging etc. Those high figures mentioned before just didn't sound right.

Still the fulcrum to sort so still plenty time to bail out if it starts looking iffy

2Kg/M sounds incredibly light for the extrusion (more like a dinghy). Without knowing the section the weight is hard to lookup on that Selden extrusion data document. But assuming something near the middle of the range, the weight is more like 6Kg/m (range is 3.7Kg/m to 15.5Kg/m across all their sections). I'd say your mast is more like 100Kg for the extrusion and then the spreaders on top.

I'm not an engineer, but would the whisker pole/endcaps (and mast section if the pole were attached to the mast itself) be strong enough?

 

[prv]

Roller reefing down already, no forestay.

What sort of rig do you have that doesn't have a forestay?

Pete

 

[neil_s]

I used to to this regularly with a 10 m mast. I could do it on my own with the boat on a swinging mooring. The going up and coming down bits are, as you suggest, simple mechanical problems. Arrange pivot at the base of the mast, lateral support to stop it swaying side to side, I favoured an A frame to direct the load, a rest for when the mast is down and a lifting mechanism - I used the mainsheet tackle directed to a sheet winch. The tricky bit is disconnecting the mast from the pivot when it's down and moving it so that it lies stably along the boat. You will find that, when down, the balance point is well aft of your transom. I managed this bit by having a gallows mast rest with a roller built into it's top.

 

[GHA]

What sort of rig do you have that doesn't have a forestay?

Pete

One that's had the roller reefing & forestay taken off yesterday

 

[rgarside]

My Parker 275 has a tabernacle. When lowering the mast I fit a goalpost support attached to the pushpit. I use a temporary A frame bolted to the toe-rails, with a 6 part purchase attached to the bow cleat just aft of the forestay, and led to the halliard winch on the coach-roof. With that set up, raising or lowering is a one person job, though if there is much cross wind I may get someone to hold a line from the masthead on the windward side. The furler / head-foil can be tied to the outside of the A frame once the mast is part down. The COG of the mast is just about on the goalpost support when the mast has landed, so removing the tabernacle bolt, and sliding the mast forward to remove rigging, etc is no problem.

Without an A frame, adequately staying the "pole" or the mast is more of a challenge, and things can go wrong very quickly.

 

[Praxinoscope]

One that's had the roller reefing & forestay taken off yesterday

So I assume you are using your genoa halyard in place of the forestay.

 

[Daydream believer]

If the boat is on the hard, have you thought about hiring (I already have some as I am a retired contractor !!!) 4 scaffold poles (20 ft) long & forming a pyramid from the ground over the boat? Get some swivel couplers to join the top conect it up & walk the feet in to raise the centre of the pyramid. If not long enough get 4 No. 10 ft poles ( or 2 mor 20ft cut in half)& 4 spigots & you have 30 ft poles. put the 10 fts at the bottom. Tie a rope across the legs to prevent spread & a couple across the deck to prevent bowing.
Then do a dead lift on the mast by attaching a loop of rope to the mast which should slide up to the spreader. Lift the mast 4 inches . Hold the foot & walk it forward as you lower it. It will be easy as it will be pivoted about the spreader.
At the same time watch the furler goes over the pulpit. Then lay the mast over the pulpit & the pushpit.
If you buy the poles (get second hand aluminium ones). You will not need any swivel joint on the deck at the mast foot & it will be much safer. Swivel couplers can be bought on line for a couple of quid each & you will need 4 No. plus 4 No. spigots. & 6No. scaffold poles & some rope & a block & tackle.
I suppose if you did not have enough poles, you could do it with 2 legs one side & one the other. I had a set of 3 for lifting RSJ's for years & some of them were a lot heavier than your mast.
Bound to be some other boats around who will see this & drop you a beer to borrow it.