Mast Lifting/Stepping - DIY

[Neraida]

I was wondering if any of you have a better memory than I.

I remember seeing in a "fall out marketing" catalogue from either YM or PBO a system where smaller boats could lift and step your own mast by means of a set of poles and a tackle set up, which would work for a keel stepped masts. i remember it quite vividly as it was only about £80, when most yards round here want £125ish for out AND in.

The time has come for Neraida to have her stick out again (keel off for refirb), and I don't really want to get lumped with the bill! So, can anyone help with the name of this thing and/or where I can get one?

Cheers

James

 

[Refueler]

Compass24 do one - telescopic alloy poles etc. - but it's well over 200 quid ..

page 142 (2008 Compass catalogue), Ref. 112 540

Mast Derrick

 

[jeremyshaw]

Compass do one, but it's a bit pricier than you mentioned - EU260. Here
http://www.compass24.com/web/catalog/shop/technology_equipment_mast_lift_derrick/2020302

Or make your own?

 

[Neraida]

That's the fella! Thanks guys. Now I have to debate whether it's worth it...

 

[VicS]

I have a simple wooden A frame, Eye bolts front and back at the apex. Forestay connects to one, the mainsheet between the other and the stem head. Simple enough to do single handed once ashore but I prefer to have someone else standing by.

However I don't use it very often as the yard (who charged £30 each way for launching and hauling out last year using a yard trolley) do not make any extra charge for stepping masts.

 

[CaptainHogwash]

Hi VicS,

Hope you don't mind sharing a few more details, as I'm about to embark on a similar DIY effort...

How tall is your A-frame in relation to the mast, and what position does it start off from - flat on deck? Also, how do you keep the A-frame 'feet' in position as the apex rises?

 

[VicS]

I am lucky in as much that the mast is stepped on a beam across the cabin top so the carpet padded feet rest up against that. It is tall enough to reach from there to the stem head fitting when lying down. It is wide enough to lie just outside the grabrails on the forecabin top.

It still does not give total lateral stability, because the shrouds are slack until the mast is upright but I find I can stand to one side and steady it as it goes up or down. A second person makes it easier of course and can disentangle the rigging from all the things it tends to get hooked on on the way up.

If I have an able bodied assistant (as opposed to SWMBO or most of the geriatrics who inhabit the yard) I get them to support the mast on their shoulders to give a bit of a start to the lift otherwise the mast starts off horizontal and the A frame vertical. It does put quite a load on the screws holding the mast step to the deck in the initial stages of the lift so I have to be sure of their integrity.

I dont do it afloat or in high winds.

One day I'll get some pictures of it in use.

 

[AndrewD]

You don't need to buy anything.

Just get two boats (preferably a bit larger than yours) rafted up alongside - one each side, obviously. Then you get a short strop and their two spinnaker halyards, and away you go.

You need five people - you, and two on each of the other boats, one grinding one tailing.

Piece of cake.

At my club we do thirty boats in a day this way, including keel-steppers. Though it's true, with the latter a little more care and accuracy is needed. /forums/images/graemlins/ooo.gif

 

[SAWDOC]

Hi andrew
how do you control the movement of the mast in your system once the foot of the mast is free? do both spinny halyards take the weight of the mast or just one?

 

[William_H]

As I read it our OP wants to remove a keel stepped mast. VicS I think is describeing lowering a mast on a tabernacle by A frame to the forestay. ie tipping over to horizontal.

I have not experience with a keel stepped mast however....

You need an A frame stood vertically just in front of the mast which is about 2.8 metre higher than the centre of gravity point of the mast. You put a strop around the mast above the Cof G ie about 2.3 metres below the top of the A frame. A tackle to the A frame top will then enable the mast to be lifted up the 1.8 metres or so necessary to clear the mast foot from the cabin top. The mast being lifted from just above the cofG means it can be forced by hand to near horizontal as the mast is lowered by tackle onto the cabin roof.

For an 8metre boat I am guessing 12 metre mast non tapered CofG
6metres from base so you need an A frame 7metres or more long. That is quite an ask. It can be made of timber or Al tubing. You will need at 4 purchase tackle to a winch with around 32 metres of rope.

The A frame must be stayed fore and aft in a manner that will clear the mast in its traverse from vertical to horizontal.
I suspect most would find the height needed for the A frame a problem.
It needs to be stood on the deck near the gun whales and be able to support its own and the mast weight. It will only lower the mast to deck height and to get the mast to the ground would require ladders and muscles. Deck height is probably very adequate for most jobs.

Just a few thoughts....good luck olewill

 

[Refueler]

[ QUOTE ]
Compass do one, but it's a bit pricier than you mentioned - EU260. Here
http://www.compass24.com/web/catalog/shop/technology_equipment_mast_lift_derrick/2020302

Or make your own?

[/ QUOTE ]

Oi !! Didn't I already link to it ??

 

[jeremyshaw]

[ QUOTE ]

Oi !! Didn't I already link to it ??

[/ QUOTE ]

The times...the times...

 

[rob2]

I would add some caution about the Compass derrick. If memory serves, it has a maximum height of around 5m, which means that the crosstrees should reach this height with the mast unstepped. That actually limits its use to a fairly small boat! I used one on my 27 foot boat and although both boat and mast survived, the re-stepping was unsuccessful and I now own a pile of aluminium scrap - twisted and bent tubes which was once a derrick.

A similar construction on the shearlegs priciple made from aluminium scaffold tubes could be achieved with much greater capability and lower cost.

 

[Refueler]

[ QUOTE ]
[ QUOTE ]

Oi !! Didn't I already link to it ??

[/ QUOTE ]

The times...the times...

[/ QUOTE ]

Mines 18:30 ..... your's 18:34 ..... /forums/images/graemlins/tongue.gif

 

[Billjratt]

Sawdoc (Sorry to hijack Andrew!) it takes a few people in the team.
Two on each winch - winding and tailing on the "crane"boats.
One person (at least) on board the 'victim' at the heel of the mast to walk it forward as the mast is lowered. He will place it on the plank across the pulpit. The forestay foil and gear will have been held by another person who will make sure it doesn't get caught on anything and can lie comfortably along the mast once it is level. Another person is stationed aft of the mast, to the side (in case it slips), ready to guide the head down to it's plank across the pushpit, making sure the instuments are clear of hazards.
Preparation: The lowers and all wiring, halliards,lazyjacks, are unfastened and tied neatly to the mast, leaving only the capshrouds, forestay and backstay loosely connected - pins ready to be pulled. (more people)
The boats are brought into line (the masts) and moored securely. A length of webbing or rope about 2 metres, is made into a loop round the mast - it must be able to slide freely up to the undersides of the spreaders. To this strop, attach the halliards from the "crane" boats, making sure they go in front of the mast and capshrouds, and a pull-down rope. (the pulldown is only to get out of jams when lowering, but is needed when raising the mast)
Tension is taken on the crane halliards until the mast is supported, then the pins can be removed from the rigging and mast foot, if applicable.
Everybody in position - then the person at the bows gives guide commands to the crane boats to raise, keeping them in sync, so the mast stays straight, until it is free at the foot. (keelsteppers get caber-tossing type of help from the man at the foot!)
Once free, the foot is walked forward and the winchmen lower it in a controlled fashion as directed by the man at the bow.
Radar scanners do complicate the process, but can be handled with care.
Raising is a reversal of the process. Usually the forestay is difficult to get the pin inserted due to it's weight and sag, extra bodies and good preparation of clevis pins and lubricated bottle screws help.
Have I forgotten anything Andrew?