A frame - masthead of fractional..

[Fantasie 19]

Hi - I've been using an A frame to raise and lower my mast for a couple of years now and am very happy with it - it's made the whole operation a lot easier... the mast is deck stepped, no tabernacle, just a bolt through a hinge so it can (at times) swing from side to side a little when raising/lowering if I'm on the water, or there's a side-wind etc. controllable if there's two of us ...

My rig is fractional, and up to now I've used the jib halyard to connect to the A frame (I use my mainsheet as the raising/lowering tackle), so the mast is being lifted/dropped from an anchor point of about 2/3rd's of its height.....

My masthead unit has the option to fit a shackle and pulley - is there any benefit in using the mast head instead of the jib halyard.... my gut feel is that the lower position is better for control, but am I right?

 

[VicS]

In the initial stages of the lift, when the mast is still close to horizontal. the angle of the halyard from the apex of the A frame to the mast will be smaller. This will increase the shear load on the mast step to deck fastenings and reduce the lifting lifting component.

OTOH the better leverage at the mast head compared with 2/3rds the way up will reduce the effort required for lifting it.

Its the shear load on the mast step fastenings that always worries me. I know mine are OK because I took the step off, made good some damage, and refixed it with new screws.

If you have no difficulty with the present arrangement I would stick to it.

But do the maths and see what difference any change will make to the loads on everything.

 

[kds]

My mast is 39 ft. and masthead rig.
I have found it much easier to control since I took the lead from the end of the "A" frame to the spreader position ( half way up the mast ) instead of the mast-head. The force required on the mainsheet pulley system to the "A" frame was greatly reduced and I was much less worried about the hinge-pin.
I do however, firmly lash a longer timber across the hull at hinge-pin height and connect pre-stretched line from the ends to the spreader roots to control any sideways movement as the mast comes up or down.
I have seen several mast-steps broken by a few degrees of sideways movement.

 

[Fantasie 19]

Excellent - thanks guys, I think that bears out my gut feel....initial thoughts as well...

KDS - my mast is only 22' but I do like the idea of that cross beam to control sideways movement - always a concern - do you leave those pre-streched lines permanently fitted to the spreader roots??

 

[earlybird]

Hi - I've been using an A frame to raise and lower my mast for a couple of years now and am very happy with it - it's made the whole operation a lot easier... the mast is deck stepped, no tabernacle, just a bolt through a hinge so it can (at times) swing from side to side a little when raising/lowering if I'm on the water, or there's a side-wind etc. controllable if there's two of us ...

My rig is fractional, and up to now I've used the jib halyard to connect to the A frame (I use my mainsheet as the raising/lowering tackle), so the mast is being lifted/dropped from an anchor point of about 2/3rd's of its height.....

My masthead unit has the option to fit a shackle and pulley - is there any benefit in using the mast head instead of the jib halyard.... my gut feel is that the lower position is better for control, but am I right?

Assuming the dimensions of the A-frame and tackle are unchanged, then the position of attachment of the halliard makes no difference to the horizontal load on the mast-step, or to the effort required of the operator on the tackle.
There will be a change to the tension in the halliard, increasing as its attachment point is moved down.

 

[Hardley]

Ive been using an A Frame now for 22 years, had a mast pin casting break in the early days due to side ways swing of mast. Since then I always try to drop mast with wind dead aft or dead ahead, I always put a line,Mooring line, around the shrouds and mast, which I keep tight whilst lowering the mast, this stops most side way swinging. I mostly lower and raise the 30ft mast on my own.

 

[TSB240]

Initially I used an a frame on our fractional rigged Trapper ts 240. It has a very tall rig with a very fragile single bolt mast foot.

I found the A frame did not support the mast well enough in cross winds nor if trying to rig the mast when afloat. This will inevitably result in a strained or broken heel casting.

The A frame is also incredibly cumbersome if you plan to trail abroad.

I now use the classic Gin pole arrangement using a cut down windsurfer mast.

I have arranged two stainless rings in line with the hinge point attached to the toe rail by two fore and aft strong dynema lashings. Similar lashings are hoisted to the cross trees using the spinaker pole uphaul and finally two lashings are attached to the outward end of the pole from the rings. The roller reefing gear complete with sail is attached to the gin pole end. The other end of the gin pole is shaped to fit the front curvature of the mast and lashed to it with a luggage ratchet strap.

I use the main sheet 4 to 1 tackle to pull the gin pole up with it attached to the bow roller/fitting.

All the lines are attached with spring clips and rigging the pole takes very few minutes.

There is little or no friction on the rings which allows the mast to rotate and because the rings are on the same pivot point. All the lines remain taught with the mast kept on the centreline and under complete control with no risk of any sidways loading on the mast foot. It becomes a genuine singlehanded no risk operation even in a crosswind.

I am considering modifying the gin pole so that it could also be used to pole out the jib as spinny pole is not the right length for this.

The loadings on the lashings are relatively low. The biggest load is taken by the gin pole, roller reefing, and the bow roller/fitting.

It can all be stowed away on board and does not weigh much.

 

[William_H]

Mast lowering

As said the A frame will not restrain the mast very much in sideways swing and this will not be any different with hoisting from top of the mast or part way down.
If you need to lower when the boat is floating then any wake from passing boats or wind from the side can make life difficult. A mast head rig can have extended chain plates fitted which force the cap shrouds (in line with mast) to pivot in line with mast pivot pin so cap shrouds stay tight through mast traverse.
With fractional rig with chain plates aft of mast pivot the shrouds go slack as so as mast goes back a little.
If you can fit small chain plates in line with mast pivot. ie on cabin top (or even use grab rail) you can fit temporary side stays from spreaders if you can reach spreaders or from a lower point. Use wire or spectra and tighten these stays so they hold the mast on centre line through the traverse.
Or do as I do and just have a person supporting mast sideways. But this is risky. You need to lower and raise quickly. good luck olewill
PS see my posts on trailer sailers

 

[Fantasie 19]

Mine of information you lot...

I wasn't sure what a gin pole was but had a Homer/smack head moment when I Googled it - happily it also lead me to this web site which was very helpful...


http://slowflight.net/upgrades/tips-GinPole.html

... particularly the bridle - think it sounds similar in function to what you (TSB240) described...

 

[William_H]

Mast raising/lowering

referring to the article in the link.
The gin pole must be stayed from each side so it does not topple sideways. I am not sure if he emphasised that. 2 poles from points on the deck support one another. But you need 2 poles versus one. Spin poles work really well and the deck pivot can be at any point down the side deck hence a longer pair of poles than the gin pole can be acomodated.
I would not use a trailer winch. Use a tackle. I find for 27ft light mast 3 purchase is good use 4 purchase on heavy mast. The purchase is taken back to the cabin top halyard winch. A sailing winch is great in that it is easy to pull the rope when load is off and easy to release rope and it is fairly easy to invoke the winch as load comes on. Remember that near vertical the load is very light near horizontal the load is great.
With lighter mast you can use a tackle and operate it with one hand pulling the rope while you get your shoulder under the mast to start raising it when near horizontal.

For real convenience... I use the forestay for lifting. I have no furler however the spin halyard or similar can be used if you have a furler on the forestay. I have a highfield lever connected to the forestay in place of the original turnscrew. This means the fractional rig is unloaded or tensioned in a moment.
I hace a piece of SS rod with a loop is the end which is clamped to the forestay. The forestay itself has a thimble type swage and is attached to the highfield lever by a shackle.
The tackle kept separate for the purpose has a stainless steel ring connected which fits between the pulley and the previously mentioned extra loop at the forestay end. This means that the forestay is used for raising but the actual end thimble is kept clear for removing and refitting the main connecting shackle.
So firstly rig is unloaded by opening high field lever. Tackle is connected between the forestay and the jib tack attachment at the bow. The tackle is tensioned up using if necessary the cabin top winch. This unloads the primary attachment shackle which is removed. The ends of the spin poles have been attached to the purpose fitted rings down the side of the deck.
The tackle is eased and the backstay pulled a bit to get the mast to fall backwards.
The mast is lowered fairly smartly and guided to land in the crutch. This is a pole that sits on the top gudgeon bolt for the rudder and is clamped to the stern rail. The crutch catches the mast quite high. Only just low enough to reach. ie about 20 degrees above horizontal.
The tackle is then eased and the poles removed.
If i am traversing under a bridge the poles are left in place and the load is shared by the crutch and the lifting tackle.
If it is a low bridge or going on the road.... The mast base pivot bolt is removed. The mast is then slid forward until the bottom of the mast passes under the bow rail and is supported by a rope sling.
The mast is then lowered by hand to the low level crutch and the upper section of crutch is removed.

All easy peasy. If I am going under bridges the boom with mainsail furled on it can left on the mast and just lays on the cabin top. It does slide back as the mast comes down. For lowering the mast further the boom is removed. On the water it is nice to have a person steadying the mast to stop it swinging sideways. I don't bother with the devices previously mentioned. Perhaps I should. olewill