| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1687.1 | | TUNER::HO | | Fri Mar 15 1991 20:27 | 29 |
| If your mast step hinges, it can be used to facilitate DIY stepping as
you described. If not, a hinge can be fabricated with some consulting
from a welder or machinist. My guess is that one season's stepping and
unstepping fees would cover the cost of such fabrication if you paid
some one to do it.
My boat has a keel stepped mast so I use a gin pole with a 3:1 purchase
to do the lifting. The gin pole is actually the top 23 feet of an old
Etchells mast with the butt sitting on the aftmost keel bolt and the
shortened upper shrouds hooked to the chainplates. I replaced the old
backstay with line which is lead through a block on the traveler to a
cleat. Since the mast is considerably taller than the gin pole, it
looks more precarious than it really is when we step or unstep the
mast. Actually, getting the gin itself up is harder than getting the
mast up, especially if it's windy.
I've seen J24 masts get stepped without any gin poles or cranes - and
they're keel stepped. You just need enough people and beer. But I
make a point of not standing any closer than a mast's length of such an
endeavor. This method works about half the time. The other half of
the time employment is provided for mast makers and repair yards.
Unstepping a J24 mast W/O a crane is much easier. Undo the shrouds and
stays, get everyone around the base of the mast, give a big heave up,
and watch the big SPLASH as the mast goes over the side. If it goes in
butt first, it'll float as the crews muscles it aboard. You gotta see
this to appreciate it.
- gene
|
| 1687.2 | J24's do it all the time!!!!! | LAIDBK::FERGUSON | | Fri Mar 15 1991 22:07 | 32 |
| Being a proud (altho often desperate) owner of a J-24 I have to ship
and unship my mast often. Down here in SoCAL, the J24 races are on
a 300 mile cicuit which requires much towing. As a result I have seen
multifarous devices for sticking up the rig.
The generally seem to fit into two types, the gin poles, and the
V-poles.
The gin pole varies from the afore mentioned etchells mast (quite
popular, they break often), to the piece of irrigation tubing I used
last weekend. In this scenario, you use a piece of tubing, or mast
section just long enough to reach past the center of gravity of the
mast. This pole has three attachment points at the top. The forward
attachment goes through a block on the bow, and the other two form
afterstays to each side of the boat, and then to a winch for tightness.
You use a three or five to one hoist to get it up. You usually need
some type of bridle to make a noose for the hoist.
The V-poles are two sections of pipe that set were the afterstays would
be in the gin pole, and are hoisted backards by the backstay
attachment, to be raised. I find this much more precarious then the Gin
pole.
Let me know if you need any more info.
I's quite a sight when we have 25-30 J24's all hoisting and lowering at
the same time, its like a assembly line.
Bruce.
|
| 1687.3 | | ELWOOD::KEENAN | | Tue Mar 19 1991 17:29 | 8 |
| Re .1
Gene,
I've been looking for a good gin pole. Can I have your E-22 mast when
it breaks? :-)
Paul
|
| 1687.4 | sooner or later | AKOCOA::DJOHNSTON | | Tue Mar 19 1991 18:12 | 3 |
| Not if, but when. ;^)
Dave
|
| 1687.5 | | ATSE::GOODWIN | | Wed Mar 20 1991 10:19 | 36 |
|
I used a variation of these methods last season, and it worked out very
nicely, even in a nasty wind.
I have a MacGregor 25, with a hinged mast step on deck. I laid the
mast down with the foot in the step and the head over the stern, and
connected the boom to the front of the mast rather than the back where
it usually goes.
If your boom won't connect this way, then it is probably worth some
trouble to rig it so it will. You could always reverse the procedure
and start with the mast head over the bow, but then you can't have your
side and back stays connected before you start, which is a Very Good
Thing to do if you can.
In either case, the boom is then sticking up in the air. Then you need
a line from the mast head, across the boom end, and down to a block or
something. I used the main halyard and ran it over the boom end and
through the bow pulpit (used as a block), and back to the cockpit where
I could haul on it while pushing up on the mast with my shoulder at the
same time. I had to tie on an extra length of line to make it long
enough to reach all that way.
Finally, to keep the boom from falling over sideways, run a line from
one side of the boat over the boom end and down to the other side.
Where these side lines fasten should be as close as possible to a
straight line through the mast step so everything will pivot through
the same line. It took a little special rigging on the sides of the
boat to accomplish this, but it wasn't difficult.
With all that in place, the mast goes up and down easily and safely
with just one person, and the yard operator doesn't take your money.
Dick
|
| 1687.6 | a couple more details, please. | ICS::R_GREEN | Ron Green 223-8956 | Wed Mar 20 1991 12:14 | 14 |
| Dick,
I've done a rough variant of this process with my 27' mast for my
Typhoon - but without the gin pole. Not hard when single handed, but
delicate in terms of applying the right amount of line at the proper
time.
during your exercize, does the boom pivot forward, or does it remain
stationary? Where on the mast and how do you connect the boom??
Ron
ron
|
| 1687.7 | Tabernacles rule | AKOCOA::DOUGAN | | Wed Mar 20 1991 12:28 | 41 |
| Once upon a time I owned a 24 footer in Perth, Western Australia.
There is good sailing in a sheltered estuary as well as the open ocean.
However the two are separated by a couple of low bridges. So every
sailing boat, up to 60+ footers, is fitted with hinging masts. Because
they potentially need to be used every time you go sailing the system
is quite sophisticated.
First you have the mast hinged just above deck-level, in a tabernacle.
Next you have the main shroud turnbuckle fixed to a metal "plate" so
that the lower attachment of the turnbuckle is also hinged and on the
same axis as the mast hinge. The attachement of the forestay to the
deck is then a pin (secured by clips) which is easily removable. You
need 2 spinnaker poles of length roughly equal to the distance from
shroud attachment to forestay attachment. That's about the right size
for poles anyway. Last but not least you have a pulley arrangement of
2 multisheave blocks, with a large ring on the top block and a fitting
which can clip to the lower stay fitting at the bottom.
To lower the mast: Tighten inner forestay (this can be a permanent
fitting or just by winching in the fore halyard throygh a block near
the stem). This loosens the "real" forestay and secures the mast.
Remove lower forestay attachment and attach to upper pulley ring.
Attach lower pulley to forestay baracket. Clip both spinnaker poles to
upper pulley ring. Clip other end of spinnaker poles to an eye near
the shroud fitting. Hold onto the rope attached to the pulley
arrangement. Loosen, remove the inner forestay, give the mast a slight
nudge to the rear and control it's descent with the rope. The mast
, the shrouds and the spinnaker poles all rotate about the common axis.
The shrouds provide much needed lateral support (they are still under
tension. gather in the rear stay so it does noy flop in the water and
tangle the propellor.
You end up with the mast lying over the transom, the poles pointing
upwards and the pulley arrangement holding things together.
It all sounds very complicated, but can be done single-handed in about
2 minutes. My wife and I did it as a routine with her in control of
motor, tiller and backstay, me up front.
Pulling the mast back up is the reverse, except it helps to use a winch
on the pulley rope.
|
| 1687.8 | Keep it straight! | MILKWY::WAGNER | | Wed Mar 20 1991 15:32 | 10 |
|
A good point between the previous reply and a few back.
In the previous, spinnaker poles kept the mast `in column' while
lowering. A few replies back, someone used rope. Once when I used rope
on my 22 footer (swept spreaders) the stretch of the lines going to the
toerail let the mast swing and torque just enough to make Kenyon (who
made the hinged step; a weak tabernacle) $40 richer.
This mast was no phone pole either.
Poorer but wiser....
Scott.
|
| 1687.9 | More questions, please? | BOSTP2::BEAU | | Tue Mar 26 1991 15:34 | 23 |
|
A couple of more questions (before I take the big step and try this out
in my back yard (where the boat is up on stands!)).
1. My mast weighs in the neighborhood of 150 pounds - its heavy!
Is the concensus to use poles rather than ropes for guys?
2. If I am to use poles, I'll need the boom (attached to the
front of the mast), then two poles that run from the boom
down to the rail on each side, right?
3. The mast is stepped on the cabin top, approximately 18 or
so inches higher than the deck (and rail). Is this going
to foul up my triangle for the guys?
4. It seems there would be a lot less tension on everything if
I were to use the gin pole idea with old shrouds (since
everything can be set up nice and slowly on deck, checked
for stresses, etc before the mast comes up). If I do this,
though, I'll have to mount the gin pole in front of the mast,
on bare cabin top. There's no bulkhead there, and I'm worried
about breaking through. I have a nice 4 x 4 that's
about the right height. Any reason it wouldn't work?
|
| 1687.10 | Without tabernacle ? | AKOCOA::DOUGAN | | Tue Mar 26 1991 19:23 | 10 |
| My 2c worth: 1. Yes use poles, 2. If you have 2 equal size poles the
boom will not be needed 3. The triangle stays OK, it will vary a few
degrees from 90 as the mast comes up but that's not a problem, what you
don't get is lateral support while the shrouds are slack. 4. That's
what concerns me most about the whole procedure, I've only ever seen
this method used with a tabernacle. There will be a lot of temptation
for the foot of the mast to move forward, especially during the early
part of the lift. I would see a U-shaped frame somehow clamped to the
deck to make sure the mast came up in the right position and did not
slide forward.
|
| 1687.11 | Keep that stick aboard! | MILKWY::WAGNER | | Thu Mar 28 1991 15:54 | 15 |
|
I like poles more than stretchy rope. Wire shrouds/halyards are
ok, but will try to grab cabintop winces, or any handy protuberance.
(Compare to amateur tuberance; the act of impersonating a potato...)
Anywho, the pivot joints must be axial, or the mast will rise as the
swing is swung, unless you have the poles going to some sliding collar
or such arrangement. Hmmm, this is sounding like a 3+ man job, at 150
lbs., it was so with my 50 pounder, since I had no real tabernacle.
You could get the pivot point up off the deck, maybe wood doodads, but
this is sounding like too much work. I still hold that the important
thing is to keep the mast on the centerline, and connected to the deck.
Where's a mechanical genius with a metal shop & nothing to do when you
need one????
Scott.
|
| 1687.12 | | ATSE::GOODWIN | | Thu Mar 28 1991 16:41 | 18 |
|
> during your exercize, does the boom pivot forward, or does it remain
> stationary? Where on the mast and how do you connect the boom??
The boom stays perpendicular to the mast, and pivots along with the
mast as it goes up or down.
The boom fastens to the mast by a bolt that normally goes into the
after side of the mast and protrudes through the front, where you
install a nut to secure it. Very simple mechanism, which also happens
to allow the boom to be installed equally easily from the front of the
mast instead of the back.
Most booms probably don't install this way, so would require some
fiddling to fasten to the wrong side of the mast.
Dick
|
| 1687.13 | | ATSE::GOODWIN | | Thu Mar 28 1991 21:17 | 99 |
|
After dropping my mast once (sideways onto the barn roof), pulling some
muscles another time, and doing it OK a couple of times, I've figured out a
couple of principles here. :-)
You have to deal with two different sets of forces, and there are
easier or harder ways of dealing with each.
1. The force required to lift/support the weight of the mast as it is
going up or coming down:
First time I tried any of this, I lowered the mast by taking it in my
hands while my son (A in the picture below) handled a line through the
bow pulpit to the top of the mast. This works fairly well because when
the mast is most upright, the line can exert the most force, and when
it is most horizontal, the person holding it can exert the most force.
The problem with it is that the lower the mast goes, the closer the
line and the mast come to being parallel with each other, and the
greater the force required on the line to exert any upward force on
the mast. This rig also exerts a strong force forward on the mast
step when the mast is close to horizontal.
.
jib or / | _.
main / | SIDE VIEW _ - /
halyard -> / | _ - /
/ | <-mast _ - /
/ | _ - /
bow o__________|_________A stern bow o________|_________A stern
| ^ |
| halyard
Adding the boom to the front of the mast changes the whole picture by
changing the angles at which the force of the line is exerted on the
mast head. The forces on all parts of this rig are considerably less
than above, especially when the mast is near horizontal.
The most convenient line to use for this is either a jib or the main
halyard. Just fasten one end of it to the mast to keep it in place, then
tie another line to it to lengthen it, then fasten that line to the end
of the boom, run it through a block at the bow and back to person (A)
to haul on.
.
/| ______________.
/ | / ` /
/ | SIDE VIEW / ` /
/_________| / ` /
| | / /
bow o__________|_________A stern bow o________|_________A stern
| |
2. The forces tending to make the mast fall over sideways after it
is lowered enough to introduce some slack into the side stays.
The method described in one note of fastening the side stays to structures
above the rails in such a way that their bottom fastening points lie on
the same axis as the mast hinge would solve the problem very nicely.
That would allow the stays to remain tight and thereby support the mast
from moving sideways during its entire trip up and down.
But most boats have their side stays fastened slightly aft of the mast
step, and slightly lower, so they slacken as soon as the mast starts
to lower.
Also, as soon as the mast and boom start to lower, the boom is going to
want to move sideways too, and the whole rig will wobble, especially
if there's a wind.
But there is a solution for this. All you have to do is run a line from
the boom tip to each side of the boat, and fasten each end to something
on the same axis as the mast step. This will allow the entire rig
to pivot 90 degrees, while keeping the boom tip up and the mast in the
middle.
As has been pointed out, two poles instead of a boom and two lines would
accomplish the same thing, maybe better. You would hinge the bottom of
each pole along the rails somewhere near the axis of the mast step, and
fasten the tops of the poles together with the main sheet fastened to the
same point. The poles would pivot up like the boom, as the mast pivoted
down. Or vice versa.
The nice thing about the boom and two lines is that they are on board
anyway, so you can use that method anywhere.
The nice thing about the two poles is that you wouldn't have to have their
bases pivot on the same axis as the mast step, and you wouldn't have to
try to fasten the boom on the wrong side of the mast.
I think I'll try the two pole method this spring and see how it works
out. It sounds like it might be easier if I can find some strong poles.
Dick
|
| 1687.14 | Oy Vey, how complicated ve get - use a GIN POLE! | LAIDBK::FERGUSON | | Fri Mar 29 1991 02:20 | 90 |
| Oy Vey, but you guys are making this hard on yourselves!
I assume you want to lower the rig only once or twice a season. If this
is so forget the tabernacles etc, and go for the gin poles.
I've used both, on a J-36 we set up a tabernacle because we had a brige
problem between us and the race course. That meant we needed all the
gunk on deck.
On other boats - my J-24, which has about a 100# rig (I think), I use a
gin pole. Think about it, You way more than your rig does, so if you
can make a gin pole base that has as much area as your feet you dont
need to worry about your deck (unless of course your deck can't
support you :-) )
Don't worry about the horizontal forces, what you have to do is lift
the rig from a point close to - but above its center of gravity, that
way you can manhandle the end to the correct position.
See how it works in the diagram.
|\ <-------gin pole, and line
| \
| !
| !
======================}========= ____
-- | /
| \______________________________________| /
\ /
\_________________________________________/
After hoisting the setup will look like this:
| /
| /
| /
|
/|
/ |
/ |
--- / | _____
\ \_____/___ |_________/ /
\ _______________________/
Move the foot towards the place you need it lower it so that the base
has enough weight to hold it down, lock the gin pole halyard, and take
your time setting up the locks.
Take down is the reverse,
Place the gin pole in place, take the weight of the rig on the gin
pole, undo the shrouds etc, raise the rig enough so that it swings,
controlling the rig base with a line around a winch or something, (the
actual rotary moment can be calculated if you are worried - but its
low), let the rig get horizontal up high, then lower the rig down to
the deck.
What you are really down here is substituting the gin pole for the
crane that you have been using.......
All that you need is a pole long enough and strong enough to hold the
rigs weight at the centre of gravity, three shrouds, I use my large
spinn sheets, a block an tackle (use the main sheet if you have to),
and away you go.....cheap, easy and used by many.
This is the only way you can do it on a keel stepped boat!
THIS IS NOT HE WAY TO GO IF YOU NEED TO DO IT ALL THE TIME!!!!
Good luck and let us know how it goes.
Bruce.
|