http://home.comcast.net/~vic-sitter/sit ... ng_System/

Interesting reading all these mast raising systems, so I googled the subject and hit 'images' and looked at what came up. I already have a long steel pole with a roller on the end that will fit down the winch post on the trailer, so this was similar to an idea I had only I thought of using water as the counterweight, pumped in with a hose at home or bucketed in at the ramp.

The idea is really the same as mast mate . Counterbalance the weight of the mast till it is negligible and then lift it yourself with all the control you need. Because I'm moored I have not had much impetus to develop this further but this guy seemed to be on the right track even though this is only a prototype. No sense in having to carry a 30kg counter weight though which is why I thought of water but then... why not use a portable heavy weight you already have ...a fuel tank with 10 liters of fuel . Then just add a little extra weight to achieve the counterbalance.



Opinions ??

Ozzie,
Another very good find. Well done.

Jeff

_________________
"There is no perfect boat. There are only those shaded to your preferences.":-)

Just another note to add to the "Sailing is all about physics and engineering" file!
Sailing really is a sport for nerds!!

Absolutely Tim and the boat came before the wheel. The boat was invented roughly 8500 BC and the wheel didn't come till 3500 BC . So boat nerds have 5000 years up on car nerds.

Give or take a millennium.

Here is a horse of another colour...

http://www.com-pacyachts.com/mastendr-mastraising.html

A bit difficult to retrofit, but the time saving on rig and derig would be remarkable. Food for thought if someone needed a new mast ? Even then fractional rigs might be difficult as well as shroud location. Liked the neat hifield lever on the forestay.

_________________
Farr 7500 (Circe') for sale, 1967 MGB roadster, 1932 Austin 7 Sports.

Bi-Pod mast raising on a Boomaroo 22

This system was created to allow a simple to set up, simple and safe to use, cheap to make, and take up minimal space.

It uses the Jib Halyard to pull on, with two long bi-pod legs used to get height for good leverage.

The chain at the front is clipped to a spare hole on the front chainplate.

The bi-pod legs have white kitchen chair rubbers to prevent damage to the deck, and stop them slipping.

For sideways stability the main halyard and the spinaker halyard are used. These are clipped to the bottom of the staunchion either side.

Raising is simply a matter of pulling the white rope, either from the cockpit, or by someone on the ground.

_________________
"There is no perfect boat. There are only those shaded to your preferences.":-)

http://sailfar.net/forum/index.php?topic=3764.0;wap2

The entry down the page by Capt Smollett may be of interest . His method is leaning back ... It has an element of Indiana Jones last step to the Holey Grail.


Choose wisely........


By the way his comments on economy of movement when raising a mast and setting up are also worth a look for newbies.

Hi,

I was just looking at some videos on youtube and found this one.

http://www.youtube.com/watch?v=nLEuLNJ4kR4

the description is: How To Equip A Trailer - Sailer Ocean Cruising Y119DVD

the bit I like was when he lowered his mast, he uses the boom. awesome..starts at about 4:35 on the video.

does anyone else use this method? seems like a good way to raise and lower your mast without the need for extra poles, winches, etc etc

cheers

alister

ps: apologies if this has been posted before.

That looks a lot like how my gin pole works, except of course it tips the mast forward rather than aft. The boom is stabilised, the mast follows it.

_________________
A man's boat is his Castle. The Gippsland Lakes are my moat. Castle 650 #10, Roller Coaster.

I have just finished rerigging during my current haulout . As I said I only raise masts occasionally but I figured the counterbalance method was worth a go, plus I was doing this in the privacy of my own driveway and so there was no no looney inventor spectacular at the ramp carpark. I recently added a heavy duty swing up jockey wheel for Spritzig II's trailer and as there is a fair bit of real estate vacant on the draw bar I left the old j.wheel clamp in place . I put an old round steel fence post I had scavenged in the clamp and a pulley hooked over the top rim attached a length of polypropylene rope to the mast and the other tied to a nylex tub to take my counterweight material. The pole was not as high as a would have liked but this was an experiment.

Now my original plan and ultimate plan was to use heavy stuff I already had on the boat ie two anchors and a full fuel tank , however as bad luck would have it the fuel tank was empty and both anchor shackles were frozen shut. So it was back to my original, original plan (see my first post ) water .

After running all my new rigging out and fitting plastic tubes over the shroud turnbuckles as per Jeff's advice someway back and fixing the shrouds and the forestay to the rails and mast with my magic foam fingers ( large foam twist ties I have mentioned before) I was ready for a solo , snag free mast lift.

I filled the nylex cube with water from the hose to full, climbed up and the mast was still fairly weighty . I then added a couple of iron round flat weights and an antique iron scale balance I use as a doorstop in the study. All up I think the total was now about 20 kg, give or take a bit of scrap iron . I climbed up again and the mast was now much lighter. It was not bouncing like you see in the mast mate videos but was a comfortable lift for me with my stuffed back to the upright position . Even the "leap of faith" from the cockpit seat to the cabin roof was no drama. Only snag was that the cube touched the ground before the mast was fully upright but it was close enough to be past the herniated spinal disc zone. I looped some of the slack around the pulpit and had everything held in place to attach the forestay at my leisure . No fuss , no muss and no rough stuff.

Refinements would be, have a pretied loop in the poly to loop over the Sampson post when the mast is up or I'm sure with a bit of fiddling I could have the post higher so the cube drop would just get to the ground or stay above it when the mast is fully raised. But as an experiment it worked fine.

Now what to do with the pole. Wood would be lighter but I think light gauge steel square section with a round 2" section bolted to the end to fit the jockey clamp would work. This could be carried slid into two brackets on the trailer, but wait there's more.

Wotif you placed brackets on both sides of the trailer then added an L bracket to take an upright? When retrieving in in a cross wind or current, you can extend this square pole out with its upright to give you an extended goal post style guide (with foam covering on the upright) on the down wind side to keep your boat square to the trailer while winching on. One pole, two sets of brackets depending on the wind direction. Or if your touchy about your hull hitting the pole put it on the upwind side with your relocated pulley and pay out a stern line as you winch ( needs two hands ) .

Wotashame I'm moored .....all this trailer/ mast raising stuff is endless fun.

By the way I'm wondering if a modified rig could be used to raise the mast on the water . Two anchors on a rope through a roller mounted on the top of the pushpit. Hmmmmmmm

The bungee used for the mastmate system provides a force which decreases as the mast approaches vertical; whereas your weight system provides a force which is constant regardless of mast position. Obviously the geometry changes as the mast comes up.

I would think if your system was still applying the full 20kg of the ballast as the mast approaches vertical, that it would reach a point where the force (strictly the moment about the mast step) due to the mast weight is no longer more than the force due to the ballast on the opposite direction and the mast-ballast system would "fall" forward until the shrouds and backstay were tight, possibly with a bit of a bang.

This might be something you want to avoid; in which case a relatively short length of bungy (multiple strands of heavy shockcord) between the ballast and the rope and careful selection of rope lengths would allow the force due to the ballast to decrease over a short distance once it hits the ground, rather than remaining constant or stopping abruptly as it did in your trial.

What's preventing the vertical pipe from bending at the drawbar? Just that it is plenty heavy enough? Could you work off the winch post which appears to be in a suitable location? Maybe drop the pipe down into the winch post if the top is open? Perhaps U-bolt a suitable pipe/post to the winch post?

_________________
A man's boat is his Castle. The Gippsland Lakes are my moat. Castle 650 #10, Roller Coaster.

Yes, the pipe was a heavy gauge, probably a little too heavy... which is why I think a lighter square section would be strong enough. The original design in the Sailnet article I got the idea from had a wood post placed inside the winch post but mine has the winch on top.

The mast was still mainly going up under my control , it never felt like it was being pulled. Interestingly I tried slightly less weight on the way down and it worked fine, at no stage did the mast feel like it was getting away from me particularly on the "leap of faith"

I think it would be a bit of experimental stuff with weight and the bungy cord would also be good to experiment with. I think even weight over a roller on the pulpit would have some benefit though obviously the mechanical advantage is not as great.

I really hope others try their own versions of this. I am surprised it is not more widespread for solo use. I only found it by accident with an "image search" on google for 'mast raising'.

Ozzie, on a side note,
If you haven't already done so, I would recommend that you fill your new jockey wheel with marine grease.
The internal screw thread of my 1 year old jockey wheel had completely seized from rust. It actually sheered in 2 when trying to force it to turn.
I imagine they leave the factory with virtually no lubrication. My new one had a whole near it's bottom so I pumped in as much blue grease as I could. A whole could be drilled if not present. The lubrication also makes raising and lowering very light work.

Island, good advice . I oil everything that moves usually but had not thought of the jockey wheel. The old one which is now transferred to my tender trailer was getting a bit stiff to turn.

The BiPod mast raising system on my MB21

[/URL]

The BiPod feet attach to the bottom of the stays and the trailer winch runs through a sheave up to the BiPod.

[/URL]

The aft side of the BiPod attaches to the mast via a rope.

The BiPod is vertical when the mast is down.



SSM

_________________
SSM (Terry)
MMSI 503006330
Pearl - Mounts Bay 21 (Swing Keel)
Mount Richon (Western Australia)

Wouldn't the feet of the bipod put a lot of strain in an abnormal direction on the base of the stays? I notice a recent poster had a failure of the through-deck chain-plate U-bolts on an Investigator (as I also did), so I wonder about putting additional strain into that area??

_________________
Peter Y
CAL 14 "Gypsy"
Investigator 563 "Tricksy"
"Myf" the skiff

Hi Peter,

There is no evidence of any failure on the glass or gelcoat around the base, I bought the boat with the system having been designed by a previous owner.

The pipes, which are only reasonably light gauge are cutout and sit on the turnbuckle which acts to locate the BiPod, The turnbuckles pivot on the U-bolts at the base in line with the designed direction of force.

I would have to try and find my old engineering tables and a strain gauge to do some maths to confirm the actual forces on the turnbuckles and U-bolts. My guesstimate is that the forces would be within the tolerances of the side loading of the turnbuckle... Twisting forces from the U-bolts on the fiberglass and supporting structure of the deck would have to be confirmed.

SSM

_________________
SSM (Terry)
MMSI 503006330
Pearl - Mounts Bay 21 (Swing Keel)
Mount Richon (Western Australia)

I use a similar system but it's behind the mast and has a bit that runs up the sail track (the poles are made out of tarp poles). It shackles on the lower Ubolts. I then use the spinnaker pole as a gin pole. Today I tried using the trailer winch to lower the mast and it works a treat. The a frame that runs up the sail track just stops the mast from going to one side or the other. I am comfortable with the forces applied to the ubolt. I keep my mast up most of the time though. I keep meaning to get photos or a video of the process but always seem to be in a rush.

Pictures would be great.

I have been playing with different positions (height up mast and length of strop) between the mast and bipod on my boat and doing some simple tests on the stresses on the turnbuckles, in most cases I can lift the base of the bipod off the turnbuckles at arms length, this I deduce requires an effort much less that the normal tensions while sailing. This would seem to suggest that the loadings do not appear to be sufficiently high enough to be of concern for overstressing the turnbuckles or the chain plates.

We are taking Pearl out this Sunday for a lap around Carnac Island, launching from Woodman Point around 0800.

SSM

_________________
SSM (Terry)
MMSI 503006330
Pearl - Mounts Bay 21 (Swing Keel)
Mount Richon (Western Australia)