Zeb's mast raising system

Discussion on how to make that Trailer Sailer go faster & more comfortable
INMA
Admiral
Posts: 5879
Joined: Nov 5th, '06, 13:07

Zeb's mast raising system

Post by INMA » May 10th, '12, 17:14

I have been watching Zebedee sort out a rigging system which rigs quickly and easily, is very simple, supports the mast properly and is safe, very safe.

To anyone considering a winter project to sort out mast raising and lowering, its worth waiting a few more weeks while Zebedee finishes his rig then have a good look at copying his work.

Ask nicely if your in Melbourne and I am sure Zeb will help design a copy for different yachts once his piece of art is sorted.

The brilliant bit about Zeb's system is it uses lines to stabilise the mast but they do not need to be attached in line with the mast pivot, zeb's side lines attach to the stanchion bases. With an electric remote winch or a line back to the mainsheet in the cockpit, Zeb lifts the mast with little or no side sway and the weight is controlled by the winch. Set up time would be less than two minutes for the rig that goes on the front of the mast, and no heavy lifting.

Patience.
RL24 Mk4 cruiser Mariner 5 2 stroke

A bad day in the Whitsundays is better than a good day at work. Unless you work in the Whitsundays.

brent53
Lakes & Bays Skipper
Posts: 410
Joined: May 28th, '11, 15:56
Location: Port Pirie, South Australia

Re: Zeb's mast raising system

Post by brent53 » May 10th, '12, 18:20

This system works very well too!
Mast is stabilized with temporary side stays.
Attachments
Mast raising 038.jpg
Mast raising 038.jpg (48.83 KiB) Viewed 14435 times
Mast raising 028.jpg
Mast raising 028.jpg (69.24 KiB) Viewed 14435 times
Mast raising 003.jpg
Mast raising 003.jpg (75.07 KiB) Viewed 14435 times
Brenton - Cole 23, Port Pirie, SA.

User avatar
zebedee
Admiral
Posts: 9964
Joined: May 9th, '07, 02:05
Location: Bayside Melbourne

Re: Zeb's mast raising system

Post by zebedee » May 13th, '12, 21:38

I've been outed.
The mast on the Castle had me thoroughly intimidated after my little Dennis. I did succeed in raising it solo once with brute force, but it clearly wasn't a practical regular approach.

So I've been developing... (see my signature line)...

A simple and stable gin pole system.

Click on the photos below, which are shrunk/cropped from three higher resolution photos, to see originals. If the image is not clickable, it's cropped from an earlier one that's already been linked.

Here's an overall view, half raised:

Image

This second prototype gin pole is made from 70x35 pine. The final design will be was made from either 40x40x1.6 Aluminium RHS ($35 for 6.5m from Ulrichs)or 50x30x2 Aluminium RHS ($51 for 3m from Bunnings). It is 2.4 metres long, just long enough to overhang the centre of the pulpit on the Castle when the mast is up.

The spinnaker halyard attaches to a saddle on the upper face of the outer end of the gin pole and is cleated or tied off.

There are a pair of green guy ropes which clip to the staunchion bases either side and slightly forward of the mast which keep the gin pole central:

Image

Because these green guy ropes are not attached to a location on the axis of rotation of the mast step/tabernacle, their lengths need to change together by the same amount as the mast is raised or lowered. In order to allow this, they pass through guide blocks at the midpoint of the gin pole, through a pair of blocks at the tip and then to a ring which is fixed at the centre of the guy rope:

Image

The mainsheet can be detached from the traveller and the boom and used to pull the gin pole down. For simplicity, the alternative, using the trailer winch, is shown.

The guy ropes meet the gin pole about half way up:

Image
The guide blocks are rotated off axis to confirm that they work properly like this. The final aluminium pole will be 40mmx40mm, not wide enough for the blocks to fit square across the pole.

A spare triple block and becket does service as a double block at the mast tip, though simply feeding the rope loop through the saddle on the gin pole works fine too:

Image

As the ring is pulled down, it maintains tension in the two guy ropes. Because it is fixed to the centre point of the guy rope, the pole cannot move across the guy rope. Because the guy ropes are anchored forward of the mast, they also provide a minor mechanical advantage in the early stages of lifting.

A similar scheme could be used if you want to guy the mast on the way up too. (Link added May 2014)


Ways to screw this up:
There are two important points I discovered along the way.

As the mast lowers, the guy ropes must become longer between the staunchion bases and the gin pole. To do this, the ring is drawn up towards the pole.

1) Critical rope length!
The guy rope must be long enough that there is always some rope left between the tip of the pole and the ring. If the ring ever runs out of rope, as the mast continues down, it will have ample leverage to break the guy rope and fall.

2) Stability.
The mast on Roller Coaster is mounted in a tabernacle, so I figured mounting the gin pole at the base of the mast, below the pivot point, would give me additional leverage.
In fact, the location of the base of the pole does not affect the available leverage; thats entirely determined by the location of the tip of the pole.
It does, however, seriously affect stability in a way that I did not see until I tried it:
  • When the top of the mast sways to starboard, the base below the tabernacle sways (much less) to port.
  • When the base of the gin pole sways to port, the guys restrain the centre, making the outer end sway to starboard.
  • When the outer end of the gin pole sways to starboard, the mast tends to follow to starboard.
  • And amplifies the sway...
Put simply, the mast swayed alarmingly.

Once the base of the gin pole is moved above the mast pivot point:

Image
  • When the top of the mast sways to starboard, the base of the gin pole sways (much less) to starboard.
  • When the base of the gin pole sways to starboard, the guys restrain the centre, making the outer end sway to port.
  • When the outer end of the gin pole sways to port, the mast is drawn back towards port.
  • And stabilised...
The following factors will amplify this stabilising effect:
  • Mounting the gin pole base further above the mast pivot to increase how far it moves.
  • Mounting the guy ropes lower on the gin pole, increasing the movement of the outer end in the opposite direction.
Do don't be afraid to mount the gin pole base quite some distance up the mast. The spinnaker pole ring is an obvious candidate.



Construction of the pole:

The pole base attaches to the mast via this rudder gudgeon (on the pole):

Image

and a transom gudgeon (on the mast) similar to the one below, but of a different brand, which fitted nicely over the gudgeon on the gin pole:

Image

With a little judicious bending, the gin pole gudgeon can be made to allow the gin pole to fold flat against the mast. The mast gudgeon should be bent slightly to render the mounting face concave (or a suitable packer used) so it is stable on the convex front surface of the mast.

The saddles at the tip of the gin pole are through-bolted so that there is no possibility of screws or rivets pulling out.

The guide blocks at the centre are a single fitting of unknown origin from my tool box, but a pair of these cheap Ronstan blocks would do the job fine:

Image

These do not need to be bolted because there is relatively little load on them and because even if they fail, the system remains up and stable.



Raising the mast (items in blue are once only when setting up the first time):
  1. Lie the pole flat along the mast and fasten the gudgeons together with a pin or bolt.
  2. Attach the guys.
  3. Attach the spinnaker halyard to the top saddle at the top of the pole and adjust the length so that the pole makes an angle of a bit less than 90 degrees to the mast. After your first trial, mark the correct length on the halyard at the halyard cleat.
  4. Attach the winch line or main sheet to the ring and take up the slack. Since your mainsheet probably won't reach the bow, add a length of rope to make up the necessary distance.
  5. Do all the usual stuff like disentangling the shrouds and making sure to loop the backstay around the prop. (With a little practice you'll remember to leave the prop out of it)
  6. Haul the mainsheet on, pulling the mast most of the way upright until you run out of travel.
  7. Grasp the end of the gin pole and pull it down the rest of the way (with the mast almost upright, this is easy). If you've got the height right, you can stand stride it and lean on it to pull the mast forward while you secure the forestay. You did remember to clip the forestay to somewhere you could reach didn't you?
  8. Either remove the gin pole or pull it up against the mast for storage. It probably won't fit in your car unless you've got a wagon.
A man's boat is his Castle. The Gippsland Lakes are my moat. Castle 650 #10, Roller Coaster.

Castle 610
Yachtmaster
Posts: 2083
Joined: Oct 26th, '06, 20:20

Re: Zeb's mast raising system

Post by Castle 610 » May 13th, '12, 22:22

Fantastic stuff Graham

I can see that Roller Coaster was wasted on me.

I think I would have to see it in the flesh to understand it.

Is the boat full of pine needles yet?

regards
Stephen
Castle 650 'Mad Mouse'
Sabre 1205 'Wasp'
Nacra 14sq 'Vamoose'

User avatar
zebedee
Admiral
Posts: 9964
Joined: May 9th, '07, 02:05
Location: Bayside Melbourne

Re: Zeb's mast raising system

Post by zebedee » May 13th, '12, 23:55

Castle 610 wrote:Fantastic stuff Graham
I can see that Roller Coaster was wasted on me.
How many times have you had Mad Mouse in the water since I picked up Roller Coaster?
I still haven't had Roller Coaster in the water!
Castle 610 wrote:I think I would have to see it in the flesh to understand it.
I had to see it in the flesh to recognise the instability/stability issue I described. It took me a little while to figure out why it was so unstable with the gin pole mounted too low.
Castle 610 wrote:Is the boat full of pine needles yet?
Only the cockpit.

Yes, a decent cover is on the endless list.
A man's boat is his Castle. The Gippsland Lakes are my moat. Castle 650 #10, Roller Coaster.

User avatar
MoodyBlue
Administrator
Posts: 3690
Joined: Oct 10th, '06, 22:24
Location: Romsey Victoria

Re: Zeb's mast raising system

Post by MoodyBlue » May 14th, '12, 13:15

Graham,
Paul (Reflections) once posted a saddle bit of kit that allows use of both the main sheet and spinaker halyards to steady the mast while raising. The good bit apart from taking almost no room, is that it raises the pivot point to that of the mast, so there is no need to loosen or tighten ropes during the lift or lowering task. It should work with you gin pole as well?
Jeff
Attachments
Mast Raising saddle.JPG
Mast Raising saddle.JPG (17.25 KiB) Viewed 14342 times
"There is no perfect boat. There are only those shaded to your preferences.":-)

INMA
Admiral
Posts: 5879
Joined: Nov 5th, '06, 13:07

Re: Zeb's mast raising system

Post by INMA » May 14th, '12, 13:38

Jeff, the great thing about zeb's setup is it does not require a bridle or other dedicated rig and the misalignment with the pivot is irrelevant because the lines adjust as the pole or mast move up and down.

When I bought INMA I tried the bridle stuff to steady the mast and it was very difficult to adjust and almost impossible to rig and rerig without issues, Zebs setup self adjusts under load making it so simple.

The sidestays are loaded continually due to the pull from the winch and weight of the mast and they hold the pole in its centerline position.

I know Zeb is working on a similar set of lines to hold the mast in position. Add a remote controlled electric winch and its almost fool proof and probably safe to use with cross winds.

I've always bragged about INMA's mast being so light I did not need to bother with mast raising tackle. I've been converted and will probably copy Zeb's system when he has finished and sorted out the little issues. I am watching eBay for a cheap Chinese winch to do the remote up and down lift (my current winch only pulls).
RL24 Mk4 cruiser Mariner 5 2 stroke

A bad day in the Whitsundays is better than a good day at work. Unless you work in the Whitsundays.

User avatar
tonyb
CompetentCrew
Posts: 116
Joined: May 23rd, '08, 14:20
Location: Mackay

Re: Zeb's mast raising system

Post by tonyb » May 14th, '12, 21:01

Twinkle has an excellent mast raising system, the best being the mast bridle that can remain attached when you are sailing. I think the pictures show it enough.
Attachments
twinkle7.jpg
twinkle7.jpg (92.13 KiB) Viewed 14310 times
Mast bridle.jpg
Mast bridle.jpg (110.59 KiB) Viewed 14310 times
twinkle12.jpg
twinkle12.jpg (104.37 KiB) Viewed 14310 times
Tony & Karin
Twinkle
Southern Cross 23

User avatar
zebedee
Admiral
Posts: 9964
Joined: May 9th, '07, 02:05
Location: Bayside Melbourne

Re: Zeb's mast raising system

Post by zebedee » May 15th, '12, 01:14

Tony,

I see that only one solid strut can serve the same function to stabilise the mast sideways as two wires or ropes; I like that touch.

What keeps the gin pole from falling sideways in the early stages of the lift or before you've got all the lines attached?

Jeff, one of the troubles with a pair of bridles is that as soon as you pull lower than the angle of the opposite (forward) arm of each bridle, (when the mast is almost horizontal) the nearer (rearwards) arm goes slack and the geometry goes out to lunch. This forces a long bridle to get the angles down, which in turn amplifies the horizontal component of the forces where the bridle fastens to the hull. Any imperfection in the dimensions of the bridles introduces slack into the system too.

Instead of two fastening points and a ring on each side, I have a single fastening point on each side and a central pull which removes any need for precision length parts. Because the guy lines attach forward of the mast and become shorter as the mast first raises, there is also some additional (about 2:1) mechanical advantage which is welcome and progressively disappears as the angles change, and the active movement of the gin pole tip in the opposite direction of the mast head suppresses mast sway more effectively.

Practising in turbulent windy weather on Sunday I had no problem placing the mast onto a 3" wide support (scooter wheels, I believe that idea came from you?) while easing the mast down with the mainsheet from the foredeck. Moving the mast forward on the scooter wheels was silly-easy too.

In fact, the whole mast handling business is silly-easy now! And only two wrong holes in the mast. There's nothing like the first hole you drill in your new boat to make it feel like its really yours.
A man's boat is his Castle. The Gippsland Lakes are my moat. Castle 650 #10, Roller Coaster.

User avatar
gazwald
Lakes & Bays Skipper
Posts: 459
Joined: Mar 10th, '09, 21:54
Location: Melbourne

Zeb's mast raising system

Post by gazwald » May 15th, '12, 09:09

Zeb,

I had dreamt up a similar system of compensating stays on the mast and stays on a gin pole when I got my boat but it was all too complex and not worth the effort to set up so I've been using the grunt method.

Your solution of mounting the gin pole aft of the mast pivot and bringing the stays to the midpoint of the pole resulting in an inherently stable system simplifies everything a great deal.

I might have to revisit it.

Cheers

G

User avatar
colect149
Yachtmaster
Posts: 2637
Joined: Oct 29th, '06, 00:55
Location: Somerville Victoria

Re: Zeb's mast raising system

Post by colect149 » May 15th, '12, 09:51

We have tried most of the mast raising systems on various boats, except the Macgregor system with the winch on the Gin Pole. Whilst they all worked with various levels of efficiency all of them added considerably to the rigging time. IMO the Grunt method of mast raising is to be avoided at all costs, The Grunt method's big failing is that at the critical point of no return the side stays or some other critical or forgotten item envitably snags on something, so a mast lift system is not only for the well being of the the sailors but getting the mast up safely and being able to check alignments and potential snagging in a controlled way. . Zebs method looks quick, efficient and inexpensive, it might almost become the traditional way of TS mast raising.
The "further up the mast for attaching the Gin Pole" puzzles me a bit, I can see with a tabernacle, putting the pole at the base of the mast would be a problem, but to me it looks like with the usual base mounted system, it would still work attached to the base?
Farr 5000 (Frodo).Tow hack Kia Sportage 2l FWD, Avan Camper, 1967 MGB roadster, 1932 Austin 7 Sports.

User avatar
MurrayF
Inshore Skipper
Posts: 262
Joined: Oct 18th, '06, 14:17
Location: Brisbane, QLD

Zeb's mast raising system

Post by MurrayF » May 15th, '12, 10:18

Without wanting to take anything away from Zeb's mat raising system, on our old Ross 780, the mast raising system used a bipod that pushed the mast up from behind. With this arrangement, you don't need to have extra ropes or wires to stabilise the mast. Like a gin pole, it's something else to carry/load but the bipod is stable enough to do mast raising/lowering on the water if so desired.

http://tinyurl.com/7vk9784

In my mind, this is a very safe way of raising (and lowering) the mast. With this method you can start, or stop the raise or lower anywhere you like, knowing the mast is absolutely rock-solid. The wind can be blowing any direction and the mast cannot move except up or down the centreline of the boat.

Whichever way you go... be safe. You don't want go dropping large lengths of aluminium on you, your crew or your boat!

User avatar
tonyb
CompetentCrew
Posts: 116
Joined: May 23rd, '08, 14:20
Location: Mackay

Re: Zeb's mast raising system

Post by tonyb » May 15th, '12, 12:48

Hey Zeb

That one little bracket stops any sideways movement of the mast (and my mast is no lite weight) The base of the bracket bolts (pins) to the deck on a bridge style base and the other end pivots off a small bracket on the mast. As the mast only travels through about 80 degrees, this bracket/brace supports it on both sides. It takes about 5mins to attach and stays on until you dismast the boat.

The gin pole is connected through a pin system to the mast base and is about 2" aluminium plate in a u shape and the gin pole can only go inline with the mast.

Best system I've ever used, simple and safe.

Tony
Tony & Karin
Twinkle
Southern Cross 23

User avatar
Furstin
Yachtmaster
Posts: 4706
Joined: Oct 17th, '06, 09:26
Location: Sydney

Re: Zeb's mast raising system

Post by Furstin » May 18th, '12, 18:05

The gin pole stabilisation / lines is a great idea.

Is there any lateral support for the mast?

The one I made up is like a few systems. I didn't want to have any extra gear required (ie: use the kite pole) and have the rest fit into a small bag.

A couple more clips, but it was easy and reliable. A side note - I recon don't use halyard snap shackles at the gin pole, shackle the tackle direct to the eye splice (the gin pole is just holding it out rather than taking any load - if that makes sense). I used to use the arrangement as a bit of a boat bender once the mast was up to make the forestay tightening quicker and easier.

Image
Borrman 38.

User avatar
9erPaul
Able Skipper
Posts: 1524
Joined: Mar 3rd, '09, 23:00
Location: S.E QLD

Re: Zeb's mast raising system

Post by 9erPaul » May 28th, '12, 08:50

Macgregors brilliant system cost a coupla hundred and I reckon it could be adapted to fit many boats. Its the same, as in a gin pole with side stays to the stauntions. The braked winch is just brilliant because you can stop winding and just walk away at any time.

As to whether it adds to setup time, I dont know, possibly 3 or 4 minutes to get it out of the cabin and set it up, however if you get any hang ups or anything, you just let go, walk over and fix it and then keep raising. It Makes things soooo much easier.
You can see how it works here
http://www.youtube.com/watch?v=bektxtfBKdY
Blue Reef yachts on the Gold Coast has them, or can get them.

INMA
Admiral
Posts: 5879
Joined: Nov 5th, '06, 13:07

Re: Zeb's mast raising system

Post by INMA » May 28th, '12, 12:58

9erPaul, the Macs system is brilliant but it does not suit boats where there is no attachment point inline with the mast pivot.

Zebs sidestays are under tension from the hauling line, the equal distance of the sidestays pulled through their respective blocks keeps the pole in position. A similar rig can be used to steady the mast, in Zeb's case his mast pivot is strong enough to steady the mast without stays.
RL24 Mk4 cruiser Mariner 5 2 stroke

A bad day in the Whitsundays is better than a good day at work. Unless you work in the Whitsundays.

User avatar
9erPaul
Able Skipper
Posts: 1524
Joined: Mar 3rd, '09, 23:00
Location: S.E QLD

Re: Zeb's mast raising system

Post by 9erPaul » May 28th, '12, 16:03

Yes its not going to just bolt on anywhere and work, but I just meant it could be adapted for many (not all) other boats. Heres one guy using it
http://www.tropicalboating.com/sailing/mastraising.html
Anyway, Zebs system is, as we would expect from Zeb, looking pretty impressive 8)

User avatar
Cookiesa
Able Skipper
Posts: 979
Joined: Nov 22nd, '11, 19:20
Location: Launceston, Tasmania

Re: Zeb's mast raising system

Post by Cookiesa » May 28th, '12, 20:00

I think the best idea would be for you to come and practise on my boat, thatway you can perfect the design on a different boat ;)
8ft Pram Sailing Dingy
19ft "Unknown" Project (Avatar)
25ft Cruising Cat Under Construction

User avatar
zebedee
Admiral
Posts: 9964
Joined: May 9th, '07, 02:05
Location: Bayside Melbourne

Re: Zeb's mast raising system

Post by zebedee » May 28th, '12, 21:26

Gee, you could have asked BEFORE I posted your jib down to you; I could have brought it with me!

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

User avatar
Cookiesa
Able Skipper
Posts: 979
Joined: Nov 22nd, '11, 19:20
Location: Launceston, Tasmania

Re: Zeb's mast raising system

Post by Cookiesa » May 28th, '12, 21:52

Always welcome for a sail (ok, so there might be a little sanding first :) )
8ft Pram Sailing Dingy
19ft "Unknown" Project (Avatar)
25ft Cruising Cat Under Construction

User avatar
linkage
Lakes & Bays Skipper
Posts: 353
Joined: Dec 31st, '07, 19:04
Location: Rockingham WA

Re: Zeb's mast raising system

Post by linkage » Jun 5th, '12, 13:53

I used Zeb's mast raising system yesterday and it worked a treat.

I used the spinnaker pole as my gin pole and clipped it to the spinnaker fitting on the mast as suggested. I used a couple of blocks hanging separately from a saddle in the middle of the pole and a double block on the end.

Instead of an O ring determining the centre of the rope system I used another block and then attached this to the downhaul. I didn't have an O ring so tried a shackle initially but there was a bit too much friction. The block takes this out of the equation.

Everything is attached to clips so that the whole thing can be quickly set up and the spinnaker pole is already with the boat. I got my wife to raise the mast by herself using the winch on the cabin top while I stood watching for snags etc.

The Noelex mast is quite light and we have been doing it without a system but if anything goes wrong, there is the potential for harsh words! We also wanted to be able to do it on the water to get under the odd bridge so this is certainly going to help.
John
Noelex 25 #1022 "Bonanza"

phum
Inshore Skipper
Posts: 253
Joined: Oct 31st, '06, 11:04
Location: Sunny Queensland

Re: Zeb's mast raising system

Post by phum » Apr 21st, '13, 11:23

Hello all,
I had a Gin Pole system for raising the mast on this boat but was never happy with the stability of the system.
I saw the ZEBEDEE system and had a play with it. I had to modify the outboard end arrangment to accommodate the geometry but otherwise similar. Works a treat, can put 9.7Mt mast up easily on my own. Thanks.

As an aside, I can't undestand why more TS's with drop keels havn't got a tabernacle to support the mast.
With it I don't have to drop the keel or do strong man acts to put the mast up and down, I can pin it with the mast horizontal and use the mast raising system to lift it from there. Better than sliced bread on the Ross. The fin on it sits 450Mm above the deck with the fin on the ground.
Peter
Attachments
outboard end mod.jpg
outboard end mod.jpg (21.59 KiB) Viewed 12774 times
outboard end.jpg
outboard end.jpg (24.97 KiB) Viewed 12774 times
inboard end , tabernacle.jpg
inboard end , tabernacle.jpg (27.55 KiB) Viewed 12774 times
Peter

User avatar
zebedee
Admiral
Posts: 9964
Joined: May 9th, '07, 02:05
Location: Bayside Melbourne

Re: Zeb's mast raising system

Post by zebedee » Apr 21st, '13, 17:35

phum wrote:I had a Gin Pole system for raising the mast on this boat but was never happy with the stability of the system.
I saw the ZEBEDEE system and had a play with it. I had to modify the outboard end arrangment to accommodate the geometry but otherwise similar. Works a treat, can put 9.7Mt mast up easily on my own. Thanks.
One thing worth keeping in mind, your gin pole is secured to the pole BELOW the mast pivot on the tabernacle. This allows the mast and gin pole to sway as a complete assembly, about an axis between the mast pivot on the tabernacle and the "stayed point" on the gin pole where the "stay" lines depart towards the gunwhales.

If you mount the gin pole ABOVE the pivot, (which is inevitable on a more conventional rig without a tabernacle), then this sway mode is eliminated.

Here's how it works:

If the gin pole is mounted BELOW the tabernacle pivot, as the mast sways to Port, the base of mast below the tabernacle pivot and the base of the gin pole go a little to Starboard. The "stay point" in the middle of the gin pole is held central, so the outer end of the gin pole follows the mast to Port.

If the gin pole is mounted ABOVE the pivot, as the mast sways to Port, the base of the gin pole which is ABOVE the pivot also goes a little to Port too, the "stay point" stays central and the outer end of the gin pole sways to Starboard, which in turn pulls the mast to Starboard, stabilising it.
phum wrote:As an aside, I can't undestand why more TS's with drop keels havn't got a tabernacle to support the mast.
With it I don't have to drop the keel or do strong man acts to put the mast up and down, I can pin it with the mast horizontal and use the mast raising system to lift it from there.
Roller Coaster (#10 of about 165 Castle 650s built) is the only Castle I've seen with the tabernacle. I reckon if I bought another Castle I'd be looking very seriously at reproducing the same tabernacle design. The keel can stay sitting on it's support in the trailer throughout the entire rigging process.
A man's boat is his Castle. The Gippsland Lakes are my moat. Castle 650 #10, Roller Coaster.

phum
Inshore Skipper
Posts: 253
Joined: Oct 31st, '06, 11:04
Location: Sunny Queensland

Re: Zeb's mast raising system

Post by phum » Apr 21st, '13, 18:08

The sway factor with the tabernacles I have built negible.
I am not going to test it to destruction but it would be less than 1Mm.
Peter
Peter

User avatar
zebedee
Admiral
Posts: 9964
Joined: May 9th, '07, 02:05
Location: Bayside Melbourne

Re: Zeb's mast raising system

Post by zebedee » Apr 21st, '13, 18:14

phum wrote:The sway factor with the tabernacles I have built negible.
I am not going to test it to destruction but it would be less than 1Mm.
Peter
Measured where?

I'm talking about the difference between a system which relies upon the tabernacle to restrain swaying versus a system which is self stabilising.
A man's boat is his Castle. The Gippsland Lakes are my moat. Castle 650 #10, Roller Coaster.

Post Reply

Return to “Performance & Modifications”