Hi all,
Just wondering if I could get some advice on a yacht that I am considering for purchase that has a keel stepped mast however however at some stage has had an alteration at the deck to so it now has lowering capabilities. I have been advised that this is quite common in Western Australia and that no strength is lost from its original state however I have my doubts. Anyone have thoughts on this? Thanks in advance!
read here ......
www.seabreeze.com.au/forums/Sailing/General/Deck-Leaks-Mast-Deck-Collar/?SearchTerms=mast,cutting
Paying attention to what forum member "patrigo28" says, you will find that it is indeed common in WA so that they can get under the bridges to play in the big puddle.
Thanks for that although I guess I am moreso interested in how much strength the mast loses (if any) from the conversion.
If done correctly why would it lose any strength? All you are really doing is converting a keel stepped mast to a deck stepped mast. There are some very serious sailors in WA and I'm pretty sure they wouldn't go and chop up their masts unless they thought they weren't losing as much as they were gaining by doing it.
If you have doubts, my advice would be to not buy the boat as you will possibly always have doubts about it.
If done correctly it is not a problem. If in dought get a Rigger to do a prepurchase check.
I guess my thinking was that when a mast is deck stepped it is generally constructed differently as to when they are keel stepped and so if the load is transferred to the deck it could potentially cause an issue. On the other hand I would say that if if the tabernacle was constructed properly the load I presume wouldnt increase on the deck. The yacht was originally an offshore yacht bus hasnt sailed more than 100 mile offshore since the conversion so your probably correct in saying I shouldnt proceed if it is going to be on my mind if I want to utilise the yacht offshore again. Cheers!
What you are describing is refereed to as a tabernacle, indeed common in WA as in Europe, for the same reasons. Not a problem at all.
Cheers, Bob.
I agree with Jode5, get a rigger to inspect the alteration. Does the boat have a compression post to transfer the load to the keel in keeping with the original design, or has the main ring frame or bulkhead been modified to take the load?
If the latter, speak to a surveyor, or the company that did the mods, if still worried, walk away.
Select to expand quotemorningsun said..
...... Does the boat have a compression post to transfer the load to the keel in keeping with the original design ...........
The original part of the mast is still in situ performing the job of compression post. Nothing has changed other than the mast now has the ability to be laid down and the shrouds had to be eased a bit to compensate for the thickness of the plates in the cut part of the mast.
Most S&S34s have a hinged keel stepped mast to get under the Swan River bridges. They seem to have survived as one of the great ocean passaging yachts of all time.
MB has a deck stepped mast without a folding hinge. I personally do find not having a hinge in the mast reassuring when being battered in a blow. On the other hand, it would be great to be able to lower the mast and go cruising up the Hawkesbury.
Select to expand quoteLooseChange said..morningsun said..
...... Does the boat have a compression post to transfer the load to the keel in keeping with the original design ...........
The original part of the mast is still in situ performing the job of compression post. Nothing has changed other than the mast now has the ability to be laid down and the shrouds had to be eased a bit to compensate for the thickness of the plates in the cut part of the mast.
A keel stepped mast with a tabernacle differs from a deck stepped mast simply because the the step is still at the keel and no stepping load is applied to the deck. A deck stepped mast requires the deck to be strong enough to support the compression loads and mast, this is usually done with compression posts and /or bulkheads.
Usually a well made tabernacle or hinge for a keel stepped mast has the hinge scarped into the mast making a large load bearing joint through out about one calibre of the mast and that the mast lowers forward. This means that back stay tension( if it has one) and shrouds to aft chain plates force the hinge closed not the other way trying to open it.
I have a deck step on my boat with a tabernacle or hinge for lowering. The mast is free to pivot forwards or backwards only held in place with the fore stay and back stay. The upper shrouds are in line and they are connected to the chain plates with a chain plate extender.The chain plate extenders create a a pivot point for the shrouds at the same height as the pivot point of the mast. This keeps the upper shrouds tight when lowering the mast,, keeping it centered and stopping it from swinging over the side as you lower it
I was on board with this topic last year and thought it was finished, but it ain't, so here goes.
What they do in Fremantle would be done Worldwide, if it was known about. What you end up with is not "a deck stepped" mast , but a keel stepped mast, with all its advantages, and none of its disadvantages at the same time as all the advantages of a deck stepped mast, with none of it's disadvantages. My below deck mast is a permanent part of the boat's down below furniture. On deck I can undo four bolts and hinge the mast down, as if it were in a tabernacle. No leaks, no movement. In Fremantle many vessels have mods to their shrouds so they can lower the mast easily. I am not interested in that side of it, just a totally non leaking keel stepped mast, that is easy to remove for painting/mods/whatever. I have only removed the mast twice in 20yrs, once for transport and once for painting. A few months ago there were various owners describing the efforts they go to, to stop their keel stepped masts shipping water. It was unbelievable! How can they live with it!
So, Seacam83, if the above is what you are looking at, and it has been done properly, it IS the only way to rig a keel stepped mast. 20yrs living with its advantages says I know. I cannot think of one disadvantage.
Legends! Thanks a lot guys. That has put my mind a lot more at ease. Think I will get a professional to check out the installation and go from there!
