richardbrennan
Well-Known Member
I am having ongoing problems with the mast support post on my Westerly Ocean 33.
This all started with mast panting problems following the purchase of a new and rather heavier main sail. I had the rig tuned to try and combat this but this resulted in the original mast support pillar bowing, this was a known problem on these boats and later ones had a beefier post with the diameter up from about 6 cm to about 9 cm. I had a new post made up from 9 cm tubing with the same wall diameter of 3.5 mm and had this fitted. I then think I rather encouraged the rigger to over tighten the rig resulting in the second post also bowing.
I then decided to go the whole hog and had a second new post made up, renewed the whole rig with low stretch wire, and had a back stay adjuster fitted. I also visited another identical later boat with the beefier post and took many measurements from which it was clear that the centre of the mast post was about 2 cm further forward than on my boat. The new post was made up taking this into account and this was fitted with about 2 degrees of rake which was what I was aiming for with the mast. On Thursday morning the mast was re-stepped and in the afternoon two very experienced riggers, one an ex Selden employee, set up the rig and unbelievably the post bowed again almost immediately but not as much as previously, at least so far.
Feeling sick as a parrot, after the not inconsiderable expense, does not even come close to how I felt. The riggers assured me that, although the rig was set up very hard, it was not over tensioned and I am really puzzled as to where I can go from here. I did consult a surveyor before having the second post made up, he made lots of calculations and assured me that the new post should be bullet proof!
The only thing slightly unusual is that the deck is not horizontal so there's a gap to the aft end of the support post top plate in it's natural state with the mast un-stepped, but readily comes down when the bolts are that secure the deck step to the plate below on the top of the support post, but I cannot believe this can be causing the problem. However, the bowing is also always directly aft rather than random which seems to suggest to me that there is a force at work that I am am not taking into account.
Any suggestions as what the solution may be, is it to beef up the post some more? or who might be able to advise me in the Gosport area, would be welcome. Unfortunately riggers do not appear to be that knowledgeable about what happens below deck, and surveyors seem happier checking hulls for moisture content rather than this sort of a problem which is perhaps more akin to structural engineering.
Thanking you all in advance.
Rick
This all started with mast panting problems following the purchase of a new and rather heavier main sail. I had the rig tuned to try and combat this but this resulted in the original mast support pillar bowing, this was a known problem on these boats and later ones had a beefier post with the diameter up from about 6 cm to about 9 cm. I had a new post made up from 9 cm tubing with the same wall diameter of 3.5 mm and had this fitted. I then think I rather encouraged the rigger to over tighten the rig resulting in the second post also bowing.
I then decided to go the whole hog and had a second new post made up, renewed the whole rig with low stretch wire, and had a back stay adjuster fitted. I also visited another identical later boat with the beefier post and took many measurements from which it was clear that the centre of the mast post was about 2 cm further forward than on my boat. The new post was made up taking this into account and this was fitted with about 2 degrees of rake which was what I was aiming for with the mast. On Thursday morning the mast was re-stepped and in the afternoon two very experienced riggers, one an ex Selden employee, set up the rig and unbelievably the post bowed again almost immediately but not as much as previously, at least so far.
Feeling sick as a parrot, after the not inconsiderable expense, does not even come close to how I felt. The riggers assured me that, although the rig was set up very hard, it was not over tensioned and I am really puzzled as to where I can go from here. I did consult a surveyor before having the second post made up, he made lots of calculations and assured me that the new post should be bullet proof!
The only thing slightly unusual is that the deck is not horizontal so there's a gap to the aft end of the support post top plate in it's natural state with the mast un-stepped, but readily comes down when the bolts are that secure the deck step to the plate below on the top of the support post, but I cannot believe this can be causing the problem. However, the bowing is also always directly aft rather than random which seems to suggest to me that there is a force at work that I am am not taking into account.
Any suggestions as what the solution may be, is it to beef up the post some more? or who might be able to advise me in the Gosport area, would be welcome. Unfortunately riggers do not appear to be that knowledgeable about what happens below deck, and surveyors seem happier checking hulls for moisture content rather than this sort of a problem which is perhaps more akin to structural engineering.
Thanking you all in advance.
Rick
