Originally Posted by GreatKetch
REMEMBER ALL: Internet
based advice is worth exactly what you pay for it! Ignore the rules of physics at your cost!
I'll give the poster the benefit of the doubt, and assume that they are thinking of lower spreaders on multispreader rigs. The angles these spreaders make is more complex and they are frequently horizontal, or close to it. Of course if he had actually read the comments, nobody talked about spreaders "flopping out" of their attachment to the shrouds, what was discussed was spreaders shifteing vertical alignment. Remember, just because that's the way YOUR boat was built, does NOT mean it is the right way!
Spreaders are COMPRESSSION members. If you don't understand what that means, then you aren't qualified to comment. You ARE 100% qualified to ask questions, however. Understand that on a forum like this you are going to get multiple answers, including answers from people who don't understand rigging
. So you still have to sort out the right answers. So you might not actually be better off than you started.
. Also seems you didn't read my post fully.
If you go and look at some modern well rigged boats you will find that frequently (probably more often than not) all spreaders on the mast
are at the same angle from the mast
(usually horizontal or very close to it - the dihedral of 5 degrees in the picture GordMay posted is common) and the spreaders shorten as they are higher. The shortening of the higher spreaders may, or may not result in exact bisection of the shroud
angles depending on the spreader lengths and the chainplate base. It is not necessarily practiced on many rigs to tip the upper spreaders up to a differing dihedral to the lower spreaders as an adjustment to get an exact bisection of the shroud
angle although by nature of the upper spreader being shorter than those below it may be close to it - in fact if the spreader is on solid through bars or other means with similar fixity then one cannot adjust it up.
Of course, if there are intermediates then their angle is never bisected by the spreaders and the rig survives regardless, even though the inners may be highly loaded.
It is not universal practice to need to wire the outer ends of spreaders to prevent vertical movement of the outer end against the shroud, particularly with spreaders with through bars and those are common. In such cases though if the shroud happens to be articulated at the spreader then it may end up locked to the spreader bar but that only because one of the articulation clevis pins happens to go through the spreader.
It can be said though if one spreader on one side of the mast is at a different angle to its mate then there is a problem and that is what the original poster asked about. He also asks if they are all loose to some degree before the rig is tightened - the answer is no they are not neccessarily so but may be, it depends on how they are fixed at the mast. If they are on through bars or are similarly rigidly fixed, for example, they should not be loose before the rig is tightened unless something has come adrift.
Enough from me on this