I have just completed a large deck core repair under the mast step. Unfortunately it seems that I have reinstalled the step to far back (about 2"-3"). Now the spreaders rigging is not straight, the cable leads to the swept spreader about 4-6" aft then forward to the mast head. The mast step is exactly in line with the spreader chin plaits. Can I modify the existing spreader or buy new ones that will alight straight out instead of swept? Straight spreaders would make the rigging straight all the way up. What are the consequences associated with this modification? Is there any reason that I should not do this? My only other solution is to step the mast and move it forward. This is not easy for me and I also do not know how it was ever any further forward due to the wiring. They are already as far back as I could put them in the boot housing. Please any info would be greatly appreciated.
I messed up and need help!!!! Spreader Alignment!!!
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The size and builder of the boat is needed.
Without knowing the brand and size of the boat it is hard to give an awnser. Ray
Without knowing the brand and size of the boat it is hard to give an awnser. Ray
It is all engineered on a Hunter
or similar boat and the mast placement would be the most important issue in that equation. I would put it back where it was designed to go. Then everything else will fit properly, too.
or similar boat and the mast placement would be the most important issue in that equation. I would put it back where it was designed to go. Then everything else will fit properly, too.
Make Model Size
This is a 1975 Pearson P-33 or 33 and is 33'. I do not have the original paperwork and even Pearson owners have not been able to select the exact model for me. Patrick: at this time that is not possible for me, there is some wiring that is inside the mast and is almost touching the back of the mast. I double checked my measurements and I think everything is where it should be yes obviously something is wrong. I am correct that the rigging would always be ran threw the spreaders in a straight line, never with a aft then back to forward bend at the spreaders right?
This is a 1975 Pearson P-33 or 33 and is 33'. I do not have the original paperwork and even Pearson owners have not been able to select the exact model for me. Patrick: at this time that is not possible for me, there is some wiring that is inside the mast and is almost touching the back of the mast. I double checked my measurements and I think everything is where it should be yes obviously something is wrong. I am correct that the rigging would always be ran threw the spreaders in a straight line, never with a aft then back to forward bend at the spreaders right?
Whoa.....
If you moved the mast step aft by 3" on a P33 then you are no longer in compression directly with the bulkhead directly underneath. The **BULKHEAD** on most 70s & 80s (Shaw design) Pearsons is what supports the mast load, the compression post merely 'stiffens' the bulkhead from buckling and supports the bulkhead to the bilge (with a wooden wedge encased in 'tabbing' underneath the bottom of the butt of the compression post, etc.). If the mast is no longer directly over (in-line) with the bulkhead underneath you simply wont have the same structural reactions. Better to think about your 'repair' and think strongly to re-repair to the original 'configuration'. "Ship happens". Better to do it 'right'. BTW .... if that 'wooden wedge' (under the compression post) that is encased inside the tabbing (which can communicate with bilge water) begins to rot, the compression post that holds/supports the bulkhead will 'shorten' in length due to the compression ... with the bulkhead relocating 'downwards'. The chief symptom will be that the door that goes to the head will become 'out or line' / hard to close .... and the door knob 'bolt' wont fit into its 'catch' due to the misalignment. A 'common' problem on older Pearsons.
If you moved the mast step aft by 3" on a P33 then you are no longer in compression directly with the bulkhead directly underneath. The **BULKHEAD** on most 70s & 80s (Shaw design) Pearsons is what supports the mast load, the compression post merely 'stiffens' the bulkhead from buckling and supports the bulkhead to the bilge (with a wooden wedge encased in 'tabbing' underneath the bottom of the butt of the compression post, etc.). If the mast is no longer directly over (in-line) with the bulkhead underneath you simply wont have the same structural reactions. Better to think about your 'repair' and think strongly to re-repair to the original 'configuration'. "Ship happens". Better to do it 'right'. BTW .... if that 'wooden wedge' (under the compression post) that is encased inside the tabbing (which can communicate with bilge water) begins to rot, the compression post that holds/supports the bulkhead will 'shorten' in length due to the compression ... with the bulkhead relocating 'downwards'. The chief symptom will be that the door that goes to the head will become 'out or line' / hard to close .... and the door knob 'bolt' wont fit into its 'catch' due to the misalignment. A 'common' problem on older Pearsons.
I think Rich is correct
Moving the mast from directly over the compression post could cause major problems with structural integrity. While I am not familiar with this boat, it certainly makes sense to have the mast base unsupported. You will also more than likely effect the sailing characteristics of the boat. Probably not for the good, as you have changed the CE for sure. I think I would undo what I had done, and put it back where it belongs.
Moving the mast from directly over the compression post could cause major problems with structural integrity. While I am not familiar with this boat, it certainly makes sense to have the mast base unsupported. You will also more than likely effect the sailing characteristics of the boat. Probably not for the good, as you have changed the CE for sure. I think I would undo what I had done, and put it back where it belongs.
Rick, Nice N Easy and Brian
Rich and Nice N Easy I should of detailed this earlier. Per my original measurements I am exactly where the mast used to be, I thought I made a mistake because I never noticed this spreader issue before. Per some other Pearson owners that have made this same repair in this model the mast was over the post but slightly forward, in my repair I removed rot and broken glass all the way down till the post and spar were both visible side by side. I am positive that I am either in the same position or even more centered on the post and spar witch are both side by side under the deck. Brian If you are looking at the port side with the bow to my left the spreader rigging looks like the Blue and Black lines. Not that drastic though. I don’t exactly understand the red line in the drawing though.
Rich and Nice N Easy I should of detailed this earlier. Per my original measurements I am exactly where the mast used to be, I thought I made a mistake because I never noticed this spreader issue before. Per some other Pearson owners that have made this same repair in this model the mast was over the post but slightly forward, in my repair I removed rot and broken glass all the way down till the post and spar were both visible side by side. I am positive that I am either in the same position or even more centered on the post and spar witch are both side by side under the deck. Brian If you are looking at the port side with the bow to my left the spreader rigging looks like the Blue and Black lines. Not that drastic though. I don’t exactly understand the red line in the drawing though.
You might even have a 33' 10M, but both had straight spreaders
as far as I know. The 33-2 that Shaw designed in the 80's had swept back double spreaders, but that's not your boat. I believe the 33 had Spruce spreaders and the 10M had aluminum, and they were both made in 1975 (I think). Some good points have been pointed out here. The misalignment of the mast from the below decks support is not good, and the change in the Center of Effort aft will increase your weather helm. In addition to your spreader problem, you may have a negative rake which means the load in your backstay will be greater than the load in your headstay , and thats not good either. I would also think that your forward lowers would be a little short, and your aft lowers a little long, though probably within the tolerance of the turnbuckles. If your only concern about moving the mast is the wires at the back of the mast you could either make a new access hole below the proper location, or bring them out of the mast just above the deck through grommeted holes, and run them down through holes in the deck with waterproof wire fittings. My recommendation also would be to try to relocate the mast where it belongs. Too many things are out of whack if you don't. Good luck Joe S
as far as I know. The 33-2 that Shaw designed in the 80's had swept back double spreaders, but that's not your boat. I believe the 33 had Spruce spreaders and the 10M had aluminum, and they were both made in 1975 (I think). Some good points have been pointed out here. The misalignment of the mast from the below decks support is not good, and the change in the Center of Effort aft will increase your weather helm. In addition to your spreader problem, you may have a negative rake which means the load in your backstay will be greater than the load in your headstay , and thats not good either. I would also think that your forward lowers would be a little short, and your aft lowers a little long, though probably within the tolerance of the turnbuckles. If your only concern about moving the mast is the wires at the back of the mast you could either make a new access hole below the proper location, or bring them out of the mast just above the deck through grommeted holes, and run them down through holes in the deck with waterproof wire fittings. My recommendation also would be to try to relocate the mast where it belongs. Too many things are out of whack if you don't. Good luck Joe S
Lines
I was just trying to show how the blue line (chainplates in line with mast, swept back spreader) makes the angles symmetric, while the red line (chainplate in line with spreader end, swept back spreader) makes the angle asymmetric. Think of the red line as if you moved the mast forward, and the chainplate stayed in the same place. No different than moving the chainplate backwards, right?
I was just trying to show how the blue line (chainplates in line with mast, swept back spreader) makes the angles symmetric, while the red line (chainplate in line with spreader end, swept back spreader) makes the angle asymmetric. Think of the red line as if you moved the mast forward, and the chainplate stayed in the same place. No different than moving the chainplate backwards, right?
Re Mast my 2c
Having owned 2 pearsons over the past 25 years I would make sure the mast is put back exactly where it was. If you messed up bite the bullet and put things back exactly where they were. Moving the mast for whatever reason is going to change the center of effort and the sailing characteristics of the boat. I think Bill Shaw knew what he was doing. I wouldnt alter his design. Not before having a naval architect look at the boat first if it has to come to that.
Having owned 2 pearsons over the past 25 years I would make sure the mast is put back exactly where it was. If you messed up bite the bullet and put things back exactly where they were. Moving the mast for whatever reason is going to change the center of effort and the sailing characteristics of the boat. I think Bill Shaw knew what he was doing. I wouldnt alter his design. Not before having a naval architect look at the boat first if it has to come to that.
Spreaders - straight line?
You wrote...."I am correct that the rigging would always be ran threw the spreaders in a straight line, never with a aft then back to forward bend at the spreaders right?" The answer may be "WRONG" not sure though. An old friend of mine had a Pearson Triton, don't remember the size. Up near the top somewhere, the shroud went to the rear on a sweptback spreader and then forward again. He thought about changing it to run everything straight. Another friend was a mechanical engineer and looked at it and explained the stresses without the calculations and recommended that he use the original configuration. You also stated "I do not have the original paperwork and even Pearson owners have not been able to select the exact model for me." My suggestion would be to actually go and get a tape measure and take exact measurements of length, beam and whatever and then figure out what kind of boat you have. How do you even know it is a Pearson? Then take it from there. Tony B
You wrote...."I am correct that the rigging would always be ran threw the spreaders in a straight line, never with a aft then back to forward bend at the spreaders right?" The answer may be "WRONG" not sure though. An old friend of mine had a Pearson Triton, don't remember the size. Up near the top somewhere, the shroud went to the rear on a sweptback spreader and then forward again. He thought about changing it to run everything straight. Another friend was a mechanical engineer and looked at it and explained the stresses without the calculations and recommended that he use the original configuration. You also stated "I do not have the original paperwork and even Pearson owners have not been able to select the exact model for me." My suggestion would be to actually go and get a tape measure and take exact measurements of length, beam and whatever and then figure out what kind of boat you have. How do you even know it is a Pearson? Then take it from there. Tony B
Pay attention, folks ...
He is saying that he has NOT moved the location of the mast (to the best of his knowledge). By the description, it sounds like there is an opening in the deck for the wiring to pass directly thru (from inside the mast?)and by this reference point, the mast has not been moved significantly. I would verify if the angle that the shrouds make (first aft to the aft swept spreaders, then forward to the head of the mast) is typical for the design of your boat. If not, it sounds like something is messed up but you can't think about changing the location of your mast.
He is saying that he has NOT moved the location of the mast (to the best of his knowledge). By the description, it sounds like there is an opening in the deck for the wiring to pass directly thru (from inside the mast?)and by this reference point, the mast has not been moved significantly. I would verify if the angle that the shrouds make (first aft to the aft swept spreaders, then forward to the head of the mast) is typical for the design of your boat. If not, it sounds like something is messed up but you can't think about changing the location of your mast.
If you have the mast positioned correctly
Assuming you have the mast positioned correctly, which is the very first thing you need to verify, then the rest is simple. Find the correct model of your boat, for absolutely positive, then determine what the configuration of everything else is supposed to be. I would not start looking to change spreaders, shroud location or anything else until I was absolutely positive where everything should go. You could not only cost yourself a bunch of money needlessly, but have to do an awful lot of unnecessary work, and very possibly screw up the sailing characteristics of the boat. I am a little bit confused though. Did you not notice where things were before you started this project. If the mast is where it was, then everything should go back in exactly the same place it was before you started. Is there any indication that the location of the chain plates has been changed. Are the shrouds the correct length to go back as they were. Should be several indicators to give you a pretty good idea of whats going on. But again, before you change anything, find out for sure where it is supposed to be. The exact measurements are available somewhere.
Assuming you have the mast positioned correctly, which is the very first thing you need to verify, then the rest is simple. Find the correct model of your boat, for absolutely positive, then determine what the configuration of everything else is supposed to be. I would not start looking to change spreaders, shroud location or anything else until I was absolutely positive where everything should go. You could not only cost yourself a bunch of money needlessly, but have to do an awful lot of unnecessary work, and very possibly screw up the sailing characteristics of the boat. I am a little bit confused though. Did you not notice where things were before you started this project. If the mast is where it was, then everything should go back in exactly the same place it was before you started. Is there any indication that the location of the chain plates has been changed. Are the shrouds the correct length to go back as they were. Should be several indicators to give you a pretty good idea of whats going on. But again, before you change anything, find out for sure where it is supposed to be. The exact measurements are available somewhere.
Scott may be correct here because we have read
"Unfortunately it seems that I have reinstalled the step to far back (about 2"-3" and "The mast step is exactly in line with the spreader chain plates" which are somewhat conflicting statements. I, along with others were more influenced by the first statement, and I was writing my post #9 while he was posting #s7&8. I'm a slow typist. In the 1980's, Bill Shaw made a big deal about using swept back spreaders, and at that time the boating design concepts were driven by the IOR rule (taller rigs, double spreaders, and narrower ends. Back in the early 70's boats still followed the ideas of the CCA rule (fuller hulls, shorter rigs, and straight spreaders). I don't believe a 1975 Pearson had swept back spreaders, but it wouldn't seem probable that both spreaders got accidently bent by the same amount while he was making deck repairs. So I guess I agree with both Scott and Nice N Easy that a little more investigation is in order before you do anything. I still wish you good luck. Joe S
"Unfortunately it seems that I have reinstalled the step to far back (about 2"-3" and "The mast step is exactly in line with the spreader chain plates" which are somewhat conflicting statements. I, along with others were more influenced by the first statement, and I was writing my post #9 while he was posting #s7&8. I'm a slow typist. In the 1980's, Bill Shaw made a big deal about using swept back spreaders, and at that time the boating design concepts were driven by the IOR rule (taller rigs, double spreaders, and narrower ends. Back in the early 70's boats still followed the ideas of the CCA rule (fuller hulls, shorter rigs, and straight spreaders). I don't believe a 1975 Pearson had swept back spreaders, but it wouldn't seem probable that both spreaders got accidently bent by the same amount while he was making deck repairs. So I guess I agree with both Scott and Nice N Easy that a little more investigation is in order before you do anything. I still wish you good luck. Joe S
I FIGURED IT OUT
I went back up the mast and did some detailed inspections. It appears that someone in the past had purposely swept the spreaders. They did this by bending the brackets, I found some cracked welds and some marks on the brackets. If you imagine the weld in there original place it would put the spreaders at 90 degrees. I have taken the brackets to a machine shop and had them straightened and the welds tacked. The spreaders are only about ½”-3/4” swept at this time. I believe that this will be with in tolerances. 2 owners ago this boat was raced, after talking to some local rigging shops they have ran into many cases where sailors have tried to modify there rigs to increase performance. In most cases it is just the opposite. I can only figure that this or some variation was the case. Thank you all for your help and info.
I went back up the mast and did some detailed inspections. It appears that someone in the past had purposely swept the spreaders. They did this by bending the brackets, I found some cracked welds and some marks on the brackets. If you imagine the weld in there original place it would put the spreaders at 90 degrees. I have taken the brackets to a machine shop and had them straightened and the welds tacked. The spreaders are only about ½”-3/4” swept at this time. I believe that this will be with in tolerances. 2 owners ago this boat was raced, after talking to some local rigging shops they have ran into many cases where sailors have tried to modify there rigs to increase performance. In most cases it is just the opposite. I can only figure that this or some variation was the case. Thank you all for your help and info.
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