Compression post offset from Stepped mast- normal? Lancer 44

[skwanderer]

I just noticed that, by design, the compression post is off to the left of center (port) of the mast and not directly underneath it. The layout of the cabin has the hallway that runs the length forward to the master berth is just to right of center (starboard), ok, fine. But following with my eye, which is now obvious and I can't not see it, the mast is not directly over the post, which is just to the side of it (in a vertical axis). It's been built this way, but seems really wrong to me. Is this a normal set up? The compression post is integrated into the walls between the berths; it's a beefy 4"x9" wood beam. I'd think the post would/should be directly underneath the mast.

I do have compression in the deck around the base of the mast, which I plan on addressing when I rehab the mast and standing rigging. I figured that's just 40 years of the stress of a stepped mast on top of a balsa core deck. Now I'm wondering if I need to correct a design fault and add a post directly under the mast itself inside the cabin. It's very doable and won't affect moving about inside the cabin area, but just seems weird it would be built like this, but I'm definitely no naval architect nor boat builder.

EDIT: i added a picture looking astern, showing the post location just to the right of the mast above (kinda see the mast through the rainy hatch above)

(PLEASE, I've had enough of Lancer haters replying to threads on here, so if you would offer an insightful experience or fact-based reply and refrain from derogatory opinions, I'd appreciate it.)

[MikeHoncho]

My 78 Hunter is off set to the port and rear by design. I’d say my a inch or two.

[skwanderer]

Originally Posted by MikeHoncho

My 78 Hunter is off set to the port and rear by design. I’d say my a inch or two.

Ok, thanks for sharing. Interesting. I can't quite tell if there's an overlap of post with mast above it in mine. If there is, it'd be only an inch or two.

[Buzzman]

Like the OP, I'm not an NA or a builder either, but I have noticed that not all boats have a compression post per se.

A lot of trimarans, for example, have a beam across the underside of the deckhead, and this is connected to a bulkhead that presumably transmits the compression loads from the mast to the keel and hull sides. But directly beneath the mast base is a companion way forrard. So, effectively, the support is split evenly to both hull sides, and thence down to the keel.

Main reason I think for this is that the hull is too narrow to have a central post and still be able to comfortable pass either side of the post.

I've also seen pics of smaller trailer sailor sized yachts that have a split S/S support that leads from the underside of the deckhead beneath the mast base to either side of the hull. Essentially a 'split support post', if you will.

I'd guess there is sufficient load transfer in your case, the support post being only slightly offset, but question that the beam doesn't go over the corridor...?? My guess is the NA who designed it oversized these to compensate for any perceived loss by 'direct vertical transfer'. IOW, the offset post has been accounted for in the load calcs, and you probably don't need to worry.

Now if the compression in the deck you mention was mainly to the 'weaker' side, away from the support post, then that might be cause for concern.

[Spot]

You could measure from the mast to the hatch on deck, then make the same measurement inside. From the drawings it looks like the mast is on top of a 'corner' made from the bulkheads at the corner of the front berth.

[skwanderer]

Originally Posted by Buzzman

...I've also seen pics of smaller trailer sailor sized yachts that have a split S/S support that leads from the underside of the deckhead beneath the mast base to either side of the hull. Essentially a 'split support post', if you will.
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...Now if the compression in the deck you mention was mainly to the 'weaker' side, away from the support post, then that might be cause for concern.

Thanks for your reply. Interesting points.

I also have a 1967 Santana 22, and as you mention about trailer sized sailboats, there is what you describe... an interior rigid arch spanning the interior under the base of the mast with posts on either side of the passageway to forward berth area (split support post), so I follow what you're saying.

But here on the Lancer there isn't such a header beam or other archway structure that would appear to transfer the load. And there seems to be a slightly perceptible steeper compression on the side nearer the post, perhaps because it can't sag across a greater area and is forced to compress at a sharper angle into the deck; I can see from interior, underneath the headliner, (directly overhead in the corridor) it's actually broken a bit of the ceiling (roving?) on the side by the post (see picture added. Poor shot, but shows the broken underneath surface)
UPDATE: That crack is not on the side but actually in the front of the mast, now that I have a better reckoning of relational distance from outside to interior. In looking harder into the headliner area, it appears the fiberglass is molded also down around the top area of the compression post on that side. Perhaps the cracked fiberglass isn't signficant, and just due to the compressed deck.

[skwanderer]

Originally Posted by Spot

You could measure from the mast to the hatch on deck, then make the same measurement inside. From the drawings it looks like the mast is on top of a 'corner' made from the bulkheads at the corner of the front berth.

Ha, good thinking! Thanks! Yeah, in measuring from the hatch outside then inside, it does seem that the mast is over the "corner" of the bulkheads where the compression post is located. So it does seem to get a bit more direct support than I initially saw, whew. But still... not quite a total vertical match up.

[Spot]

I am starting to think that there should have been a little more support or the post should be more under the mast. Hopefully more people will chime in and offer ideas about the situation, this one is above my pay grade so to speak. Any issues with moisture or leaks around the mast step?

[DefinitelyMe]

Structurally I don't think it should make much difference if the post is a little offset. The shear strength of the deck should be huge and the load should be transferred to the post no problem by the stiffness of the deck. But:

More of a concern to me is that you say the deck is balsa cored beneath the mast. It should not be. That's lazy work on the part of the builder. The deck beneath the mast should be solid glass and there should be no compression at all.

[Lancerbye]

I also have a Lancer 44 and the compression post is directly under the mast. It sticks out in the hallway by 4 inches. On top of the post is a 1 foot square 1 inch thick aluminum plate. On top of that is solid fiberglass to the deck skin. I know this boat had lots of upgrades just prior to my purchasing it 13 years ago but I thought this was original. Is your 44 a motorsailer and what is the build year?

[skwanderer]

@Spot, yes, I detected some wetness when I went poking around underneath the headliner, and that's when I saw the crack in the fg, and then dawned on me that the mast isn't direct over the post.

@DefinitelyMe, I'm making an assumption about the balsa core here on this deck, as I've had all the other surface decking replaced, as it was all balsa core and comprimised (spongy in places). I'll find out for sure when I re-mast and re-rig this summer. Which is why I'm on this investigation now, actually... should I modify and move over the post?? Hmmm

@Lancerbye, you've added a significant detail in your reply, thanks! If you can share a pic, I'd appreciate it. I've added more pics today, as you can see the post is tucked into the closet, behind the wall. Also added more pics of the base of the mast area

[Boatyarddog]

Originally Posted by skwanderer

Thanks for your reply. Interesting points.

I also have a 1967 Santana 22, and as you mention about trailer sized sailboats, there is what you describe... an interior rigid arch spanning the interior under the base of the mast with posts on either side of the passageway to forward berth area (split support post), so I follow what you're saying.

But here on the Lancer there isn't such a header beam or other archway structure that would appear to transfer the load. And there seems to be a slightly perceptible steeper compression on the side nearer the post, perhaps because it can't sag across a greater area and is forced to compress at a sharper angle into the deck; I can see from interior, underneath the headliner, (directly overhead in the corridor) it's actually broken a bit of the ceiling (roving?) on the side by the post (see picture added. Poor shot, but shows the broken underneath surface)
UPDATE: That crack is not on the side but actually in the front of the mast, now that I have a better reckoning of relational distance from outside to interior. In looking harder into the headliner area, it appears the fiberglass is molded also down around the top area of the compression post on that side. Perhaps the cracked fiberglass isn't signficant, and just due to the compressed deck.

As an owner of a design that has a deck stepped mast without a compression post I'd look into fabricating a lateral cross support to address that.
The support should be able to be positioned under the mast base and bolted to compression bulkheads.

I had similar problems with a noticeable compression spot at my base.
As the support had been installed I found that one bulkhead had rotted enough to allow sagging to one side.
I was able to loosen the standing rigging enough to jack the mast up from inside, had to remove some flooring to align the jack with the mast, and on top of the keel.
Once jacked enough to see some light between the cabin skin and the metal support was able to shim with aluminum plate.
I repaired the bad bulkhead and reinforced the tabbing to the hull.
The area is solid now.

Having read that the other poster with the Lancer 44 mast is supported under the mast and protrudes into the hallway down to the keel would be the right way to support the mast.

Mariners of the year I own just wanted an open design without the post in the way, and only had a FRP stringer across the top.
That was not adequate, so the lateral support was adopted as a fix.
I imagine that eventually you'll encounter this issue, the evidence being the crack that has formed under it.

With the mast not completely flat to the cabin top and the base tipped a bit ( likely from mast alignment and sagging) it will with use loosen and your standing rigging adjustment will become loose as well.

Any better pictures to see where a support could be placed to address this issue?
SV Cloud Duster

[MikeHoncho]

I could see a little deflection on mine from inside. The tool liner was puckering down and around the compression post by about 1/8 due to the steel support in the bilge failing. The alignment of all of it was buckling. I fixed the steel support. Added a 5mm carbon fiber plate between the roof liner and compression post to expand the footprint of the compression post then added a second compression post in front of the original. I couldn’t sister it up to the original due to needing a pocket for my head door to pass between the two. Turned out well.

[clakiep]

Originally Posted by skwanderer

I just noticed that, by design, the compression post is off to the left of center (port) of the mast and not directly underneath it. The layout of the cabin has the hallway that runs the length forward to the master berth is just to right of center (starboard), ok, fine. But following with my eye, which is now obvious and I can't not see it, the mast is not directly over the post, which is just to the side of it (in a vertical axis). It's been built this way, but seems really wrong to me. Is this a normal set up? The compression post is integrated into the walls between the berths; it's a beefy 4"x9" wood beam. I'd think the post would/should be directly underneath the mast.

I do have compression in the deck around the base of the mast, which I plan on addressing when I rehab the mast and standing rigging. I figured that's just 40 years of the stress of a stepped mast on top of a balsa core deck. Now I'm wondering if I need to correct a design fault and add a post directly under the mast itself inside the cabin. It's very doable and won't affect moving about inside the cabin area, but just seems weird it would be built like this, but I'm definitely no naval architect nor boat builder.

EDIT: i added a picture looking astern, showing the post location just to the right of the mast above (kinda see the mast through the rainy hatch above)

(PLEASE, I've had enough of Lancer haters replying to threads on here, so if you would offer an insightful experience or fact-based reply and refrain from derogatory opinions, I'd appreciate it.)

With this rigging a slight offset sideways is not critical, anyhow not as critical as an offset fore or aft. The mast bending under compression transfers the load fore and aft, and this would than add to an installation offset.

Capt. Claus - ocean tramp of the eighties

[skwanderer]

Very, very helpful replies! Thanks everyone!
I think I'll investigate adding further compression post support, perhaps another one directly inline with the mast (may end up heavily bolting into the side of existing post, if I can't run another post directly down to keel, as my fuel tank may be in the way since it runs under the hallway, I just can't tell yet). I'll also look into adding a plate across the ceiling, to help disperse the pressure across the area. And then also reinforce the decking where the depression is.