Precision 21/23 owners, convert to sliding boom goose neck vs fixed mount

[eaglecreeksailor22]

Hello all, On my P21 I have factory furnished Rolly Tasker main sail. When fully hoisted it is 4" to 6" from the top of the mast. This is due to the Precision having a fixed boom attachment to the mast. AS Precision owners know the boom sets low in the cockpit.

Gaining that 4" to 6" in head room would be helpfull with adding a bimini. Has any one converted to a sliding gooseneck?  it also can be usefull when a cunningham has not been built into the mainsail.
Is the pre set height of the boom to balance the rig?

Thanks in advance, always appreciate the knowledge that is here.

Rich,
P21 Nepenthe
   

[tjspiel]

How old is your sail?

Though it really doesn't address your head room problem, the sail might not be going up as high as you'd expect due to bolt rope shrinkage.

They shrink a surprising amount. I think I lost 6 to 8 inches on my original P-18 sail.

[eaglecreeksailor22]

Thank you, I was not aware of bolt rope shrinkage, makes sense. I believe the main is from 2001

[pgandw]

In my Mariner world, many of the racers want the class rules to allow fixed boom mounts instead of the standard sliding gooseneck. This is because the sliding goosenecks have a habit of folding up and breaking in heavy winds.

The advantage of the sliding gooseneck is pulling the sail to the top of the mast, and then using a downhaul to set luff tension.

Fred W
Stuart Mariner 19 #4133  Sweet P

[eaglecreeksailor22]

I usually did not use the winch to tension it much. Would it be advisable to try to put tension on it, not real aggressive but to gain back or slow down the shrinkage?

[Riggerdood]

In my Mariner world, many of the racers want the class rules to allow fixed boom mounts instead of the standard sliding gooseneck. This is because the sliding goosenecks have a habit of folding up and breaking in heavy winds.

The advantage of the sliding gooseneck is pulling the sail to the top of the mast, and then using a downhaul to set luff tension.

Fred W
Stuart Mariner 19 #4133  Sweet P

Interesting observation Fred. When you say "sliding goosenecks have a habit of folding up and breaking", which part of the assembly are you referring to? The reason I ask is that my DS had a sliding gooseneck, and after I added a fairly powerful vang, I noticed some distortion of the center part of the gooseneck's "U-joint", which was an open/hollow cube with the holes for the clevis pins. I had a solid cube machined to replace that, and problem solved. My RS22 has a fixed gooseneck, but the U-joint had the same hollow cube, which I also replaced with a solid one. The cube is part #6 in this exploded view.
You cannot view this attachment.

[pgandw]

Interesting observation Fred. When you say "sliding goosenecks have a habit of folding up and breaking", which part of the assembly are you referring to

On other Mariners, I have seen the ears to the mast slot slider fold, or break.  This is then typically followed by bending in the universal (the square section).

The difference from your diagram is the Mariner standard gooseneck has a spring on bolt 3 to allow roller reefing (which nobody ever attempts today).  The Mariner gooseneck has a long slug to fit the mast slot, with ears on the outside to hold the slug in the slot.

I have had (twice) the vertical pin holding the U-joint together fall out while trailering.  I ended up replacing pin with a 1/4" bolt and lock nut.  No problems since.

The racers - who push things further than I do - want a fixed gooseneck like your diagram shows, and use a cunningham rather than a down haul on the goose neck for adjusting luff tension.  New Mariners and/or booms can be ordered with a fixed gooseneck (like your diagram), so apparently breakage is a real issue.

There are 2 advantages to the sliding goose neck.
1.  It's a lot easier to just hoist the main all the way up, and then use a boom downhaul to adjust luff tension.
2.  Easy disconnection/connection of the boom for trailering.

Fred W
Stuart Mariner 19 #4133  Sweet P

[Riggerdood]

On other Mariners, I have seen the ears to the mast slot slider fold, or break.  This is then typically followed by bending in the universal (the square section).

The difference from your diagram is the Mariner standard gooseneck has a spring on bolt 3 to allow roller reefing (which nobody ever attempts today).  The Mariner gooseneck has a long slug to fit the mast slot, with ears on the outside to hold the slug in the slot.

I have had (twice) the vertical pin holding the U-joint together fall out while trailering.  I ended up replacing pin with a 1/4" bolt and lock nut.  No problems since.

The racers - who push things further than I do - want a fixed gooseneck like your diagram shows, and use a cunningham rather than a down haul on the goose neck for adjusting luff tension.  New Mariners and/or booms can be ordered with a fixed gooseneck (like your diagram), so apparently breakage is a real issue.

There are 2 advantages to the sliding goose neck.
1.  It's a lot easier to just hoist the main all the way up, and then use a boom downhaul to adjust luff tension.
2.  Easy disconnection/connection of the boom for trailering.

Fred W
Stuart Mariner 19 #4133  Sweet P

Yes, I know my diagram shows the fixed gooseneck version, but it was the best exploded view I could find. My DS also had the spring loaded roller reefing version. I tried that exactly one time, and immediately installed slab reefing!

What kind of pin were you using on the U-joint? A clevis pin with a cotter pin is best, but a bolt/locknut works.

I'm curious to know if the Mariner class rules have been or will be changed to allow a fixed gooseneck? If not, what is the pushback from the class? I can't see an obvious drawback to the solution, as long as the measurement rules clearly state where the fixed gooseneck is to be attached to the mast.

I don't necessarily disagree with your sliding gooseneck advantages, but I haven't really found the fixed one to be any more or less of a pain. A cunningham is used instead of a boom downhaul, and setting it is really no different. That being said, I rarely use mine, and pretty much just use halyard tension. As far as easy connect/disconnect, I just use a long quick pin in the vertical U-joint hole. I'm not really concerned if it somehow comes out (it never has), as the boom would still be connected to the boat by the Boomkicker, vang, mainsheet, and main luff in the mast slot.

I'm a big fan of the Mariner BTW. When I was looking for a slightly bigger boat than the DS, I pretty much had my wish list narrowed down to a Mariner or a Precision 18/21. I couldn't find any of these in decent condition anywhere near me, and I ended up going with the RS22, which was designed by Jim Taylor, who also designed most of the mid-sized Precision boats. I've had her for nine years now and have been really happy with her.

[pgandw]

On other Mariners, I have seen the ears to the mast slot slider fold, or break.  This is then typically followed by bending in the universal (the square section).

The difference from your diagram is the Mariner standard gooseneck has a spring on bolt 3 to allow roller reefing (which nobody ever attempts today).  The Mariner gooseneck has a long slug to fit the mast slot, with ears on the outside to hold the slug in the slot.

I have had (twice) the vertical pin holding the U-joint together fall out while trailering.  I ended up replacing pin with a 1/4" bolt and lock nut.  No problems since.

The racers - who push things further than I do - want a fixed gooseneck like your diagram shows, and use a cunningham rather than a down haul on the goose neck for adjusting luff tension.  New Mariners and/or booms can be ordered with a fixed gooseneck (like your diagram), so apparently breakage is a real issue.

There are 2 advantages to the sliding goose neck.
1.  It's a lot easier to just hoist the main all the way up, and then use a boom downhaul to adjust luff tension.
2.  Easy disconnection/connection of the boom for trailering.

Fred W
Stuart Mariner 19 #4133  Sweet P

Yes, I know my diagram shows the fixed gooseneck version, but it was the best exploded view I could find. My DS also had the spring loaded roller reefing version. I tried that exactly one time, and immediately installed slab reefing!

What kind of pin were you using on the U-joint? A clevis pin with a cotter pin is best, but a bolt/locknut works.

I'm curious to know if the Mariner class rules have been or will be changed to allow a fixed gooseneck? If not, what is the pushback from the class? I can't see an obvious drawback to the solution, as long as the measurement rules clearly state where the fixed gooseneck is to be attached to the mast.

I don't necessarily disagree with your sliding gooseneck advantages, but I haven't really found the fixed one to be any more or less of a pain. A cunningham is used instead of a boom downhaul, and setting it is really no different. That being said, I rarely use mine, and pretty much just use halyard tension. As far as easy connect/disconnect, I just use a long quick pin in the vertical U-joint hole. I'm not really concerned if it somehow comes out (it never has), as the boom would still be connected to the boat by the Boomkicker, vang, mainsheet, and main luff in the mast slot.

Don't have an answer other than the fixed gooseneck failed to get enough votes to change the class racing rules.

The pin on my gooseneck fell out while trailering (twice).  The Mariner boom is inches too long to fit in the cabin.  So everybody lashes the boom to the mast while trailering.  The 2nd time the pin fell out, I found the gooseneck pieces laying on the deck.  That's when I replaced the clevis pin and circular cotter with a bolt and nut.

A Mariner issue is the height of the boom.  The mast is 24ft 11in long.  Racing rules require a tape line at 24ft from the bottom of the masthead main halyard block.  No sane person wants their boom this low anymore.  And a really low boom turns the vang into a gooseneck destroying device instead of holding the boom down.  Unfortunately, if you buy a racing main without specifying the luff length you really want, and the sail maker goes by published specs, you will end up with a low boom.

At the other end of the boom height fiasco is the boom length is a backstay snag if the boom is at all higher than it should be.  Which makes a vang a critical Mariner control to prevent the boom from lifting into the backstay during a gybe.  Last year the class did authorize split backstay for class racing.  This gives a couple of critical inches on boom clearance compared to the off-center factory backstay.

Not mentioned, but another weak point of the Mariner is lack of a bulkhead where the shrouds attach.  In heavy winds the boat will flex and make the lee shrouds look incredibly loose (flopping loose).  I found out the racers had long ago inserted a pole in the cabin between the 2 chainplates to stop the flex in heavy winds.

I love my Mariner, but I'm always learning.  My neighbor has a Precision 14 that we are learning how to use.

Fred W

[talbot]

Not a lot of people race P21's, but boats are generally expected to stick to their design specs. There is often a black stripe on the mast (and sometimes the boom) indicating the maximum distance for the head and clew from the tack. My P21 mast had one. Makes it pretty easy to see if someone is using an oversized sail.

I also sailed looseneck Daysailers. There are some disadvantages: when you drop the sail, you drop the boom. That makes it harder to reef or to rig a boom tent.

I would push back on the idea that Precision's have low booms. They may be low for a specific Bimini, but you can gybe the boats without having to duck. That's not something you can assume if you crew on a different boat.

What is more characteristic of Precisions is that they are tender. Raising the sail to the peak of the mast will further reduce their righting moment and will force you to reef sooner and more often.

Jim Taylor had to balance a lot of factors in designing the P21. Beware of changing that balance to serve one desire (e.g., a particular Bimini), because the overall effect may be hard to predict.

[eaglecreeksailor22]

Thank you Talbot, many good points made in your post.