Rig tuning for my H30

[malyea]

I'm seeing a bit more sag in my forestay (yeah, I know...not as young as I used to be!!!) than I think is normal so I'mgoing to do a rig tune - my first.

'Bout Time is an '82 H30 with an old Hood Seafurl 2 RF for the 150 genny. The forestay attaches to the stemhead via a Norseman fitting that attaches to an adjustment stud that attaches to a terminal shaft attached to the boat - no turnbuckle involved.

Question 1 - any tips on adjusting forestay with this type older RF model?

Question 2 - any really good, basic links to how to go about tuning her rig for the first time since I bought her a year ago?

Thanks

 

[Ed Schenck]

Have you measured the mast rake? Maybe the sag is actually the backstay. And if the bend is not right with the shroud adjustments then you will get forestay sag. I don't even have the numbers for my own H37C so I am no help there. I just tune fore/aft for about six inches of mast rake and no bend. I tune shrouds by sailing, taking the slack out of the leward side. Takes several tacks to get out the slack without taking the mast out of perpendicular.

 

[rardiH36]

A good soul on the "Ask All Sailors" forum (I think it was that forum anyway) a ways back posted a link to Kemp Sails in the UK:

http://www.kempsails.com/component/option,com_docman/task,cat_view/gid,8/Itemid,12/

In particular, on the page is a link to a pdf file that contains a step-by-step process for tuning masthead rigs. It's the most straightforward and useful description for a DIY'er that I've seen and it is what I followed the last time.

I've also attached the file here.

I particular, the document gives rationale why the forward lower shrouds are tighter than the aft lower shrouds. I always observed this but never understood why.

 

[rardiH36]

Here's a sidebar to your post:

Do you have a split backstay?

If so the attached photo (sorry about the monster size), shows a simple to install backstay tensioner. (The picture is not of me or my boat. Just came across it on a local sailing website.)

I added something similar to my boat. I keep it relaxed when not sailing or when the wind is light. In heavier air, its tightened. The reduction is headstay sag is very noticeable.

 

[malyea]

Thanks guys!

Great link rardi, I just learned that rake and pre-bend are two different animals - didn't realize that; previously thought rake was the aft bowing of the mast but that's pre-bend...right?

'Bout Time has a split back-stay and I'll look into the tensioner add-on. Do you add a cleat to secure the tensioned line or a jam cleat?

Thanks

 

[David in Sandusky]

Rig tuning procedure

Here is a rig tuning procedure for our '77 h27:

http://forums.hunter.sailboatowners.com/showthread.php?p=99303&highlight=tune rig

Use the same procedure for your h30, except your tensions will be higher - I think you have 1/4 inch wire.

Your mast is meant to stay in column, but you do want some rake as described.

 

[rardiH36]

Your mast is meant to stay in column, but you do want some rake as described.

David:

Thanks for this fact which is very useful to know and will prevent me from stressing out the rigging by trying to achieve any significant prebend.

On my Cherubini H36, even with the mast in column (totally straight with no bend fore/aft) the forward shrouds have always needed to be much tighter than the aft shrouds (as I have observed on other masthead rigged boats). The Kemp Sails instruction says for a masthead rig, adjust pre-bend to 25-50% of the chord length. My boat's fore/aft mast thickness is about 8"; implying a 2" - 4" prebend. I don't have a tension gauge, so I don't know for sure how much tension I've really got. But to achieve a prebend of about just 1" took a lot of effort with my 1 foot wrenches on the forward shroud turn-buckles, even with the aft shrouds being noticeably looser in comparison.

I'll cease and desist attempting to try for any more prebend. But I will keep my already achieved 1" for now which probably will do a bit better with my older full batten Catalina 36 mainsail.

I'll keep this topic in mind when I eventually order-up a brand new sail specific to the 1980 H36.

Again, thanks for the heads up.

 

[rardiH36]

.... I'll look into the tensioner add-on. Do you add a cleat to secure the tensioned line or a jam cleat?

Thanks

Malyea:

I'll describe what I did below, but first just to note that my tensioner wasn't meant to be high-performance in any respect. I just wanted to conveniently get some more fore/aft stay tension when needed and it does that for me.

On my boat, the split backstays are attached to the port/starboard deck at the stern-most corners by U-bolts. The "U" part is oriented up and the thread ends face down underneath the deck. On the up side, there was enough of an opening still remaining in the U's on both sides to add small shackles. The line that leads up and through the lower block of the three block cincher cluster is tied off on the shackle on my port side. After angling back down from the cluster block toward the starboard side, the other end of this line attaches to a single block with a becket. In the slack position, this block comes to rest high up near the block cluster which is just below the Y-fitting that attaches the backstay to the two split stays. On the port side, I've attached a smallish two sheave fiddle block to the port shackle. This block is free to rotate. The connecting line between the two blocks starts at the upper block becket, routes down to the upper sheave of the fiddle block, back up to sheave of the upper block and then finally through the lower sheave of the fiddle block. Pulling up on the line from the fiddle block yields a 4:1 purchase. To tie off, I'm using a shroud cleat which is mounted/positioned on the port split backstay about a foot or two above the fiddle block. This is convenient because the effort of pulling up is easily maintained to the cleat without off-center strain to the back.

One plus of this routing compared to the arrangement shown in the pic that I posted is that everything is contained close to and parallel to the split backstays. The space right behind the helmsman remains open. He/she can stand back without any new lines right behind.

One safety caveat is to be very careful when uncleating from the tensioned condition. Hold on to the line tightly. The block cluster will want to rush back up with a lot of speed and the line will rush through your hands quickly = rope burn.

I leave the tensioner slack when I'm not sailing.

 

[malyea]

Great detailed description; thanks.

 

[rardiH36]

Update to Previous Post and More General Info

Malyea:

I visited my boat yesterday to make sure everything was closed up prior to the expected heavy rains last night.

When there I looked at my aft-stay tensioner fiddle block attach point and saw that I didn't quite do it as I described yesterday.

Attached is a starboard side pic of the small fiddle block and the shroud cleat:

1) The block is attached to the toe rail, not the U-bolt. (But I did use the u-bolt on the other side.)

2) The shroud cleat is mounted only about 1 foot up. From the picture, you can probably visualize that it's a good "in-line" pull up and cleat off by the helmsman in the cockpit. Also since the bottom side of the cleat rests against the top of the fitting into the turnbuckle, it won't ever slip down any further.

Here's a link to the Garhauer (block manufacturer) website showing pre-made assemblies for backstay cincher type tensioners:

http://garhauermarine.com/catalog_process.cfm?cid=70

The first of the two appears to be for using rope into the subsequent block purchase system. The second is for wire rope.

The sponsor of this site carries Garhauer products and probably can get them for you.

Also here is a link to a Sail Magazine article about backstay tensioners. It describes what they do and the various types.

http://sailmagazine.com/boatworks/upgrades/adjustable_backstays/index.html

regards

 

[malyea]

Thanks again for the great info!