Running Rigging Size

[jetdrvr393]

Hey All,

I just received the new running rigging I ordered for our new (to us) Catalina 30. I ordered Samson LST, 7/16" for the Genny sheets and 5/16" for the traveler lines. I didn't realize it before but the new stuff is much smaller in diameter than the old stuff. I got the specs from the Catalina 30 parts catalog but I am still a little worried. Was the PO that far off on what he was using or should I have gone bigger than recommended?

Thanks,

Joe

[knuterikt]

Originally Posted by jetdrvr393

Hey All,

I just received the new running rigging I ordered for our new (to us) Catalina 30. I ordered Samson LST, 7/16" for the Genny sheets and 5/16" for the traveler lines. I didn't realize it before but the new stuff is much smaller in diameter than the old stuff. I got the specs from the Catalina 30 parts catalog but I am still a little worried. Was the PO that far off on what he was using or should I have gone bigger than recommended?

Thanks,

Joe

Different priorities.
When siszing rope there are some things to take into consideration.

• Breaking strength (vs expected load)
• Stretch - larger size with same load = less stretch
• Lead through blocks, cleats, sheaves and cluthes
• Handling (thicker lines are easier on the hand)
• Self tailing winches (tailers are designed for a spesific range)
• Price
• Weight

You don't say what dimensions the old rope is..
You should not worry I think your dimensions are ok

[SlowButSteady]

For most recreational sailboats, running rigging lines (particularly sheets) are usually sized more for their "feel" when handled, than for strength per se. If the new lines work with your existing deck hardware, and the sheets feel like a comfortable size for your hands, I wouldn't worry too much about it.

[heinzir]

I've noticed that when I buy new line that is the same nominal diameter as the old line, the new line is almost invariably thinner. My old 3/8" sheets feel thicker than the new 3/8" sheets even though they are of the same type and construction. It's like dimension lumber: a 2 X 4 board actually used to measure 2" by 4". Now it's what, 1-1/2" X 3-1/2"? Reverse grade inflation?

Could it be that the lines are manufactured to metric specs and rounded up to the closest inch size when sold?

Not to worry at any rate; they are plenty strong. With new manufacturing techniques and new materials, thinner lines are usually stronger than thicker older ones.

[blt2ski]

In Heinzir example, could the old lines also be frayed or have some inbedded dirt that make them a bit thicker than when they came?

I've noticed that sometimes older lines are thicker, not much, but a tad.

Marty

[delite]

I noticed the same thing this spring when I did the running rigging on our C27. I think the previous owner went way overboard on size. I went with what Catalina specified and have not had any problems although I wish I had made some of the lines a little longer.

[olson34]

The line should feel OK when handling, fit OK through the clutches without slipping under load, and hold without slipping in your ST winches.
Strength, per se, is not an issue on any modern line.
We use 5/16" T-900 (an old school hi tech line) for all halyards on our 34 footer, for instance. It passes the above tests.

(Note further that most any modern low-stretch line in those sizes has enough strength to substitute for any of the ss shrouds on your boat!)

Our mainsheet and genny sheets are 1/2" , IIRC.

L

[heinzir]

Originally Posted by blt2ski

In Heinzir example, could the old lines also be frayed or have some inbedded dirt that make them a bit thicker than when they came?

I've noticed that sometimes older lines are thicker, not much, but a tad.

Marty

No, the old lines were still in great shape. I replaced them for color coding. Including control lines I have about 20 different lines coming to the cockpit. Using different colors makes it easier to distinguish which is which.

[WDS123]

The Previous owner may changed quite a bit of the lines.

The loads are fairly small on your 30 ftr, I didn't look up the allowable load on those lines, but would guess they are fine since they Cat says they are

the critical questions will be
do the lines run smoothly in the blocks ?
Do the clutches now slip ?
do the lines feel right ?

[blt2ski]

Henry,

I can understand the color coding part, IIRC I have about 15-20 clutchs at the aft end of the cabin for the lines coming from the mast area etc.

I've also as I need to replace some of the lines, going smaller, especially the halyards to keep the wt aloft lower, Granted a small amount, but in my case, 5 halyards aloft can start adding up!

Marty