Jack Frantz, Norwalk, CT asks:

I’m planning on replacing all the running rigging on my 1978 Tartan 37 this spring for the first time since I bought the boat over 10 years ago. All my lines are now polyester, and I’m wondering if it makes sense to buy more modern high-modulus line. There are now so many different types of rope, however, that I’m getting confused. What types are best for a cruising boat like mine that rarely races? Can I get just one type of rope, or do I need different types for all the different lines on board? 

Win Fowler REPLIES

For a Tartan 37 used mostly for cruising, I recommend you use high-modulus rope for the main and headsail halyards and spinnaker guys. A rope with a Dyneema core (SK 78 or better) with a polyester cover that can be removed from the working ends would be best. To avoid excessive wear, make sure your halyard sheaves are the proper type for whatever line you select. For all remaining running rigging, you can use polyester double-braid rope.

Cordage stretch for a given load is proportional to a line’s length. The combination of high loads and long working length make it important to use low-stretch Dyneema for the halyards and guys. Sheets are also highly loaded, but the shorter working lengths and/or multi-part purchases make stretching less of a problem. You could go with all Dyneema line, but this would be much more expensive, and I think you would see little benefit.