Dyneema halyards

Submitted by Dmain9348 on Tue, 05/14/2019 - 11:28
Forums: 
Owning, Rigging, and Sailing the Flying Scot

Have there been any discussions about allowing dyneema line in place of the wire halyards on a Scot?  I assume it would still fit on the spools of the winch box?

sawyerspadre

Wed, 05/15/2019 - 22:39

I haven’t heard any.  I ask what would the benefit be?  Is Dyneema lower in stretch, than a steel cable?
I would think they would cost more.
Not trying to be negative, but it would be interesting to hear what you think the benefit would be,  The current steel cables are pretty durable, and not very expensive to replace.
 

FS5516's picture

FS5516

Fri, 05/17/2019 - 16:40

I don't even think they make anything that small.

Chris Edwards

Mon, 06/17/2019 - 08:17

They actually do make it very small.
Amsteel Blue:
 

 
DIAM. inch
CIRC. inch
WEIGHT PER 100 FT. lbs
AVG. STRENGTH lbs
MIN. STRENGTH lbs
 
DIAM. mm
CIRC. mm
WEIGHT PER 100 M kg
AVG. STRENGTH kg
MIN. STRENGTH kg
 
ISO 2307 STRENGTH metric tons
 

 
7/64
5/16
0.3
1,600
1,400
 
2.5
7.5
0.45
730
650
 
0.73
 

 
1/8
3/8
0.5
2,500
2,300
 
3
9
0.74
1,100
1,000
 
1.1
 

 
5/32
15/32
0.75
4,000
3,600
 
4
12
1.1
1,800
1,600
 
1.8
 

 
3/16
9/16
1
5,400
4,900

Chris Edwards

Mon, 06/17/2019 - 08:21

Dyneema is lighter, stronger and just as cheap as steel wire.  Easier on the hands and very easy for the common sailer to splice and rig over steel wire.

FS5516's picture

FS5516

Mon, 06/17/2019 - 18:07

If you are planning on installing them and race at FSSA events, it's possible it will be deem not class legal. The Handbook specifies that the halyards are to be wire.

sawyerspadre

Wed, 06/19/2019 - 11:35

The steel halyard might weigh 2 pounds.  The Dyneema halyard might weigh 8 ounces, and is not likely class legal.  The boat weighs like 700 pounds and the people weigh 300-400.  Seems like a miniscule benefit.
Sandy Douglass was very careful about the Scot, to not create an incremental arms race, in an ever changing spec for the boat.  What’s next a carbon mast and boom?  BTW, they would be lighter!
If you feel this is an important improvement in the Scot, you may want to ask FS Inc, if they think it’s good idea, and then craft a request for a Chief Measurers Ruling, which is a formal process for ruling on whether items are class legal.  It usually applies to items that are not already specifically spelled out.  The halyards are already specified as wire.