Not knowin' ....
Ronstan Constrictor
Ronstan CT312P001 Constrictor TC Single 12mm
Like a turbo-charged update of the old finger handcuff, the novel Ronstan Constrictor clutch relies on cordage, rather than cam-induced pressure, as a locking device. A two-foot length of braided Dyneema cover acts as a glove-tight skin over a halyard or other piece of running rigging. Allowing this cover to stretch taut binds the line, transferring the load to the machined titanium mount.
When the control line attached to the sleeve is tensioned, the halyard slides through freely. And when the time comes to lock the line, this control string is released, and the braid cover is stretched by a bungee cord.
The Ronstan Constrictor can immobilize a highly loaded line, and it does so with the least amount of cover abrasion and core torment of any clutch tested. With the recommended 1/2-inch diameter lines, testers found the textile clutch performed poorly. It was stubborn to take hold, and once set, equally unwilling to let go until the load was taken up by a winch. However, with smaller-diameter lines (3/8- and 7/16-inch), it performed as advertised. We will be conducting more onboard testing to evaluate durability and performance in real-world applications.
Bottom line: We’d only use the Constrictor at deck level or on or near the mast in long-term applications, such as a halyard on a furling headsail. Installing it up near the mast as a main halyard lock would be more of a gamble.
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To me, only two things suggest constrictor clutches:
- The textile part is a 3-5 year item.
- They have a narrower line size range for a given cover.
- They can be sticky on textured ropes.
Ronstan Constrictor
Like a turbo-charged update of the old finger handcuff, the novel Ronstan Constrictor clutch relies on cordage, rather than cam-induced pressure, as a locking device. A two-foot length of braided Dyneema cover acts as a glove-tight skin over a halyard or other piece of running rigging. Allowing this cover to stretch taut binds the line, transferring the load to the machined titanium mount.
When the control line attached to the sleeve is tensioned, the halyard slides through freely. And when the time comes to lock the line, this control string is released, and the braid cover is stretched by a bungee cord.
The Ronstan Constrictor can immobilize a highly loaded line, and it does so with the least amount of cover abrasion and core torment of any clutch tested. With the recommended 1/2-inch diameter lines, testers found the textile clutch performed poorly. It was stubborn to take hold, and once set, equally unwilling to let go until the load was taken up by a winch. However, with smaller-diameter lines (3/8- and 7/16-inch), it performed as advertised. We will be conducting more onboard testing to evaluate durability and performance in real-world applications.
Bottom line: We’d only use the Constrictor at deck level or on or near the mast in long-term applications, such as a halyard on a furling headsail. Installing it up near the mast as a main halyard lock would be more of a gamble.
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To me, only two things suggest constrictor clutches:
- Dyneema cover lines or Dyneema single braid (which is nasty to winch anyway).
- A desperate need to save ounces.