March 2018
rapidCAST User’s Guide
Page
30
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
Line Properties
Spectra Line is composed of braided High-Molecular-Weight-Polyethylene.
•
Negligible stretching means line does not snap back violently if severed under load.
•
Rated tensile strength of 226 kg.
•
Can splice multiple segments together.
•
Spectra Line is very sensitive to heat, especially heat caused by friction. Portions of line that
have been exposed to high heat should not be used, as heat permanently damages the line and
makes it prone to breaking.
Never wrap line around fingers or limbs while the winch is powered, as the line’s high tensile
strength can cause serious injury if body parts get caught by line as the winch is moving.
The very bottom layer of line is attached to the spool via adhesive tape and is not fixed in a
permanent way. This is intentional. If the probe is snagged by a submerged obstacle, the idea
is to allow the probe to be pulled cleanly off the spool once line runs out, rather than allow
the winch to be damaged by a permanently tethered probe.
Mission-critical cruises would typically carry backup line and probes. Backup winches,
however, are less likely to be carried, so the probe was considered the more expendable
element in this worst-case scenario.
Each spool is loaded with a grand total of ~1954 meters of line, of which ~1700 meters can be
used for normal operation. The line is spliced in three main sections:
•
55 m of “Leader” Red Line: When reeling in the probe, this warns users that the
probe is near the vessel.
•
1645 m of White Line: Normal line used for deployment.
•
254 m of “Terminal” Red Line: Bottom part of the spool. The RapidCAST winch
software prevents this portion from being paid out, and in fact, automatically stops
deployment before this portion of line is reached. If, for some reason, the winch
ends up using this segment of line (perhaps through misconfiguration, improper
homing, or this safeguard is overridden). If line is still being deployed and you start
to see
red line, use the EMERGENCY STOP BUTTON.
