The inspiration for MoorGuard came in the aftermath of an earthquake, granted not the normal maritime event.
In 2002 the 7.9 magnitude Denali Earthquake in Alaska, the largest recorded in the interior of the US for more than 150 years, generated seiches on bodies of water as far away as New Orleans where the inventor lived. In twenty minutes the water level in the bayou surged and fell over two feet, tearing the deck cleats from the 26 ton motor yacht ‘Blackwatch’. The cleats had been secured with 14” long stainless steel bolts. After surveying the damage the inventor concluded that if the mooring lines had been able to stretch without breaking, like a ligament, no damage would have occurred.
THE LIGAMENT BECOMES A FUSE
In turning the ligament idea into a practical device for mooring the concept of an electrical fuse offered the best approach. Research indicated three elements were needed for a rope fuse to be both practical and safe:
- It needs to hold a load both before and after activation, a key difference from an electrical fuse.
- It needs to have shock absorbing ability or it will be too brittle to do work.
- It needs to be safe in real world situations, not subject to random failures or dangerous failure mechanisms.
A NEW FIBER
Reducing these needs to a practical fuse proved difficult with available materials. Any rope fuse must be able to dissipate dangerous potential energy while at the same time maintain a secure connection with the load. The MoorGuard fiber was invented to solve this problem. The MoorGuard fiber behaves as an ordinary synthetic fiber until it reaches its Minimum Elongation Load (MEL) at which time it stretches, at a constant load, to prevent the buildup of dangerous potential energy while giving ample warning to halt the dangerous activity.
When paired with a secondary trigger mechanism, the unique shock absorbing characteristics of the fiber allow for the fabrication of very small, compact and inexpensive fuses for the largest and strongest of lines.