The auto-locking hoist hooks have gotten a lot of press in the last couple of years, and for good reason – dynamic rollout is a “clear and present danger” when using hoisted devices that are susceptible to rollout and when using hooks that can be in an unlocked state while lifting.
To recap, dynamic rollout (also called “ring rollout,” “hook rollout,” “forced rollout,” or just “rollout”) is the unintentional separation of a hoisted device (rescue strop, seat, basket, litter, etc) from the hook.
Rollout can only occur if all three of the following conditions exists:
- Susceptibility – the geometry of the hoist device lifting eye must allow for the hoist hook to be rotated in such a way that the lifting eye rests across the gate/keeper of the hook. Some devices simply are not susceptible to rollout but many devices are susceptible.
- Slack – there must be sufficient slack in the cable for #1 to occur, and then the slack is pulled tight. When #1 and #2 are present, a hook with a “beak” increases the likelihood of a rollout event by presenting a snag hazard at a very vulnerable point (what we call “undesirable position geometry”).
- Security – the locking mechanism for the gate/keeper must be unlocked.
Bottom line is, remove any one of those three conditions and rollout cannot occur.
Thus, the MEDEVAC Project Office has been working this issue with all three conditions in mind:
- Susceptibility – Where possible, worked with manufacturers to change the geometry of the device lifting eyes in order to remove or reduce susceptibility.
- Slack – We need slack in the cable to do our job. Educating users on the importance of managing that slack is part of what we do. A safe approach to Slack Management is to grasp the cable upstream of the hook/spring/bumper assembly and pull everything downstream tight, visually inspecting that all elements are in their proper places, and keeping it tight while checking to see where the slack goes before giving the UP command (i.e. not standing in a loop of cable).
- Security – We worked with PD MEDEVAC to get a number of auto-locking hooks approved for use. If the hook is always locked (or is auto-locking), a rollout cannot occur.
A new auto-locking hook is now entering testing. Capewell Aerial Systems, the manufacturer of both the Slide-Lok and the Auto-Lok, has spent the last three years designing a completely new hook – the Ultra-Lok.
The hook has been designed, from the ground-up, to be everything “ultra,” where the meaning of ultra comes from the Latin, “on the far side of; beyond.”
- Ultra-DESIGNED – with a team of engineers taking input from all major services over the past several years. This will be the only hook designed from the ground-up to meet ALL the requirements of the military hook specification, and all major components (including the latch mechanism) will be forged instead of cast. It is the perfect balance between BEAUTY and BRAWN.
- Ultra-ERGONOMIC – with visual and tactile features to determine hook orientation, as well as latches/locks that are easily disengaged with the fingers but protected from inadvertent release.
- Ultra-TESTED – with the US Navy performing a battery of both destructive and non-destructive testing to ensure that the requirements of the latest MIL-DTL-23599 are met or exceeded.
- Ultra-USEABLE – with specially-designed ergonomic opposing triggers to accommodate the full range of user hand sizes, a utility eye that is closer to the centerline of the hook, and a deeper throat and increased loading area to accommodate all common loading hardware. The Ultra-Lok will have a larger loading area than any of its competitors.
- Ultra-SAFE – with a streamlined exterior profile to minimize snag points, enhanced visibility features, and a safety factor of more than 28 times the maximum rated load of the hoist.
…because you’ve got a lot riding on this!