Securing a life raft with a hydrostatic release

[oldfatgit]

After having re-read the MAIB report on the Ouzo, I have concluded that in case we are run down, either in fog or in the dark or, as nearly happened a couple of years age in broad daylight by very large and fast motor yacht complete with inattentive helm, it would be best if our life raft were secured with a hydrostatic release.

I have purchased a HAMMAR H20 and have been considering how to secure the life raft with it. The point is that, in its cradle, the life raft (an Avon in a cannister) is secured with 2 web straps attached to ring bolts. So I have to change the arrangement so one release detaches both straps or whatever I replace the straps with. The instructions which have come with the hydrostatic release only consider securing one securing line and fail to mention my situation. I have a few ideas but thought it would be wise to canvas the views of the forum as somebody has already solved this problem.

 

[andygc]

Usual way is to have the two straps replaced by a single strap running through a senhouse slip hook (like this), with the straps attached in the original places on one side of the cradle to make a V. The hydrostatic release is hooked onto the senhouse and the other end lashed down to an eyebolt. The V strap is the equivalent of the "white rope" in the guide for small liferafts on the Hammar web site.

The senhouse permits you to launch the liferaft quickly without waiting for the boat to sink. The shackle between the Hammar unit and the eyebolt in the Hammar instructions is probably best replaced by a lashing - otherwise you have to be spot on with the length of your webbing.

 

[photodog]

Other than the senhouse... that is exactly how we have ours set up..... with quick release accomplished by a rotating locking pin under the lashing which is on the bottom of the hammar... the top of the unit then is fitted to a stianless D loop, via a shackle, which the webbing runs through...

 

[oldfatgit]

Thank you Andy. My only concern is that a V strap will not exploit the current lashings on the cradle and the strap groves on the canister which is clearly designed to be held around each end. I have 2 ideas, the first being to run one strap over one end, turn through 90 degrees at a ring bolt, pass along the bottom of the canister, up through the next ring bolt and thence over the top to the H20. The second idea was similar but to replace the horzontal part with cord of the same gauge as the strong line in the H20 threading the H20 onto it at about half way. The latter being both simpler and leaving 2 short light lines to un-thread on activation. Manual deployment being provided by the release of slip hooks between straps and current eye bolts. I will exploit the Hammar weak link on the firing line as intended, just that it will be separate from the H20. Any views.

 

[jdc]

I think your proposed way is ingenious, and may very well try it. However so far I've used the 'V' method on my Avon cannister, and as you say it doesn't make good use of the grooves. However I also have two conventional straps which lie in the grooves - sems silly to have a hydrostatic release and then nullify it's purpose, so let me explain.

In normal weather, and especially in fog, I take off the straps and rely on the V and the Hammar release. However when it's rough and I reckon that the danger of being run down is now less than that of foundering through weather or hitting a semi-submrged container I put back the straps so that a rogue wave can not carry it away. Perhaps my worry about hydrostatic releases triggering on a knock-down are ill found - the experience of others would be interesting.