MOB systems - Page 2 - SailNet Community
 2Likes
Reply
 
LinkBack Thread Tools
post #11 of 16 Old 09-08-2012
Reward for lost Kraken!
 
hellosailor's Avatar
 
Join Date: Apr 2006
Posts: 11,481
Thanks: 5
Thanked 132 Times in 129 Posts
Rep Power: 11
   
Re: MOB systems

delite, I don't understand your repeated reference to the boom as a danger. A boom is a boom, is a cargo boom, is a crane. That's how you reach out to lift things, and there's no reason it should endanger the crew or the MOB any more than a boom endangers everyone on deck at all times. Which it normally does, all of the time.

There are only three ways to approach a MOB in the water. You can try to back onto them, generally a bad idea since the prop is a pointy thing that likes to chew flesh, and you've got the prop and rudder and the stern is going to be bouncing up and down trying to kill the MOB unless you're in dead flat water.

If you've ever tried a stern boarding in the water, even in two foot seas, you won't want to be recovered that way.

So then you can approach the MOB from either upwind or downwind and try to recover them miships, which is how NOAA and others prefer to recover divers. Midships the hull is bouncing around less and the situation is more stable. Except, how do you approach the MOB? If you drift down on them, you may steamroll them with the hull. If you come up to them against the wind, as soon as you depower you'll fall off away from them.

Best bet? Come alongside them, either upwind or downwind as conditions merit, and get a line on them. Then USE THE BOOM so you can lift them clear of the water AND CLEAER OF THE HULL and swing them inboard.

If you can't control the boom, leave it trimed in and secure as best you can, you'll still have the advantage of having a multiple part block and tackle to give you LIFT against the MOB's weight.

We rigged a snatch block from a spare 6-part block and tackle, used a bit of light line to make sure it can't tangle while stored. MOB procedure is to clip it on the aft end of the boom and run the line out to the MOB however possible when it is time to recover them.

Using a multi-part block and tackle will make it possible to lift that big wet heavy MOB out of the water and clear of the hull before they get steamrolled by it. The boom? Is no more dangerous than it has been all day every day. Where else are you going to rig a pulley set that gives you lifting advantage and keeps the MOB clear of the hull?

Of course there are other ways to recover someone, and this is not to say a blanket roll in a sail isn't going to be better. That all depends on weather, spare hands, and everything else you need to judge on the spot.
hellosailor is offline  
Quote Quick Reply Share with Facebook
Sponsored Links
Advertisement
 
post #12 of 16 Old 09-08-2012 Thread Starter
Senior Member
 
Join Date: Nov 2009
Location: Vancouver BC
Posts: 206
Thanks: 0
Thanked 4 Times in 3 Posts
Rep Power: 6
 
Re: MOB systems

Great inexpensive way to go. I might worry about the snap shackle on the end attached to the lifting tackle on the backstay or a halyard though and would probably go with a bowline on that corner.
delite is offline  
Quote Quick Reply Share with Facebook
post #13 of 16 Old 09-08-2012
Reward for lost Kraken!
 
hellosailor's Avatar
 
Join Date: Apr 2006
Posts: 11,481
Thanks: 5
Thanked 132 Times in 129 Posts
Rep Power: 11
   
Re: MOB systems

There are shackles and there are shackles. Like the carabiners used on rigging, versus the ones sold as keychains. Ornamental shackles have no place on rigging.
hellosailor is offline  
Quote Quick Reply Share with Facebook
post #14 of 16 Old 09-08-2012
Senior Member
 
Geoff54's Avatar
 
Join Date: Oct 2011
Posts: 712
Thanks: 5
Thanked 8 Times in 8 Posts
Rep Power: 4
 
Re: MOB systems

Quote:
Originally Posted by hellosailor View Post
Then USE THE BOOM so you can lift them clear of the water AND CLEAER OF THE HULL and swing them inboard.

If you can't control the boom, leave it trimed in and secure as best you can, you'll still have the advantage of having a multiple part block and tackle to give you LIFT against the MOB's weight.
As I see it, using the boom presents two potential problems:

1. On many boats the boom is too low to lift someone high enough to clear to lifelines and swing them aboard.

2. To really take advantage of using the boom, you need to swing it out so that the MOB is kept clear of the hull but still control the swing. On most boats that requires running a line forward, like a preventer, so that the boom can be restrained between that and the main sheet. Could be quick and easy or slow and difficult depending on the boat, crew and level of preparedness. Just leaving it sheeted without a second line , pulls too horizontally so the MOB isnít clear of the hull. In those circumstances I think you would be better of using a halyard so that the lift is more vertical. You can use a winch to gain some mechanical advantage.

If you plan use the boom, you need to have tried it out on that particular boat before you really need to use it. It might be a great method for you and your boat but it might not.
Geoff54 is offline  
Quote Quick Reply Share with Facebook
post #15 of 16 Old 09-08-2012
Reward for lost Kraken!
 
hellosailor's Avatar
 
Join Date: Apr 2006
Posts: 11,481
Thanks: 5
Thanked 132 Times in 129 Posts
Rep Power: 11
   
Re: MOB systems

"you need to have tried it out on that particular boat before you really need to use it."
Absolutely, Geoff!
With any MOB plan, you need to try it, and make sure the whole crew is familiar with it. And if anyone disagrees with it, work that through and see if they've found a flaw.

If you have a decksweeper the boom may not be high enough. And if you have a conventional boom, it still may not be high enough unless you drop the lifelines, or take the main halyard back to lift the aft end of the boom. Either way, we figured the multiple purchase of the 6:1 block would be a great advantage and the boom would be enough to get a MOB well out of the water, which is a good start.

Then again, we also have Standing Orders:

Rule #1, Stay on the Boat
Rule #2, Never walk on water in public, it tends to start religions
hellosailor is offline  
Quote Quick Reply Share with Facebook
post #16 of 16 Old 11-02-2012
Senior Member
 
Join Date: Jul 2012
Location: Toronto
Posts: 250
Thanks: 2
Thanked 6 Times in 5 Posts
Rep Power: 4
 
Re: MOB systems

It is similar to the quick stop but the MOB I was taught in my Intermediate Cruising course was to immediately heave to. Once hove to release the wheel / tiller in short bursts to make a circle, coming up below the MOB.

I did this in the middle of Virgin Gorda Sound in a driving rain that hurt my face. It was much easier than putzing around with the figure 8 that we had been taught in the basic course.

I can attest to the effects of cold water. In late 80's I took my dinghy course (then called White Sail) on the Ottawa River in May. Part of the course was flipping our Albacores or Lasers and righting them. The week before that particular lesson one of my boat mates took out a laser while the other student and I rigged the Albacore. AS we launched from shore we watched the laser flip, get righted, flip again, right again and finally go down for a 3rd time. The team learning to man the rescue boat (this was a co-op type sailing club) could not get the engine started so we sailed over. The instructor asked the guy in the water if he needed help. "yyyyyyyesss" was the faint reply. The instructor told us that one of us had to jump in so I volunteered. I was wearing jeans, my white shirt from work, a fishermans knit sweater, a shell and my life jacket. As I hit the water my heart and breathing stopped for about 30 seconds it was so cold. I helped right the laser and then held on to one side while he crawled in the other. I swam back to the Albacore but I had no strength left in my arms. From the water the Albacore looks about 8 feet up. The instructor and the 3rd student grabbed my life jacket and hauled me up. I had been in the water a total of 10 minutes max and I was wiped out. We still had our lesson and then burgers and beer after. My nuts have only recently reappeared. I have supreme respect for cold water.
i_amcdn is offline  
Quote Quick Reply Share with Facebook
Reply

Quick Reply
Message:
Options

By choosing to post the reply above you agree to the rules you agreed to when joining Sailnet.
Click Here to view those rules.

Register Now



In order to be able to post messages on the SailNet Community forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
Please note: After entering 3 characters a list of Usernames already in use will appear and the list will disappear once a valid Username is entered.


User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Similar Threads
Thread Thread Starter Forum Replies Last Post
Mooring systems GoodOldBoat Good Old Boat 4 05-23-2015 06:48 PM
Cooling Systems hearts desire Gear & Maintenance 1 05-30-2003 05:31 AM
C.A.R.D. systems BertV Gear & Maintenance 2 02-12-2003 06:36 PM
Low-Pressure Systems Michael Carr Seamanship Articles 0 12-08-2000 07:00 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome