SparTalk
EDUCATION CATALOG RIGGING CONSULTATION HOME CONTACT US

Go Back   SparTalk > SparTalk
FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Display Modes
  #1  
Old 03-23-2013, 08:22 AM
Tarzan Tarzan is offline
Junior Member
 
Join Date: Mar 2013
Posts: 4
Default Aloft DVD

The DVD says that the harken block has a 2:1 advantage. BT's book in diagram 2.2 says that there is no mechanical advantage which appears to be the same lift as in the DVD.

What am I missing?

Thank you.
Reply With Quote
  #2  
Old 03-23-2013, 10:48 AM
Ian McColgin Ian McColgin is offline
Senior Member
 
Join Date: Jun 2005
Location: Hyannis, MA
Posts: 368
Default

Not looking at the video so I may be missing what's up but if you have a single block at the top - like a halyard - with the fall attached to your harness or chair, then someone at deck hauling you up has no mechanical advantage and must lift your whole weight. If you, sitting in the chair, have the hoist in hand to pull yourself up, half your weight is in your hands while the other half is in the seat - giving you a 2:1 advantage.

Postition is everything.

G'luck
Reply With Quote
  #3  
Old 03-23-2013, 01:13 PM
Tarzan Tarzan is offline
Junior Member
 
Join Date: Mar 2013
Posts: 4
Default

That occurred to me a couple of hours later as a possibility. Positioning indeed. So true, so true.

Thank you for replying.
Reply With Quote
  #4  
Old 03-25-2013, 03:59 PM
Brion Toss Brion Toss is offline
Moderator
 
Join Date: Jun 2005
Posts: 1,180
Default It's even better

Hi,
And when you are hauling yourself up the front of the mast (possible if the rake isn't extreme), you can place your feet against the mast and "hip thrust" as you pull. This takes even more weight off your arms. It also puts the stress more onto your back muscles, not just the biceps.
Fair leads,
Brion Toss
Reply With Quote
  #5  
Old 03-26-2013, 07:06 PM
Tarzan Tarzan is offline
Junior Member
 
Join Date: Mar 2013
Posts: 4
Default

Nice of you to chime in Brion. I am enjoying your DVD's (3) and books (2).

I decided to go with two Harken blocks just in case I need the mechanical advantage: a 1572 ratchet block with becket for the mast head and a 1549 ratchet block attached to my harness.

The blocks are rated for 9/16's maximum diameter line. In the DVD the rope you are using to haul yourself up appears to be quite thick, perhaps one inch and easy to grip. What size is it?

Fair vines.

Tarzan
Reply With Quote
  #6  
Old 03-27-2013, 08:11 AM
Brion Toss Brion Toss is offline
Moderator
 
Join Date: Jun 2005
Posts: 1,180
Default Options

Hi again,
That's 5/8" Regatta Braid, which feels nice and fat, stows (not coils) nicely in my line bag, and fit's well in those Harken blocks.
Note that, with two ratcheting blocks, plus the extra advantage, pulling yourself will be much easier, so you won't have to grip as hard, so 1/2" Regatta should be just fine. Oh, and you will probably have to turn off the ratchet on the lower block to descend -- that's how effective they are.
Fair leads,
Brion Toss
Reply With Quote
  #7  
Old 03-28-2013, 05:01 PM
Tarzan Tarzan is offline
Junior Member
 
Join Date: Mar 2013
Posts: 4
Default Take-a-knee

Insightfull & brief as always. Thank you very much.

All the best with knew knee.

Don't rush it. Do what feels right.

Tarzan
Reply With Quote
Reply


Thread Tools
Display Modes

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

vB code is On
Smilies are On
[IMG] code is On
HTML code is On


All times are GMT -7. The time now is 08:56 AM.


Powered by vBulletin® Version 3.6.7
Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.