ATN Mastclimber line recommendations, etc.

[peaman]

I acquired an ATN Mastclimber right after I became an Ericson owner 3 years ago, and used it (much to the concern of the selling broker) to inspect the masthead before I sailed away with my new boat. But I had difficulty with the device due, apparently, to the elasticity of my halyards. I think that I would like to have a dedicated low-stretch line which I would use to replace a normal halyard for the purpose of climbing the mast. So I am asking for a recommendation for a low-stretch line (3/8"?) and any other comments on best effective use of the ATN Mastclimber or similar rigs.

 

[Dave G.]

But I had difficulty with the device due, apparently, to the elasticity of my halyards

Those would have to be some real "stretchy" halyards to not hold your weight. You sure it was the line stretching and not slipping maybe ? Even the most basic double braid 3/8 line has 4000lb breaking strength and shouldn't be stretching at all with that load .

 

[RedDog]

True…A “stretchy” halyard is a defective halyard. New England Sta-Set for example has very low stretch.

 

[peaman]

You sure it was the line stretching and not slipping maybe ?

Yes.
Nothing "slipped". Breaking strength is not at all related to "stretchiness" (modulus of elasticity). Source: retired professional mechanical engineer.

I'd love to hear from anyone who has used the ATN mast climber or a similar rig. The ATN uses two clutch devices. One supports the bosun's chair and the other supports foot loops. In use, the climber, resting on the chair, raises the "foot clutch" (while the climber raises his feet), then weight is shifted to the foot straps so the bosun's chair and its clutch may be raised. And the process is repeated. In my observation, the efficiency of the process is very dependent on the deflection of the line which supports the clutches and the climber. And that deflection comes from the elasticity of the line and the fact that the climber is, at any weight, an offset/eccentric load. My limited experience is based on using (surprise!) New England Sta-Set which has been represented here as having "very low stretch". I expect that better performance of the device will be found with a line of lower elastic modulus. But actual data on "stretchiness" or modulus of elasticity is not readily found with average Googling skills. Certainly someone out there has recorded the percent elongation under various loading for various lines used by modern mariners?

 

[Dave G.]

While not the pinnacle of ropes Sta -set is pretty much the go-to for a lot of folks. On my halyards I use New England VPC which is a little stiffer. This is the only "spec" i could find for sta-set.

https://www.teufelberger.com/media/contentmanager/content/downloads/Product_Data_Sheet_Sta-Set.pdf

 

[Dave G.]

Here's a test Practical Sailor did a while back. A little hard to read as it takes 2 pages and you have to correlate which lines are what on page 2 results If you print them it would be easier but alas.... This is old so there are more choices now but still good info. This is where I found VPC way back when.

https://www.practical-sailor.com/wp-content/uploads/2020/02/1110-rigging.pdf

 

[Christian Williams]

Kinleven Mast Ladder and Mast Climbing Options [Master Thread]

Today arrive my kinleven mast ladder. The first impression, the quality is superb!! I attached few pictures, will add more over the weekend when having time to use it. The whole ladder comes with a very sturdy bag and another net plastic bag inside. A little strap is included to storage the...

ericsonyachts.org

 

[vanilladuck]

When I use my ATN mastclimber I anchor the halyard I'm climbing to a chainplate or some other rock solid loop on the deck. Then I crank in some tension on the halyard from a winch. This keeps me moderately stable while climbing/descending.

@peaman - It sounds like this may be your process too, since you mentioned deflection of the line?

 

[southofvictor]

Like Bryan I found that with the ATN its easier to climb with your halyard really tight as opposed to a grigi system where you need a fair amount of slack.

Like others I’d be surprised if it’s a line stretch problem on a halyard, but maybe the sheath is sliding over the core? What kind of line is it?

 

[Dave G.]

What kind of line is it?

The OP stated it is NE Sta-Set.

 

[Kenneth K]

I'm not sure what the attraction is to ATNs. They are expensive, they damage the mast, they damage the lines, they can't be moved from one line to another once aloft. All of these issues can be avoided by using simple rope prussik loops.

I usually go aloft with six prussiks: one on a primary line, two backups, and 3 spares. The spares are useful for tying off objects while aloft. With a second locking carabiner on your harness, you can even switch ropes when aloft, if needed (i.e., climb one halyard and descend on another).

 

[southofvictor]

Ken when you say “one on the primary line” is that one at your harness? Do you use one of the “backups“ for your foot? And how do you descend? Just backing down the prussiks or do you carry a rap device?

Agreed on the ATN, it always sketches me out hearing that thing grate against the mast.

 

[Christian Williams]

Kinleven Mast Ladder and Mast Climbing Options [Master Thread]

Today arrive my kinleven mast ladder. The first impression, the quality is superb!! I attached few pictures, will add more over the weekend when having time to use it. The whole ladder comes with a very sturdy bag and another net plastic bag inside. A little strap is included to storage the...

ericsonyachts.org

 

[Kenneth K]

My primary line is usually my jib halyard, a newer, 7/16" VPC line. I put both the foot and harness prussiks on this same halyard.

My backup line is either a spinnaker halyard, or if I'm doing a lot of mast work, I'll hang a temporary line from the masthead and use that as a backup line. On backup lines, I only attach a harness prussik, not another foot loop.

As a third backup, I hang ropes over each set of spreaders and tie a prussik to each of these hanging lines. I clip/unclip my harness (using a second locking carabiner) to these spreader lines as I ascend/descend. That way, even if something gives way at the masthead (or, on deck where the masthead lines are made fast) I still have something draped around the spreaders to stop a fall.

I descend the same way I go up, alternating the foot and harness prussiks lower. I suppose you could repel, but it might be hard to keep your feet from slipping off the mast or hitting the spreaders on the way down.

 

[peaman]

Then I crank in some tension on the halyard from a winch.

I think this may be the main key, along with possibly a lower stretch line, like Dyneema core. The data sheet offered by @Dave G. shows that a 3/8" Sta-Set halyard may need something like 800 pounds pre-load in order to be stiff enough to climb efficiently. And, as @vanilladuck suggests, my "process" may need review, but I'm not sure what I can change until I try again. The process is basically alternating between sitting down and standing up, which one would think should gain a foot or so height with each cycle, but I was only able to progress around 6" of line with each cycle.

 

[vanilladuck]

My inch-worming with the clutches only produces about a foot at best each cycle. Any more than that and I feel like I'm going to invert.

For reference: I usually use my spinnaker halyard, which is made from Samson XLS3 10mm double braid poly rope