Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Ascending & Working Aloft On a Ship's Mast - No Halyards Available
(OP)
Hello all,
On the retired steamship where I volunteer, a number of the flag hoists have developed issues; the only way to correct the problems is with hands-on effort, aloft.
For example, on the port forward spreader the US ensign [as an honourable mention to our American contributors and guests] with the house flag beneath it was hoisted at the beginning of the season. Unfortunately no deck or engineering personnel were consulted beforehand, nor was any consideration given to the condition of the hoist line itself.
Since then, one yarn of the line has parted just above the spring-loaded clip, meaning where the upper end of the hoist of the flag is attached to the line, and has ravelled a distance of two feet or so on the descending side of the upper sheave. As a consequence it is no longer possible to lower this hoist of flags since the loose yarn catches on the cheeks of the upper sheave attachment and no longer reeves through. As near as I can tell actually getting up there is the only way to correct this problem; and once this one's fixed the the hoist that goes to the very peak of the mast will need some work as well...
Other hoists have different issues, but I'm sure you all get the idea.
Since our budget is quite shoestring, the idea of hiring a long-armed shore-based Bronto or similar bucket-equipped hoist is a fiscally daunting prospect. The cheapest alternative seems to be to undertake a number of manual ascents from the deck of the ship itself.
The masts in question are smooth painted steel, with no steps or other projections. Based on my on-line research so far, my thoughts are running to using three webbing straps [very similar to lifting slings] tied around the mast with Klemheist ["K"] knots, which some of you may know are reported to slide fairly easily when loose but that will tighten when a downward load is applied.
Two of the straps would be for the climber's right and left feet respectively, with the third being tied above the other two and attached to a fall arrest harness worn by the climber along with a lineman's belt. The lengths of the straps would have to be very carefully chosen, since as I envision it the climber, while standing in the "stirrups," would have to first loosen and lift the upper K knot on the safety line, slide it up as far as possible, then pull down on it to tighten it into place. Next the K knots for the left and right "stirrups" would be raised as far as possible one at a time by an amount properly matching the vertical distance the climber can step up, with the lineman's belt serving to ensure the climber's body is held in close to the mast while all of the climber's weight is on the leg opposite the sling being slid up.
By repeating the cycle as often as needed it should be possible to securely make the climb and always have either a stirrup or two to stand in, with a safety line as a backup from the upper sling, all of the foregoing hopefully precluding any preventable injury or death.
It might take six hours in total to do just one repair, but at least each would get done safely.
What I'm trying to find out is whether a Klemheist knot can be safely used around a steel mast; all the info I've been able to find to date suggests that K knots are for use around another line, not around a mast itself. A Prusik knot seems to be if anything even less suitabe for the application than is the Klemheist...
Once the ascent has been made, the plan is to haul up a safe and comfortable bosun's chair or equivalent for the climber to sit in while determining the actual problem, then effecting repairs, line replacement, sheave lubrication or loosening, or whatever else is required.
Any advice?
On the retired steamship where I volunteer, a number of the flag hoists have developed issues; the only way to correct the problems is with hands-on effort, aloft.
For example, on the port forward spreader the US ensign [as an honourable mention to our American contributors and guests] with the house flag beneath it was hoisted at the beginning of the season. Unfortunately no deck or engineering personnel were consulted beforehand, nor was any consideration given to the condition of the hoist line itself.
Since then, one yarn of the line has parted just above the spring-loaded clip, meaning where the upper end of the hoist of the flag is attached to the line, and has ravelled a distance of two feet or so on the descending side of the upper sheave. As a consequence it is no longer possible to lower this hoist of flags since the loose yarn catches on the cheeks of the upper sheave attachment and no longer reeves through. As near as I can tell actually getting up there is the only way to correct this problem; and once this one's fixed the the hoist that goes to the very peak of the mast will need some work as well...
Other hoists have different issues, but I'm sure you all get the idea.
Since our budget is quite shoestring, the idea of hiring a long-armed shore-based Bronto or similar bucket-equipped hoist is a fiscally daunting prospect. The cheapest alternative seems to be to undertake a number of manual ascents from the deck of the ship itself.
The masts in question are smooth painted steel, with no steps or other projections. Based on my on-line research so far, my thoughts are running to using three webbing straps [very similar to lifting slings] tied around the mast with Klemheist ["K"] knots, which some of you may know are reported to slide fairly easily when loose but that will tighten when a downward load is applied.
Two of the straps would be for the climber's right and left feet respectively, with the third being tied above the other two and attached to a fall arrest harness worn by the climber along with a lineman's belt. The lengths of the straps would have to be very carefully chosen, since as I envision it the climber, while standing in the "stirrups," would have to first loosen and lift the upper K knot on the safety line, slide it up as far as possible, then pull down on it to tighten it into place. Next the K knots for the left and right "stirrups" would be raised as far as possible one at a time by an amount properly matching the vertical distance the climber can step up, with the lineman's belt serving to ensure the climber's body is held in close to the mast while all of the climber's weight is on the leg opposite the sling being slid up.
By repeating the cycle as often as needed it should be possible to securely make the climb and always have either a stirrup or two to stand in, with a safety line as a backup from the upper sling, all of the foregoing hopefully precluding any preventable injury or death.
It might take six hours in total to do just one repair, but at least each would get done safely.
What I'm trying to find out is whether a Klemheist knot can be safely used around a steel mast; all the info I've been able to find to date suggests that K knots are for use around another line, not around a mast itself. A Prusik knot seems to be if anything even less suitabe for the application than is the Klemheist...
Once the ascent has been made, the plan is to haul up a safe and comfortable bosun's chair or equivalent for the climber to sit in while determining the actual problem, then effecting repairs, line replacement, sheave lubrication or loosening, or whatever else is required.
Any advice?
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]





RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
The strap needs a high friction coating like rubber or vinyl. Beyond that I can't see that we can provide you with enough details to create a safe procedure.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Good thought on the 'stickiness' aspect; my concern with having too grippy a sling was that it might make it harder to loosen its hold on the mast and add to the climber's efforts, both on the way up and down...then again, a more secure grip might compensate for any sub-optimal or off-design use of the Klemheist knot.
I also thought I'd take a chance on there being some forum readers who are climbers and might have some pointers for me...
For instance, since posting the above I've started to wonder if much faster progress could be made both up and down one of the wire rope shrouds that support the mast using some sort of readily available cam grippers [again, using three of them; one for the feet, one for the lineman's belt, one for the safety line attached to the fall arrest harness]...although going this route it might take a more agile climber to transfer into a bosun's chair than with the first method...
Hmmm, as I think on it further we might be better served to see if we can find someone from the area who's [a] a climber, [b] mechanically inclined, and [c] more youthful [!] to grant us the favour of a one-off work arc to help us deal with all of these issues in one git-'er-done campaign; after all, I'm in my fifties but still one of the youngest volunteers aboard...
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
They'll sort you out in a jiffy.
Cheers
Greg Locock
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RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
The tie-in point on a fall arrest harness isn't in the ideal place to support you while working - nor are they the most comfortable things to be hanging around in for hours on end. A sit-harness is probably a lot more suitable. Climbers will have their own.
The traditional approach to this would use just two friction knots - the upper one tied directly to the tie-in at waist level on the harness with a lower one attached to the mast somewhere above waist level, driven by one or both feet at the bottom, with a safety tie-in to the harness in case the top knot slips. You'd use a stand-sit action to climb, rather than a left foot-right foot. Instead of a linesman's belt, you could either run a loose sling round the mast from the tie-in on the harness (this area is going to get quite congested) - or just wrap an arm round the mast while pushing up.
Think a bit about how you get down when the job is over - down-prusiking is harder than going up and a lot more prone to things slipping in an inconvenient and embarrassing fashion.
Think a bit about what you're going to do if you lose confidence in one of your slings (say for instance it gets cut on a sharp edge.
Think a bit about what you're going to do if one of your kleimheists gets stuck on the mast.
Think carefully about what your mates are going to do (seriously) if you become tired or otherwise incapacitated while up there - make sure they know too, and have the right kit to hand - and make any necessary changes to your rig before you start climbing - this looks like the mother of all "I need to get above you to rescue you, but I can't because you're in the way" scenarios.
Even if you get a team of experienced climbers in, think about all these things anyway - it's your site and there's several things about this job that are going to be very different from a run-of-the-mill day out at the local crag.
A.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Good luck.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
A lot here depends on how high the spreader is above the rest of the rigging.
Some years ago my uncle used to work for Decca Radar co., his people often faced this problem bolting a radar antenna on a ships mast.
Their solution was to use several dozen pairs of self locking pliers ( vice grips) in the rigging, they would clamp these to the shroud wires to form a ( stepladder), up which they would ascend to do the work. Once they got up to the spreaders, then they would set up working tackle for the job at hand. When the job was done, the last guy down would unclip the grips, one by one, on the way down.
B.E.
You are judged not by what you know, but by what you can do.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Mike McCann, PE, SE (WA)
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
1. Given that a major component of the job is the ascension, establishing a workspace and the descent, maybe a shore based lift is not as "fiscally daunting" as you might imagine. Can you take some time to prepare the job on the ground, then moor to a dock that can accommodate a EWP and hire one for a half day? I see American rates in the order of $180 for a 34 foot knuckle boom. Even a $300 full day buys a lot of risk mitigation. Transport and licenses might be a killer, but worth looking in to I think.
2. Speak to a local arborist? I routinely see these guys scale awkwardly shaped trees with various protrusions, working at height and carrying a bunch of tools. You might want to see if you can negotiate an alternative to their climbing spikes though...
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
This is beginning to sound more and more like the way to go...
Which is why I wrote: "Once the ascent has been made, the plan is to haul up a safe and comfortable bosun's chair or equivalent for the climber to sit in while..." I do very much appreciate your concern of all the things to think about, zeusfaber, which is precisely what led to the creation of the OP.
With all due respect, that was one of my first actions; unfortunately climbing is not my strong suit, and I readily admit that I didn't understand a good bit of whatever it was I found.
I had to Google "abseilers" to grasp the intent of this one...and I'm even more convinced to try and find a local climbing team or group who'd rise to the challenge of helping us get done what we need to do. And once again, with all due respect, I'd have to disagree with one thing you said, because imho the job IS in fact just as abseilutely dangerous and complicated as it seems, and requires a great deal of strategizing, especially in re to being prepared for contingencies.
I'm guesstimating the spreader height as 25 to 30 feet above deck level, and the masthead at 55 to 60 feet up.
Very serious heights indeed, and far too great to entrust any one's life or limbs to a series of Vise-Grips.
You're not kiddin!
That was definitely something I was going to include in the plan; after all, I didn't want us to have to jump through such a number of hoops more than once...and I'm thinking two dual redundant halyards would be required on each mast, one to hoist the climber and one to provide a back-up connection for the fall arrest gear, with both requiring grinders so that the safety line is not permitted to develop dangerous slack during either ascent or descent.
One other point is that since this is a steamship and not a sailing vessel, there are not any existing winches fit for this purpose, so we will need to acquire a pair of suitably sized portable winches that we can use for future ascents. Even though I can envision the campaign to achieve the end state needing as many as a dozen people to execute [by the time you factor in spotters, mechanics, rescuers on standby and so on], I'm hopeful that future ascents should not need more than a squad of four.
Thank you again for all the input.
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Overlapping posts; I missed yours.
What's a WAG?
What's an EWP? Elevated Work Platform, perhaps?
The old girl is permanently tied up along shore, and would not need to be relocated for the task; but the grade of the adjacent lot would pose some serious issues for any kind of bucket truck, and significant blocking would have to be provided under the stabilizers in order to level the equipment. But that being said, the issues probably aren't insurmountable.
Engaging an arborist has possibilities; I had initially dismissed the idea, but I will have to re-consider...
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Which boat is this? The Obrien, or the Lane Victory?
B.E.
You are judged not by what you know, but by what you can do.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
SWAG = Scientific Wild A$$ Guess
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
That is a probably what the liability insurance for what you are contemplating will cost you.
Or if you are foolish enough to just send someone aloft with jury-rigged equipment and something happens how much will the ensuing lawsuit cost you?
Just do it right. Faster. Cheaper. Better.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Neither...and as I have stated in other posts I remain enjoined from disclosing the name of the vessel or my association with the organization that has leased it due to unfounded fears that I might in some way bind the organization...not that I'm that dumb; as the saying goes, "Yes, I was born at night...but it wasn't last night."
This link
https://maps.google.com/maps/myplaces?ll=44.747564...
is to a vessel permanently tied up along the shore that may be of assistance in illustrating the scenario I'm describing. I can neither confirm nor deny whether it is the vessel in question...
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
The 60 feet I referred to earlier was from the deck to the mast peak; alas, the hurricane deck is another 30 to 35 feet higher than the adjacent ground level. Additionally, the centreline of the vessel is at least 30 feet horizontally away from the edge of the quayside. Does a 'telescopic lift' have the ability to go, say, one hundred feet up, then thirty or forty feet over?
With respect, we are not that slipshod; we do have liability insurance in place, but only as a measure of last resort.
We perform all of our work to IAPA [Industrial Accident and Prevention Association] standards, and have available and use the personal protective and safety equipment required, and the correct tools applicable to, the task at hand.
Our engineering group includes among others stationary and marine engineers, project engineers, an electrical engineer, tool and die makers, a number of millwrights, and a retired construction superintendent.
Any kit we may assemble for a given job uses quality materials, tools, equipment and supplies, and we accompany this with a careful mindset and a professional approach to our work; a cavalier or devil-may-care attitude is simply not tolerated.
If we don't know how to do something, we engage those who do.
Our intransigence in this regard is the cause of much moaning and protest by our bookkeepers and treasurer, since in our refusal to do otherwise we expend a sizable chunk of the organization's revenue stream, which can be problematic when the cash flow isn't robust to begin with.
End of rant.
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
In other words, "challenge them" with a difficult and tricky job out of their usual "rocky cliff" comfort zone to apply their training and tools and experience. Give them the problem, then see what they come up with as a solution.
It is sort of like the old story where about the "stone soup" - Each villager willingly "volunteered" to contribute a little meat, a few potatoes, a handful of vegetables, some salt, seasonings, etc to the soldier's hot water and wet stone, but would have refused if the items were demanded.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Cheers
Greg Locock
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RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Reach out for an expert, entice them with fame and a shiny plaque with accolades mounted on the ship. Your shoestring budget probably can't cover potential medical costs if attempted.
"Art without engineering is dreaming; Engineering without art is calculating."
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RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
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RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
I applaud your volunteerism in trying to tackle an unfortunate repair with innovative means. However, please proceed with caution. Should there be any accident by some rock climber or tree arborist the MOL will be all over you, likely with dire financial consequences that would far outweigh the cost of crane access. The typical pole/tree climber relies on spikes attached to their boots that penetrate the wood and provide 100% of the support while climbing. This will not work with a steel mast. Two independent means of support are required for work such as this. Every time I was raised up a sailboat mast via bosuns chair, I was always connected with two halyards.
I understand funds are tight, but given that the likely owner of the likely steamship has deep pockets. I would recommend lobbying for $1k or $2k from the owner, or delay until additional funds can be raised. Is the repair worth the risk???
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
See if your local coast guard would like to take part in an exercise involving attaching a rope to the top of a mast?
B.E.
You are judged not by what you know, but by what you can do.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Now that's an idea that might have some legs.
A.
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Mike McCann, PE, SE (WA)
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Cheers
Greg Locock
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RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Hi Greg, that's a tough one to answer; I'd have to try and determine what the axis of roll is, and how much above or below the waterline said axis is. But if i could determine that, the rest would be a simple matter of polar co-ordinates calculation using summation of vertical height from axis of roll to masthead peak and a given number of degrees of roll to yield an approximation of possible lateral displacement.
Or just do the job on a calm day...
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Ah.
Enlightenment has occurred.
I see where you're going, and a 'boat-centric' [nice phraseology!] approach certainly does away with having to tinker about with the hardware on the mast peak as it drifts a foot or two either side of the tinkerer's arms...which points more in the direction of challenging some climbers/spelunkers to help us with this conundrum.
Perhaps we'd need to see if the climbers would be willing to sign indemnity waivers, just in case something happens despite every measure we take to ensure it doesn't.
FWIW I had considered using a scissors lift on ths ship itself for the job, but had to dismiss this on the grounds that [a] the hurricane deck was never built to support the weight of such a machine, [b] we'd have to rent a crane to hoist the scissors lift onto the ship from the quay and back, and [c] there's not enough of a "footprint" anywhere near enough to the aft mast to make the lift feasible.
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
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RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
I have also climbed trees by throwing a rope over a limb, and pulling up a ladder. The ladder was lashed to the tree at intervals as I climbed. Can you use a bow and arrow to shoot a line over the cross arm to pull up a heavier rope?
You can use a telescoping "Hot Stick" to place a rope with a properly shaped hook on the end over a protrusion. Once the hook is hung the hot stick is used to pick up the hook from the other side and pull the rope over and down. This will get you up about 30 feet. I once went up as far as I could by ladder and belted off. Then I used the hot stick to change a fuse another 30 feet higher. (By the time I was finished, there was a crowd watching. When I closed in the new fuse and the streets lights came on, I got a round of applause. The only time I have received an ovation for changing a fuse.)
Bill
--------------------
"Why not the best?"
Jimmy Carter
RE: Ascending & Working Aloft On a Ship's Mast - No Halyards Available
Another huge benefit is that we'd be able to hoist the scaffolding sections up the thirty or so feet from the ground to the hurricane deck with just the existing service hoist with no need to hirea crane at all...
Thanks, Bill; that thought hadn't occurred to me at all.
Although I have doubts the other things you've done would work very well in our situation, I very much enjoyed hearing about them!
CR
"As iron sharpens iron, so one person sharpens another." [Proverbs 27:17, NIV]