Wtb mini porti

I've got a Bassett Metal Studio...BMS Belay Spool...for sale. Superior to other bollard type lowering tools.

This is the real one. Made from a block of stainless steel.

Its not the redesigned aluminun junk that was sold for a little while

Tom Dunlap

Thread 'OLDS-Overhead Lowering...'

OLDS=Overhead Lowering Device System

Probably fifteen years ago I found a friction tool that I thought would work as a lowering device.

Take a look:

http://bmsrescue.com/blayspl.html

Read the paper on the spool:

http://bmsrescue.com/bspaper.html

Carroll has other papers that should be read too.

After talking with Carroll about the application as a rigging device he agreed that it should work very well.

After getting the spool it didn't take long for my crew to work out a smooth system for using the friction in the tree. I cam up with the name OLDS because we had a...
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Hope you find a deal on one! Silly how much they cost. Great piece of kit though! I spliced up a amsteel ultra sling for mine and it’s almost light enough for daily carry. So many good uses.

I too would love to see this belay spool! Unfortunately the link was expired. Having friction control in the tree can be such a game changer for production. Especially when there’s only one guy on the ground.
 
Tom Dunlap said:
I've got a Bassett Metal Studio...BMS Belay Spool...for sale. Superior to other bollard type lowering tools.

This is the real one. Made from a block of stainless steel.

Its not the redesigned aluminun junk that was sold for a little while

Tom Dunlap

Thread 'OLDS-Overhead Lowering...'

OLDS=Overhead Lowering Device System

Probably fifteen years ago I found a friction tool that I thought would work as a lowering device.

Take a look:

http://bmsrescue.com/blayspl.html

Read the paper on the spool:

http://bmsrescue.com/bspaper.html

Carroll has other papers that should be read too.

After talking with Carroll about the application as a rigging device he agreed that it should work very well.

After getting the spool it didn't take long for my crew to work out a smooth system for using the friction in the tree. I cam up with the name OLDS because we had a...
  • Like
Click to expand...
Tom, the belay spool looks interesting, those links are expired but I found some pics online. Do you have any pic of it in use? Dimensions? Thanks
 
Phil said:
Careful with that. Amsteel is hmpe fibers. They don't handle shock loads or abrasion well. It's meant for steady static loads to get its strength. Shock load it and it'll bust before polyester line will.
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HMPE is very abrasion resistant. It's definitely not fond of shock loading, but if your peak force is less than 20% of MBS, the you should be fine. With a mini porty, I don't imagine they'd be running anything over 1/2" line, and even if you are using 1/2" Stable Braid, with it's 10,500# MBS, you wanna aim to keep peak force under 2k. Even if you are rigging off a 3/8" Amsteel (17,600# MBS) sling, you should be fine as long as you limit ypur peak force appropriately. Where people fuck up is not calculating the peak force correctly because with a more static rigging point, the forces get higher for the same weight piece falling the same distance before it catches. Rope stretch reduces peak forces, which is something that some guys really lean into, so if that is your style, HMPE could get you into a lot of trouble. Letting it run properly will greatly reduce peak loading too, so I would feel comfortable rigging appropriately sized pieces on an appropriately sized sling of HMPE. I would never recommend it to anyone without sufficient experience and knowledge though.
 
A technical thought. IIt is known that knot tightening or settling is a method or means that absorbs and lowers the peak spike of a shock load, including half hitches grabbing a spar log. So in that case the X crossing is rope on rope and a potential (actually seems more like a certainty to me) instantaneous friction heating location. Uhmpe is the poorest temperature performer. I bet more failures come from temperature weakening than plain overload than people are aware of. Only sometimes is glazing left behind as a clue to temperature being a factor.
 
Phil said:
Careful with that. Amsteel is hmpe fibers. They don't handle shock loads or abrasion well. It's meant for steady static loads to get its strength. Shock load it and it'll bust before polyester line will.
Click to expand...
I appreciate the heads up, duelly noted and definitely put into consideration . I’m aware it shouldn’t be shock loaded and it is generally used in static applications. When used in a negative rig aspect it is let run liberally. With all things have to be cautious and understand the WLL and nature of the rope your choosing. I feel pretty comfortable with how I use it and in what applications. And in the correct application it’s a pretty epic light weight setup. I also have several 1/2 tenex slings spliced up if I want to get shockey with it.

It is a great point to bring up and for sure the one weak point of Amstel. Thanks
 
Matias said:
HMPE is very abrasion resistant. It's definitely not fond of shock loading, but if your peak force is less than 20% of MBS, the you should be fine. With a mini porty, I don't imagine they'd be running anything over 1/2" line, and even if you are using 1/2" Stable Braid, with it's 10,500# MBS, you wanna aim to keep peak force under 2k. Even if you are rigging off a 3/8" Amsteel (17,600# MBS) sling, you should be fine as long as you limit ypur peak force appropriately. Where people fuck up is not calculating the peak force correctly because with a more static rigging point, the forces get higher for the same weight piece falling the same distance before it catches. Rope stretch reduces peak forces, which is something that some guys really lean into, so if that is your style, HMPE could get you into a lot of trouble. Letting it run properly will greatly reduce peak loading too, so I would feel comfortable rigging appropriately sized pieces on an appropriately sized sling of HMPE. I would never recommend it to anyone without sufficient experience and knowledge though.
Click to expand...
Just to nitpick playfully other factors to consider with not using a block, is peak forces on the rigging point is substantially higher. Transmitting more force on the sling.
The lowering rope needs to be the weak link in the chain for many reasons.
With taking wraps you loose a lot of energy absorption with lack of rope stretch. So with a material choice such as amsteel tou get more shock load than you’d normally would. With your numbers of 10k and 17k that still doesn’t leave too much margin, couple that with fiver bending issues and derating with a choke there isn’t much forgiveness.
Other issues I’ve encountered with amsteel as a sling are load dispersal on the stem itself, squishing the bark and potentially even peeling it like a banana (learned those lessons by trial and error.

Just additional limiting factors. I’d pair 3/8 amsteel with aerial friction to 3/8 stable braid, keeping the loads smaller and able to run. No negative rigging of loads more than a couple of hundred pounds (200-300ish max).
With a remote rigging point this works great for a holdback.
 
Evo said:
Just to nitpick playfully other factors to consider with not using a block, is peak forces on the rigging point is substantially higher. Transmitting more force on the sling.
The lowering rope needs to be the weak link in the chain for many reasons.
With taking wraps you loose a lot of energy absorption with lack of rope stretch. So with a material choice such as amsteel tou get more shock load than you’d normally would. With your numbers of 10k and 17k that still doesn’t leave too much margin, couple that with fiver bending issues and derating with a choke there isn’t much forgiveness.
Other issues I’ve encountered with amsteel as a sling are load dispersal on the stem itself, squishing the bark and potentially even peeling it like a banana (learned those lessons by trial and error.

Just additional limiting factors. I’d pair 3/8 amsteel with aerial friction to 3/8 stable braid, keeping the loads smaller and able to run. No negative rigging of loads more than a couple of hundred pounds (200-300ish max).
With a remote rigging point this works great for a holdback.
Click to expand...
I agree 100%, I was just presenting a most extreme example. I would probably run a stretchier rope like an arbormaster or true blue, but otherwise just as you described.
 
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