Tools you wish you'd bought sooner...
Discussion
hidetheelephants said:
DaveyBoyWonder said:
Yikes; those are a good demonstration of "just because you can doesn't mean you should".skwdenyer said:
hidetheelephants said:
Those are used extensively because they work very well. Obviously you have to choose your situation carefully. I wouldn't use one on a steeper pitched roof, or one that used a lower-mu covering GeneralBanter said:
skwdenyer said:
hidetheelephants said:
Those are used extensively because they work very well. Obviously you have to choose your situation carefully. I wouldn't use one on a steeper pitched roof, or one that used a lower-mu covering The roof example is more subtle. I don't agree that this particular illustration creates the problem you fear. But I do agree that the level of knowledge required to determine safety is higher, and I'd be less happy with a novice on that set-up on a different roof. But then a novice has no place putting a ladder up on a roof in the first place - for obvious Rod Hull reasons, as articulated.
Anyhow, the point is we're going around and around. A poster asked for examples of ladder stabilisers. There are many. But the moment you move past a simple ladder on level ground scenario, you're asking for the user to have an understanding of physics greater than the norm in order to determine safety. The ones I posted can all be used safely. But they can't all be used safely in all situations by all users.
And we haven't even touched on fore-aft restraint (stopping the base of the ladder moving relative to the wall) or preventing tipping. There's a reason many Sky dish installers (for instance) install eye bolts and base stand-offs and restraint straps before working up a ladder.
The bottom line is that ladders are simple machines with great risks. Most people aren't great at assessing those risks. For those that are, there are a wide range of solutions available. For those that aren't, I also agree with you that the Big Grip (or whatever it was called) is a great solution as being the easiest to understand and least likely to cause harm to the user.
hidetheelephants said:
Yikes; those are a good demonstration of "just because you can doesn't mean you should".
Back in 2012 I started working part time for a mate of mine working on ventilation and extraction systems mainly industrial stuff. Here's a photo I took of the first job I was involved with. Most of the work was inside fitting a large air handling unit for a 'booth' using 500mm diameter ductwork to the outside via the roof. All fine and interesting work until we had to go onto said roof to cut the hole for the last piece of spiral duct and terminate with a very large and heavy Jet Cowl similar to this to give some scale............Here's how he got onto the roof.............
That ladder was on full extension - I shat myself just footing it
Edited by dickymint on Tuesday 21st November 13:58
skwdenyer said:
For the staircase example, how is sideways slippage going to occur? I can't construct a force diagram that results in the device doing anything more than being safely forced *towards* the other side of the ladder, not away from it. The weight of the ladder is firmly between two points, not creating any sort of lateral force or turning moment.
The roof example is more subtle. I don't agree that this particular illustration creates the problem you fear. But I do agree that the level of knowledge required to determine safety is higher, and I'd be less happy with a novice on that set-up on a different roof. But then a novice has no place putting a ladder up on a roof in the first place - for obvious Rod Hull reasons, as articulated.
Anyhow, the point is we're going around and around. A poster asked for examples of ladder stabilisers. There are many. But the moment you move past a simple ladder on level ground scenario, you're asking for the user to have an understanding of physics greater than the norm in order to determine safety. The ones I posted can all be used safely. But they can't all be used safely in all situations by all users.
And we haven't even touched on fore-aft restraint (stopping the base of the ladder moving relative to the wall) or preventing tipping. There's a reason many Sky dish installers (for instance) install eye bolts and base stand-offs and restraint straps before working up a ladder.
The bottom line is that ladders are simple machines with great risks. Most people aren't great at assessing those risks. For those that are, there are a wide range of solutions available. For those that aren't, I also agree with you that the Big Grip (or whatever it was called) is a great solution as being the easiest to understand and least likely to cause harm to the user.
I’m not too sure from your post whether you get what is about to happen at all ! The moment on a ladder base exerts down and out but this is complicated by load/movement changes when going up & down. The roof example is more subtle. I don't agree that this particular illustration creates the problem you fear. But I do agree that the level of knowledge required to determine safety is higher, and I'd be less happy with a novice on that set-up on a different roof. But then a novice has no place putting a ladder up on a roof in the first place - for obvious Rod Hull reasons, as articulated.
Anyhow, the point is we're going around and around. A poster asked for examples of ladder stabilisers. There are many. But the moment you move past a simple ladder on level ground scenario, you're asking for the user to have an understanding of physics greater than the norm in order to determine safety. The ones I posted can all be used safely. But they can't all be used safely in all situations by all users.
And we haven't even touched on fore-aft restraint (stopping the base of the ladder moving relative to the wall) or preventing tipping. There's a reason many Sky dish installers (for instance) install eye bolts and base stand-offs and restraint straps before working up a ladder.
The bottom line is that ladders are simple machines with great risks. Most people aren't great at assessing those risks. For those that are, there are a wide range of solutions available. For those that aren't, I also agree with you that the Big Grip (or whatever it was called) is a great solution as being the easiest to understand and least likely to cause harm to the user.
The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
GeneralBanter said:
I’m not too sure from your post whether you get what is about to happen at all ! The moment on a ladder base exerts down and out but this is complicated by load/movement changes when going up & down.
The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
For the stair problem, all (or substantially all) the weight on the left hand side of the unit is acting through two rubber points that are sinking into the lower step carpet & will provide ample grip. The upper step is preventing a rotational movement clockwise - friction doesn’t come into play there.The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
Sketch it out with forces if you like For all likely load cases, the lower step contact is a pin joint with a limiting level of lateral restraint.
skwdenyer said:
GeneralBanter said:
I’m not too sure from your post whether you get what is about to happen at all ! The moment on a ladder base exerts down and out but this is complicated by load/movement changes when going up & down.
The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
For the stair problem, all (or substantially all) the weight on the left hand side of the unit is acting through two rubber points that are sinking into the lower step carpet & will provide ample grip. The upper step is preventing a rotational movement clockwise - friction doesn’t come into play there.The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
Sketch it out with forces if you like For all likely load cases, the lower step contact is a pin joint with a limiting level of lateral restraint.
Cold said:
skwdenyer said:
GeneralBanter said:
I’m not too sure from your post whether you get what is about to happen at all ! The moment on a ladder base exerts down and out but this is complicated by load/movement changes when going up & down.
The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
For the stair problem, all (or substantially all) the weight on the left hand side of the unit is acting through two rubber points that are sinking into the lower step carpet & will provide ample grip. The upper step is preventing a rotational movement clockwise - friction doesn’t come into play there.The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
Sketch it out with forces if you like For all likely load cases, the lower step contact is a pin joint with a limiting level of lateral restraint.
skwdenyer said:
Yes, because the ladder feet aren’t constrained vertically, so the ladder can’t impart a turning moment. All that can happen is a small difference in vertical load between the two ladder feet, but that will always be downwards. Any lateral resistance of the ladder is provided by friction of the ladder against the wall.
I'd like to see you videoing your demonstration of your theory. I will enter 999 on my phone and hover my finger over the dial button. Last ladder you'll need for uneven ground - had mine 25 years
https://www.hailo-shop.co.uk/store/ladders/combina...
https://www.hailo-shop.co.uk/store/ladders/combina...
Cold said:
skwdenyer said:
GeneralBanter said:
I’m not too sure from your post whether you get what is about to happen at all ! The moment on a ladder base exerts down and out but this is complicated by load/movement changes when going up & down.
The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
For the stair problem, all (or substantially all) the weight on the left hand side of the unit is acting through two rubber points that are sinking into the lower step carpet & will provide ample grip. The upper step is preventing a rotational movement clockwise - friction doesn’t come into play there.The stair is a classic - I’ve already said the weight is on the chamfered end of the ‘block’ on a rounded step edge and the other end on the other rounded block end and both ends are shiny on nice slippy carpet. You could probably tap the block out with a light tap.
In all these cases the most stable place to be is motionless right at the top when it’s possible to take away one support foot completely and rely on the friction of the two top feet against the wall to keep upright.
Sketch it out with forces if you like For all likely load cases, the lower step contact is a pin joint with a limiting level of lateral restraint.
skwdenyer said:
For the stair problem, all (or substantially all) the weight on the left hand side of the unit is acting through two rubber points that are sinking into the lower step carpet & will provide ample grip. The upper step is preventing a rotational movement clockwise - friction doesn’t come into play there.
Sketch it out with forces if you like For all likely load cases, the lower step contact is a pin joint with a limiting level of lateral restraint.
Need to see it oneself to properly make any clai of course but the part on the upper step looks well sketchy to me. There doesn't seem enough on the step, with the rounded bullnose+carpet+underlay+ possible historic wear to contend with I'd like to see it reaching further into the step.Sketch it out with forces if you like For all likely load cases, the lower step contact is a pin joint with a limiting level of lateral restraint.
And thats from someone who uses a stairmate so not afraid of what the sissies say.
skwdenyer said:
Sketch it out with forces if you like For all likely load cases, the lower step contact is a pin joint with a limiting level of lateral restraint.
it’s not a pin joint if it’s on something like a nice slippy surface such as a lump of metal on carpet or the edge of a stair. In these cases any weight transfer to that side will be unrestrained with only friction at the top against the wall stopping it. So half way up a double extension where the bending moment is greatest is a risk.It beggars belief these photos are used for marketing. For a start the ladders are just about vertical !
Cold said:
Has the eighteen stone bloke at the top, balancing on one leg, stretching sideways to paint the final section of the wall been included in the calculations?
That reminds me of someone I worked with many years ago.When I visited him during his recovery from several broken ribs and a broken arm I could see, as I approached the house, a beautifully described stripe of paint curving from the (UK not US) second floor towards the ground. He was very lucky.
On the subject of ladders, there has been a few threads or posts about the 6m versions of the telescopic ones. This pic appeared the other day on another site, thread was nothing to do with the ladder but that's what it ended up being about. Don't know if all those length ones are hinged in the middle, but looks errrr sketchy.
mgtony said:
On the subject of ladders, there has been a few threads or posts about the 6m versions of the telescopic ones. This pic appeared the other day on another site, thread was nothing to do with the ladder but that's what it ended up being about. Don't know if all those length ones are hinged in the middle, but looks errrr sketchy.
Wow that's grim. Centre hinge is the least of its worries, allows it to function as a stepladder, but using them things is nasty at 2 or 3 M.Gassing Station | Homes, Gardens and DIY | Top of Page | What's New | My Stuff