Corrugated sheet handling problem...

[Wedg1e]

Quick one for the crowd: we've got a job on which involves a bunch of guys dangling on ropes while they inspect the wall of a 20m tall storage tank. The tank is lagged and clad in corrugated sheeting, which needs to be removed to gain access. Not sure what the sheet material is or exact size, but the thing that's got us scratching our heads is how we hold the sheets while they are lowered (safely!) to the floor. There's no scope for powered access (or we wouldn't be using rope access techies).
We envisage a pulley system fixed to the tank top, with ground-level operators lowering the sheets off once they're freed.
Plate lifters won't work since they'd have no clamping force until the load comes on; anything that involves clamping jaws would need some pretty big jaws, but how would they work on corrugations; and although we could punch holes and bolt lifting lugs on to the top edge before each sheet is detached, it would be extremely time consuming and cumbersome.
Anyone got any experience we could tap into?

 

[8ob]

A couple of the scaffolders clamps would do the job. One each side of a sheet .

BIGBEN® Scaff Corro Clamp

The BIGBEN® ScaffCorroClamp is easy to operate – use a standard scaffold spanner to secure and release the clamp on to as many as 6 sheets at a time (SWL 66 kilos).

leachs.com

 

[Hitch]

I assume the sheets are verticle... one of them as Bob showed both sides...
And I assume metal sheeting...?
Or a screw type sheet grab..one in the middle...
Pop it on the top, then take out the lower screws.

 

[Wedg1e]

Aha, well spotted... thanks, I'll pass that on. Not sure how our google search for 'corrugated sheet lifter' didn't find that...

 

[gaz1]

if they are verticle fitted you want one to the side like 8obs but you also want one in the middle or just off set with a half clamp fitted to the top of the sheet

this will stop it swinging out and will keep it vertical until on the ground

 

[Agroshield]

Would a lifting magnet work? If you can find one designed for round objects (pipes), it might have a vee in its base to hug the wrinkles. Please do not shoot me for this, but your lowering system would benefit from something on it so that if the person lets go the rope, it does not drop like a stone.

Special thanks to 8ob for the one he found. I saw someone using one the other day (tin roof for loft conversion) and have been wondering what it was.

 

[mtt.tr]

Is the cladding to be reused? If not drill a hole and use a shackle.

 

[mtt.tr]

Would a lifting magnet work? If you can find one designed for round objects (pipes), it might have a vee in its base to hug the wrinkles. Please do not shoot me for this, but your lowering system would benefit from something on it so that if the person lets go the rope, it does not drop like a stone.

Special thanks to 8ob for the one he found. I saw someone using one the other day (tin roof for loft conversion) and have been wondering what it was.

If these chaps are irata they will set up a secondary lowering point most likely use a petzl rig or similar

 

[Hitch]

Here's what I was talking about...
One of these.. at the top centre... any marks left would be covered by the lap/flashing when re cladding.

And an auto braked gin wheel to be on the safe side, operated from the ground and that's it.
I mean what Is a 6m sheet of tin, 40kg at most.

 

[Prajna]

How are the sheets currently fixed? Is it possible to use the current fixing holes for lowering?

 

[gaz1]

How are the sheets currently fixed? Is it possible to use the current fixing holes for lowering?

not allowed to use them on uk sites

you mean just use a hook through the bolt holes

they used half round tube lifting clamps years ago to lift them up and also fix one side of it first

 

[eLuSiVeMiTe]

A couple of the scaffolders clamps would do the job. One each side of a sheet .

BIGBEN® Scaff Corro Clamp

The BIGBEN® ScaffCorroClamp is easy to operate – use a standard scaffold spanner to secure and release the clamp on to as many as 6 sheets at a time (SWL 66 kilos).

leachs.com

Beat me to it. Useful bits of kit when they're doing an up and over

 

[Prajna]

not allowed to use them on uk sites

you mean just use a hook through the bolt holes

they used half round tube lifting clamps years ago to lift them up and also fix one side of it first

I would opt for just reversing that process, but then what do I know?

 

[8ob]

These things are quite chunky, they wouldn’t slip off.

 

[gaz1]

@8ob there only good for side lifting onto roofs

they are no good for vertical lifting of the sheets so the rain runs downwards on those old water tanks

the sheets used to be holed at company before being coated then hooks was fitted at the top of the sheet so they could be vertically lifted

h&s crippled that lift as they quoted unsafe you need a bolt grip that failed as well with poeple not fastening the clamp tight enough and a few slipped out heading to the floor

 

[mtt.tr]

@8ob there only good for side lifting onto roofs

they are no good for vertical lifting of the sheets so the rain runs downwards on those old water tanks

the sheets used to be holed at company before being coated then hooks was fitted at the top of the sheet so they could be vertically lifted

h&s crippled that lift as they quoted unsafe you need a bolt grip that failed as well with poeple not fastening the clamp tight enough and a few slipped out heading to the floor

Only need a shackle

 

[gaz1]

what the user wants is an L shaped lifter with 2 sheet fasterners and one off set fastener so they can be lifted vertically

so they can be fastened at one side before first bracket (top ) is disconected then they can follow around bolting new sheets back on

its also the opposite if you want to bring down the sheets vertical

 

[Agroshield]

Would a vacuum lifter work?

These people offer special pads for crinkly stuff: https://www.righettivacuumlifters.c...-panels/roof-tile-shaped-panels-special-pads/

These people say their lifter work in both vertical and horizontal mode: https://www.vaclifting.co.uk/our-products/clad-boy/

 

[Kayos]

Can you elaborate "dangling on ropes"?

What are they suspended on?

 

[James1979]

Has anyone asked the RA Techs what their method statement is?

Might also be worth an email to the clamp people asking for a tech / data sheet to see if they can be used vertically. I cannot see why one each side of a sheet would not work but its not me thats got to sign off onto Risk Assessment