UKC

Does anyone know if any of the gear manufacturers publish dimensions for their smallish triple locking carabiners?

Looking at the DMM, Edelrid and Petzl websites, they give you overall length, overall width, and open gate width but i need to know depth (i.e. the section size) and ideally the shape of the nose etc to know whether they'll work for the intended use. A CAD model would be perfect but I don't think any of them publish that information.

I think I can remember seeing much more detailed dimensional information a few years ago when Petzl were marketing a new carabiner model but I can't find anything now.

I'm aiming to use the carabiner to replace a small screwgate delta link (not much larger than a bail maillon) with a more secure connection. The delta link connects into a hole that is too small diameter for most carabiners to fit.

It is for a work use rather than climbing. Not for use as PPE, but still safety related.

What's the diameter of the hole the carabiner has to go through?

I think it's 9 or 10mm diameter. The hole is about 10mm from the edge of a plate which is about 6mm thick.

All dimensions are approximate as I'm at home. Will be able to confirm accurate dimensions tomorrow.

DMM Ultra O is 12.5mm across the bar at the top of the oval.

If you can't make the hole bigger, would it be possible to put a welded ring in place instead? Another option would be an Edelrid Cupid. These would then give you free choice of krabs.

Welding or permanent modifications to the plate won't be an option. The plate is part of a product that will periodically be returned to the manufacturer for maintenance and i don't think they would take too kindly to any permanent modifications.

If there aren't any carabiners that will fit, the Cupid might be an option. After installation, the product could potentially be left in situ for a few months at a time before being removed and either reinstalled elsewhere, or sent back to the manufacturer for maintenance. So something that is a bit fiddly to install like the Cupid would be fine, as it won't need to be opened regularly.

Other options that may work depending on requirements:

Bolt securing some kind of lifting eye in place with a nut on the otherside. Possible issues with corrosion, vibration, damage to product's surface finish.

Shackle with pin directly through the hole, easily removed, possible concerns about directional loading/ cross loading which would apply with a krab too.

Threading slings/ rope/ steel rope etc through the hole when required (if edges are not sharp).

Is this for a lifting application? If so you will need to look at LOLER and make sure your solution is compliant and that you do a proper lifting plan so that the operator has confidence the lift can be done safely. Consider your safety factors etc too, the ones typically used in industrial lifting are substantial (compared a lifting sling with your skinny 8mm dyneema ones!). You may find that the manufacturer has a solution that you can pay for from them which has already had all of this done (likely cheaper than having an engineer do the design and then getting someone to implement a solution for you).

I aren't at work to check, but we use the steel trilock petzl oxan and it's one of the few carabiners that is narrow enough to fit through the swivels we use once it's been tagged. If it's being left without the need of regularly removing it, wouldn't a maillon be better?

https://hownot2.store/collections/carabiners now include many dimensions of their carabiners, but they may not stock what you want, so may not have the dimensions.

Thanks everyone for your assistance, I've got enough to ponder and work out if/how to proceed.

This will fall under LOLER, it's for a secondary rigging line which would only be loaded following a failure of the product's primary fixing. The utilisation of the SWL would be very low.

The product is subject to some vibration during routine use, and is exposed to the elements.

An incident (not ours) was reported involving the product following a failure of the primary fixing during an extreme weather event (hence having to be a bit vague on details). The product manufacturer's proposed amended secondary rigging has not satisfied us that it has eliminated the mechanism of that failure. We're exploring the options for whether we can safely return the product to use.

The main factors we need to get right are:

- avoiding any pinching, binding, rubbing that would reduce the effectiveness of the secondary rigging (this is likely to require different connections to be used for different installations).

- ensuring the secondary rigging remains effective following routine use and any extreme weather events (or that it is removed prior to any such events)

​​​- ensuring an adequate inspection regime to ensure the above