Hard Points

I posted a question on facebook / instagram asking people what steps they take if they’re going to suspend in an unfamiliar place. Is there anything they typically do to assess the hard point? Stuff they look out for, tests they do, particular questions that they like to ask the venue owner etc.?

A few people asked if I could publish the responses so I’ve collected and listed them here… I’ve deleted any duplicate answers but otherwise I haven’t really done any editing on this at all.

Some of the people responding were qualified (structural engineers, climbing instructors etc.), others were not and so at this stage this information should probably be taken more as an opinion survey than reliable facts. Although I’m more than happy if anyone qualified wants to send me suggestions/corrections (info@gestalta.co.uk), and at some point I’ll also edit it to read a little more concisely.

QUESTIONS TO ASK VENUE OWNERS

What materials is this made of?
How old is the hard point?
What is it typically used for?
How often do you perform tests on it?
What temperatures (weather and friction) do these points go through, and how does this affect the materials used?
Do you understand how this building was constructed?
Who installed these points, and what were their qualifications?
Has the point been rated or certified by an engineer?
What’s the dynamic load of the hard point?
Do you have inspection records?
Are you using rated construction materials / climbing gear?

And finally… you’re more likely to get a good response if you approach people with curiosity (“can you tell me how this works?”) than loaded questions (“Is this dangerous?”)

A few people said that asking someone should be a secondary option if they can’t see how something has been engineered. Although even if you can see you should still ask about anything that you don’t recognise.

As for responses… there was a bit of a split with some people having a definite idea of what kind of answers they were looking for, and others just wanting to judge that reaction of the owner, to see if they seemed confident and knowledgeable.

I’ve mixed the responses of people who knew what responses they were looking for in with the stuff that people were looking for in general because a lot of the responses were similar.

WHAT TO LOOK FOR

A minimum of 1000 KG WLL (working load limit) was suggested (guessing this might be more relevant for people who are doing very dynamic suspensions and that people who do more static styles of rope / bamboo work etc. might get away with a little less??)
A second person suggested a 240 KG SWL (safe working load) - working load usually takes into account a 4x safety factor (so 240KG will actually break at 960KG).

CONCRETE (or masonry) This seemed by far the most controversial material to use as it’s brittle and can fail without warning and without prior deformation. Wood and metal (and also bamboo!) can bend, crack or otherwise deform before breaking (giving you time to react and get the model down).

Some people preferred to avoid concrete altogether (which might be a better option if you don’t know what you’re looking for). For those who were happy to use it:
Avoid single points in the concrete, at minimum you are looking for 2 concrete mechanical or chemical (epoxy resin?) fasters of M12, although 3 x M16 (a quick google lead me to believe that M12 means 12mm diameter / and M16 means 16mm diameter - is this right?) spaced at at least 200 mm centers is better.
One person suggested a single point might be ok if it was a large bolt fixed with high quality epoxy resin - although I’ve no idea how common this is or how easy this is to do / test / verify.
A few people suggested plates screwed in with multiple bolts.

HARDWOOD / METAL / BEAMS etc.
Several people said they would also look for points which are doubled in these materials also (when screwed directly up into the ceiling), although others said that where possible it may be better to put the bolt through the beam, or to put a load rated sling over the beam.
You should ideally be looking for the structural foundations that hold the building together and attaching from these points. “If it’s a steel rod as in production set up make sure they are attached to the foundations or look at the weight distribution from the weakest point and reinforce where you can.” « this was a helpful sounding thing from Lau Bau; I don’t really feel I have enough knowledge to understand how to put into practice myself but someone else might find useful / be able to clarify.
Use of a beamspreader: C-clamp was also suggested.

GENERAL ADVICE Avoid hardpoints that you can’t clearly see all parts of (unless you can ask the owner for clarification). Check that the screws are going in straight / that they’re all the way in.
Look for fraying, metal chips, rusted metal, wear on whatever it is anchored to etc. Look for any breakouts near the screw.

TESTING THE POINT

If you’re using a tripod rig do a test swing to make sure it can’t fall over and that it’s pinned/weighted to the ground properly.

People suggested testing points with the dynamic weight (eg. swinging) of anything from 1 to 4 people, but there was some debate over which situations this would actually be helpful in. Most common suggestions were:
Weight test is generally more useful on metal (steel) or wooden points as you should be able to see if something doesn’t look right - you should look out for things such as bend, movement, torque etc. Listening to the sound it makes, seeing if anything falls from the point.
Metal / wood will show signs of excessive loading before they actually fail which is why this test is useful… whereas concrete will break suddenly so the test doesn’t really tell you much. A couple of people suggested that in this case it might even add risk.

OTHER ADVICE
One person (a climbing instructor) said that they sometimes add an extra line for security just as you would in climbing… which I’m guessing is similar to adding a second bolt into the ceiling, even if done in a slightly different way.