Basic Height Safety Facts
Passive safety systems
Passive safety systems are things like handrails, stairs and gates. They are understood by everyone and as such require no training to use them. They are always the safest option as a control measure for height safety as they should ensure that no one ever falls off or over anything.
Engineering out the problem
This, like passive safety, is the best method to ensure safety if we can achieve it. An example of engineering out a problem would be, you have a valve that requires to be open or closed on occasion and to reach this valve requires climbing a ladder to access it. The hazard of climbing the ladder may be engineered out by installing a chain operated valve that comes to ground level, or making the valve electric so that it can again be opened or closed from a switch at usual working height.
Fall restraint is a way of working where there is an edge that could be fallen over, but you have provided a system that guarantee’s that the worker can never fall over this edge. The chance of a fall when using fall restraint must be zero, so the equipment used must ensure this and uses no deceleration method as it is not required.
So planning is critical, as if fall restraint equipment is used incorrectly and a fall takes place the injury to the wearer will be catastrophic. Fall restraint equipment is governed by EN358 and tested in accordance to this standard.
When you cannot guarantee that there will not be a fall you will need to wear fall arrest equipment. This equipment ensures that if a fall takes place the impact upon the wearers body must be less than 6kN.
This can be achieved through expanding packs that slow the rate of descent, or through inbuilt clutch mechanisms, both of these types of deceleration methods can be found in numerous products for fall arrest. There are numerous standards and EN designations for fall arrest that cover all aspects of the equipment from the anchorage to the body harness. For more information on the EN standards required, please look at our EN number descriptions.
What is a Kilo Newton or kN?
A Kilo Newton is a force that engineers often refer to but can easily be converted to Kilogram’s that we can all understand it easier.
This is easy to do by just multiplying the amount stated as Kilo Newtons by 100. So 1kN is 1 x 100 = 100kgs, 3.2kN is 3.2 x 100 = 320kgs, 28.32kN is 28.32 x 100 = 2832kgs and so on.
So for instance, the 6kN force that all fall arrest blocks have to manage to come under, equates to 600kgs.
How fast do I fall?
To make this easier we have limited it to just the first 3 seconds as you will soon see everything else is irrelevant:
- In ½ a second you will fall 1.2 metres
- In 1 second you will fall 5 metres
- In 1½ seconds you will fall 11 metres
- In 2 seconds you will fall 20 metres
- In 2½ seconds you will fall 31 metres
- In 3 seconds you will fall 44 metres
So if we take an average 2 storey building including the roof at 10 metres, in a fall of 1½ seconds in time you would have travelled further than its full height.