Last month, and the month before that, we posted two items regarding safety assessments workers should perform, before entering a suspended scaffold. Part 1 covered safety practices in line with OSHA’s standards and requirements, whereas Part 2 listed the requirements for Europe’s EN 1808. In this last part of the series, we will have a closer look at where the two differ and look at the possible reasons why they do.
1. Suspension rig
The first thing users will notice from the outside, is that USA’s OSHA requires tie backs when systems like parapet clamps or outriggers beams are used. The European EN standard however, doesn’t require any secondary safety for suspension rigs.
Although applying tiebacks adds safety by preventing the equipment from falling down in case of failure or wrongful use, it brings a certain hazard as well. Especially in the case of an outrigger beam, where tiebacks are often mounted low, there is an increased tripping hazard. Other reasons against the use of tiebacks are additional costs and the demand for additional anchor points.
2. Fall Protection
Looking at fall protection requirements, we see one of the most important differences. Although both standards require the use of a guardrail system, OSHA also requires that a Personal Fall Arrest System (PFAS) is used. The PFAS used, needs to be attached to either a vertical lifeline, horizontal lifeline, or scaffold structural member by means of a lanyard.
Europe’s EN 1808 does not require users to wear a PFAS per se. Only when a specific safety assessment deems it necessary, users are required to use such a system. This is because the EN 1808, in addition to the suspension wire, requires the use of secondary wire ropes which have to be attached to separate attachment points.
We see a similar requirement in OSHA’s 1926.451(g)(3)(iii):
“When lanyards are connected to horizontal lifelines or structural members on a single-point or two-point adjustable suspension scaffold, the scaffold shall be equipped with additional independent support lines and automatic locking devices capable of stopping the fall of the scaffold in the event one or both of the suspension ropes fail. The independent support lines shall be equal in number and strength to the suspension ropes.”
The main difference is that the EN 1808 does not let you choose between two safety precautions, but prescribed the one they think is safest. In this case, they choose collective fall protection over personal fall protection.
The most important safety factor for hoists are the same in both regions: users must always take the Working Load Limit (or Rated Load) into account and be sure to not overload the system. To make sure this doesn’t happen, both the OSHA and the EN 1808 require the use of an overload detection system.
It’s here where we find the main difference between the two standards. OSHA states that the stall load of hoist (the load at which a hoists stalls, or power is disconnected automatically) shall not exceed 3 times its rated load. In practice, this means that protection against overloading may be activated as late as WLL x 3.
The EN 1808 however states that overload devices used on temporary suspended platforms shall be triggered at or before reaching a load of 1.25 times the (reduced) WLL of the hoists, so: WLL x 1.25.
This means the EN 1808 is more strict in its requirement, so safer. However, users should take their responsibility as well, and respect the Working Load Limit written on the hoists’ marking by not adding more than is stated.
4. Wire rope
Although wire rope specifications also vary per manufacturer and per hoist, both standards do set some minimum requirements regarding wire rope quality.
OSHA requires the suspension rope to be capable of supporting, without failure, at least 6 times the maximum intended load applied or transmitted to that rope.
The EN 1808 gets more technical/complicated on this subject. It states that the “calculated coefficient of steel wire rope” is calculated with the minimum breaking load of the wire rope, divided by the hoist’s WLL plus the wire rope’s mass when the platform is at its lowest point. It also states that this coefficient should be equal to or greater than 8 for single active rope suspension systems, and equal to or greater than 12 for double active rope suspension systems, such as swing stages.
One thing you might notice is that the EN 1808 specifically mentions that wire ropes should be used, whereas OSHA talks about suspension rope, leaving the choice of material open. Another difference is that the European norm has separate requirements for single suspension rope and double suspension rope systems, whilst OSHA has one requirement applicable to both. And of course, the last, but very important difference, is that the required tensile strength in Europe is twice as high as in the USA.
5. Falling objects
Our final safety subject is the influence of external factors, namely: weather. For this safety factor, OSHA does not state any specific requirements such as minimum or maximum temperatures or maximum wind speeds. However, OSHA does state that employers have a duty to provide a place of employment free from recognized hazards that are causing or likely to cause death or serious physical harm. It also states that Work on or from scaffolds is prohibited during storms or high winds. This means that it is the responsibility of the competent person to determine whether the external conditions allow for safe work.
The European EN 1808 also does not state specific requirements for temperatures. However, in its scope it does assume that the working ambient temperature range is between –10 °C and +55 °C. Furthermore, the EN 1808 refers to the manufacturer’s manual information about inclement weather conditions: maximum wind speed, range of ambient temperature and lightning. This means, the responsibility to determine if the weather conditions allow for safe use lies with the manufacturer.
Safety assessment checklist
With this post, we conclude our series of suspended scaffold safety assessment. If you haven’t done so yet, you can still download our checklists for safe suspended scaffolding, according to both the OSHA as well as the EN 1808 standards. If you would like to know more about safe work with suspended platforms, or if you would like to get trained, don’t hesitate and contact one of our experts.