While the Scaffold & Access Industry Association swing stage competent person training (CPT) course has more than 100 questions, there is only one that directly relates to roller bumpers, despite the fact several other questions relate to them.
Questions on spacing, platform to wall surface, and angulated wire ropes directly depend on this abused component. So what is the one question on roller bumpers? OK, pop quiz.
Question: Where are roller bumpers located?
There are two things all these answers have in common—definition and purpose. Roller bumpers are a suspended platform guide roller designed to contact the outer face or wall structure or building. Their purpose is to help keep the platform stable to prevent damage to the structure and to guide the platform as it is moving.
If you have taken the suspended CPT test, you better have answered b. However, there are different types of roller bumpers which can make c, d, and e legitimate answers. We can rule out a because it is only there to be confusing.
Answer c. – On the outer edge of the platform. This is possible. Normally you mount rollers on the toe board of the platform, then clamp them down to prevent accidental dislodgement to prevent it dropping on someone below. Here is a classic example of the abuse they take and why they must be secure.
Today with the wind industry being part of the scaffold and access market, we can have multiple sets of rollers. Some are adjustable to fit the contour of the turbine blade as the pitch increases and decreases toward the blade tip.
Answer d. – On the underside of the platform. This is confusing but possible. Telescopic roller bumpers are being used more due to setbacks and slopes on building facades. They normally attach to the platform underneath or near the end of the platform and can be pushed out or back in as the building façade changes. Caution must be taken that they do not create a trip hazard if mounted on the toe board in the middle of the stage. Again, ensure the connection is sound to prevent dislodgement.
Answer e. – On each end of the platform. This can be true but not very common.
Although roller bumpers purpose is the same, the material they are made of can be quite different. Manufacturers often make different type rollers for different types of wall material; it’s common to see the wrong type of roller on the wrong wall surface.
Today the most common type material used is the same as your boat bumper. They are durable, long lasting, and can be used on almost all surfaces.
Okay, another pop quiz.
Question: What determines the position of a suspended scaffold in relation to the work surface?
Relatively easy question – I hope you answered d. It’s common to see the beam outreach either out or in too far with the wrong size roller bumper. The wire ropes should be plumb hoist-to-hoist and hoist-to-wall surface at all times unless you’re intentionally doing angulated roping, which sets the beam in slightly on the roof causing the swing stage to press against the work surface. If the outreach is too far and the bumper roller is too small they are useless and the platform could damage the building. Therefore, once the beam outreach has been determined, choosing the correct size roller bumper is critical. Always be cautious considering that any size roller bumper, big or small, can get caught on a ledge during ascent or descent.
Remember this abused component and what needs to be asked before the job starts because not all roller bumpers are the same.
And remember to check them often, as they do become loose.