20 Mar Components of Operable Partitions
As mentioned before, operable partitions (also known as airwalls or operable walls) are comprised of several components that encompass the entire system. In this segment I will detailing the suspension component. This entails the structure, track and trolleys.
The suspension must be able to handle the weight of the panels which generally range from approximately 8 lbs to almost 13 pounds per square foot (PSF) and more. Steel is almost always required, but in certain instances robust wood support might be viable depending on the height and sound rating of the panel. Since the panels are so heavy, they do cause deflection in the support including steel. It will sag when the panels are out. Most times a structural engineer is necessary to do the calculations to avoid possible failure of the support and to ensure smooth operation of the panels. For those of you designing, the allowable deflection according to ASTME 557 is 1/8th” every 12’. Adhering to this is crucial in order to ensure the panels will move properly, especially if fixed sweep are being specified in lieu of operable seals. We’ll cover more about seals in another blog
The track is the next component of the support system. The track will either be aluminum or steel. Steel is the stronger of the two and will last much longer than the aluminum. This is because the aluminum is a softer metal and is prone to many more issues. When turns are required for single panel systems, the track will either be right angle or curved radius. The right angle track is much more difficult to use and tends to abuse the trolleys. As you can imagine, the curved radius track allows the panels to flow smoothly without ever having to come to a stop at a “T” intersection. The first point of failure on the aluminum right-anlge track is almost always these intersections and this is either due to abuse of the system while moving panels or degradation of the coating on trolleys used on aluminum systems. I’ll cover more on that in the next section.
The trolleys are the last piece of the structure component. The trolleys will either be vertical trolleys or horizontal trolleys depending on the configuration. Sliding pucks are also an option, but use of these has become almost obsolete since they are notoriously hard to move. Steel vertical trolleys on steel track make up the most robust and easiest functioning configuration. The aluminum track system utilizes steel trolleys encased in a resin known as Delrin. This is true for both the vertical trolleys and the horizontal trolleys in systems using aluminum track. The main issue with these types of systems is that the casing will inevitably come off. Once that happens then the steel underneath will make contact with the aluminum. Since steel is much harder than the aluminum, it starts to chew up the track. Once the aluminum track is damaged, it becomes a viscous cycle because if the damaged trolleys are replaced the track will erode the casing on the new trolleys and continue to do so from that point forward. Steel track on steel trolleys is the most functional and most durable. Think about this: have you ever seen a train running on aluminum track with polymer covered wheels?
Explaining the difference between the vertical and horizontal trolleys seems appropriate here. Think of the vertical trolleys as a spindle. The operate by having two “wheels”, one on top of the other, that spin in opposite directions while moving in the track. They call these omni-directional because one can move them in any direction. Certain proponents will say this is an advantage, but I disagree since it allows the panel order to get changed. When this happens the system becomes less effective regarding sound blockage since the panels are adjusted individually so that they fit together in the tightest way possible to block as much sound as possible. The curved radius track with horizontal trolleys allows for the ability to program the trolleys to ensure they will only go where they are designed to go. This is achieved by adding opposing fins to the track and trolleys that are of different depths. In a dual-stack configuration, the panels with horizontal, programmed trolleys will only go to the side they are meant for. This ensure proper set up and storage every time. I have seen panels with vertical trolleys designated to a specific side with paint and stickers to ensure that they operators place them in the correct stack location and in the correct sequence. It seems ridiculous to me to spend anywhere from $7k to over a $1,000,000 on a system and then have to degrade it with stickers or paint in order to ensure it is used correctly. When shopping or designing a system ensuring you have selected and designed the best system for you consider these points.
While this blog post is meant to help educate the populace on the components of operable partitions and airwalls, keep in mind that maintenance and repair of these systems are best left to professionals. Contact Specialty Building Services for your San Antonio airwall repair and Austin operable partition maintenance.
Support Steel with bracing and bolts for track
Vertical trolleys: new / broken
Damaged Aluminum intersection
Steel Curved Radius Intersection