We recently were called out to look at a ladder that did not meet OSHA standards (1910.27) for clearance on the back side of the ladder. The ladder also had two angles of climb as shown in the above photo. When climbing up the ladder, the concrete walk was too close to the ladder for you to safely grasp the rung and also to put your foot on the rung while climbing. The ladder was accessing the top of the traffic control tower at an airport, and as such, we had to work around a variety of factors to ensure a proper replacement or modification of the ladder could take place without interrupting operations. As the install location was at an airport, the use of a crane to bring a replacement ladder to location would have been a logistical nightmare. We decided that whatever the solution was, it was to be brought up from the inside of the tower.
Our first option was to remove the ladder and replace it with a 90 degree ladder. That is the most common fixed ladder type. There were, however, issues with supplying a replacement ladder. First off, the concrete walk and rail were extended beyond the top of the tower. This meant that our replacement ladder would need to be very far from the structure in order to give us the required 7” clearance behind the ladder at the concrete walk location. That is not a deal breaker, but holding so far off the structure would have also required an extra-long crossover to reach the tower roof. OSHA allows the ladder to have a maximum 12” step across at the top of the ladder. As the ladder has to stand 7” off of the wall (or the furthest obstruction off the wall) you can get by without a step across platform if the obstruction is 5” or under (5+7=12). The replacement ladder would have been very large. Ordinarily, this too can be dealt with by using our modular line. Our Modular Fixed Ladders come in pieces no larger than 7’L. Each ladder section bolts to the next one and has a pair of standoff brackets before and after the splice.
We could not accommodate additional standoff brackets required by the modular design so we would have needed to weld each splice together. Again, this was not a deal breaker either, but it did make this option less economical than other options.
We decided that it was more economical to modify the existing ladder. The top of the ladder was already angled at an 81 degree angle. In the field we ran a laser down the ladder from the top to see where we would land if we kept that same angle throughout the climbing run. By cutting the ladder at the bend, and then cutting each of the lower standoff brackets, we were able to gain close to a foot of clearance at the concrete landing, well within the acceptable tolerances of OSHA’s standards. This option was not without its challenges though. As the ladder was going to be sticking off the wall even further than before, we were concerned about having a stable climb.
We added cross bracing across the two standoff brackets to stiffen the ladder up with the extended bracket length. After modifying the ladder, the bottom rung was still within the 14” allowed by ANSI A14.3, so no additional ladder rungs were required. Each welded location was then sanded down to remove any sharp edges or burrs and painted with a rust inhibiting primer. The end user was going to have their maintenance department repaint the ladder after completion of the work to help cut down on costs.
The ladder modification was completed at budget and within the scheduled time. Most importantly, the customer now had safe access to their roof. If you have a unique situation like this, give us a call. We can help you come up with the solution that fits your site requirements and budget, too.