 are designed to be as safe as possible. Years of research have gone into analyzing different types of guardrail, median barriers, even sign supports that are designed to break away if a vehicle hits them. These devices can and do save lives. And maintaining them is one of the most important jobs we have. This program covers the procedures to follow for guardrail maintenance. In this program, we'll look first at the components that make up guardrail, and then we'll look at some common maintenance procedures. So let's get started. Basically, there are three components. The rail itself, the post, and the block. All three components work together to soften the impact, as well as to redirect the vehicle. Here's a quick look at how guardrail works. To begin with, the posts are placed a certain distance apart from each other. The closer the posts, the stronger the guardrail. The block helps to absorb the crash. As you can see, this block is crumbled. It's made that way to soften the impact. If the block was stronger, the vehicle would be more severely damaged, and the passenger is more likely to be injured. The element is somewhat forgiving as well. And because of the post spacing, the rail can bend between the posts. Again, to soften the impact and to redirect the vehicle. And that's basically how the components work together. The important thing to remember is that all repairs have to be made so that the guardrail is restored identical to the original installation. If the guardrail is repaired differently from the way it was installed, the protective nature of the rail may be altered. With that in mind, let's look at three different types of installations and the procedures for maintaining them. Probably the most common installation you'll repair is known as a typical section. Typical sections are sections of guardrail that run along a steep grade. The other two installations we'll look at are end sections and attachments to bridges. Let's start with a typical section. In this example, the damage is bad enough to require repair, but still minor in terms of the amount of guardrail damaged. However, the procedures you'll see here will show how each component is repaired. As with any other job, the first thing to do is set up all the necessary traffic control devices and signs. Then the next step is to decide how much of the rail has to be removed and replaced. In this example, at least one post will be needed. But even though the post was broken, the block can be used again. The next post is okay, but the block is crumbled, so a new block is needed here. As for the rail, this section obviously gets replaced. The next section is half damaged, but an entire section will be used as a replacement. Never try to splice a new rail to a damaged rail. Always replace entire sections. Okay, now that you know what has to be repaired, you can begin removing the damaged components. The first rule is to always stand behind the rail when you loosen the bolts. In most cases, the rail is under a great deal of pressure because of the crash, and it can swing out and seriously hurt you if you're in front of it. So again, always stay behind the rail. The second rule is to loosen the bolts with a wrench when it's possible. A cutting torch should be used only when other tools won't work. The heat from the torch can weaken the remaining sections of the rail. Of course, there are situations where cutting is the only way to remove the rail. As you can see, this is where most of the damage is. And because this post absorbed a good deal of the impact, there's no room to get to the bolts. So they have to be cut. Notice that he's standing in front of the rail. That's okay as long as he moves behind the rail when he completes the cut. This element doesn't pop out too far, but always be aware of the danger. Some of them will really fly. Now the bolts can be cut off. If it's at all possible, someone should stand behind the rail and hit the bolts with a hammer. That way you know when you've applied enough heat to the bolts. Don't apply any more heat than is necessary. The damaged sections can be removed. Handling the rail elements is the most dangerous part of the job. Guard rail is heavy and sharp. So always use enough people to handle the section safely. You should all lift and drop at the same time. The next step, of course, is to hang the new rail. Be especially careful to overlap the rail sections in the direction of traffic. Otherwise the rail could snag a vehicle's fender. Here's another time that the torch has to be used at the intermediate posts. You have to cut a hole for the bolt to be inserted through the rail. The holes are already made where the rails overlap. As far as hanging the rail, the only thing remaining is to tighten the bolts. You know that you've tightened the bolts at the overlaps enough when this gap is closed. Now let's look at replacing a post. One way to remove the posts is to raise it out with two picks. So dig around the post to make room for the picks. Then attach a pick on each side and use leverage to raise it out. You'll have to repeat this procedure a couple of times because the post is buried about three feet in the ground. Always replace the posts in the same hole that you took them out of. Remember, the post spacing affects the strength of the rail system. And you don't want to make it any stronger or weaker than it was originally. Pack the material around the post as well as you can. Before attaching a rail to a post that you replaced, it's a good idea to make sure that its height matches the height of the other rails. So set a level at one of the old posts and adjust it. Then move to the new post to make sure it's the same height. This one's fine, but sometimes you'll have to make adjustments to get the post the same height. If it's off, you'll have a tough time getting the new rail on. And you'll have to use the torch to cut through the rail. But in this case, you're also cutting through the block. And that's the procedure for repairing a typical section. Now let's look at repairing end sections. As you can see, ends of guard rail sections are turned down. The rail element bends a little more at each post until it lies flat. After all the traffic control is in place, the first step is to decide what needs to be done. In all cases, the entire turned down rail section will have to be replaced. So you're mainly concerned with the brackets and the posts. And because the turned down section is under a great deal of strain, you might have to cut the damaged element to relieve the pressure. That way when you take the last bolts out, the rail won't snap away from the brackets. You can see how each of the brackets turns the rail a little more. And as you can see, all of the brackets and posts are in good condition. That's normally the case because the posts are driven so far into the ground. The next step is to attach the tip of the turned down to the rail. In some cases, you may have to dig out around the last post to make room for the tip. Now you can hang the rail section. Always start by firmly connecting the new rail to the old. And if you have a jack, use it. Sometimes it takes a while to make the connection. The next step is to secure the other end. The entire crew should help at this point. Again, the rail is under tremendous strain. And using the whole crew is just a smart safety practice. Now with both ends secured, you can go back and bolt the rail to all the brackets in between. The last step, of course, is cleanup. All rail sections have to be firmly secured to the truck. And it's a good idea to look over the area to see if you've forgotten any tools or hardware. There you have it, the new turned down end. Now let's look at attachments to bridges. The procedures here follow pretty much what you've seen already. You'll have to remove damaged sections and replace posts and blocks as needed. The major difference, of course, is that the end of the guard rail is attached to the bridge, normally on the parapet. But always refer to the standard drawings to find the bolt locations. As you can see, there's a big difference between the exit end and the approach end for bolt locations. Whenever you're ready. And that brings us to the end of this program covering guard rail maintenance. Remember, there are many inherent dangers involved with handling guard rail. So try to keep the points you've seen here in mind, particularly those relating to safety.