经过马克·范·德·费斯特
卡车公司基础知识：地面消防梯子的基础知识
很大的一部分truck company operationsis fire ladders, especially ground fire ladders. Every火器will be equipped with at least two ground ladders: a straight single-roof ladder and an extension ladder. This is mandated byNational Fire Protection Association (NFPA) 1931,制造商设计的消防部门地面梯子的标准，用于设备规范。NFPA 1931详细说明了什么地面梯子和他们是如何构造的。这些标准s are not interesting reading material, but they do contain some important information that we need to know as part of the basics, such as the following:
- 在梯子束内部发现的热传感器标签预设为300°F。
- 阁楼梯子将不超过16英尺。
- Minimum distance inside between beams for single ladders shall be 16 inches.
- 阁楼梯子之间的梁之间的最小距离应不少于7½英寸。
All ground ladders are tested to ensure that they meet the NFPA 1931 standard. Most of us have never witnessed these tests being conducted, but they are intrusive and designed to test the extreme limits of the ground ladder.
相关的消防员培训
- 你是地面Ladder Savvy? Part 1|Part 2
- 卡车公司运营：波士顿的梯子文化
- Ground Ladders, Not Just for Egress
- Throw Back to Basics: Ground Ladder Tip Placement|Ground Ladder Markings
In photo 1, we can see a地面梯子undergoing the Horizontal Bending Test. In this test, a load of 750 pounds is applied to the middle of the ladder. Notice that the地面梯子完全扩展；从梯子的每一端至少六英寸，它的支撑都由两个支架支撑。该测试的重量为750磅，因为NFPA 1931要求所有组合，单个和屋顶梯子as well as extension ladders must have a duty rating of 750 pounds when raised at a 75° angle.
(1) Photos by author.
Any test being conducted on a ladder must maintain a five-minute time limit. Notice how the ladder is bending under the test weight. There is probably a one-foot deflection occurring under these extreme weight limits. But are these extreme weight limits? If we were to use a ground ladder to rescue a civilian, there is a good chance that the ladder will endure some extreme weight.
完全用个人防护设备戴的消防员的平均体重为300磅。这是NFPA用来评估任何操作的消防员活动重量的数字。一名地面梯子上的一名消防员试图营救一名可能体重高达300磅的平民，现在在梯子上增加了600磅的重量。根据平民的行为，地面梯子会在下降时反弹。我们为什么要知道这个？这是为了建立我们对地面阶梯的信仰和信任。它旨在在压力很大的情况下工作，并在许多情况下证明自己是非常有效的工具。
作为基础知识的一部分，我们需要知道我们使用火器设备的梯子的长度第一次正确的高度。没有什么比看着两名消防员抬起并降低地面梯子并试图选择适当的高度更糟糕的了。如果我们知道我们的梯子长度，地板之间的平均距离，窗户的高度，距地板的高度，梯级之间的距离以及当我们将底座拉出并从墙壁上拉开时，梯子尖端会掉落多少能够正确估计我们应该在第一次提高梯子的确切高度。
有关的：Petrillo on Moving Beyond Standard Ground Ladders”多诺万：梯子的考虑”Zaitz在地面梯子上放置
In photo 2, we can see three different ladders being used to access different windows. Each one is accessing a different level of the building. We have a 12-foot ladder accessing the second story, a 24-foot extension ladder accessing the third story, and a 35-foot ladder accessing the fourth story.
（2）
Ladder math is a good tool to use when trying to determine to what height a ladder should be raised and which ladder to choose for the job. We know that in a typical structure, the height between floors will be 10 feet. The window sill will be around three feet from the floor. This gives us a total height of 13 feet to reach. If we grab a 14-foot roof ladder, will it reach the window sill? Yes. When moved away from the wall, a ladder will drop one foot for every four feet of horizontal movement.
When a 14-foot roof ladder is moved away from the wall to the correct climbing angle, it will have a vertical height of 13 feet. If we had a 12-foot roof ladder, it would also work; we may be about 18 inches below the window sill, but it will still allow us to gain access or rescue a civilian.
Our extension ladders are usually 24 feet. The bed of the 24-foot ladder measures 14 feet. Each rung on the ladder is about one foot apart. When we extend the fly section of the ladder, we need to count the number of clicks from the dogs to raise the ladder to the correct height. A 24-foot ladder fully extended will measure 24 feet. We can then theoretically reach a third-story window with a 24-foot ladder that has a vertical height of 23 feet from ladder tip to the ground. We need to consider other factors such as raised basements and sloping surfaces; this will add to our total height that we need to reach.
The best way to know the limitations of your ground ladders is to practice with them. Use existing buildings in your area and ladder the windows on different stories. Ask the crew to estimate how high the ladder must be raised to reach certain windows. By doing this, your crew can practice estimating ladder heights, and they will know exactly the limitations of each ladder. They will also know which ladders to use to reach certain windows if they get called to that building one day for a fire.
马克·范·德·费斯特自1999年以来一直在消防部门，是加拿大安大略省的一名全职消防员。他是加拿大，美国和印度以及FDIC的国际教练。他是宾夕法尼亚州消防学院的地方镇压教练，也是不列颠哥伦比亚司法研究所的讲师。188博金宝体育1他还是住宅消防救援（Pennwell）的主要作者。
更多Mark Van der Feyst
