相片and articles by Mark van der Feyst
Inour last discussion，我们从旋转锯的功率和力学以及可以使用的刀片类型的角度来看。本月，我们将重点关注有关实际应用的锯的操作考虑因素。
The first practical application is going to be safety. As mentioned previously, the rotary saw will rotate three times faster than that of a vent saw. Because of this increase in speed, there is more noise associated with the small engine working faster. Using a rotary saw will be loud. Depending on what position you are holding it in, the decibels coming off of the saw will be enough to cause temporary hearing loss or a ringing in the ears for some time afterwards. The noise created is not only from the small engine but also from the cutting of the material. The contact between the material and the blade will be the biggest contributor of the noise. The type of material being cut will dictate how loud the noise will be. Depending on the operation itself, hearing protection will be a good idea to wear when using the saw.
(1)
在切割金属状材料时会产生的火花以及噪音。当锯片和金属之间建立接触时，将产生大量火花。如照片1所示，良好的火花流很好地表明刀片正在正确切割，但它也将火花和其他飞行的碎屑从刀片和操作员带到操作员。使用锯时，请确保在使用锯时具有适当的个人防护设备，以防止火花燃烧。确保将刀片罩适当放置，以使火花从操作员的脸部偏离。
安全的另一个区域是旋转刀片。随着刀片旋转的垂直轴，正在创建离心力。在这里，操作员会感觉到锯需要在跑步时握住锯时“走开”的地方。有时认为这一点是使用旋转锯的负面因素之一。当锯不垂直固定时，锯将产生离心力。使用锯的关键是将其保持在0º或90º处。这将使锯保持一致，而不会导致锯“走开”。
Along with the blade being held straight, it can present itself as a cutting hazard to other firefighters while it is spinning. When the cutting operation has been completed, the saw blade will not stop automatically as it does on a vent saw or on a saw that has an electric brake. The blade will continue to spin freely until it stops by force or until it loses enough momentum to stop on its own. The operator must bury the blade into some type of material next to the cutting area to stop the blade by force.
The last area associated with the safety aspect of the saw is to maintain a circle of safety. When cutting operations are being conducted, a circle of safety always needs to be maintained by the crew members around. This involves giving enough space around the saw and the operator so that they are not directly interfered with by the cutting operation. This will ensure that no one gets hurt or affected by the saw and the operation of it.
下一个实际应用涉及旋转锯的物理局限性。这是疲劳因子设置的地方。在长时间切割操作发生时，旋转锯可能会使消防员疲劳。消防员的位置和持有的锯的位置将导致整体疲劳因素。成对工作时，间歇性地进行切割操作以减轻整体疲劳并不是一个坏主意。
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The last practical application is the different positions to hold the rotary saw. On the saw there are grab handles all around to allow the firefighter to hold the saw in different positions. The first position to consider is cutting at mid height, as shown on photo 2. When we must use the saw at this height it is best to rest the saw on the forearm like you are cradling a baby. This will allow your whole upper body to be used to hold the saw and allow you to gain better control over it.
(3)
如图3所示，要考虑的下一个位置是割伤头顶的位置。同样，请使用提供的抓杆将锯保持在切割时。该职位将使消防员感到疲劳，因此请确保您在需要时与同事进行贸易。这不是理想的切割位置，因为锯位于头部面积上方。在此位置时，锯和控制降低。
（4）
The last position is where we are cutting at head or shoulder height as shown in photo 4. In this position, the firefighter will want to rest the saw on their shoulder if they can, or, as seen in the photo, lock their one arm underneath the saw to hold it in position. This position will expose the firefighter to the extreme noise of the saw, which will warrant hearing protection.
无论您使用旋转锯的位置如何，对这些位置的熟悉都将成为消防员的资产。如果您的消防部门有旋转锯，请训练它，以熟悉其安全考虑，持有它的位置以及其物理考虑的需要。
Mark van der Feysthas been in the fire service since 1999 and is a full-time firefighter in Ontario, Canada. He is an international instructor teaching in Canada, the United States, and India, and at FDIC. Van der Feyst is a local level suppression instructor for the Pennsylvania State Fire Academy. He is also the lead author ofResidential Fire Rescue(Pennwell).
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