落基山救援组，科罗拉州，博尔德
Yellow Spur Rope Failure Investigation
对Yellow Spur绳子被割断事故的调查报告
by
调查报告人：落基山救援组
翻译：tethys （小t）
March 6, 2011
时间：2011年3月6日
On the morning of June 22, 2010, Joseph Miller fell while leading the second pitch of the Yellow Spur route on the Redgarden Wall in Eldorado Canyon State Park. During the fall the climber’s rope failed, resulting in a fatal ground fall.
2010年6月22日清晨，Joseph Miller在攀爬Yellow Spur路线的第二段时冲坠。（Yellow Spur位于Eldorado Canyon State Park的Redgarden岩壁。
路线信息可查看链接http://mountainproject.com/v/colorado/boulder/eldorado_canyon_sp/105748657，
Eldorado Canyon State Park的信息可查看链接 http://parks.state.co.us/parks/eldoradocanyon/Pages/EldoradoCanyonHome.aspx）
坠落过程绳子失效，攀爬者坠落至地面，死亡。
Due to the unusual occurrence of a climbing rope failure, the Rocky Mountain Rescue Group3 (RMRG) conducted an accident investigation focused on the cause of the failure. This report contains the activities, findings and conclusions of that investigation. The intent of this report is to objectively determine what most likely happened during the accident. RMRG has no special relationship with any of the individuals or equipment manufacturers mentioned heREIn nor did RMRG receive any compensation for conducting this investigation. We encourage others to repliCATe our testing of this or similar scenarios.
鉴于攀爬绳索被割断的情况极为罕见，落基山救援组（RMRG，www.rockymountainrescue.org） 针对失效原因进行了事故调查。本报告包含调查过程的经过、发现以及结论，意在客观的确定事故最可能发生的情况。RMRG与文中所涉及到的任何个人或设备厂商没有特殊关系，RMRG也没有得到关于进行事故调查的任何报酬。我们鼓励其他机构或个人重复我们所进行的测试，或相关测试。
Figure 1a shows a photo of the Yellow Spur route with the area of the accident outlined in yellow. The second pitch of the route starts from a tree and traverses to climber’s left before heading up a dihedral (Figure 1b). The route was closed temporarily following the accident in order to gather on-site information in support of the initial investigation conducted by the Boulder County Sheriff’s Office (BCSO). Prior to re-opening the route, a detailed inspection of the second pitch of the route was performed by RMRG, and photographs were taken of the climbing protection placed by Miller during the climb.
Figure 1. a) Accident location on the 2nd pitch of Yellow Spur. b) 2nd Pitch of Yellow Spur labeled with approximate climbing route (dashed line), and approximate locations of the belayer, protection and lead climber prior to the fall.
图1（左）给出了Yellow Spur路线的照片，事故发生位置被黄线圈出。路线的第二段从一棵树起步，横切至攀爬者左侧，到达一个二面角下方（图1右）。事故发生后，博尔德县警长办公室（BCSO）展开初步调查，为了采集现场证据，关闭了此路线。在重新向攀爬者开发此路线之前，RMRG对第二段路线进行了详细的调查，并对Miller攀爬时设置的保护站进行了拍照。
图1. 左图：在Yellow Spur第二段发生事故的位置；右图：红色折线标示出Yellow Spur第二段的大致攀爬路线，三个黄色箭头由下至上分别大致标示出保护员所在位置，保护点位置以及攀爬者发生坠落的位置。
Interviews
访谈
Interviews with a number of nearby climbers who witnessed the EVENTs leading to the fall and/or the fall itself were conducted by RMRG. Miller’s climbing partner, who was belaying at the time, was also interviewed. The primary purpose of these interviews was to understand the situation leading up to the fall and the sequence of events during the fall itself. The information provided by witnesses and the belayer were consistent with each other and allow us to present the following sequence of events:
RMRG对目睹导致坠落事故发生或亲见坠落过程的附近攀爬者进行了访谈。当时给Miller做保护的搭档也接受了采访。进行这些访谈的主要目的是了解导致坠落的原因以及坠落过程的续发事件的顺序。目击者和保护员提供的信息相符合，据此我们可以得出续发事件为以下顺序：
Miller followed the first pitch, climbing it smoothly and without any difficulties. He reached the belay anchor set up by his partner at the tree in Figure 1b. During a brief discussion, he and the belayer decided that Miller would lead the second pitch. The belayer was anchored to the tree and was using an ATC-Guide (Black Diamond) in a standard belay configuration from his harness. Miller placed three pieces of climbing protection as he led the second pitch. The highest point on the route reached by Miller was in the lower portion of the dihedral in Figure 1b. The third piece of protection placed by Miller was near this high point. Miller appeared to be having difficulty with the climbing near the point where the third piece was placed and was being encouraged by the belayer. Miller fell shortly thereafter. During the fall, the third piece of
Miller跟攀第一段路线，顺利通过没有遇到困难。他到达由搭档在图1（右）树的位置设置的保护点。经过简短的讨论，他们决定由Miller领攀第二段路线。保护员在树上设置保护站，使用ATC-Guide （Black Diamond）保护器与安全带相连，保护器使用设置正确。Miller在第二段攀爬过程中达到的最高点位于岩壁两面角的低处（见图1右）。Miller在此位置附近设置了第三个保护点。在尝试通过这个保护点的时候，Miller遇到些困难，不过保护员鼓励他继续攀爬。之后不远处Miller冲坠。坠落中第三个保护点被拉出，但是第一和第二个保护点依然固定于岩壁上。
protection pulled out, but the first and second pieces held. Miller continued to fall straight down and past a small ledge. The speed of his fall appeared to slow very briefly as if the rope had begun to arrest the fall. However, the climbing rope then severed and Miller struck the ground near the base of the route.
Miller继续垂直坠落并越过一个小平台。他的坠落速度短暂减缓，貌似绳子开始受力。然而，绳子被割断，Miller撞到路线起步附近的地面上。
There are two additional important points from the belayer’s account of the accident. First, he indicated that the initial protection placed by Miller had a long sling such that it did not cause the rope to change directions between the belayer and the second piece of protection. Second, the belayer indicated that he felt very little force on the belay from the fall. That is, he was not pulled significantly sideways or upwards by the rope as would typically be the case when catching a leader fall from this belay location. Immediately after the fall, the belayer pulled the remaining rope up to the belay and saw that the rope had been severed. He removed the first piece of protection placed by Miller before rappelling down to the base of the first pitch. The middle piece of protection (which held the fall prior to the rope failure) remained in place and was photographed during the initial investigation (Figure 2).
根据保护员对事故情况的描述，还有两点重要信息。第一，他指出由Miller放置的第一个保护点有一个长扁带，用来防止绳子在保护员和第二个保护点之间改变方向。第二，保护员声称在发生坠落时，他没有感觉到绳子上有明显的拉力。也就是说，他并没有类似通常情况下发生先锋冲坠时被绳子拉到一边或者向上拉起。发生冲坠后，保护员立刻收起余下的绳子，发现绳子已经被割断。下降到第一段路线起步位置之前，他移除之前由Miller设置的保护点。中间的保护点（在冲坠发生后和绳子失效之前受力）留在了远处，初步调查时对它进行了拍照。（图2）
Figure 2. Protection that held during the fall (viewed from above).
图2：黄色箭头指示的是坠落发生后承受拉力的保护点（从路线上方拍摄）
Inspection of Equipment
装备的调查
The climber’s rope was 200 feet (60 meters) in length, 9.7mm in diameter and manufactured by Beal. Three pieces of climbing protection had been placed by Miller while leading the second pitch. The highest piece was a #0.5 Black Diamond Camalot camming device that was attached with a 24-inch Dynex sling and two wire-gate carabiners. This piece pulled out during the fall. The second piece was a #0.4 Camalot, also with a 24-inch sling and wire-gate carabiners; this piece held during the fall. The lowest piece was a mid-sized stopper (unknown brand) placed a short distance from the belay.
攀爬者使用的绳子是200英尺（60米），9.7mm粗，由Beal制造。Miller在先锋攀爬第二段路线时设置的三个保护点，最高处是一个0.5号Black Diamond Camalot机械塞，与之相连的是一根24英寸的Dynex扁带和两把丝门锁。冲坠发生后这个保护点被拔出。第二个保护点是一个0.4号Camalot机械塞，也是连着一根24英寸扁带和两把丝门锁；坠落发生后这个保护点起到制动作用。最低的保护点是设置在保护站附近的一个中号岩石塞（生产厂家不明）。
A detailed inspection of all climbing equipment found on the route was performed. In general, the equipment appeared to be in good condition. Inspection of the #0.5 Camalot found damage to the lobes consistent with a shallow or open placement and a force considerable enough to pull the device from its placement (Figure 3). Damage to its associated carabiners and sling were also consistent with damage caused by high impact with rock. The #0.4 Camalot and its associated carabiners and sling were found to be in good condition. The climber’s rope was inspected over its full length.
The rope failure occurred approximately 20 feet (6 meters) from a figure-8 knot that connected the rope to the climber’s harness. There were light abrASIons along the rope for several feet on the climber’s side of the failure. In addition, there were dark discolorations on the belayer’s side of the failure consistent with a loaded rope moving across a carabiner. The remaining ~175 feet (53 meters) of rope was in good condition. During this investigation, we found no reason to suspect that there was any rope defect or that this rope was particularly susceptible to the damage that occurred.
我们对路线上找到的所有攀爬装备都进行了细致的调查。总体来说，装备处于正常状态。对机械塞凸轮上发现的损坏情况的调查与放置点的浅缝或开合程度以及坠落发生后可以把它拔出的足够强的拉力相符合（图3）。与之相连的主锁和扁带上的损坏情况也与在岩壁上发生高冲击的情况吻合。0.4号机械塞以及相连的主锁和扁带状态良好。我们对攀爬者的绳子也进行了完整长度的检查。
绳子大约在距与攀爬者安全带相连的八字结20英尺（6米）处断裂。在攀爬者这一端的绳子若干英尺的长度上有轻微磨损。此外，在保护员这一边的绳子上有深色污点，这也与负重绳子从主锁中磨擦穿过相吻合。余下的约175英尺（53米）的绳子状况良好。在调查中，我们没有发现绳子有任何失效预兆的证据，或者导致这种断裂发生的可疑现象。
Figure 3. Close up of damage to cam that pulled out during fall.
图3：坠落发生后崩出岩壁的机械塞损坏部位的特写照片。
测试
RMRG Test Tower Facility
RMRG测试塔设备
The majority of the testing presented in this paper was conducted on RMRG’s 35-foot (10.7 m) tall steel test tower
本文所述的大部分测试都在RMRG的35英尺高（10.7米）钢架测试塔（图4 测试塔的具体介绍可参见链接 http://www.rockymountainrescue.org/randd.php ---原文注）上完成。
Figure 4. The RMRG test facility
图4.RMRG测试设备
(Figure 4). The tower is outfitted with a mechanical hoist and a stack of thirty 33-pound (15 kg) steel plates (for a total of 1000 pounds (455 kg)), which can be used to create a wide range of test loads. Drops are initiated using a pneumatic release mechanism (McMillan Design’s “Sea Catch”) and can be triggered either manually or via computer. Data is collected by a laptop computer with a National Instruments data acquisition card (Model 6251) and LabView 8.2 software. A variety of sensors collect load, temperature, and distance measurements. The load sensors have an operational range of up to 10,000 pounds (44.5 kN) and the data acquisition system allows sampling rates greater than 2500 samples per second. The system is sufficient for capturing the critical information in the drop tests reported here. Additional details of the tower and testing equipment are available in Holden et al. 2009
5 Holden, T., May, B., and Farnham, R. (2009). “On the Utility of Rescue Randy Mannequins in Rescue System Drop Testing.” International Technical Rescue Symposium, Pueblo, CO. Retrieved February 13, 2011, from www.itrsonline.org/PapersFolder/2009/Holden-May-Farnham2009_ITRSPaper.pdf.
测试塔配备了一架机械吊机，30块钢板，每个的重量为33磅（15公斤），总重1000磅（455公斤），这些钢板用来提供足够大范围的测试载重。坠落冲击由一个启动释放装置触发（McMillan设计的“Sea Catch”），此装置可以手动或通过电脑触发。数据通过安装在一台笔记本上的国家仪器数据采集卡（Model 6251）和LabView 8.2软件进行采集。多个传感器负责记录载重、温度以及距离的测量数据。载重传感器可采集最大10000磅（44.5千牛）的重量，数据采集系统每秒可记录超过2500个样本的数据。此系统为本报告中设计的坠落冲击测试有效记录了重要数据。与测试塔以及测试装备相关的其他详细信息可参见Holden等.2009(Holden, T., May, B., and Farnham, R. (2009)，“关于救援系统坠落冲击测试中‘营救Randy ’ 人体模型的使用”， 国际技术救援研讨会，普韦布洛县。www.itrsonline.org/PapersFolder/2009/Holden-May-Farnham2009_ITRSPaper.pdf. ----原文注)
At any given time during the year, a number of studies are being performed at the RMRG test tower facility, including safety tests of rescue systems and new equipment. In addition, testing services are provided to other rescue organizations around the state, as time allows. Each scenario at the tower is planned in advance, and the set-up for each configuration can take several hours. The tests included in this investigation spanned seven days at the tower.
在一年里任何指定的时间里，RMRG测试塔设备上会进行数个研究测试，包括救援系统以及新设备的安全测试。此外，只要时间允许，还对附近州的其他救援组织提供测试服务。每个在测试塔上进行的情景再现测试都事先设计安排，每次设置都需要数个小时。我们这次调查共花费七天时间在此塔上进行测试。
Many of the following tests involved rope-over-rock configurations. A variety of rocks with similar density, crystalline structure, and sharpness to that found on the Yellow Spur route were collected and mounted on the tower. The majority were readily available flagstone (sandstone) slabs. The ropes utilized were all commercially available climbing ropes of diameters between 9.8 mm and 11 mm. During the drop tests, load sensors were mounted on both the climber and belayer sides of the rope to measure any differences in loading. All test sequences were recorded on digital video.
以下测试中的多个项目都涉及到绳子与岩石接触的设置。我们从Yellow Spur路线上收集了多种具有相似密度、晶体结构和锋利度的岩石，并堆放于测试塔上，其主体是路线上常见的薄层砂岩（石灰砾岩）板。测试所使用的绳子都是市面上出售的攀岩绳，直径在9.8mm至11mm。在冲坠测试中，载重传感器装置于连接攀爬者和保护员的绳端，以测量载重过程中的所有差异。所有测试都依次记录于数码录像中。
Fall Forces
坠落强度
The estimated distance of the climber’s “leader fall” (not including the distance traveled after the rope severed) was 20-30 feet (6.1-9.1 meters). Such a fall can generate forces of around 800 pounds-force (3.6 kN). This force estimate is based on previous experiments and is highly realistic for such a fall. However, the belayer reported feeling significantly less force from the fall than he would have expected. Therefore, two testing sessions were dedicated to measuring the potential forces exerted on a belayer during such a fall under a variety of configurations.
攀爬者“先锋冲坠”的估算距离（不包括绳子割断后坠落的距离）为20-30英尺（6.1-9.1米），产生的冲坠强度大约为800磅（3.6千牛）。此强度数据根据之前测试获得，与现实中发生类似冲坠的情况符合。不过保护员声称在冲坠发生时，他感觉受到远小于预计的拉力。因此，我们设计了两组测试以测量在不同情况下发生冲坠时施加于保护员的潜在拉力强度。
First, a 165-pound (74.8 kg) rescue mannequin was used to simulate a leader fall of approximately 25 feet (7.6 meters). The configuration was designed to replicate the general geometry of the Yellow Spur accident: a clean fall was caught by a Bluewater Enduro 11 mm dynamic climbing rope running through a carabiner and down to an anchored belayer using a standard belay device (ATC). The photo in Figure 5 shows this configuration on the testing tower.
首先，使用一个165磅（74.8公斤）的救援人体模型模拟大约25英尺（7.6米）高的先锋冲坠。实验场景基本再现了Yellow Spur事故发生地点的地形：一根Bluewater Enduro 11mm动力攀岩绳穿过主锁，通过标准的保护器（ATC）与固定于保护点的保护员相连，另一端（连接着人体模型）进行坠落（坠落过程没有阻碍）。图5中的照片显示了此实验在塔上的具体设置情况。
Figure 5. a) Climber and belayer forces drop test. b) Climber and belayer forces during leader fall.
图5. 左图：攀爬者与保护员的冲坠强度测试（文字框由上至下的内容依次是：攀爬者，主锁，保护员。---译者注）； 右图：在先锋冲坠过程中，攀爬者和保护员受到的拉力强度（蓝线为攀爬者，红线为保护员，绿线为二者之比。---译者注）。
Load sensors at the belayer and on the falling climber measured the resulting forces. Figure 5b shows the change in force (left vertical axis) and force ratio (right vertical axis) over time (horizontal axis). The force ratio is defined as the ratio between force experienced by the belayer to the force experienced by the climber. The force on the climber reached a peak of around 800 pounds-force (3.6 kN) at approximately 1.2 seconds. The force at the belayer was about 600 pounds-force (2.7 kN) at its peak. The ratio of the forces was approximately 0.7, consistent with the rope running cleanly through a carabiner.
装置在保护员和坠落攀爬者身上的载重传感器记录下受力强度。图5的右图显示了力度随时间（水平轴）的变化（左竖轴）以及力度比（右竖轴）。保护员承受的拉力与攀爬者承受的拉力之比得出力度比值。攀爬者承受的力度在接近1.2秒处达到最大值约800磅（3.6千牛）。保护员受力峰值为600磅（2.7千牛）左右。力度比接近0.7，与绳子穿过主锁直接运动的情况相符合。
The impact of 600 pounds-force (2.7 kN) lifted the belayer off the ground as the belay device caught the falling dummy during this test. Had a similar force been translated to the belayer during the Yellow Spur accident, he would have been yanked suddenly to the side (the second pitch starts with a traverse) as the rope came taught. Therefore, we can conclude that the belayer at Yellow Spur experienced a rope tension significantly less than 600 pounds-force (2.7 kN).
在这个测试中，绳子通过保护器拉住坠落的人偶时，600磅（2.7千牛）的拉力施加于保护员身上，使之离开地面。如果在Yellow Spur事故中保护员受到相似的拉力，他应该会在绳子受力后被猛拉至一边（路线第二段开始处是一段横移）。因此我们可以断定事故中的保护员受到绳子延展后的拉力远小于600磅（2.7千牛）。
Fall Forces Over an Edge
在边缘上的坠落强度
The photo in Figure 2 shows the #0.4 Camalot and its associated sling and carabiners as they were found immediately after the accident. Prior to the fall, the climber’s rope would have run up from the belayer, through the carabiner, and up to the climber’s harness. As the climber fell past this point, the rope would have made a sharp bend through the carabiner and another sharp bend over the rock edge below the carabiner at the end of the sling. Another testing day was dedicated to measuring the resulting forces on a belayer under such circumstances. Figure 6a shows a close up of the geometry tested.
图2照片显示的是事故发生后我们立即找到的04号Camalot机械塞和与之相连的扁带及主锁。在冲坠之前，攀爬者的绳子应该是从保护员一端，穿过主锁，连接于攀爬者的安全带上。因为攀爬者坠落时越过此点，绳子应该于主锁处发生了明显的弯折，另一个弯折则发生于扁带底部相连的主锁的下方岩壁边缘上。我们在另一个测试日里测试了在这种情况下保护员的受力强度。图6左图显示了情景再现的设置。
Figure 6. Rope changes direction over rock and through a carabiner: a) testing configuration & b) forces during a direction change.
A quasi-static experiment was conducted to simulate the moment of peak loading. The belayer’s end of the rope was anchored to the lower right. The rope was then run through a carabiner simulating the piece of protection that held, then back down over a rock edge. A 1000-pound (455 kg) weight was slowly lowered by a separate rope onto the climber’s side of the configuration, simulating the peak tension in the rope. The rope tension on either side of the carabiner was measured separately.
图6.绳子在岩石上和通过主锁处改变了方向。（箭头指示的左边绳子为连接攀爬者的受力一端）：左图：测试设置；右图：方向变化过程中的受力情况（蓝线：攀爬者一端，红线：保护员一端；绿线：二者比值；文本框里内容：通过主锁的绳子在岩石边缘发生方向改变。岩壁上的主锁导致绳子发生一些压缩。）
我们先做了在准静态环境下对载重峰值时刻的模拟测试。绳子右侧低处系在保护员身上，之后模拟事故现场，绳子穿过主锁并弯折覆盖于岩石边缘之上。攀爬者一边用一根单独的绳子系上1000磅（455公斤）重量并缓慢放下，模拟绳子受力拉伸的峰值。主锁两端的绳子受力情况是分别计量的。
Several variations of this general configuration were tested to determine whether and to what degree the carabiner could pinch the rope against the rock, and thereby contribute to a reduction of rope tension on the belayer’s side of the carabiner. The results showed that the pinching effect may have contributed to the reduction caused by the rope bending over the rock edge. Figure 6b shows the forces measured in one such test as the weight is lowered onto the system. The graph includes the entire sequence from zero force on the climber’s side to a peak of 1000 pounds-force (4.4 kN). During that time, the force on the belayer’s side reaches a peak of approximately 150 pounds-force (0.7 kN) for a ratio of ~0.15. The reduction in force from climber to belayer in this configuration is quite large. When the climber’s side of the rope is loaded to 800 pounds-force (3.6 kN), only 100 pounds-force (0.4 kN) occurred on the belayer’s side.
测试环境的主体架构不变，我们进行了一些改动以观察主锁是否以及以何种强度把绳子挤压向岩石，这种情况将减少保护员一端主锁上所受的绳子拉力。测试结果显示，因绳子在岩石边缘弯折而发生的挤压可以减少保护员一端绳子的受力强度。图6右图显示了这个系统中采用不同重量的受力强度结果。此表中攀爬者一端的受力从零增加至最大值1000磅（4.4千牛）。与此同时，保护员一端的受力强度达到峰值约150磅（0.7千牛），比率约为0.15。此组数据显示了从攀爬者一端至保护员一端的受力强度的锐减情况。攀爬者一端的绳子受力800磅（3.6千牛）时，保护员一端只受到100磅（0.4千牛）的拉力。
These tests did not include manipulating the angle at which the rope bent over rock. However, the ratio of force reduction discussed above is exponentially sensitive to the angle of bend, such that an increase in the angle of bend would further reduce the belayer load. While it is difficult to determine the exact angle of bend that occurred during the Yellow Spur accident, the angle used in these tests was based on the photo in Figure 2 and is therefore similar to the angle that occurred during the actual accident. Therefore, these findings indicate that it is very possible for a belayer to feel little of the force of such a fall, given the geometry outlined above.
这些测试并没有包括绳子在岩石上发生弯折的角度差异。不过，绳子弯折的角度会以指数级别影响上述讨论的强度减少的比率，也就是说增加绳子弯折的角度会极大的减少保护员的受力强度。因为我们难以确定在Yellow Spur事故中绳子弯折的角度，所以我们根据图2照片来设置测试中的绳子弯折角度，以接近事故中的真实情况。因此，实验结果可以说明，在类似地形的冲坠中，保护员是很可能感受不到太多拉力的。
Comparison of Damage in Climber’s Rope to Various Cutting Methods
对比不同切割方式对攀爬者绳子的破坏情况
Figure 7 shows images of the climber’s rope at both sides of the failure. The damage occurred over approximately two inches of rope. A short length of the rope’s core strands were pulled out of the sheath at the point of failure during the accident.
图7显示的是攀爬者绳子断裂处两端的照片。断裂大约覆盖2英寸绳子。绳子断裂处的一小截绳芯在事故发生时被拽出绳皮。
Figure 7. Climber’s rope at either side of the failure.
图7.攀爬者绳子被割断处两端的照片。
The testing done as part of this investigation included cutting similar ropes under various conditions in order to determine the possible mechanism of failure. These tests show that ropes cut under different conditions display distinctive damage characteristics. Figure 8 shows two cuts performed under different test conditions. In each case, the rope was loaded to 800 pounds-force (3.6 kN), and the rope was cut with a sharp object. The image on the left shows the type of damage that results when a sharp knife is lightly pressed against a loaded rope. The damage occurred very quickly, and the strands showed very little elongation. The image on the right shows the type of damage that occurs when a sharp rock is used to saw across a loaded rope. The resulting damage was more uneven. Core strands near the sharp edge broke at approximately the same time as the sheath while core strands further away stretched and survived slightly longer.
调查中所做的测试包括在不同情况下割断绳子，以推断绳子失效的可能原因。这些测试显示了绳子在不同情况下被割断，会呈现出迥异的破坏特征。图8显示了两种不同测试环境下绳子被割断处的照片。这两个测试中，绳子负重800磅（3.6千牛），由一个锋利物体割断。左图显示的是锋利的刀刃轻压在承重绳子上，绳子割断后的状态。破损发生的非常迅速，绳皮几乎没有发生拉伸变形。右图是使用一块锋利的岩石割承重绳子导致绳子断裂后的状态。可以看到这种情况下断裂处更加参差不齐。刀刃割断的绳子断裂处的绳芯几乎与绳皮同时被割断，而被岩石割断的绳子，绳芯被拉长伸出。
Figure 8. a) Tensioned rope cut with a sharp knife. b) Tensioned rope cut with a sharp rock.
图8.左图：受力的绳子被锋利的刀刃割断。右图：受力的绳子被锋利的岩石割断。
The damage characteristics of the accident rope (Figure 7) are consistent with the rock-cut test depicted in Figure 8b. These findings indicate that during the accident, the rope ran over a sharp object and failed at or near the highest point of tension.
事故绳子的断裂处特征（图7）与图8右图被岩石割断的测试结果相吻合。这些发现说明了在事故发生时，绳子通过一处锋利物体，在被拉伸至延展峰值附近断裂。
Dynamic Drop Tests
动态冲坠测试
Following the relatively static tests described above, the investigation team initiated a sequence of dynamic drop tests at the RMRG test tower. The primary purpose of these tests was to understand the combination of forces, angles, and rock structures required to cause the specific type of rope failure that occurred in this accident. The testing attempted to re-create the damage observed in the accident rope by creating fall dynamics that could have occurred during the Yellow Spur accident.
进行完上述相对静态的测试，调查小组开始在RMRG测试塔上进行一系列动态冲坠试验。这些测试的主要目的在于分析清楚拉力、角度以及岩石结构的何种组合可以造成事故中绳子的断裂情况。在测试中我们尝试通过制造Yellow Spur 事故中可能发生的动态冲坠来再现事故绳子上的割断状态。
Rope Failure Test – Directly Over Sharp Edge
绳子失效测试---直接作用于锋利的边缘上
As mentioned previously, the photos taken on scene immediately after the accident led the investigation team to hypothesize that the climber’s rope passed over the rock edge near the carabiner connected to the sling in Figure 2. It is possible that the rope failed as it passed over this edge. Two testing days were devoted to investigating rope failures directly over similar sharp edges of rock during a leader fall sequence.
如上文所述，事故发生后立即拍下的现场照片让调查小组成员推测攀爬者的绳子通过了图2中扁带末端主锁的附近的岩石边缘。有可能是在绳子通过这个边缘时被割断。我们花了两天时间调查先锋冲坠中通过相似的锋利岩石边缘对绳子断裂的影响。
In each test, a rock with a sharp edge was mounted to a beam on the test tower. Figure 9 shows a typical pre-drop configuration with the belayer’s side of the rope attached to a load sensor. The rope then traveled through a carabiner, over a sharp edge, and down to a 200-pound (90.7 kg) weight stack on the climber’s side. The rope used in these tests was a commercially-available 9.8 mm dynamic climbing rope.
我们在每个测试中都把一块带有锋利边缘的岩石放置在测试塔的横梁上。图9显示了典型的冲坠前期设置，保护员一端的绳子连接在载重传感器上（图中上方箭头所指处）。绳子穿过一把主锁，通过岩石的锋利边缘，下方，即攀爬者一边，悬吊着200磅（90.7公斤）重物（图中下方箭头所指的绳端）。这些测试中所使用的绳子为市面可购买到的9.8mm动力攀岩绳。
Figure 9. a) Example pre-drop configuration. b) Typical partial rope failure result.
图9. 左图：冲坠前期的设置实例。右图：绳子发生部分失效的常规现象。
Numerous drop tests were executed with several variations of carabiner-to-edge locations, types of rock edges, and fall line angles, such that the rope slid 1 to 3 inches along the sharp edge during the simulated fall. Each test resulted in significant damage to the rope. However, in several cases, the rope did not sever completely. Figure 9b shows the rope damage after a drop where the sheath failed but the majority of core strands survived.
我们进行了多次冲坠测试，改变靠近边缘的主锁的位置，采用不同的岩石边缘，冲坠角度，使得在模拟坠落过程中绳子沿着锋利的岩石边缘滑动1至3英寸。每个测试都对绳子造成严重损坏。然而，在一些情况下，绳子并没有完全被割断。图9右图显示了在一次冲坠测试后，绳皮撕裂，但是绳芯的主体部分并未断裂。
图10左图显示的是绳子完全被割断的测试的数据结果。蓝色变量显示了随着时间变化，由于磨擦力在作用，绳子被岩石边缘临时“抓住”并释放过程的受力情况。绳子的受力强度在达到峰值之后急剧减少为零，这显示了绳子完全失效的时间点。在此试验中攀爬者一端的绳子承重最大值尽略高于1200磅（5.3千牛）。
Figure 10. a) Typical loading during rope failure test. b) Typical damage caused during rope directly over sharp edge scenarios.
图10.左图：绳子失效测试中，典型的载重变化值。右图：绳子直接作用于锋利边缘而导致的典型损害情况。
Figure 10b shows the type of damage done during each of the tests in which the rope failed completely. The sheath failed quickly and exposed the core strands to the edge. However, the core strands did not all fail at the same point. It is likely that as the rope is tensioned, it flattens across the edge, thereby protecting core strands that are further away, at least for a brief period of time. In addition, as the rope stretches, some of its length will become exposed to the edge and therefore the damage is spread across several inches.
图10右图显示的是测试中发生绳子完全失效后的被割断部位情况。绳皮迅速被撕裂，绳芯暴露在外与岩石边缘直接接触。然而，绳芯并未在同一位置断裂。我们推断是因为绳子处于受力延伸状态，通过岩石边缘时变平缓，因此至少在一段时间内受保护的绳芯位置稍离开一些。此外，延伸的绳子会有一段长度与岩石边缘接触，因此损害部位覆盖几英寸的绳子。
While many of these tests were successful in creating complete rope failures, the characteristics of the damage were inconsistent with that of the accident rope (Figure 7). The damage to the accident rope occurs over a very short length, as if the contact point with the sharp edge did not change as the damage occurred. Therefore, it is unlikely that the accident rope failed due to the mechanisms or configurations demonstrated in this portion of the testing.
虽然上述多个测试可导致绳子的完全失效，但是其结果特征与事故绳子（图7）的损坏状态并不吻合。事故绳子断裂处的损坏部位非常短，应该在损坏发生时与岩石锋利边缘接触的绳子并未发生位置变化。因此，这一阶段的测试设置或机制并不能导致类似事故绳子的割断现象。
Pendulum Rope Failure Tests
摆荡绳子失效测试
Another possible mechanism for failure of the rope involves a fully loaded rope sliding sideways across a sharp rock edge. Conceptually, this is similar to the rope cut tests described above, where a sharp rock was used to saw across a loaded rope: the contact point of the rock on the rope does not change (Figure 8b). This mechanism may be present in a leader fall when the climber is not directly above the last piece of protection, introducing a sideways component to the fall. Based on previous testing at the RMRG test tower, the majority of such a pendulum movement occurs after the rope is highly tensioned. That is, a fall continues straight downwards until the rope stretches sufficiently to take a significant portion of the load, which then results in the falling object swinging from the fall line toward the last piece of protection. If there is a sharp edge between the climber and the last piece of protection, the rope will slide across it.
造成绳子失效的另一个可能原因是完全载重的绳子侧向滑过岩石的锋利边缘。从概念上讲，这与之前所做的绳子割断测试类似，在之前的测试中我们用一块锋利的岩石割断了载重的绳子：与绳子接触的岩石部位并未发生改变（图8右图）。我们现在要做的摆荡绳子失效测试意在呈现攀爬者并未处在最近保护点的正上方时，冲坠后发生摆荡的情况。基于之前在RMRG测试塔上完成的测试项目，绳子在高度拉伸的情况下发生摆荡运动。也就是说，先是垂直方向上的坠落，直到绳子受到足够的载重拉力之后，坠落物开始向最后一处保护点方向摆荡。如果在攀爬者和最后保护点之间有一块锋利的边缘，绳子将会从这一段滑过。
Two testing days were conducted to evaluate this pendulum failure theory. Figure 11a shows one of the many configurations used for the pendulum tests. The rope used during these tests was a commercially available 10.2 mm dynamic climbing rope.
我们花了两天时间验证提出的摆荡失效理论。图11左图显示了用于摆荡测试的多个设置中的一个。所用绳子为市面上出售的10.2mm动力攀岩绳。
6 This rope was thicker than the accident rope but it is reasonable to assume that a thinner rope could fail with the same characteristics. A rock with a sharp edge was mounted to the test tower. The test rope was attached to the tower approximately 3 feet (1 meter) higher than the rock and a weight stack was loaded onto the rope. In these tests, the weight was not dropped. Instead, it was allowed to swing sideways, dragging the rope along the sharp edge of the rock as indicated by the direction of the yellow arrows (Figure 11a).
（测试用的绳子比事故绳子粗一些，不过可以假设如果是更细的绳子，在同样的情况下也会失效。---原文注）我们在测试塔上放置了一块带有锋利边缘的岩石。测试绳子悬挂在高于岩石约3英尺（1米）的位置，绳子下端系有载重物。在这组测试中，载重物并不坠落，只是发生侧向摆荡，牵引着绳子沿图中黄色箭头方向滑过岩石的锋利边缘（图11左图）。
The weight was pulled to the right side of the photo and attached to a release mechanism at the side of the tower. The blue piece of equipment clamped to the wooden beam is a smooth metal angle used to keep the loaded rope from rubbing on the rock edge prior to the release of the weight stack. This provided for less friction than would occur if the rope slid along the wood.
重物被拉向照片右侧，与之相连的是测试塔另一端的一个释放装置。被夹钳在木质横梁上的蓝色装置是一段光滑的金属角，用于防止载重绳子在重物被释放之前与岩石边缘发生摩擦。如果绳子滑过木板，此装置将减少绳子在木板上受到的摩擦。
Figure 11. a) Test tower pendulum configuration. b) Pendulum test rope damage.
图11.左图：测试塔上摆荡测试的设置情况。右图：摆荡测试中绳子受到的损坏情况。
Different loads were used to simulate the downward force of a pendulum fall. Contact with the sharp edge of the rock during the pendulum resulted in considerable damage to the rope in each test. Using a load of 300 pounds-force (1.3 kN) caused the rope to fail, but only after sliding back and forth along the edge a number of times. However, there was no indication from witnesses to the accident that any such back and forth motion occurred prior to the rope failing. The remaining pendulum failure tests used a load of 760 pounds-force (3.4 kN). In each of these cases, the rope failed with only a single pass along the edge of the rock. Slow motion review of the video captured during the test showed that the rope passed over approximately 2 inches of the edge before failing.
我们采用了多种不同载重物来模拟摆荡坠落中的下坠冲击力。每个测试中，绳子与岩石锋利边缘接触的部位都在摆荡中受到严重破损。在采用300磅（1.3千牛）载重时，绳子发生断裂，但是这只发生在沿着边缘来回滑动数次之后。然而，据事故现场的目击者称，在绳子被割断之前，并未发生类似的前后摆荡现象。我们在余下的摆荡失效测试中采用了760磅（3.4千牛）的载重物。在这组测试中，绳子在第一次滑过岩石边缘时就发生断裂。拍摄下来的视频慢镜头显示，绳子在滑过边缘约2英寸处被割断。
Figure 11b shows the damage to the rope caused by the pendulum test with a load of 760 pounds-force (3.4 kN). The damage is isolated to a very short section of rope such that the sheath and core are cut at approximately the same location. The results of this test created a slightly cleaner cut to the rope than either the accident rope (Figure 7) or the test of the loaded rope cut by sawing a sharp rock across it (Figure 8b). In each of those cases, more of the core was exposed. Thus, it is possible that some amount of stretch occurred as the damage was occurring during the Yellow Spur accident. It is also possible that variations in the sharpness of the different rock edges could account for the different damage characteristics. However, it seems clear that this type of failure mechanism was likely responsible for the rope failure during the Yellow Spur accident.
图11右图显示了载重760磅（3.4千牛）的摆荡测试中绳子受到的损坏情况。损坏部位只发生在绳子非常短的一段距离上，并且绳皮与绳芯几乎在相同位置被割断。与事故绳子（图7）的割断处以及被锋利岩石割断的载重绳子（图8右图）相比，这个测试结果显示了一个稍微整齐的割断面。这组测试中，更多的绳芯暴露在外。因此，可推断在Yellow Spur事故中，绳子被割断处应该发生了一定程度的拉伸。不同岩石边缘的锋利程度不同也可能导致不同性质的损坏。然而，可以明确的是这种失效设置与Yellow Spur事故中的绳子失效情况相似。
Re-creation at Yellow Spur
在Yellow Spur重现事故
As part of this accident investigation, RMRG attempted to re-create the conditions of the fall on Yellow Spur to evaluate interactions between the climber’s rope and the rock during the fall. A fully-loaded fall sequence was not attempted on the route due to the time and resources required for such a recreation, the popularity of the Yellow Spur route, and the possibility of damage to the route itself. However, a simulated lead fall with a load of approximately 30 pounds-force (0.1 kN) was conducted from the climber’s estimated high point in order to evaluate the pendulum characteristics of the accident, based on the best-known locations of the belayer, climber, and his protection.
作为本次调查的一部分，RMRG尝试在Yellow Spur现场重现坠落过程，以评估在坠落过程中攀岩者一端的绳子与岩石之间的相互作用。考虑到重现事故所需的时间和资源，Yellow Spur路线的受欢迎程度以及对路线本身可能造成的破坏，我们不会尝试进行与事故相同载重的坠落测试。不过，基于已掌握的保护员、攀爬者以及保护点的位置，我们在攀爬者所到达的最高点附近设置了一个约30磅（0.1千牛）的重物进行坠落测试以评估事故中摆荡特征。
The photos in Figure 12 show the start of the second pitch from the viewpoint of the belayer at the tree marked in Figure 1b. The investigator in the first photo (Figure 12a) is at the approximate location of the start of the fall. The rope (A) is an RMRG rope used by the investigators to access the route. (B) is the simulated climber’s rope. The near end of the climber’s rope runs through an investigator’s belay device at the tree. The carabiner (C) is attached to a similar configuration of #0.4 Camalot and associated sling and carabiners that held the fall during the accident, and which have been placed according to the photo documentation in the initial investigation (Figure 2). The rope (D) connects the climber’s rope and was used to provide weight during the drop.
图12显示了从保护员一边（图1右图中标记的树的位置）的视角所看到的第二段路线的起始位置。第一张照片里的调查员（图12左图）所处的位置大约就是发生冲坠的起始地点。调查员使用一根RMRG绳子（A）攀爬这条路线。（B）是模拟的攀爬者绳子。攀爬者绳子末端附近穿过在树附近的调查员的保护器。主锁（C）连接在相同的一个0.4号机械塞和扁带上，在发生事故的过程中，主锁承受了坠落冲击，我们根据之前调查（图2）的照片文档设置了主锁放置的位置。绳子（D）与攀爬者一段的绳子相连，为坠落提供重量。
Figure 12. Re-creation configuration on Yellow Spur; a) just prior to dropping the rope & b) just after dropping the rope.
图12.在Yellow Spur岩壁上再现事故现场的设置。左图：坠落之前；右图：坠落之后
During the interview of the belayer, it was indicated that Miller fell straight down from approximately the investigators location (Figure 12a). In this re-creation, the investigator in the image dropped the simulated climber’s rope straight down without adding any outward or sideways component. While the amount of force resulting from this simulated fall is much lower than what would have occurred during the actual fall, the configuration was sufficient for estimating the general rope movement characteristics during the incident.
在对保护员进行的采访中，我们得知Miller从调查员所在位置（图12左图）垂直坠落。在本次事故再现测试中，图片中的调查员在竖直方向上掷下模拟的攀爬者绳子，未添加任何向外或侧向因素。虽然与实际冲坠中产生的力度相比，测试中的冲坠力度要小的多，但是此设置足以估算在事故中绳子运动的大致特征。
Figure 12b shows the resulting configuration of the simulated climber’s rope after being dropped from the position indicated in Figure 12a. In the image, (A) is the investigator’s access rope, (B) is the climber’s rope, and (C) is the carabiner. The fall line of the drop was about 2 or 3 feet (1 meter) climber’s left (into the image) from the resting location of the rope. The rope dropped straight down and then pendulumed climber’s right (toward the belayer) along the edge below the carabiner, finally ending up in the notch as shown in the image. The rope between the belayer and the carabiner did not contact any rock surface and there was no obvious place along that line where the rope could have snagged. The climber’s side of the rope hung in free space below the overhang at the bottom of Figure 12b. There are no other obvious edges near the carabiner other than the main edge over which the rope is draped. While there are certainly other possible rope movements that could have occurred during the actual fall, this sequence and resulting position are consistent with the available information.
图12右图显示了在图12左图中所示位置模拟的攀爬者绳子发生坠落后得到的结果。照片中（A）是调查者身上所系的绳子，（B）是攀爬者绳子，（C）是主锁。坠落轨迹大约距绳子静止处左侧2或3英尺（1米），在攀爬者的左侧。绳子垂直下落，随后沿着主锁下方的边缘朝向攀爬者右边摆荡（朝向保护员），最后停止并卡在岩壁凹槽处，如图所示。保护员与主锁之间的绳子并未与任何岩面接触，在坠落轨迹上也无任何明显物体可导致绳子被阻挡。攀爬者一端的绳子在图12右图中的下方悬空垂吊。主锁附近除了挂住绳子的边缘处，再无其他明显边缘。在事故中的冲坠过程中绳子存在发生其他运动的可能性，但是测试中的结果位置与已掌握的信息相符合。
图13左图显示了0.4号机械塞上方的最终设置。攀爬者的绳子向左摆荡，向下滑过边缘，最终停止于凹槽内。主锁呈现的状态和所处位置与事故发生后立即拍下的照片相符合。图13右图显示的是绳子停止于凹槽之前滑过边缘的近处照片。凹槽本身也是锋利的，其右侧绳子滑过的边缘部分更是锋利。
Figure 13. Re-creation on Yellow Spur. a) Looking down at the final configuration after simulated fall, b) Close up of the edge.
图13.Yellow Spur模拟事故再现。左图：模拟冲坠之后（右侧中间三个箭头所指的就是锋利的岩石边缘，右侧上方箭头所指示的是摆荡方向。左侧箭头指示保护员方向），从坠落发生后的最终情形处往下看；右图：边缘附近
During the process of the re-creation, investigators saw no other combinations of fall characteristics and/or sharp edges that could match the known location of equipment that held during the fall and eyewitness information. If the rope movement during the actual fall followed a similar sequence as the re-creation, then nearly the full force of the fall would have been applied to the rope as it came taut over the rounded edge to the right in Figure 13a. It could then have pendulumed down along the edge toward the notch and across the very sharp edge shown in Figure 13b.
在模拟事故再现的过程中，调查员没有发现其他坠落现象和/或锋利的边缘也可以与已知的在冲坠中承重装备所处位置以及目击信息相符合的组合情况。如果实际坠落中绳子的运动与模拟事故再现的测试相同，那么冲坠产生的所有冲击力都作用于绳子之上，因为绳子到达图13左图中右侧圆滑的边缘之后被拉紧。之后绳子可能沿着岩石边缘向凹槽摆荡，绳子滑过图13右图中锋利的边缘到达凹槽处。
Analysis and Discussion
分析与讨论
The purpose of this investigation was an attempt to understand the factors contributing to the death of Joseph Miller on June 22, 2010. The results indicate that a narrow set of circumstances likely led to the failure of Miller’s climbing rope during a typical leader fall. Climbers may be comforted to know that it was difficult to re-create a complete failure of a standard dynamic climbing rope under realistic climbing conditions. The commercially-available climbing ropes utilized in these experiments often survived the severe tests undertaken, although with significant damage.
本次调查的目的在于尝试澄清导致2010年6月22日Joseph Miller死亡的因素。调查结果显示一系列小范围的情况可导致Miller的攀岩绳在一次典型的先锋冲坠中发生断裂。攀岩者可能更乐意得知在现实的攀爬中很难再次发生标准动力攀岩绳完全失效的情况。市面出售的攀岩绳在极端的测试中即使被严重损坏，但仍然保持一定作用。
Non-pendulum drop tests wherein a climbing rope was loaded such that it ran for some distance over a sharp edge (without a significant lateral motion) resulted in sheath failure occurring significantly before core strands began to fail. In many cases, some of the core strands survived and ultimately held the load. This type of damage, however, was qualitatively different from the damage found in the accident rope. Therefore, it is unlikely that the failure of the accident rope was caused while elongating over a sharp edge.
未摆荡坠落测试中使用的攀岩绳被系上载重物，以便它在通过锋利的边缘时运动一段距离（不发生明显的横向运动），结果显示了在绳芯失效之前，绳皮明显破损。在许多测试中，绳芯没有失效，并最终承受住了冲击力。然而此类型的损坏与事故绳子上发现的损坏有质的区别。因此，事故绳子的失效不可能发生在悬吊拉伸于锋利边缘的过程中。
Eyewitness reports indicate that the falling climber traveled straight downward and appeared to be decelerating immediately before the rope failure occurred. This is consistent with the rope failing under high tension during the maximum forces created in the fall. Furthermore, the damage found in the accident rope was consistent with results from the rock-cut and pendulum tests wherein a rope tensioned to approximately 800 pounds-force (3.6 kN) moved laterally over a sharp edge. These findings suggest that a pendulum effect contributed to the failure.
据现场目击者声称，坠落的攀爬者垂直下落，在绳子被割断之前骤然减速。这与发生坠落的过程中，绳子处于高度拉伸状态下达到拉力峰值时的情形相符合。此外，事故绳子上发现的损坏现象与岩石割断绳子测试以及摆荡测试（横向滑过锋利边缘时绳子延伸受力达到约800磅（3.6千牛））中的现象符合。这些现象显示了摆荡效果造成了绳子被割断。
Potential Accident Sequence
事故的可能顺序
While the exact alignment of the climber and the protection he placed cannot be determined with certainty, the best estimates suggest that the fall line from the climber’s high point was a few feet climber’s left of the #0.4 Camalot that initially held the fall. This geometry would have resulted in the climber falling straight down until the rope between the climber and the #0.4 Camalot began to stretch. The left hand pane of Figure 14 depicts the fall relative to this piece of protection (labeled ‘R’). At this point in the sequence, shown in the middle pane of Figure 14, a pendulum effect would have begun, swinging the climber to his right. The rope would therefore have moved laterally across any rock edge between the climber and the #0.4 Camalot. The right hand pane depicts the potential configuration prior to rope failure from the side 7. Re-creation of the accident events on the route itself demonstrated that such a sequence was possible and that the rope would have pendulumed across a sharp edge. It is therefore likely that Miller’s rope failed under such circumstances. 7 This view is similar to the picture in Figure 12b taken during the re-creation.
因为我们无法确定攀爬者以及他设置保护点的准确位置，关于从攀爬者坠落发生位置开始的坠落轨迹，我们的最佳推断是位于0.4号机械塞左侧距攀爬者几英尺的地方，此保护点在坠落中首先承受住了冲坠力。这种设置会导致攀爬者垂直下落，直到在攀爬者和0.4号机械塞之间的绳子开始受力拉力。图14的左格图里画出的是在这一阶段保护中的坠落过程（标记为‘R’）。在这一刻，见图14中间栏，摆荡发生，至使攀爬者向右边荡去。绳子因此滑过攀爬者和0.4号机械塞中间的某一块岩石的边缘。右栏图示显示的是绳子被割断之前可能呈现的状况（此图与图12右图照片中的情况相似。---原文注）。在这条路线上进行的事故再现测试自身也表明这一系列事件的可能性以及绳子摆荡滑过一段锋利的边缘。由此可得，Miller的绳子很可能在这样的情形下被割断。
Figure 14. Potential accident sequence. Left and center pane depict sequence facing the route. Right pane depicts fall position prior to rope failure from the side.
图14. 事故的可能顺序。左栏和中间栏显示的是面朝路线时的情形。右栏显示的是从侧边所见的绳子被割断前的坠落位置。
Conclusion
结论
There is no way to know exactly what caused the rope failure that resulted in Miller’s death on Yellow Spur. However, it seems likely that a specific sequence of events occurred during this accident. First, the investigation found no indication of intrinsic (manufacturing) defect or deterioration of the rope or associated climbing equipment due to their prior use. Second, Miller appeared to be having some difficulty while climbing the route and took a typical leader fall, a fairly common occurrence among lead climbers. Third, it appears that Miller placed a piece of protection very close to his high point. Had this protection held, it is likely that the fall would have been arrested after only a very short distance. A combination of this highest piece of protection pulling out and the distance to the next piece resulted in a longer fall. Had the rope not failed, it is very likely that this longer fall would still have been stopped relatively safely. Fourth, the geometry observed during the re-creation of the accident indicated that the rope likely pendulumed across a sharp edge during the instant it was under high tension. If Miller’s fall had not resulted in a pendulum, the rope may have survived running over the sharp edge (although likely with some damage). Had the fall generated a smaller force, it may also have survived the sharp edge. As with many accidents, it appears that a sequence of events rather than a single issue resulted in Miller’s death.
无法准确得知至使Miller在Yellow Spur丧命的绳子失效原因。然而，事故中可能发生了一系列特定的事件。首先，调查发现绳子以及相关攀爬装备在他们使用之前并没有本身（人为的）的缺陷或损坏。其次，Miller在攀爬这条路线的过程中显现出遇到了难点，并发生典型的先锋冲坠，这在先锋攀爬者身上是非常常见的现象。第三，证据显示Miller在他坠落的最高点附近设置的保护点。如果这个保护点起到应有的作用，那么冲坠可能在落下非常短的距离之后就被拉住停止。最高的保护点被拔出以及距下一个保护点的距离导致了一次长距离的冲坠。如果绳子没有被割断，这种长距离的冲坠应该还是会被相对安全的承受住并停止。第四，在重现事故的测试中，对现场地貌的观察显示出绳子在高度拉伸的情况下，很可能摆荡滑过一段锋利的岩石边缘。如果Miller的冲坠没有发生摆荡，绳子可能在通过锋利岩壁的过程中不会被割断（虽然绳子可能受到损坏）。如果冲坠产生稍微小一些的冲击力，绳子也不会被锋利的边缘割断。综上所述，造成Miller死亡的原因不止一个，它是一系列事件的结果。
Safety Lessons for Climbers
攀爬者需吸取的教训
All lead climbers accept the possibility of a leader fall. Climbers evaluate and manage the level of risk they are willing to accept. Doing so effectively involves understanding the potential consequences of any fall. However, the general assumption among climbers is that “ropes do not fail” — or, at least, that rope failure is extremely rare. As such, climbing accidents that result in a rope failure attract considerable interest from the climbing community and may provide useful lessons for safety education. Two such lessons can be extrapolated from the current findings.
所有先锋攀爬者都要清楚发生先锋冲坠的可能性。攀爬者评估并应对他们愿意接受的风险程度。有效的做到这一点包括了解任何冲坠所带来的潜在结果。不过，攀爬者经常持有的假设是“绳子不会断的”---或者，至少不太容易发生绳子被割断的情况。因此，发生绳子被割断的攀登事故在攀岩圈里引起相当大的关注，并且对安全教育也提供了宝贵的教训。从当前调查和结论里我们可以得到两点教训。
Lead climbers often place protection after passing a ledge in order to help prevent hitting the ledge during a fall. Protection may also be placed in order to prevent falling past the ledge, especially if such a fall would result in the rope running over a sharp edge. Clearly, any ledge with a sharp edge that a leader might fall past represents an extremely high risk factor. However, the rope failure tests done during this investigation suggest two additional factors to consider during such ledge transitions. First, lead climbers should attempt to visualize the geometry of a potential fall past a ledge, and consider whether a potential pendulum effect may result in a tensioned rope moving laterally across the edge. Second, climbers should consider how that geometry could differ given the failure of any piece(s) of protection along the route, possibly leading to the rope coming in contact with nearby sharp edges that may not be directly in line with the initial fall. In some cases, hazardous situations might best be managed by altering the route in order to avoid the area or even by backing off the route.
先锋攀爬者经常在通过一段突出的平台之后设置保护点，以此防止冲坠时撞击到平台。防止坠落时越过平台的保护措施也要设置，尤其是当坠落会导致绳子滑过一段锋利的边缘时。显而易见，先锋攀爬者发生冲坠后通过的任何具有锋利边缘的平台都是极度危险的因素。不过，在本次调查中进行的绳子失效测试显示，在过渡平台的时候还要考虑两点因素。第一，先锋攀爬者应该尝试观察可能冲坠并通过平台的地貌，并权衡可能发生的摆荡效果是否会导致拉伸受力状态下的绳子横向运动滑过边缘。第二，攀爬者必须考虑在路线上任何一处的保护点失效的情况下，地貌也会发生变化，此时会导致绳子与之前冲坠时不会直接接触的附近锋利边缘相接触。在一些情况下，若路线存在诸多危险，最好是改变原始路线绕过这个区域，或者停止攀爬直接下来。
Acknowledgements
致谢
The members of the Rocky Mountain Rescue Group would like to express their condolences to the deceased’s friends and family. We would like to thank the belayer and eyewitnesses for providing invaluable information during the course of the interviews. We would also like to thank the Boulder County Sheriff’s Office for allowing the investigation team to inspect the accident rope and associated equipment that had been placed in evidence. Finally, we would like to thank the climbing community in general who expressed considerable interest in the results of this investigation and showed extraordinary patience in awaiting these results.
落基山救援组的全体成员向受难者的亲人及朋友致以深切的哀悼。我们感谢保护员以及目击者在接受访谈时为我们提供的宝贵信息。我们也要感谢博尔德县警长办公室允许调查小组检查已列为物证的事故绳子以及相关装备。最后，我们要感谢攀岩圈子里所有关注本次调查的岩友们，感谢你们如此耐心的等待事故报告的结果。
