2024年3月撞上巴尔的摩主要大桥的货船，在经历了两次停电美国国家运输安全委员会周二透露，最初由于电线安装不当而断电。
该机构表示，NTSB还发现了与达利号机械和电气系统相关的安全问题，这些问题阻碍了该船在最初的停电后完全恢复。
2024年3月26日凌晨，新加坡船只Dali撞上了关键大桥上的一个桥墩，导致大桥坍塌，六名正在填补桥上坑洞的建筑工人丧生。
“这场悲剧本不该发生，”美国国家运输安全委员会主席珍妮弗·霍曼迪(Jennifer Homendy)在周二举行的听证会上说，该机构对这起事故进行了20个月的调查。“生命本不该逝去，因为我们调查的所有事故都是可以预防的。”
据NTSB称，在坠机当天，一根因连接不稳定而逐渐松动的电线最终从断路器上断开，导致推进力和转向力丧失。该机构发现，一个标识电线电源的标签阻止它完全插入断路器。
Homendy称赞她的员工的这一发现。
“我们的调查人员通常会完成不可能的任务，这次调查也不例外，”她说。“达利几乎有1000英尺高，和埃菲尔铁塔一样高，有数英里长的电线和数千个电气连接。在成千上万的电线中找到一根松动的电线就像在埃菲尔铁塔中寻找一个松动的螺栓一样。”
NTSB表示，松散的电线本来可以在检查中发现，但该机构表示，该船运营商Synergy Marine Group进行的检查不够充分。
在最初的电力故障之后，NTSB号发现，备份系统的多个部分没有正确配置，这些部分本应恢复船只的电力和功能，并防止推进力丧失。
NTSB说，第二次停电是由于燃料压力不足，在第一次停电期间，用于向两台发电机提供燃料的冲洗泵关闭，并且没有重新启动。调查人员发现，机组人员对冲洗泵的操作“不恰当”，因为在停电后恢复供电时，泵无法自动重启，必须手动重启。
“根据船只的船级社，作为燃油服务泵的泵的操作不符合分类要求，因为它不能自动重启，”NTSB海洋安全办公室的工程师巴顿·巴纳姆在听证会上说。
据NTSB报道，该船在失事前一天停靠码头时经历了两次停电。巴纳姆说，第一次停电是由人为失误造成的，而第二次停电同样是因为冲洗泵关闭了。
NTSB认定，Synergy没有阻止工作人员将冲洗泵用作燃料辅助泵，因此监管不力。
NTSB发现，达利公司的工作人员对第一次停电反应迅速而及时。
集装箱船上的工作人员能够就故障向官员发出警告，让他们有时间在事故发生前关闭大桥。
NTSB周二表示，桥上的工人没有收到大理紧急情况的任何警告。如果他们得到通知，他们“可能有足够的时间开车到桥上没有倒塌的部分，”NTSB公路因素工程师Scott Parent说。
他说，美国国家标准协会(American National Standards Institute)没有针对公路工人的标准，要求他们接收有关工作区内危及生命事件的紧急信息，强调“有效和即时沟通的必要性”。
调查人员还确定，关键桥梁倒塌的一个促成原因是“缺乏对策来降低桥梁因远洋船只撞击而倒塌的脆弱性。”这些措施NTSB表示，“如果马里兰州交通管理局按照美国州公路和交通官员协会的建议进行了脆弱性评估”，该项目本可以实施。
作为调查的结果，NTSB向多个团体发布了17项新的安全建议。
马里兰州运输管理局(MDTA)周二表示审查NTSB的调查结果和建议。
“MDTA坚持认为，弗朗西斯·斯科特·基大桥的倒塌和悲惨的生命损失是大理的唯一过错，是其所有者和经营者的重大疏忽，”它在一份声明中说。
在听证会之前，MDTA周一表示，它“将继续与联邦公路管理局合作，快速安全地推进大桥的重建”。
当局表示，重建现在估计耗资43亿至52亿美元，预计将于2030年底开放。官员们此前表示，大桥的重建预计将耗资17亿至19亿美元，最早将持续到2028年。
代理运输部长兼MDTA主席Samantha Biddle在一份声明中说:“更新的成本范围和时间表与材料成本的增加和强大的码头保护系统直接相关，该系统旨在保护新的关键桥梁，并降低未来船只撞击桥梁基础码头的可能性。”
MDTA表示，新桥将具有更长的跨度和更高的主桥墩，以适应更大的海上交通，并符合美国国家公路和运输官员协会对新桥的现行指导方针。
Cargo ship initially lost power due to loose wire before crashing into Key Bridge: NTSB
The cargo ship that rammed into Baltimore's Key Bridge in March 2024, shortly after experiencingtwo blackouts, initially lost power due to an improperly installed wire, the National Transportation Safety Board revealed on Tuesday.
The NTSB further found safety issues related to the Dali's machinery and electrical systems that prevented the ship from fully recovering following the initial blackout, the agency said.
The Dali, a Singaporean vessel, struck one of the piers on the Key Bridge early on the morning of March 26, 2024, causing the bridge to collapse and killing six construction workers who were filling potholes on the span.
"This tragedy should have never occurred," National Transportation Safety Board Chair Jennifer Homendy said during a hearing on Tuesday on the findings of the agency's 20-month investigation into the crash. "Lives should have never been lost, as with all accidents that we investigate, this was preventable."
According to the NTSB, on the day of the crash, a wire that had loosened over time due to an unstable connection ultimately disconnected from its breaker, resulting in a loss of propulsion and steering. A label identifying what the wire powered prevented it from being fully inserted into the breaker, the agency found.
Homendy commended her staff for this discovery.
"Our investigators routinely accomplish the impossible, and this investigation is no different," she said. "The Dali is almost 1,000 feet, and it's as long as the Eiffel Tower is high with miles of wiring and thousands of electrical connections. Locating a single wire that is loose among thousands of wires is like looking for a loose bolt in the Eiffel Tower."
The NTSB said the loose wire could have been identified during inspections, however the agencies said the inspections performed by the ship's operator, Synergy Marine Group, were not adequate enough.
Following that initial power failure, the NTSB found that multiple parts of the back up systems that were supposed to restore power and functionality to the ship and prevent the loss of propulsion were not configured correctly.
A second blackout occurred due to insufficient fuel pressure after a flushing pump being used to supply fuel to two generators shut off during the initial blackout and wasn't restarted, the NTSB said. Investigators found the crew's operation of the flushing pump was "inappropriate" because the pump was not able to restart automatically when power was restored following a blackout and had to be restarted manually.
"According to the vessel's classification society, the operation of the pump as a fuel oil service pump did not meet classification requirements because it was not able to restart automatically," Barton Barnum, an engineer with the NTSB's Office of Marine Safety, said during the hearing.
The ship experienced two blackouts while docked the day before the crash, according to the NTSB. The initial blackout was caused by human error, while the second similarly occurred because the flushing pump had shut off, Barnum said.
The NTSB determined that Synergy provided inadequate oversight by not stopping the crew from using the flushing pump as a fuel service pump.
The Dali crew responded quickly and in a timely manner to the first blackout, the NTSB found.
Crews onboard the container ship were able to warn officials about the malfunction, giving them time to close the bridge to oncoming traffic before the crash.
The NTSB said Tuesday that the workers on the bridge, though, had not received any warnings of Dali’s emergency situation. Had they been notified, they "may have had sufficient time to drive to a portion of the bridge that did not collapse," Scott Parent, an NTSB highway factors engineer, said.
There are no American National Standards Institute standards for highway workers to receive emergency information regarding life-threatening events in work zones, stressing the "need for effective and immediate communication," he said.
Investigators also determined that a contributing cause to the collapse of the Key Bridge was "the lack of countermeasures to reduce the bridge's vulnerability to collapse due to impact by ocean-going vessels." These measurescould have been implemented "if a vulnerability assessment had been conducted by the Maryland Transportation Authority as recommended by the American Association of State Highway and Transportation Officials," the NTSB said.
The NTSB is issuing 17 new safety recommendations to multiple groups as a result of its investigation.
The Maryland Transportation Authority (MDTA) said Tuesday it isreviewing the NTSB's findings and recommendations.
"The MDTA maintains that the collapse of the Francis Scott Key Bridge and the tragic loss of life were the sole fault of the DALI and the gross negligence of its owners and operators," it said in a statement.
Ahead of the hearing, the MDTA said Monday that it "continues to work in partnership with the Federal Highway Administration to quickly and safely advance the rebuilding" of the bridge.
The rebuild is now estimated to cost between $4.3 billion and $5.2 billion and is expected to open in late 2030, the authority said. Officials had previously said the bridge's reconstruction was expected to cost between $1.7 billion to $1.9 billion and last through 2028 at the earliest.
"The updated cost range and schedule are directly correlated to increased material costs and to a robust pier protection system designed to protect the new Key Bridge and reduce the likelihood of a future ship strike to the bridge’s foundational piers," Acting Transportation Secretary and MDTA Chair Samantha Biddle said in a statement.
The new bridge will have a longer span and increased height of the main piers to accommodate larger marine traffic and comply with current guidelines from the American Association of State Highway and Transportation Officials for new bridges, the MDTA said.
