东海撞船事件的原因何在？
伊朗油轮“桑吉号”(Sanchi)在东海沉没，32人丧生。这次事故令外界产生疑问：怎么会发生这样的撞船事故?分析人士和交易员把注意力放在这艘船的导航和卫星跟踪系统上。
The Sanchi was carrying about 1m barrels of condensate — a light, highly flammable oil — from Iran to South Korea, when Chinese authorities say it hit the CF Crystal, which was loaded with grain, 160 nautical miles east of the mouth of the Yangtze river nine days ago.
9天前，中国当局表示“桑吉号”油轮在长江口以东160海里处撞上装载着粮食的长峰水晶(CF Crystal)散货船时，“桑吉号”正载着约100万桶的凝析油(一种轻质、高度易燃的石油)从伊朗驶向韩国。
Yet vessel tracking services say the Sanchi was last spotted almost 24 hours prior, off Taiwan’s coast. After this point the tanker’s automatic identification system (AIS) did not appear to submit information.
然而，船舶跟踪公司表示，“桑吉号”最后一次被发现是在近24小时之前的台湾附近海域。此后，这艘油轮的自动识别系统(AIS)似乎就没有再提交信息。
The communications system used by vessels to continuously broadcast their identity and position over public airwaves, using unencrypted radio signals, has become an essential tool over the last 15 years for ensuring safety at sea.
船舶使用的这种通信系统，利用未加密无线信号在公共波段持续播报船舶身份及位置。该系统已成为过去15年确保海上安全的重要工具。
Rumours have swirled about whether an intentional shutdown of the AIS, poor signal or a fault in the system, contributed to the collision involving the tanker owned by the National Iranian Tanker Company.
坊间盛传各种说法，猜测导致此次撞船事故的原因是否跟如下几点有关：有人故意关闭自动识别系统、信号差或该系统出现故障。涉事油轮“桑吉号”由伊朗国家油轮公司(National Iranian Tanker Company)所有。
A big concern now is the environmental impact, as crews on Monday tried to clean up a giant oil spill left behind after the sinking of the burning tanker.
现在的一项严重担忧是环境影响。工作人员周一试图清理在这艘燃烧的油轮沉没后遗留的大面积漏油。
As a substitute, investigators could turn to the voyage data recorders, akin to a ‘Black Box’ on aeroplanes, from both vessels. Still, the incident casts a spotlight on the role of AIS in the shipping and oil industries.
作为替代选择，调查人员可以借助两艘船只的航行数据记录仪——类似飞机上的“黑匣子”。然而，该事件让外界关注自动识别系统在航海和石油行业中扮演的角色。
Originally intended as a near-shore security and navigation device, a plethora of companies now use the system to track movements of oil globally, getting an early jump on data — from Chinese imports to shipments from big Opec exporters — that can be traded on.
这种系统原本是被用来保障近海安全和导航的，如今很多公司利用这个系统跟踪全球的石油运动轨迹，以提早获得可用于指导交易的各种数据——从中国石油进口数据、到石油输出国组织(Opec，简称：欧佩克)主要石油出口国的发货数据。
Matt Smith, director of commodity research at ClipperData, a vessel tracking company, said it was possible the Sanchi had turned off its AIS transponder. Iranian vessels have at times sought to hide their movements when exports from the country were restricted by sanctions. While Iranian barrels have been freed up by the nuclear deal in the past two years, there have been incidents of vessels “going dark”.
船舶跟踪公司ClipperData的大宗商品研究主管马特•史密斯(Matt Smith)表示，“桑吉号”有可能关闭了船上的自动识别系统应答器。在伊朗出口受到制裁限制时，该国船舶有时会试图隐藏其运动轨迹。过去两年，伊朗核协议解除了对伊朗石油的限制，但船舶关闭应答器的事件仍时有发生。
“In the last two months we have recorded a number of incidents of Iranian vessels apparently manipulating their AIS signals,” said Mr Smith, adding that when rhetoric ramps up around reimposing sanctions, as it has done in recent weeks, Iran has a greater tendency to shutdown AIS signals for its tankers.
史密斯表示：“过去两个月，我们记录到多起伊朗船舶似乎对它们的自动识别系统信号动了手脚的事件。”他补充称，在有关重新实施制裁的言论增多时(就像最近几周那样)，伊朗就有更大可能性关闭其油轮的自动识别系统信号。
Other tanker tracking companies, including Israeli-based Windward, said it may not, however, be a case of the ship going dark on purpose. AIS technology has limitations, such as when too many ships are in range and signals jam each other.
但其他油轮跟踪公司(包括总部位于以色列的Windward)表示，有可能不是油轮故意关闭应答器。自动识别系统技术具有局限性，例如在太多船舶处于同一水域时，信号会互相堵塞。
One shipbroker added: “Sometimes when you are mid-ocean it doesn’t receive signal.”
一家船舶经纪公司补充称：“有时，当你处于远海时，系统收不到信号。”
Windward said it had assessed only seven incidents between July 2015 and July 2016 where it was confident Iran’s tanker company NITC had intentionally turned off AIS, four times before sanctions were lifted and three times after.
Windward表示，2015年7月至2016年7月之间，它只检测到7起它确信伊朗国家油轮公司故意关闭了自动识别系统的事件，在制裁解除前为4次，在制裁解除后是3次。
Nevertheless investigators are likely to focus on whether the two vessels — with the Iranian Suezmax tanker as long as many skyscrapers are tall — failed to somehow spot each other, or if there was a mechanical fault.
然而，调查人员可能会关注于这两艘船(这艘伊朗苏伊士型(Suezmax)油轮的长度堪比很多摩天大楼的高度)是否未能发现对方，或者是否出现了机械故障。
The practice of turning off AIS to avoid tracking has not been limited to national oil companies, with some of the world’s largest oil traders also employing it. Crude shipments from the semi-autonomous Iraqi Kurdistan, which the federal government in Baghdad opposes, often go offline shortly after leaving Turkey’s Mediterranean port of Ceyhan, before making deliveries or taking part in ship-to-ship transfers.
关闭自动识别系统以避免被追踪的做法并不限于国有石油公司，一些全球最大石油交易者也在这么做。从半自治的伊拉克库尔德斯坦地区发出的原油，经常在离开土耳其地中海港口杰伊汉后不久就关闭应答器，在交货或与其他船只对接进行货物转移前才打开。伊拉克联邦政府与库尔德斯坦地区政府对立。
The International Maritime Organization said piracy or other security incidents might also prompt a shipmaster to turn off the AIS to prevent the vessel from being compromised.
国际海事组织(International Maritime Organization)表示，海盗或其他安全事件也可能促使船长关闭自动识别系统，以防范船只遭到破坏。
But Pottengal Mukundan at the International Maritime Bureau said this is less likely in the East China Sea. “One of the risk areas where you might do that is the Somali basin or off the coast of Aden but not there.”
但国际海事局(International Maritime Bureau)的波廷加尔•穆昆丹(Pottengal Mukundan)表示，在中国东海，不太可能出现这种情况。“你可能会在索马里海盆或亚丁湾等高风险海域这么做，在那里不会。”
Iman Nasseri, consultant at FGE Energy, said even without AIS tracking there are other means to track the ship which is why an accident of this magnitude is difficult to understand.
FGE Energy的咨询顾问伊曼•纳赛里(Iman Nasseri)表示，即便没有自动识别系统追踪，也还有其他途径追踪这艘船只，因此发生这么大规模的事故让人很难理解。
“The vessel’s radar should have worked even if AIS was off, a collision should not be possible,” Mr Nasseri said.
纳赛里表示：“即便自动识别系统关闭，这艘船的雷达也本应运转，这种撞船事故原本应该是不可能发生的。”
