注意！私自变更原有设计酿成大祸

What the type of casualty

事故类型

Very Serious Marine Casualty: Explosion of observation glass resulting in a fatality.

非常严重的海难事故：观察镜爆炸事故

What happened

事故经过

A bulk carrier was three months into its maiden voyage. An engineer on board was draining accumulated fluid from the main engine starting air receiver as part of a normal daily routine. The fluid drained into a drainage pot which was fitted with a toughened glass observation panel. The glass shattered and severely injured the engineer, who later died from the injuries sustained.

一艘散货船首航三个月后，一名轮机员正在例行从主机启动空气瓶中排出积累的液体，液体被排入到一个安装有钢化玻璃观察孔的排水罐中。玻璃突然爆裂导致该轮机员严重受伤，后不治身亡。

Why did it happen

事故分析

The observation glass and drainage pot were not fit for the purpose for which they were being used. The drainage pot was originally designed as an open-topped container with a drainage line leading to an appropriate bilge. During the construction of the ship, at the request of the owner's representative, the drainage observation pot was modified by the shipbuilder to incorporate a toughened glass observation panel, the objective being to allow observation of the drainage without any splash-back. The modification could not withstand any significant build-up of pressure within the pot. The modifications were not submitted for classification society or flag Administration approval.

安装的观察孔和排水罐不适合于为压缩空气瓶排出积液。排水罐最初被设计为一个开放式的容器，带有一条排水管通向舱底。在船舶建造过程中，应船东代表的要求，船厂对排水罐进行了改装，加入了钢化玻璃观察面板，这样做的目的是为了避免在观察排水时液体飞溅。此种修改不能经受罐内任何压力的增加，并且这些修改建议没有提交至船级社或船旗国主管机关批准。

What can we learn

事故启示

Compressed air can store a lot of energy, especially at the storage pressure found in main engine starting air receivers (30 bars in this case). It needs to be treated with the utmost respect. Significant back pressure can occur in small bore, lengthy condensate drainage lines, especially if, in the case of effluent from a starting air receiver, the drained fluid contains any emulsified lubricating oil.

（1）压缩空气瓶内储存有大量的能量，特别是在主机启动空气瓶内已经建立储存压力的情况下（本案例的启动压力为30bar），需要对此予以足够的重视。在直径较小且长度较长的冷凝水排水管道中可能会出现显著的回压现象，特别是从启动空气瓶中流出的流体中含有乳化润滑油的情况下。

When making any design changes, an appropriate engineering analysis needs to be undertaken, especially for any modifications that effectively change an open drainage system into a pressurised closed one. Design validation and appropriate testing need to be undertaken. The classification society and flag Administration should be consulted and, if so directed, drawings submitted for approval.

（2）在变更任何设计时，需要开展合适的工程分析，特别是将开放式排出系统转变为高压封闭排出系统的修改。如需修改，需要对此种修改进行设计验证和适当的测试，同时应咨询船级社和船旗国主管机关，如果需要，还应提交图纸以供审批。

During the final stages of a ship's construction, vigilance is needed by all parties concerned to ensure that any deviation from approved arrangements are carefully and appropriately addressed and agreed. Agreed changes should be recorded.

（3）在船舶建造的最后阶段，所有有关方都需要保持警惕，以确保任何偏离原批准设计方案都认真地标注和得到批准。所有批准方案应该进行记录。

Who may benefit

此文对谁有用

Ship builders, owners, operators, classification society surveyors, and crews.

船厂，船东，船舶经营人，验船师，船员