The tug nearly turned turtle twice, but I managed to keep her upright.是什么意思？

The tug nearly turned turtle twice, but I managed to keep her upright.

拖船两次都差点翻个儿，但我设法稳住了船身。

the

art. 指已提到的人（物），指说话人与听者已知的人（物），用于独一无二的事物前，与形容词最高级和序数词连用；

例句
He did have a real knowledge of the country...
他对该国的确知之甚多。

tug

vt.& vi. 用力拉，使劲拉，使劲，挣扎，[航海]用拖船拖曳，竞争；n. 猛拉，推力，绳索链条，[航海] 拖船，竞争，斗争；

例句
The tug was seaward of the Hakai Passage on a course that diverged from the Calvert Island coastline.
托船驶离卡尔弗特岛海岸朝哈凯航道驶去。

nearly

adv. 几乎，差不多，险乎；

例句
His increasing alignment with the Reagan administration nearly cost him re-election.
与里根政府日益紧密的关系差点让他失去了连任的机会。

turned

v. （使）转动( turn的过去式和过去分词 )，旋转，（使）改变方向，（使）不适；

例句
With one accord they turned and walked back over the grass.
他们步调一致地转身走过草坪。

turtle

n. [动]龟，[动]海龟；vi. 捕海龟，捕鳖，（船等）翻没，倾覆；

例句
The tug nearly turned turtle twice, but I managed to keep her upright.
拖船两次都差点翻个儿，但我设法稳住了船身。

twice

adv. 两次，两倍，两遍；

例句
Although he was twice as old as us, he became the life and soul of the company.
虽然他的年纪是我们的两倍，但他却成为了公司的灵魂人物。

but

conj. 但是，而是，除了，只因为；prep. 除…以外；adv. 只，不过，只是，另一方面；n. 借口，推辞，但是，反对；pron. [关系代词，意义相当于 who…not, which…not]；vt. 对…说“但是”；

例句
English food can be wonderful but the normal English diet is abominable.
英国也有美食，只是一般的日常饮食太过糟糕。

managed

v. 使用( manage的过去式和过去分词 )，完成（困难的事），经营，明智地使用（金钱、时间、信息等）；

例句
Greenpeace managed to assemble enough boats to waylay the ship at sea...
绿色和平组织设法聚集起足够数量的小船在海上拦截该船。

to

prep. 向，朝着，到，关于，属于；adv. 朝一个方向的，到某种状态，关闭；

例句
I suggest you leave it to an expert...
我建议你把它留给专家来解决。

keep

vt. 保持，保留，遵守，阻止；vi. （食品）保持新，保持健康；n. 保持，保养，供养，抚养，生活，生计，饲料；牧草；

例句
The company say they're able to keep pricing competitive...
该公司说他们能够使定价保持竞争力。

her

pron. (she的宾格)她，(she的所有格)她的，她，指某个国家，（一艘）船；

例句
There was a terrible sadness in her eyes...
她眼神中流露出深深的悲伤。

upright

adj. 直立的，垂直的，正直的，诚实的；adv. 垂直[竖立]地；n. （支撑用的）直柱，立放构件；

例句
When I pushed his door open, Trevor was sitting bolt upright in bed.
当我推开特雷弗的房门时，他正腰杆笔直地坐在床上。