How to translate the two sentences?

How to translate the two sentences?
The most dramatic moment Tower Bridge has witnessed occurred in December 1952 when a London 'Double-decker' bus entered the Bridge while it was opening the point of no return.The bus cleared the gap between the opening bascules.
塔桥是怎么样的结构？

The most dramatic moment Tower Bridge has witnessed occurred in December 1952 when a London 'Double-decker' bus entered the Bridge while it was opening the point of no return. The bus cleared the gap between the opening bascules.
在伦敦塔桥的历史中最具戏剧性的一幕发生在1952年的12月,有人目击了一辆双层大巴在塔桥升起的时候驶入, 当时升起的桥板已经不可能再放下了,于是这辆大巴就卡在两个升起的桥板的中间.
塔桥的桥面是分为2半的,当由大型轮船通过泰晤士河的时候,塔桥所在的地方往往不够高,也就是说从水面到桥面的距离比船的高度矮,所以需要把桥面从中间拉起.
这是塔桥平时的形态：“--”
这是塔桥桥伴升起时的形态：“/ \”
由于这里不方便贴图,所以最好搜索一下塔桥的图片,这样就会很清楚了