For even bigger machines, Let's look at Crossrail tunneling machines.

对于更大的器，我们看看 Crossrail 隧。

Most tunnel boring machines are  normally around 17 metres in diameter.

大多数隧的直径通常在 17 米左右。

In 2010, a massive tunnel-boring machine began its work underneath 92nd Street.

2010 ，一台大型隧开始在 92 街地下工作。

I think we need to have at least a tenfold improvement

所以，是的，隧通常非常困难。

With an excavation diameter of 16.07 meters and a length of about 145 meters, the 4,500-tonne shield-tunneling machine adopted in the project is independently designed and made by Chinese enterprises.

项目采用的 4500 吨盾构开挖直径 16.07 米，长约 145 米，由中国企业自主设计制造。

And just a few years after that, in  2020, the company was using its own specialised tunnel boring machine to carry  out what is an unusually narrow excavation.

就在那之后的几，也就是 2020 ，该公司使用自己的专用隧行异常狭窄的开挖。