The British foreign secretary used this in an important interview recently linked here, and all over the net, but not making it to the BBC, characteristically: https://skwawkbox.org/2018/04/03/video-johnson-porton-down-said-categorically-no-doubt-pd-ceo-no-we-didnt/
It's important because if it had been shown by the BBC and other mainstream 'news' providers, he would have had to resign, but the BBC showed only an edited chunk and said they "couldn't find the alleged lie".
Anyway: "the clattering train". Is this the same as "the runaway train", meaning, I think, an insane body of thought / group of supporters that have gathered momentum?
(for interest, the BBC did a similar thing with burying a video.of a Manchester police officer pleading with May not to continue with police cuts, with her response being "stop crying wolf" and "stop scaremongering". Had that been re-aired as many asked them to do - again it was all over the internet - after the Manchester bombing and before the general election she would have been toast. Thanks to the 'British-Establishment Broadcasting Corp.' the most elitist government in memory is still in power.