As you, BOB2, correctly noticed, I referred to passenger/transit rolling stock.

An example to show the situation is with light rail/streetcar vehicles. At the time, there were some highly (federal) government funded attempts to "create" an US light rail manufacturer, another world-wide active manufacturer built up a quite successful product line. I am talking of the Citadis by Alstom.

Yes, there was government money involved, but not for the development of the rolling stock; for the creation of the systems.

The success is shown… they say that there are more than 2000 Citadis in operation worldwide.

It could have been an US company building up such a market share…