Stalingrad Gold Don Bridges

[CheerfullyInsane]

I really don't like reading the manual from the computer as it makes the old eyes tired after a while.

I get that, I'm quickly approaching the age where I have to take my glasses OFF to read anything  
The advantage of the PDFs though is that you can do word-searches for what you're looking for.

I am hoping that if I carry out the what you describe when the engineer moves off the bridge and goes back to deployed mode then this will change and the engineer will be able to attempt to blow it ?

Presumably. Aside from quoting the manual, I am of very little help in this particular case.
I don't think I've ever attempted to blow up a full-hex bridge.