For the millionth time, the engines on Class 800s are not downrated/derated or anything else.
In normal diesel mode the engine management system is set up to draw less than the maximum power output from the engines. But if an engine fails, the engine management system calls for the maximum output from the others to compensate and can be reset to call for maximum output from all the engines all the time - like the set-up for the AT300/Class 802 - if that is what is wanted, assuming someone will foot the bill for the increased engine maintenance and overhaul bills for the Class 800s that would result from such a change.
Well despite your exaggeration about the number of times that you claim to have explained that you don't call it 'derated', what you have explained above does not have any relevance to my post. So call it whatever, in the scenario that I outlined where one of the units couldn't run under OLE power, it would be switched over to diesel operation. As far as that 5-car unit was concerned, it would be fully functional so the class 800 set would run at the 'reduced' power level (or 'downrated' to many other people but let's not get hung up on words), assuming that its controls allowed it to when there was an OLE-powered. My original question was just that, i.e. 'would the controls allow it'. This unfortunate unit would however get a fair bit of help from its partnered unit which would have much more power as it would be running on OLE. So, would it be allowed to run at speeds above 100mph on suitable track whilst being partly dragged/pushed along by the fully functional unit?