Omg this thread is the most ridiculous thing. Though many of you are making sensible points.
Op. Why in gods name would an engine/car factory such as rolls Royce have the design, the individual components, the ability, the machines let alone the staff to suddenly start building ventilators. The type used in ITU are incredibly expensive, specific machines that are highly calibrated because they can be incredibly dangerous to patients if used incorrectly. They may as well ask you or your milk man to make them, it's just as big of a leap!!!
As pp has said, needs must a patient can be manually ventilated. But that's tiring 1:1 work and takes the nurses away from doing other things.
The gov will hopefully have spoken to ACTUAL manufacturers of ventilators and asked them to increase the manufacturing. But given all the parts pretty much will come from overseas I think that might take some time.
Next problem: who pays for them (normally individual trusts) if they don't have the money they need to do business cases. This takes time. Next problem who determine who gets to use them? Even if you have a central pot and hospitals put forward their case to use one for x patient they have, that will have to be weighed up against the next hospital bidding to use one. Again takes time.
I get you're scared and frustrated at the lack of planning, we all are. But try and calm down and use a sense of common sense x