Bedikat Chametz in a Tank

Q: Do soldiers have to check for chametz in a tank?
A: Yes, since they eat there.
Q: Should they recite a blessing?
A: No, a tank is not a house. They are inside for long periods of time but this does not transform it into a house.
Q: Should they check the tank with a candle?
A: No or else you will perform Bedikat Chametz and Biur Chametz (destroying the chametz) at the same time. The same applies in checking a car. The basic Halachah is that it is possible to use any source of light to check but the custom is to use a candle.