Worse still if the cathode target material has a low melting point such as aluminium the cathode spot can evaporate through the target resulting in either the target backing plate material being evaporated or cooling water entering the chamber.
32.
In the resulting discussions, Terrell suggested replacing the cork with rock to deflect the hard core of an armour-piercing bullet so that it hit the backing plate at an angle, dispersing its energy so that it would not penetrate.
33.
Later " traverse-flux " systems at his Imperial College laboratory, such as Magnetic river avoided most of the problems of needing to have long, thick iron backing plates when having very long poles, by closing the flux path laterally by arranging the two opposite long poles side-by-side.
34.
These Mokes had slightly modified suspension, and used spacers and backing plates so that the wheels sat on and tracked on gauge track Similarly, the Federal Government, through either its Commonwealth Railways or Australian National Railways Commission, ran at least two similarly set up Mokes on its Central Australia Railway.
35.
The prototype, FV 4211 or the " Aluminium Chieftain ", was fitted with a welded aluminium add-on armour, in essence a box on the front hull and front and side turret to contain the ceramic modules, of which box the fifty millimetre thick inner wall due to its relative softness could serve as their backing plate.
