In a rush

The blurry man is Albert, busy with the exchange of hydrogen out of the alternator of unit EC3.
He has put several valves in the right position and is going to check out the measurementsystem.
The hydrogen is exchanged by carbondioxide (CO2) and the CO2 is replaced by air.
After that the necessary maintenance at the bearings of the alternator can take place.
Hydrogen is used as a coolant because it's cooling capacity is better than air.
But: it's highly explosive in combination with air so a special oilsystem is used to avoid the hydrogen from coming into direct contact with air.
That's why we use CO2 as an intermediate.
The exchange is done by following a checklist.
A complete exchange takes about 6 hours.
After the maintenance is finished we have to follow the checklist and work the opposite way.

Here in LARGE....