Looking at the birth certificate...that is not the place of employment, but rather the type his occupation.
Millwright - Electrical Engineering Works St. Albans, Herts
He WAS a Millwright(usually someone who maintains machinery) at an Electrical Engineering Works. So you should be looking for an Elec. Eng. Works in St. Albans.
I have found the name of one firm in St. Albans...it is Miskin & Rice Electrical Engineers.
Hope this helps