EP3061867A1 - #4 Limestone Ballast
the ballast should preferably be machine crushed. Hand broken ballast can be used in exceptional cases with the prior approval of the chief track engineer or the CAO (chief administrative officer). Such approval should be obtained prior to the invitation of tenders.Ballast noun device used for stabilizing current in an electric circuit (e.g. in a tube lamp supply circuit) Aggregate noun (roofing) Crushed stone,
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