Engine Out SIDs are normally published in the companys part B4 manual. For every runway at every airport, companies usually establish their own set of escape procedures as you put it. ATC normally are not aware of these as they can differ from the published missed approach. Normally it is recommended to turn towards the lowest Minimum sector altitude. In HKIAs case, it would be towards the South where MSA is around 3300 feet as opposed to 4000 to the north. Hope that helps. It would be very difficuly to obtain Cathays B4 manual anyway...