As part of TGP's contract scope for work on MTRC's Hong Kong Airport Railway Scheme, we produced the design and details of all permanent sub-structures for the Rambler crossing plus approach viaducts.  The approach sub-structure totals 13 reinforced concrete piers, each of which consists of up to six individual track supports plus connecting cross-beams.  The main Rambler crossing substructure comprises six piers which are cast onto drilled pile foundations in the channel bed.  TGP's work included the design of temporary RC caissons in which the crossing's pilecaps and piers were cast in situ onto the drilled piles.  The crossing's piers were designed to withstand a 1000 tonne ship impact and incorporate an advanced impact detection system and cathodic protection.