The works comprise:(a) Two 6.3m internal diameter TBM mainline tunnels from east end of DIH to Kai Tak North launching shaft including 4 cross passages with 2m minimum clear width;(b) Diaphragm wall construction for Kai Tak North launching shaft;(c) Construction of Kai Tak North cut & cover tunnels within the proposed Kai Tak North launching shaft;(d) Two Stud tunnels at south end of the Kai Tak North launching shaft for connection to tunnels by others;(e) CEDD Entrustment Works for the Upgrading of Nullah no. 2 at Kai Tak;(f) Tree felling and off-site tree compensation/transplanting works;(g) Provision and Installation of Permanent Signage and Metal Railings / Barriers within tunnel;(h) Provision and installation of brackets, niches, supporting frames, platforms, cat ladders, ducts and civil provisions for works under other Designated Contracts;(i) Interface requirements associated with Designated Contracts;Key Features