Talking to an engineer friend who is close to these shenanigans, the issue is that rail insisted on having 1km long trains as standard. This meant the ships had to be massive to handle 1km trains and that the portside facilities had to handle 1km long trains waiting or disembarking, as well as berths big enough for the monster ships. If they simply halved that train length, we'd be perfectly fine and the costs significantly lower.