A point worth remembering is the East line north of Seymour and the SG south of Seymour is the original SG line from Melbourne to Albury AND it was built VERY cheaply, particularly the drainage of it being VERY poor. ARTC has put a massive effort in trying to improve the line south of Seymour where the rainfall is highest, but the line really needs rebuilding from the ground up.
The problem is not the ARTC's fault, it is the government being tight fisted is the basic cause, in a democracy by definition then the blame falls back on us for not wanting to pay enough funds to run Australia's transport system (rail , roads, air and sea) in a truly long term sustainable fashion.
I do not hold high hopes for the Melbourne, Brisbane rail project, it will be built in the same tight fisted manner and end up in the same fashion.
It may surprise some people, but the world WILL still exist next year and it would best to look after it!!!!
Ironically, the cost of all the "patch up jobs" is probably the same as if they had replaced the entire track completely in the first place.