Dandenong - Pakenham: 26.8 km 22 minutes average 73kph, speed X2 save 11 minutes : extra double track cost $500M Pakenham - Warragul: 41.8 km 31 minutes average 82kph, speed X2 save 15 minutes : extra double track cost $500M I did point out previously where you can get the big bang for the bucks. You might not like it, but the 3rd & 4th on the list are the more achievable and deliver the most time saving.I'm sorry John but I must be missing something here, can you please explain what upgrades you think will achieve a doubling of speed between Dandenong - Pakenham and Pakenham to Warragul?
It's a bit rich for some here to assert that the line outwards from Dandenong is so bad that it cannot be improvedThe line outwards from Dandenong isn't bad per se, but i'm struggling to think of what upgrades you have in mind that would come anywhere near the figures you listed. Sure you could upgrade the line from Dandenong to Pakenham to 130 or 160 (and ease out some curves) but all that is going to do is allow the V/Line service to catch up to the stopping all stations spark quicker.
Same again for the section Pakenham to Warragul, where is this additional speed and time saving coming from that provides this 'bang for buck' you speak of? There's only two restrictive curves on the south line between Pakenham and Longwarry, both of which are 140km/h and don't really affect trains at all. The Nth line has a couple more curve boards due its lesser standard but again, they don't greatly affect running times. There is potential between Longwarry and Warragul to increase speeds slightly but due to the terrain time savings would be measured in seconds rather than multiple minutes like you claim.
I'm interested to hear your justifications, but to me at this stage your theory can't be transferred into reality.
as you may have guessed by now, I am not an engineer, so my general observations is:
give an engineer a reasonable budget and a defined target to achieve and you will get a sensible plan to make it happen.
Trouble happens when the budget gets fiddled and/or the target is not well defined, if at all.
Having said that, I will have a go at suggesting why my "theory" is possible.Dandenong-Pakenham
I will take your word that Dandenong-Pakenham isn't so bad per se.
Metro trains do have to do a lot of stop/start which isn't a good mix for expresses.
So spend the money on a new express track.
Since it does not stop at any mid stations, then doesn't need to go through their platforms at all - ie: no station alterations required. Additionally can occasionally deviant from the current path to ease some curves.
It doesn't have to be more than a single. A 10 minute run is a simple passing for a line with 2-3 tph each way.
BUT of course, then it would be all those pesky cars at 12 LX making the train slow down.
Some protection upgrade is needed to allow V/line to pass through at speed. Never going to be able to pay for 12 LX replacements, so need smarter solutions to the danger.Pakenham-Warragul
You suggested 3 savings yourself, Restrictive curves, lesser standard, terrain.
But then dismiss each as "a few seconds" "don't really affect" - well the accumulation of all those things does add up to a resulting rubbish average speed.
Taking the most innocent sounding "restrictive curve... 140kph". It is not just the 20kph difference around the curve, it is the slow down time approaching and the acceleration afterward.
20kph difference for about 4km is 12 minutes lost, an exaggeration I admit, but do you see the point.
Plus the small single track section needs to be double. It's the slow down/acceleration across the points adding it's contribution to the delays.
Plus yet another 12 LX to be worked out.
Is that enough superficial reality to work upon.