I think the Inland Rail specifications are the likely template for what we can expect, with a few notable deviations where a passenger train might go on the old corridor.
The Inland Rail corridor largely runs on a corridor already protected by the state government, so it’s unlikely we’d get much more out of the route. The good thing is, the route from Calvert through to Gowrie has good straights and gentle curves on paper. Most of it is planned at grade or on embankments - viaducts only really feature on the range ascent past Helidon. The questionable thing is that it only needs to meet a design specification for 115kph (with a typical curve radius of at least 800m or thereabouts), which might mean some tighter curves than would be optimal for 140 or 160kph service (although a tilting unit might get close to sustaining 140 even under those specifications). The curves on embankments on the climb up to the tunnel through to Gowrie might be at the worse end/closer to 800m radius.
The distance from Calvert to Gowrie on Inland Rail is ~75km (47km from Calvert to Helidon and 28 from Helidon to Gowrie). It’s about 6km from Rosewood to the Calvert turnout, and another 10km or so from Gowrie into Toowoomba station. So we’re looking at about 90km all up - before you think about whether you’d retain the existing alignment into Laidley itself (add approx an extra 1-2km), and if you can accept a new Helidon Station north of the existing one on the IR alignment (otherwise consider retaining the existing alignment that weaves around Grantham. add an extra 3-5km). So up to just shy of 100km perhaps. Putting aside the IR sections, Rosewood to Calvert is fairly straight. Gowrie to Toowoomba less so. I’m aware of a particularly pesky 25kph ‘S’ bend a bit north of Willowburn (north Toowoomba).
At minimum I’d expect 3 stops after Rosewood (excluding Toowoomba) - Laidley, Gatton and Helidon. There are also small communities at Grandchester, Forest Hill, Lawes/UQ Gatton, Grantham and Gowrie that you could consider for a two-tiered ‘all stops’ service but don’t really make the cut for an express service (and would probably be questionable to go to the expense of building stations at when they could be serviced by a feeder bus).
Taking an assumption that we can get a limited stops train from Brisbane to Rosewood in an hour as read, the target average speed then becomes a function of distance and time. If you want the trip to take an hour (total journey time 2 hours), and just doing it ‘back of the envelope’, take 3 minutes off for 3 stations, do 90km in 57 minutes and I think the average speed is about 95kph. To do 45 minutes, 90km in 42 minutes and I get around 130kph.
So perhaps just a little re-design from the IR specifications for a target speed of 130-140kph (perhaps suitable for tilting units at 160 if rolled out) in this section would get the job done.
If you have long distances and low density, high speed and wide station/stop spacing is the way to go. I would say the main feeder would be P&R in these locations as well.
I just think that we should be ambitious when building new rail or substantially modifying existing. Let’s not build to an already obsolete 150/160 and aim for more with acknowledgement that in the future it will all be upgraded.
That was my understanding too - the 210kph was a record run on a patch of dead straight track north of Bundaberg in 1999. The tilts have been known to run a bit faster under isolated circumstances, maybe 170-180, but I suspect 200+ isn’t really on the cards for 3ft 6in/1,067mm track unless all conditions are completely optimal.
At the end of the day, the late-night fastest road time between Toowoomba and Brisbane CBDs is 90-110 minutes. If a train can do 90 minutes reliably at all times of the day it will be extremely competitive — and anything more than that takes money away from something else.
Conversely if the train takes more than 2h it will be a good bit less competitive outside of peak, maybe not even that worthwhile.
I think 160 km/h running speed from Ipswich to Helidon (excepting tunnels) is achievable (perhaps with a tilt to avoid losing too much speed in the corners) and is probably necessary to hit 90 min unless we can find more time savings east of Ipswich.
There’s no easy solution here, especially when you consider the mess-around getting from Gowrie to Toowoomba CBD (though there is an opportunity for a big P&R station at Willowburn).
What data do we have that supports this limit for usual revenue operations? Could the 160 km/hr limit just be custom or tradition and not an actual engineering limit?
It’s most likely a combination of track geometry and appetite for risk on the part of QR - especially where there are road/rail interfaces.
The Inland Rail plan has some level crossings. Remove those, adjust your track plans to a minimum curve radius of, say, 2,000m, ensure your vertical grade isn’t too steep and you could probably go to speeds in excess of 160kph in a fashion that would be workable and might just satisfy the risk assessment officers. You obviously have to make sure the freighters are well-parked in the loops and the train doesn’t run into the turn-outs by accident at high speed (see XPT crash from a couple of years ago).
No idea how much that would increase the cost by though.
I’m less worried about speed in the proposed tunnels. They’re single track and straight. The Hokkaido Shinkansen is limited to 160 in the Seikan Tunnel because the engineers are worried the bow air pressure wave in a 55km long tunnel could blow the freight containers right off the narrow gauge freighters that use the tunnel at the same time, but there are proposals to reserve a freighter-free slot in the tunnel to run the Shinkansen at 250-260 on a couple of runs a day. So in a single track tunnel I cant see speeds in the order we’re talking about being a major worry.
We are definitely working in a cost v benefit world, but knowing the approach that our government takes with PT, the bigger/better that it can be built in the beginning is desirable because it will stay like that for many decades to come.
Maybe it should built with an overall target of 160km/h average, with sections of 200km/h included when and where possible.
It will probably take R&D, but we should be doing that anyway as the 2nd largest 3ft 6in rail network in the world. The solution won’t land in our lap like it would if we were using standard gauge.
They are of course the masters of efficiency and precision, but they don’t have a whole lot of fast narrow gauge rail (they opted for the Shinkansen instead).
The Hokuhoku Line, which was the old link between Kanazawa/Toyama and the Joetsu Shinkansen at Echigo-Yuzawa ran at up to 160kph on a stretch of track built specifically for that purpose. It was superceded when the Hokuriku Shinkansen was extended beyond Nagano.
The limited express between Sapporo and Asahikawa runs at 140kph in some sections.
120-130kph would be the typical maximum speed amongst most of the rest of the narrow gauge network, even amongst the limited express services. Those Limited Express services have very nice train sets to make a comfortable journey as well. The ‘Mini Shinkansen’ services have all been reguaged or dual gauged, so even though they were old alignments, they’re standard gauge now.
Tbh I would question the cost of extra investment in a distance as short as Brisbane to Toowoomba to get higher speeds vs potential increased trip times.
Given each trip will likely involve a minimum of 5 stops, and maybe more on some runs, perhaps investing in trains that can accelerate to a 160 km/h top speed more quickly would bring more benefits. Just a thought.
I definitely think faster acceleration may save more time than faster top speeds, especially given the inevitable budget constraints. Incidentally this is one of the main advantages of electric multiple units vs any other form of propulsion, but especially vs loco-hauled diesel. Because you have so many more driven axles and you can temporarily pull immense amounts of power from an overhead line without huge engines you’re able to accelerate MUCH faster, which makes stops quicker.
Take Caltrain in the US as an example - they significantly reduced trip times when they switched from diesel loco haulage to EMUs. According to this flyer the San Francisco-San Jose all stops train time was cut from 100 minutes to 75 just by this change, with no other realignments or route improvements.
No doubt. Even electric locos vs diesel-electric can make a difference. I remember a suburban driver telling me back in the SX set days that that had to intentionally drive slowly if they got a 3900 on a run timetabled for a DEL, or they’d run far too early.
Big difference is that the Blue Mountains start basically on the edge of the Sydney Metro area. There’s not 80 km of very low density farmland in between.