Pretty cool video of a high-speed train

[Qapla]

Not the point of the video - but notice the cross-arms

 

[jiml]

That's a pretty standard UK level crossing. They do a better job than most places in North America, so your point is well-taken. Just for clarification though, that LNER Azuma is not a high-speed train but more similar to an Amtrak Acela - capable of 125mph.

 

[west point]

Slo mo notice power jumpers across top of cars.

 

[Qapla]

Yes, I thought it was interesting that only one catenary contact device was deployed and the power jumpers were at the top of the cars.

 

[JontyMort]

That's a pretty standard UK level crossing. They do a better job than most places in North America, so your point is well-taken. Just for clarification though, that LNER Azuma is not a high-speed train but more similar to an Amtrak Acela - capable of 125mph.

It needs full barriers, because the line speed is in excess of 100 mph (I suspect it‘s the full 125 in that location). Half-barrier crossings are actually more common than full barriered ones. This is mainly because half barriers are permitted on lines where the speed is not in excess of 100, provided that there are not more than two running lines (and provided certain other conditions are satisfied - mainly in relation to curvature, sighting, and gradients on the road approaching the crossing).
There are still a surprising number of level crossings on the East Coast line on four-track sections.

 

[JontyMort]

Yes, I thought it was interesting that only one catenary contact device was deployed and the power jumpers were at the top of the cars.

Yes, normal operating practice is one pantograph only - per unit. The 25kV bus line is also standard practice with unit trains - bearing in mind that all the cars are motored (so in that sense different from the Acela sets). The TGVs have them also, but they are banned in the Channel Tunnel.

 

[jis]

Yes, I thought it was interesting that only one catenary contact device was deployed and the power jumpers were at the top of the cars.

The Avelia Liberties have this feature but they are not as obviously visible as in the older TGVs. That is apparently common in the new generation TGVs known as Avelia.

In terms of speed capabilities, the Azumas fall somewhere between Northeast Regionals and Acelas of any generation. They can do 140mph on routes equipped with ETCS, but on routes not equipped they are restricted to 125mph. Acelas can do 150mph on routes equipped with ACSES. Avelia Liberties will be allowed 160mph on ACSES equipped, select track segments, though on properly equipped and laid out trackage they can be easily upgraded to 186mph.

 

[Qapla]

It needs full barriers

I like the design of those barriers

 

[JontyMort]

In terms of speed capabilities, the Azumas fall somewhere between Northeast Regionals and Acelas of any generation. They can do 140mph on routes equipped with ETCS, but on routes not equipped they are restricted to 125mph. Acelas can do 150mph on routes equipped with ACSES. Avelia Liberties will be allowed 160mph on ACSES equipped, select track segments, though on properly equipped and laid out trackage they can be easily upgraded to 186mph.

That’s true, of course, but in many ways the comparison is unfair to the Northeast Regionals, whose performance is arguably hampered by a sexy marketing-led approach - “the new Avelias will reach 160 mph” - in preference to a steady engineering-led approach of incremental improvement - eliminating constraints and raising the lowest speed restrictions. If - and it’s a big “if” - the Avelias are able to use the extra 10 mph for 40 consecutive miles in Rhode Island and Massachusetts, that will save… one minute.

Bringing us back to the East Coast route in Britain - on which the Azumas run - the maximum speed has been 125 mph for 45 years. Experiments with 140 mph running - with conventional signalling - in the 1980s got no further than that, it being realised that the money was better spent elsewhere. The example often cited is the removal - in the 1970s - of the 10 (ten!) mph restriction at Peterborough (eased to 125), saving ten minutes for non-stopping trains. More recently, one grade-separation project has been completed, and another is nearing completion. The big constraint - this bullet remains to be bitten - is the two-track section over the viaduct and through the tunnels at Welwyn, where quadrupling would be massively expensive.

But if you parachuted an ACS-64 on to this line - especially with new push-pull stock with cab cars - performance would be perfectly satisfactory.

 

[jis]

There will be anothe 25-ish miles of 160mph in NJ, where they are primarily being tested for pantograph stability, and eventually another 40 miles or so in Delaware/Maryland, when they get around to it, which, with the cash infusion may be sooner rather than later. Admittedly, the actual running time reduction will be relatively minuscule.

 

[JontyMort]

There will be anothe 25-ish miles of 160mph in NJ, where they are primarily being tested for pantograph stability, and eventually another 40 miles or so in Delaware/Maryland, when they get around to it, which, with the cash infusion may be sooner rather than later. Admittedly, the actual running time reduction will be relatively minuscule.

Yes, the problems between New York and Boston seem to be totally different from those between Washington and New York.

 

[Cal]

though on properly equipped and laid out trackage they can be easily upgraded to 186mph.

Is 186 the actual possible top speed for the Avelias?

 

[jis]

Is 186 the actual possible top speed for the Avelias?

If they are standard Avelia sets then it should be an easy uprate. Currently I don't think they have been outfitted or tested for 186mph. Structurally they are more or less the same as a TGV set.

 

[George Harris]

Most people on here already know this, but for those who are wondering, 186 mph is the closest nearest mph to 300 km/hr.

Yes, I thought it was interesting that only one catenary contact device was deployed and the power jumpers were at the top of the cars.

Having only one pantograph up is normal, and is virtually a necessity with an AC powered overhead wire systems due to phase breaks in the power. I leave that to some with far more electrical knowledge than I have to explain this and its significance. Suffice to say that having electrical contact across a phase break is somewhere between exciting and a disaster for the electrical system.

 

[jis]

Having only one pantograph up is normal, and is virtually a necessity with an AC powered overhead wire systems due to phase breaks in the power. I leave that to some with far more electrical knowledge than I have to explain this and its significance. Suffice to say that having electrical contact across a phase break is somewhere between exciting and a disaster for the electrical system.

Well you can have as many pantos as you like but you cannot link them together. That is what would lead to great pyrotechnics across phase breaks. Acelas today regularly use two pantos, but the two power untis are not connected together and HEP can be delivered from only one power unit to the trailers. So there is no problem at phase breaks. This is true of EMUs too. Each Unit in a string of EMUs is electrically separate.

 

[JontyMort]

Well you can have as many pantos as you like but you cannot link them together. That is what would lead to great pyrotechnics across phase breaks. Acelas today regularly use two pantos, but the two power untis are not connected together and HEP can be delivered from only one power unit to the trailers. So there is no problem at phase breaks. This is true of EMUs too. Each Unit in a string of EMUs is electrically separate.

The other point about multiple pantographs is that at high speeds the kinetic wave effect of the first has the potential to have nasty effects on the second. Incidentally, the Acelas - in common with most British stock - use the high speed pantograph developed in the 1980s by Brecknell Willis - a specialist located in sleepy Somerset.

 

[nti1094]

There will be anothe 25-ish miles of 160mph in NJ, where they are primarily being tested for pantograph stability, and eventually another 40 miles or so in Delaware/Maryland, when they get around to it, which, with the cash infusion may be sooner rather than later. Admittedly, the actual running time reduction will be relatively minuscule.

The jersey speedway will be limited to 150 Mph MOS on track 2 and 3 because of limitations in the catenary tension hybrid system they engineered. They were severely limited in what they could do because of being stuck with Public Service high voltage overhang. But the difference in the end would be less than one minute, and the real benefit should be increased reliability.

 

[Tlcooper44]

That’s true, of course, but in many ways the comparison is unfair to the Northeast Regionals, whose performance is arguably hampered by a sexy marketing-led approach - “the new Avelias will reach 160 mph” - in preference to a steady engineering-led approach of incremental improvement - eliminating constraints and raising the lowest speed restrictions. If - and it’s a big “if” - the Avelias are able to use the extra 10 mph for 40 consecutive miles in Rhode Island and Massachusetts, that will save… one minute.

Bringing us back to the East Coast route in Britain - on which the Azumas run - the maximum speed has been 125 mph for 45 years. Experiments with 140 mph running - with conventional signalling - in the 1980s got no further than that, it being realised that the money was better spent elsewhere. The example often cited is the removal - in the 1970s - of the 10 (ten!) mph restriction at Peterborough (eased to 125), saving ten minutes for non-stopping trains. More recently, one grade-separation project has been completed, and another is nearing completion. The big constraint - this bullet remains to be bitten - is the two-track section over the viaduct and through the tunnels at Welwyn, where quadrupling would be massively expensive.

But if you parachuted an ACS-64 on to this line - especially with new push-pull stock with cab cars - performance would be perfectly satisfactory.

Your use of the word sexy was truly laugh out loud. I’m in complete agreement.

 

[Tlcooper44]

Is 186 the actual possible top speed for the Avelias?

The trains themselves are capable of 220 on straight track from what I read, but of course that will never happen. That said, that’s just Wikipedia, so maybe there’s a more nuanced answer.

 

[jis]

The trains themselves are capable of 220 on straight track from what I read, but of course that will never happen. That said, that’s just Wikipedia, so maybe there’s a more nuanced answer.

It is fair to say that their very close cousins are capable of doing 220 out of the box. As for what these are capable of is a different matter since they may have been downrated in various ways to meet Amtrak's requirements for the NEC.

 

[JontyMort]

It is fair to say that their very close cousins are capable of doing 220 out of the box. As for what these are capable of is a different matter since they may have been downrated in various ways to meet Amtrak's requirements for the NEC.

The latest TGVs and the e320 sets operated by Eurostar have a service speed of 320 km/h = 200 mph. They have to do a run at 110% of service speed for authorisation purposes - hence that 220 mph figure looks right.

 

[west point]

See an overview of planned upgrades.
download (railwaygazette.com)

 

[Qapla]

Seems they want me to sign up to read anything ... I'll pass