ALFA-X

[daniel_leavitt2000]

Japan is testing their next generation Shinkansen trains named the ALFA-X:
https://www.thedrive.com/news/28023/japan-begins-testing-electric-249-mph-bullet-train-named-alfa-x


There are two prototypes to test nose styles. And those noses - not so pretty. Though I think the second one looks better, I personally feel the aesthetics reached a high point with the 500 series followed closely by the E and W700 series.

[learmoia]

Looking at that console.. Where is the conductor supposed to sit?

At least it still has a seat.. no smart trains in the next 5 years...

[peteski]

I agree 100% with Daniel about the aesthetics. The designers have jumped the shark a while back.  I wonder if the aerodynamic advantage is *THAT*  much greater with those long funky snouts?   

[nkalanaga]

Part of the reason for the "long funky snouts" is to keep the train from going airborne.  It not only reduces air resistance, which a traditional "bullet" nose would do just as well, but provides downward force to keep the train on the track.

[peteski]

Part of the reason for the "long funky snouts" is to keep the train from going airborne.  It not only reduces air resistance, which a traditional "bullet" nose would do just as well, but provides downward force to keep the train on the track.

Couldn't they just have installed spoilers like they do on race cars (to produce down-force)? 

On a serious note, I have found something interesting on https://engineering.stackexchange.com/questions/13621/why-do-some-high-speed-trains-have-long-noses-while-others-do-not

A train, given its size, has a ridiculously small cross section. This small frontal area footprint is being 'pushed' by the inertia of hundreds of tonnes of metal.

All high speed train have aerodynamic noses, but some will tend to be pedantic about how many thousandths of a percent efficiency they can squeeze out of an aerodynamic profile.

There are a couple of other factors that come into play with the design of the nose and that is the pressure pulse that is generated as a train passes another object, generally another train going in the opposite direction or a tunnel. It's why passengers are told to stay away from the platform edge as fast trains pass by, its not that you'll be blown away, but may sucked towards the train by the low pressure.

Two high speed trains passing each other can generate a huge amount of suction between them at the nose, because of the low pressures there, so having a longer nose helps spread this out a bit and reduce the area of minimum pressure. If not the trains could be pulled towards each other, or some instability set up by the rapid sideways pressure pulse. The nose of the E5 Series, at 15 metres, is a massive 9 metres longer than the previous incarnation of the bullet train (Shinkansen), the E2 Series. This, according to its designers at JR East, will help eliminate the phenomena of "tunnel boom".

Japan's rail tunnels are somewhat narrower than their European counterparts, so when the Shinkansen enters a tunnel at speeds above 200 kilometres per hour, the sudden increase in air pressure can cause a loud "boom" at the other end of the tunnel. In some cases, such shock waves are thought to have damaged tunnels in Japan, ripping chunks of material from tunnel ceilings.

The shape of the front car has evolved gradually to combat this danger, and the striking "Long Nose" design of the E5 Series is the result.

[C855B]

Part of the reason for the "long funky snouts" is to keep the train from going airborne.  It not only reduces air resistance, which a traditional "bullet" nose would do just as well, but provides downward force to keep the train on the track.

Mmmmmmm... I dunno. It still appears to be a designer thing. The pronounced snout shouldn't offer that much of an airflow advantage over more conventional angled-cab designs, and chin spoilers are certainly sufficient for controlling lift vectors. I'll allow for the possibility that part of the aero consideration could be mitigating turbulence when two trainsets pass in opposing directions.

Anyway, the world record for fastest steel wheels on steel rails in a commercial trainset is held by the LGV Est (TGV) at >350 mph, 100 mph greater than the ALFA-X target. The LGV has a conventional aero profile, and it certainly didn't leave the rails in the record-setting run.

[drift]

FWIW, the fastest manned steel-wheels-on-steel-rail record was a rocket sled at Holloman AFB, 632 mph in 1954. The "pilot" was Col. John Stapp, who lived a couple doors down from my family after he was transferred to Edwards AFB. My father bought my first trains - an American Flyer collection - from Col. Stapp. (Stapp had a penchant for witty sayings, and is alleged to be the originator of Murphy's Law.)

[/drift]

[Ed Kapuscinski]

From what I understand the real reason for the noses is to help reduce issues when entering tunnels at high speeds.

[C855B]

From what I understand the real reason for the noses is to help reduce issues when entering tunnels at high speeds.

Now that makes sense. Lot's o' tunnels on many of the Shinkansen routes.

[Maletrain]

They should paint the front end to look like a crocodile. 

[MK]

Is it just me or each time i glance at this thread's title i keep getting reminded of that duck in the insurance commercial on TV? 

[Albert in N]

   With that much speed, they must be powered by Kato!

[peteski]

Is it just me or each time i glance at this thread's title i keep getting reminded of that duck in the insurance commercial on TV? 

AFLAC!!!

Actually, I agree with the others that it looks more like an alligator than a duck.

[nkalanaga]

Peteski:  OK, I'll accept "tunnel boom" as the main explanation, as it DOES make sense.  The air in the tunnel has to go somewhere, and most RR tunnels aren't much bigger than the trains.

I do know that there are places where the TGV slows going up hills to help prevent take-off at the summit, but that's a matter of momentum rather than aerodynamics.  The lead car is light enough that it could lift enough for the flanges to clear the rails. 

Their record-setting runs are usually on flat track.  But that's part of the reason magnetic levitation hasn't caught on.  Every time the Germans built a faster maglev train, the TGV would beat it.

[peteski]

Their record-setting runs are usually on flat track.  But that's part of the reason magnetic levitation hasn't caught on.  Every time the Germans built a faster maglev train, the TGV would beat it.

A 19 mile MAGLEV train line exists in China. Top speed   431 km/h (268 mph).
https://en.wikipedia.org/wiki/Shanghai_maglev_train

[learmoia]

TGV test runs up to 357mph 

~Ian