Why are Azumas so noisy at speed ?

Edders23 · 21 Dec 2019

I have noticed if I am stuck at one of the ECML crossings as I often am that you can hear the Azumas coming a long way off not sure if it is the motors or the traction blowers but they are a lot noisier than the stealth bomber sets and almost equal to HST's for noise level at speed.

It surprises me because aircraft and vehicles have been getting quieter over the years to meet ever stricter noise legislation so I would have thought railway equipment would also

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mpthomson · 22 Dec 2019

Edders23 said:
I have noticed if I am stuck at one of the ECML crossings as I often am that you can hear the Azumas coming a long way off not sure if it is the motors or the traction blowers but they are a lot noisier than the stealth bomber sets and almost equal to HST's for noise level at speed.

It surprises me because aircraft and vehicles have been getting quieter over the years to meet ever stricter noise legislation so I would have thought railway equipment would also

I live right next to the ECML, my back door is 15m from the running lines. Azumas are far, far quieter than either the HSTs and Class 91s that they’ve replaced, to the point of hardly noticing them.

Even on diesel they’re quieter than just about everything other than 158s and Pacers.

soccermad · 22 Dec 2019

Do people think the nose level variation from stock type to stock type depends on the line speed variation ?

jamesst · 22 Dec 2019

Edders23 said:
I have noticed if I am stuck at one of the ECML crossings as I often am that you can hear the Azumas coming a long way off not sure if it is the motors or the traction blowers but they are a lot noisier than the stealth bomber sets and almost equal to HST's for noise level at speed.

It surprises me because aircraft and vehicles have been getting quieter over the years to meet ever stricter noise legislation so I would have thought railway equipment would also

Sorry to totally hijack this thread but I never realised the ECML still had crossings? Does the WCML have any?

Mag_seven · 22 Dec 2019

jamesst said:
Sorry to totally hijack this thread but I never realised the ECML still had crossings? Does the WCML have any?

There are some on the Scottish section and around the Hest Bank area near Lancaster. Anyway this is off-topic.

37057 · 22 Dec 2019

Possibly the sound of multiple vented brake discs.

Elecman · 22 Dec 2019

jamesst said:
Sorry to totally hijack this thread but I never realised the ECML still had crossings? Does the WCML have any?

Yes it does

LiftFan · 23 Dec 2019

Can't say about Azumas but from the perspective of a railway worker the IETs on GWR are very quiet at speed, turn your back for a couple of seconds and you won't hear it sneak up on you

cactustwirly · 23 Dec 2019

mpthomson said:
I live right next to the ECML, my back door is 15m from the running lines. Azumas are far, far quieter than either the HSTs and Class 91s that they’ve replaced, to the point of hardly noticing them.

Even on diesel they’re quieter than just about everything other than 158s and Pacers.

Agreed! I live close to the GWML, I could hear the HSTs from my back garden, but can hardly hear the 800s unless you listen really closely

fgwrich · 23 Dec 2019

Edders23 said:
I have noticed if I am stuck at one of the ECML crossings as I often am that you can hear the Azumas coming a long way off not sure if it is the motors or the traction blowers but they are a lot noisier than the stealth bomber sets and almost equal to HST's for noise level at speed.

It surprises me because aircraft and vehicles have been getting quieter over the years to meet ever stricter noise legislation so I would have thought railway equipment would also

Actually, I know the sound you're on about. While they are quiet coming up to you, they do make a much louder whooooshing noise as they pass. I've yet to work out whether this is as a result of the aerodynamic's of the design or anything else such as pantograph design. Being an electric unit, it does pass quickly, but it certainly is noticeably louder than other high speed EMU's such as a 390 etc.

66Yorks · 23 Dec 2019

I live 500m from the ECML and can't hear the Class 800's at all.

A 66 or 68 on the otherhand....

hexagon789 · 23 Dec 2019

From the lineside they sound much quieter generally than an HST or 225 but the noise they do make lasts throughout passing rather than once for a 225 or twice for an HST because of how the traction is distributed, that's the main thing I've noticed

SteelWeelApeal · 23 Dec 2019

It also makes a big difference for an HST whether it is accelerating or not, whereas it makes little if any for IET. At Pangbourne down HSTs (still on full power) were always louder that up HSTs, even though they were travelling more slowly. I’d say an IET is about the same as an HST without power cars, which is probably what I’d expect. At speed, the pantographs (I think) make a very distinctive whoosh noise. On a related note, I’ve surprisingly found electrostars much louder than the diesel turbos they replaced (GWR) when accelerating from a stop.

Edders23 · 23 Dec 2019

The location I mostly encounter them is generally 100+ mph running and you certainly hear them coming towards you as well as passing

Deepgreen · 23 Dec 2019

LiftFan said:
Can't say about Azumas but from the perspective of a railway worker the IETs on GWR are very quiet at speed, turn your back for a couple of seconds and you won't hear it sneak up on you

Must be why they have a couple of mini-suns blazing away on the nose.

samuelmorris · 23 Dec 2019

Edders23 said:
I have noticed if I am stuck at one of the ECML crossings as I often am that you can hear the Azumas coming a long way off not sure if it is the motors or the traction blowers but they are a lot noisier than the stealth bomber sets and almost equal to HST's for noise level at speed.

It surprises me because aircraft and vehicles have been getting quieter over the years to meet ever stricter noise legislation so I would have thought railway equipment would also

It's not just that the track near your crossing has had its rails ground recently is it? The vast majority of the noise trains make at speed is now produced by the rails rather than the trains themselves. If your area has just been ground it'll have suddenly got a lot noisier, and of course now that there are increasingly many Azumas operating, could it be that?

An example of the noise I mean:

Note how all sorts of different units are all producing the same noise on every vehicle, but more pronounced in one particular direction.

Why are Azumas so noisy at speed ?

Edders23

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