Noise made by passing trains

[whole diary]

[grahame]

Can anyone point me at information about the noise levels of various types of trains?    Comparison to buses, cars, HGVs at the same distance?    Would be great to know about freight / diesel passenger / electric passenger and if anyone has comparable decibel levels for 150/153, 158 and 165/166 it would be magic.

[patch38]

I'd be interested to see if this data exists. It would be wholly speed-dependent and would, ideally, have to be measured on the same stretch of track, as track condition (and weather condition) would also play a part. Old Dalby would probably be the only place where this could be done reliably. Most equipment is measured anechoically (i.e. in a near-silent environment with few or no relfective surfaces). I've been in lots of anechoic chambers in my life, including ones large enough to hold a car, but never in one big enough to hold a locomotive or carriage!

[stuving]

Here's a start - from perhaps the obvious place, RSSB^▸ (Rail Safety and Standards Board) research.

Project T835, February 2009, was called "Trends in GB^▸ (Great Britain) rolling stock noise levels". There is a report under that number, and a research brief.

The report was actually done by Delta Rail, who seem to be guardians of the indistry's noise database. It seems to have averaged similar stock classes in that database, so if you want really detailed information you'll need to find someone with access to that. There's no references - sadly.

The report is open to all, but now you need to register with the SPARK database to get access to RSSB reports (unlike the brief). I found it then told me I needed to register with RSSB too, but failed to do that (with an error). However, it is possible to get it via SPARK alone, if more clumsily, but I can't give a link that works without being logged on.

[LiskeardRich]

I live around 250-300 metres from the railway. The only trains I hear (or notice anyway) are the night riviera each morning and evening,

[BerkshireBugsy]

Can anyone point me at information about the noise levels of various types of trains?    Comparison to buses, cars, HGVs at the same distance?    Would be great to know about freight / diesel passenger / electric passenger and if anyone has comparable decibel levels for 150/153, 158 and 165/166 it would be magic.

Graham just curious to know why you want to know

[Electric train]

Grahame

Noise from trains depends on so many factors, type of rail and the profile, type of sleeper (timber, concrete, slab track) type of ballast used, type of pad used between concrete sleep and rail, type of rolling stock whether it is electric or diesel, the wheel profile, line speed and that is before the surrounding environment is taken into account.

[grahame]

Graham just curious to know why you want to know

We had early concern on the TransWilts trial service about the extra noise made by the train, and a further question has now been asked about noise levels in the Trowbridge to Westbury area.   I prefer to comment from a position of at least overview knowledge of what I'm talking about, hence my researching it.

The answers so far are very informative, thanks - Stuving's link showing an age of stock v noise level chart (on what I think i the same basis for each) is interesting, and confirmed by richwarwicker's comment that only the night riviera - loco and coaches - brings itself to his attention.  A further piece of research from the Transport Research Lab / folks shows HGV noise significantly higher than rail noise (but, I agree with Electric Train, these comparisons are very hard indeed to make ... to put it mildly) but that modern / newer vehicles are quieter than older ones.

I suspect our correspondent will be agreeably surprised into the TransWilts future - frankly, I don't suppose she'll notice a 153 replaced by a 158 then by a 166 in 2017 / 2018, nor the addition of another 7 trains each way per day to bring it up to hourly at the time of the 2018 change.  Much more noticed noise-wise in that area will be changes in road traffic levels, and / or diverted freight trains at times that they're coming through there rather than passing Reading on their way from Southampton to the Midlands and North.  However, I can understand / appreciate the worries of not knowing.

Extra source - Road report data

[stuving]

One thing that struck me about the figures for train noise is that a lot of them only relate to the regulations in the TSIs. There is now one noise TSI for "conventional" and HS^▸ (High Speed (short for HSS^▸ (High Speed Services) High Speed Services)) rail, which is worth looking at (it's quite short and the figures easy to find):
COMMISSION REGULATION (EU^» (European Union - about)) No 1304/2014
of 26 November 2014
on the technical specification for interoperability relating to the subsystem ^rolling stock ^ noise^

Of course it's hard to know how that relates to existing, or real future, trains. Note that while T835 is limited to "by-pass noise" at 80 km/hr, the new TSI covers the train's maximum speed, and starting.

For DMUs^▸ (Diesel Multiple Unit) in particular, starting is much noisier than cruising. So, in reality, people not near a station (or other common stopping point) don't have a noise problem, some who are may do. So have you seen "The Calculation of Railway Noise (DoT 1995)"? This may be too detailed and technical, making it difficult to extract simpler data and be certain what it means, but may help.

[LiskeardRich]

Stuving's link showing an age of stock v noise level chart (on what I think i the same basis for each) is interesting, and confirmed by richwarwicker's comment that only the night riviera - loco and coaches - brings itself to his attention.

That's interesting. Ive always assumed its because I haven't learnt to ignore a less frequent service.
I have lived in 3 houses in last 5 years that are within a stones throw of the line
18 months almost underneath Angarrack Viaduct
12 months above Penryn station, and 2 1/2 years at my current location in Redruth

[grahame]

Stuving's link showing an age of stock v noise level chart (on what I think i the same basis for each) is interesting, and confirmed by richwarwicker's comment that only the night riviera - loco and coaches - brings itself to his attention.

That's interesting. Ive always assumed its because I haven't learnt to ignore a less frequent service.
I have lived in 3 houses in last 5 years that are within a stones throw of the line
18 months almost underneath Angarrack Viaduct
12 months above Penryn station, and 2 1/2 years at my current location in Redruth

Chart attached.   You'll see diesel loco symbols all none to far from 90 Db and modern units rather quieter.  Quite which unit is which spot, and whether an HST^▸ (High Speed Train) is coaches and locos, or a unit, as far as the surveyors are concerned, I know not ... what is overall interesting is a general trend towards modern trains being quieter

[Phil]

Most of this discussion seems to centre around noise emitted by engines. My experience of stone trains passing through Melksham is that their wheels tend to screech on the curves, which is backed up by speaking to someone last evening who referred to the locally-named "Dilton Marsh Squealer" which passes through that part of the world in the early hours.

Just putting that out there - it's not based on any evidence as such.

[patch38]

Interesting chart. As Grahame says, it logically suggests that modern trains are quieter. There's some supporting information missing but I'd say it's safe to take 85 - 90dB as the average noise of a 'train' (take your pick whether it's a DMU^▸ (Diesel Multiple Unit), EMU^▸ (Electric Multiple Unit), diesel loco etc.) passing, over a period of time - that's what the 'LAeqT' refers to - at 80km/h 7.5m away. What you now need to do is extrapolate the distance to your complainant's location. In a free-field (no reflections) this will reduce by 6dB for every doubling of distance. So if it's 90dB at 7.5m it will be 84dB at 15m, 78dB at 30m and so on. BUT... in the real world there will be wind direction, wind speed, temperature, humidity and other things helping to confuse the data. Your only real course of action to get accurate results would be to get a decent sound level meter (preferably with a decent acoustic consultant holding it  ) and take a series of actual readings at the location.

[ellendune]

The first time I was stood on the platform at Swindon when one of the new Class 70? locos went passed I was amazed that it was so quiet that I could continue my conversation.

[4064ReadingAbbey]

One of the biggest reductions in wheel/rail noise was brought about by the introduction of disc brakes replacing tread brakes. The running surface of disc braked stock is smoother and generates less noise than the surface of tread braked stock where the cast iron brake blocks scoured the surface and gouged bits out of it. Who cannot remember the showers of sparks which could come from a tread braked locomotive?

The other change that disc brakes have brought about is the removal of all the brake rigging from under the vehicle which would rattle and clatter when it was hanging loose when the brakes were not applied.

[Brusselier]

I think the frequency can make a difference as well as the actual noise level. I live about 200m from Maidstone East Station and since the last timetable change there have been more class 375 electostars on the route instead of class 465/9 networkers. the 375s seem to be much more noticeable when they pull out of the station in the up direction, and hit a certain speed. It seems to reflect off of the buildings along the river and, when the window is open, is audible over the A229 dual carriageway. But in a station environment, I notice the 465s more.

465/0s with Hitachi traction package are less noticeable. Tunnel freight VERY noticable in the wee hours. but the railway was there first!

Also when out the back it's often possible to hear the Eurostar go through as well, even though that is 2.5 miles away, and the other side of the M20. quite a distinctive sound on that one!