Consultation comments received on Railway Group Standard
GM/RT2484 issue 2
Audibility Requirements for Trains
Closing date 24 January 2007
Summary of Responses from Railway Organisations
Consulted:
Number consulted
172
Number ticking "yes"
13
Number ticking "yes with
9
amendments"
Number ticking "no"
1
Number ticking "no comment"
10
Total returned
33
Date responses returned to
15/02/07
organisations
1. Ms A Vinten, (Document Controller, First Great Western)
2. Mr D Edge (HSBC Rail)
3. Mr M Drew (Alstom Transport UK)
4. Mr N Green (Works Infrastructure Ltd)
5. Mr P Ross (TfL London Rail)
6. Mr M Buckley (Trent Instruments)
7. Ms F Shakeshaft (Merseyrail Electrics 2002 Ltd)
8. Mr JA Nutty (Amey Infrastructure Services)
9. Mr A Schofield (South West Trains)
10. Mr L Gregory (Angel Trains)
Consultation
No Page Section
1
General
2
PP204_L10A
General
Revised
Page Section
Classification Code: (CC)
DC Document changed
NC No change
Comment
By
Why do we need a new national standard on horns at this 10
time -UIC 644 seems to be the basis for the rest of
Europe and will presumably become the basis for a TSI?
The perpetuation of a different requirement for the UK
serves to constrain unit cost reductions.
1 of 9
10
CC Response
NC UIC644 was the basis for the old (pre 2005)
RGS requirements and the impact of this led
to changes in 2005 and also the current
review. The results of this work will be used to
influence future TSI and EN requirements.
NC The revised requirements will be used to
influence future TSI and EN requirements.
Version 8 November 2005
Consultation
No Page Section
3
General
Revised
Page Section
4
General
8
5
General
6
General
3.2.1.2
Comment
By
Does the issue of this revision affect the interface with the 10
published TSI on noise?
The RGS will be mandatory for any "all work that affects 10
warning horns on vehicles, whether new or modified" this
is very poorly drafted, and could be interpreted as routine
maintenance to restore designed performance. It should
be made clear the level of modification that would trigger
compliance.
10
What is the cost benefit forcing compliance across the
whole of Great Britain? We understand the changes are
intended to reduce nuisance from noise in response to
particular sensitive areas on the network. This should
therefore be a route specific decision and not impose
cost across the board where it may have no benefit.
Is the purpose of this revision (to control nuisance noise)
within the remit of the RSSB and if so on what basis?
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CC Response
NC Train warning horns are outside the scope of
the Noise TSI, they are addressed in the
respective sub-system TSIs
DC Text amended to clarify that it applies only to
new vehicles and when warning horn
equipment is modified.
NC There is no compulsion about the proposals,
and the opportunity to consider changes on a
route specific basis (as you propose) is
therefore protected. The revised requirements
are not anticipated to have a material impact
on the cost of procuring train warning horns
and therefore will not impact on the overall
costs for new trains.
NC Yes. RSSB’s remit, and that for Railway Group
Standards, relates to compliance with the
Health and Safety at Work Act 1974. This
requires that businesses take account of the
impact of their operations on the health and
safety of the public. We have established
through survey that the impact on the public
includes a significant number of cases where
the health of neighbours is affected. Horns
had previously been considered to be an
environmental issue, but when we have
evidence of a causal link between operations
and the health of the neighbours, it brings it
directly into scope.
Consultation
No Page Section
7
General
Revised
Page Section
Comment
By
10
If TOCs apply for a non-compliance prior to 2nd June
2007, what will be the method by which the RSSB plan to
control i.e. TNC or derogation and will there be time
limitations and what will be required to obtain?
CC Response
NC A non compliance, pending standards change,
has been put in place to permit the early use
of this revised standard if Operators wish to
use it.
NC The requirements apply to new warning horns
and would be part of any compliance
assessment. There is no requirement within
the standard to test existing horns, though
operators may choose to do so as part of their
routine maintenance or in response to any
public complaints.
NC No it is not. All duty holders have a
responsibility to comply with their SMS, but
unless a change of horn is triggered, there are
no obligations to bring existing horns down to
the new levels, though operators may choose
to do so as part of their response to any public
complaints.
NC This information confirms the view that train
horn noise levels reduce over a number of
years and that the sound levels typically
measured from trains with a long service
history was less than when newly introduced.
This therefore confirms the step change that
has been identified with new ‘compliant’ trains.
The revised specification is set at a level that
has been demonstrated to be acceptable to
all.
8
General
How recent will horn testing measurements need to be to 10
validate the RGS? An external party could make a fortune
testing horn levels…
9
General
The implications it will have on the TOCs is that if a unit is 10
reported with an excessively loud horn then the TOC will
need to demonstrate that the horn is RGS compliant
before entering back into service. Please confirm if this is
the correct understanding?
10
General
What I thought may be useful , initially, would be to dispel 6
the theory that the new Airchime horns are louder than
the original SSD type ( as used on all new builds from the
1960`s through to the mid 1990`s)
The original SSD data sheets detailed DB levels of 110 &
112 db @ 30 metres.
This equates to 141db @ 1 metre / 127db @ 5 metres.
This is identical to a standard Airchime KS horn. This is
hardly surprising as the SSD horns were made under
license from Airchime & share identical internals (which
generate the sound) . All of the readings assume 7 bar air
pressure.
The data sheet for CS horn shows 132db @ 1 metre.
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Consultation
No Page Section
11
General
12
General
Revised
Page Section
Comment
By
6
The output of the horns is a direct result of a correlation
of air pressure & flow.
We can effect the air flow by orifice restriction, but there
may need to be regulation of the input pressure as well.
I am including a typical testing record ( which we get with
every horn) - this shows a speaking db level
of 131@ 1 metre @ 1 bar - this illustrates the db
reduction that can be achieved by reducing pressure - the
balance is by restriction.
To assist in relating our 1 metre readings to db levels @
distance - a Nomograph (supplied separately) has been
used. This is extremely easy to use, and can be used
either for 1 metre out, or from distance back to 1 metre.
eg; to calculate the 30 metre reading from the SSD horn take a line from the right scale starting at 110db - pass
through the 30metre division line on the centre scale until
you reach the left scale. Then, from this point pass back
through the centre scale @ the 5 metre division line &
read the db level on the right scale.
Another item that may be of interest is a polar plot of the
KS horns (supplied separately) shows that there is
an approx loss of 6db sound level @ 90 & 270 degrees
(to the side) than directly in front of the horn.
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6
CC Response
NC This is helpful to indicate that the revised
specification is technically achievable by
currently available suppliers of warning horns.
NC These plots indicate the change in sound
pressure levels to the side of the sound source
compared to the forward facing values. This
information, coupled with the revised
mandatory requirements indicated that the
revised values will provide acceptable warning
horn volumes.
Consultation
No Page Section
13
General
Revised
Page Section
Comment
By
On recent trials utilizing modified CS horns, we achieved 6
db ranges form 95 @ stationary, & from 101 @ 10MPH
to 111 @ 100MPH - this was with variable outputs
relative to the speed of the vehicle.
I feel it necessary to stress that this success was
achieved because of the correlation between the reduced
flow & controlled / regulated input. The Airchime EPRE
controller, which gave us the variable control, was
extremely effective in controlling the air pressure particularly at the lower pressure band ( which is what is
required to achieve your stated numbers)
Hence, I am extremely comfortable stating that we can
achieve a db band of 101 - 106, with our CS horn &
regulated input.
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CC Response
NC This is helpful to indicate that the revised
specification is technically achievable by
currently available suppliers of warning horns.
Consultation
No Page Section
14
General
Revised
Page Section
Comment
By
6
From experience, we have noted that with the reduced
orifice, the horns can be prone to freezing. This is
usually as a result of internal condensation, with droplets
freezing at the inlet due to Wind Chill factors. This also
explains why some operators register freezing horns in
traffic, that, when the vehicles are returned to sheds, the
horns work perfectly. We have heard of intermittent
failures in the past, and this is probably the reason
For this reason, we strongly recommend that all modified
horns are upgraded to our heated version. The heaters
are controlled by a thermostat, which ensures the heaters
commence working as soon as the temperature drops to
a pre-set figure (e.g.: 4 deg.C) The heaters ensure the
horns are kept warm & dry.
It is highly unlikely we would warrant against freezing
instances/failures if the operator decides against heated
versions.
CC Response
NC This information is helpful and will be passed
forward to those procuring train warning horns
to the proposed new standard.
The sound output from the CS horns is particularly
pleasing, and I am sure will negate any future complaints
from the public.
15
2
3.2
16
6
2.1.4.3
3.2
Impact Assessment for Changes to Railway Group
Standards – “The requirements will only apply to new
warning horns, or when warning horns are modified”. So
therefore, current or ‘old’ design horns could be fitted to
new trains? Please clarify.
10
DC The text relating to compliance has been
amended to clarify when requirements are
implemented.
Should the final word be “rolling stock” or “vehicle” rather
then “train”?
2
NC The term train has been used to be consistent
with the opening text of this section.
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Consultation
No Page Section
17 6
2.1.4.3
Revised
Page Section
18
2.1.4.4
6
2.1.4.4
19
6
2.1.4.4
6
2.1.4.4
20
6
2.1.5.1
6
2.1.5.1
Comment
This clause has not been marked as a change, but has
changed. Previous clause (3.1.4.4 in GM/RT 2484 Issue
01) stated that it was appropriate to allow use of a two
tone horn as well as an 'automatically varying' one,
though preferring an automatic one. The clause does not
state a preference for an automatic varying horn but does
suggest that this is an appropriate method. If a two
volume horn is not stated as being specifically allowed
then it could be interpreted as being precluded. The
standard could be interpreted as now requiring a 3 level
volume horn for trains that travel faster than 160km/h.
While it is appreciated that the requirement to fit an
additional warning device is not mandatory, there is a
concern that by not specifying appropriate tones and
levels this could lead to a variety of specifications being
used by different manufacturers and operators. This
presents problems to manufacturers who would like to
offer the same solution for each rolling stock order. If
TOC requirements diverge then there may also be
additional costs when stock is moved to other routes or
stabled at another operator's depot.
This is a new clause but has not been marked as a
change. Generally this clause is welcome since it
specifically states a lower level device is allowable within
depot and shunting sidings, which is in line with London
Rail’s proposals for Class 378 EMUs. However, it would
have been useful if some indication of acceptable volume
levels and tone had been given.
By
5
CC Response
NC 2.1.4.3 and 2.1.4.4 are technically similar to
the existing text of the current standard
(section 3.1.4.4) and have been separated to
clarify the requirements.
3
DC Additional information has been provided to
support this clause.
5
Insert “reasonably” between “so far as is” and
“practicable” otherwise too onerous.
2
DC 2.1.4.3 and 2.1.4.4 are technically similar to
the existing text of the current standard
(section 3.1.4.4). It has been separated into
two sections to clarify the requirements. The
scope of Railway Group Standards can only
mandate requirements on the controlled
infrastructure. Additional information has been
provided to support this clause.
DC Text amended
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Consultation
No Page Section
21 6
2.2.1.1
Revised
Page Section
22
8
3.2
8
3.2.1.2
23
8
3.2.1.1
8
3.2.1.2
Comment
If the purpose of the horn is to alert persons on or about
the track, it is suggested that sound pressure levels are
measured 5m in front of the train at the height of an
average person – not at the same height of the horn.
It is assumed that “in line with the centre of the vehicle”
means the vertical centre line of the vehicle. It is
suggested that this is clarified in the text.
Whilst the briefing note and impact assessment both
highlight that this standard is not retrospective, I don’t
believe the text in section 3.2 makes this clear
"Scope" states the requirements apply to all new
equipment.
By
4
CC Response
NC The measuring method chosen is to ensure
that the audibility requirements of the warning
horn at 400 metres is achieved.
Figure 1 details the measurement position.
9
DC Text amended to clarify compliance
requirements.
1
DC Agreed – text amended to clarify
requirements.
7
DC Text amended to clarify compliance
requirements.
Although the number of horns changed is generally low, it
is on an individual basis.
However according to the interpretation of "new"
equipment this could require the additional cost of
replacing the second working horn of each pair when one
is found damaged or defective. The initial assessment
states there will be no material costs to the industry, so
FGW presume that like for like replacement will be
permitted. Having horns with different loudness when
there is no campaign change in progress is likely to lead
to low volume horns being reported as defective.
Suggest clause is therefore reworded as "new build or
modified systems, excluding like for like replacement of
existing horns" or this definition is included on page 9.
24
8
3.2.1.2
8
3.2.1.2
Clarification required on meaning of “all work”, eg does
this include normal maintenance activity?
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Consultation
No Page Section
24
3.2.1.1
Revised
Page Section
8
3.2.1.2
26
8
3.2.1.1
3.2.1.2
Comment
Clarification of the test “The Requirements of this
document apply to all new equipment used for train
horns” to make explicit that there is no requirement to
modify existing designs when undertaking any direct
replacement (maintenance / failure replacement).
What is the precise definition of "new"? Does this mean
"equipment used for warning horns" which is first
designed, or ordered, or manufactured, or delivered or
brought into use after 2nd June 2007?
By
3
CC Response
DC Text amended to clarify compliance
requirements.
5
DC Text amended to clarify compliance
requirements.
DC Text amended to clarify compliance
requirements.
DC Text amended to clarify compliance
requirements.
It has been a practice in the past to be explicit and link
implementation dates to e.g. VAB ‘design certificates’,
equipment 'first brought into use' to give TOCs and
manufacturers reasonable time to implement mandatory
changes without delaying delivery programmes for trains
ordered but not yet delivered.
27
3.2.1.2
8
3.2.1.2
Similar comment
3
28
3.2.1.2
8
3.2.1.2
What is the precise definition of "work that affects
warning horns….whether new or modified"? Would, e.g.
scheduled maintenance or direct replacement of a
defective piece of equipment anywhere in the horn
system mean the requirements of GM/RT 2484 Issue 02
would need to be complied with on that train from that
point in time?
5
29
9
30
31
Definitions 9
Definitions
9
Definitions
Definitio Typos – LA and LC should have subscripts (viz.
ns
questionnaire)
"Possession-only rail vehicle" is defined but not used in
the standard.
“Possession – only rail vehicles” appears in Definitions
but does not appear to be referred to in the standard.
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2
DC Text amended
3
DC Agreed – definition deleted.
8
DC Agreed – definition deleted.
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