Deviation from a Railway Group Standard

Uncontrolled When Printed
Deviation from a Railway Group Standard
(In accordance with the Railway Group Standards Code, Issue Four, part 7)
Deviation Number:
13/179/DEV
1. Start and End Date:
N/A
2. Details of applicant:
, Thameslink Rolling Stock Project Manager, First Capital Connect, Hertford House,
1 Cranwood Street, London EC1V 9QS
3. Your reference number:
N/A
4. Status of applicant:
Railway Undertaking, RSSB Member
5. Title of certificate:
Class 700 (Thameslink EMU) shoegear height.
6a. Details of Railway Group Standard (RGS):
RGS Number:
Issue No:
Issue Date:
Title:
GM/RT2149
Three
February 2003
Requirements for Defining and Maintaining
the Size of Railway Vehicles
6b. RGS clause(s):
B10.2
6c. RGS clause requirements:
“B10.2 Shoegear
Shoegear and associated equipment shall not infringe the limiting swept envelope prescribed in Appendix B
of this document, when subject to the following two sets of conditions:
Case A: Displacements Towards the Outside of a Curve:
a) The curve overthrows resulting from a 160 m radius simple curve.
b) The kinematic displacements when operating at the speed which produces maximum design cant
deficiency with an installed track cant of 150 mm.
Case B: Displacements Towards the Inside of a Curve:
a) The curve overthrows resulting from a 160 m radius simple curve.
b) The kinematic displacements when operating at a speed of 5 km/h with an installed track cant of 150
mm.
Conditions a) and b) in each of the two cases are independent conditions and are not intended to be coincident.”
Reference: 13/179/DEV
Page 1 of 3
Uncontrolled When Printed
7. Scope of deviation:
Class 700 ´Thameslink EMU´ and all its subclasses.
8. Duration of the deviation:
For the lifetime of the vehicles.
9. Method of elimination:
N/A
10. Impacts of complying with the current RGS requirement:
This deviation relates to the Class 700 ´Thameslink EMU´ non-compliance with the swept envelope for
shoegear as defined in Clause B10.2 and Appendix B of GM/RT2149.
Complying with the requirements by raising the shoegear height would cause extremely poor contact
between the conductor rail and the shoegear.
It is important to note that, if the shoegear is set higher in order to comply with GM/RT2149, then the
following risks arise:
1. The shoes will lose contact with the third rail and thus prevent the Class 700 ´Thameslink EMU´
from being powered if static, and cause unreliable operation if moving.
2. When moving the shoes would periodically lose contact with the third rail, which will cause
significant arcing and the electrical interference generated as a result of this may give rise to
signalling compatibility issues.
Drawing number M59134-02-LT provides the assessment of the shoegear against the swept envelope
defined in Appendix B of GM/RT2149. This assessment includes:

the maximum lateral movement derived for Cases A and B (defined in Clause B10.2) for any
vehicle condition,

vertical movements for any relevant vehicle condition (i.e. load or wear condition).
Irrespective of Case A or B, the Class 700 ´Thameslink EMU´ shoe exceeds the swept envelope in
Appendix B by maximum 7 mm at its lowest point in some vehicle conditions. This equates to a lowest point
of 43 mm above rail level (ARL).
The scope of this deviation is therefore to obtain acceptance of the infringement of the swept envelope in
GM/RT2149 where compliance with Network Rails Document 'Guidance for Compatibility Between Electric
Trains and Electrification Systems' (NR/GN/ELP/27010) can be shown. As outlined below, the extent of this
infringement will ensure that, under dynamic conditions, the shoegear on the Class 700 ´Thameslink EMU´
will be compliant with NR/GN/ELP/27010 Issue 02 and GM/RT2113 Issue 1 Draft 1c.
The height setting of the shoegear on the Class 700 ´Thameslink EMU´ is consistent with Clause 5.9 of
NR/GN/ELP/27010 issue 02 which states: “The minimum height from the running rail to the lowest point of
any collector shoe under all dynamic conditions should not be less than 25 mm”.
It is also consistent with Clause 4.4.3 of GM/RT2113 Issue 1 Draft 1c which states: “The setting of the downstop shall prevent any part of the current collector going below 34.5 mm above the plane of the running rails
under all dynamic operating conditions.”
This contradicts with the requirements of GM/RT2149, hence the reason for this deviation.
The height setting of the shoegear is also consistent with the ramps of the third rail as defined in
NR/GN/ELP/27010 Issue 02 Appendices E to G, where the maximum height of the face can be determined
to be 76+10-64=22 mm ARL, which is, in any case, below the minimum height of the Class 700 ´Thameslink
EMU´ shoe of 43 mm ARL.
11. Proposed alternative provisions:
1. Application of NR/GN/ELP/27010 Issue 02.
The extent of this infringement will ensure that, under dynamic conditions, the shoegear on the
Class 700 ´Thameslink EMU´ will be compliant with NR/GN/ELP/27010 Issue 02 and GM/RT2113
Issue 1 Draft 1c:
Reference: 13/179/DEV
Page 2 of 3
Uncontrolled When Printed

The height setting of the shoegear on the Class 700 ´Thameslink EMU´ is consistent with
clause 5.9 of NR/GN/ELP/27010 Issue 02 which states 9 'The minimum height from the
running rail to the lowest point of any collector shoe under all dynamic conditions should not
be less than 25mm' and clause 4.4.3 of GM/RT2113 issue 1 draft 1c.`

The height setting of the shoegear is also consistent with the ramps of the third rail as
defined in NR/GN/ELP/27010 issue 02 App. E to G. where the maximum height of the face
can be determined to be 76+10-64=22mm ARL, which is in any case below the minimum
height of the Class 700 ´Thameslink EMU´ shoe of 43 mm ARL.
2. Reference to existing deviations 10/218/DGN and 08/145/DGN.
Class 700 ´Thameslink EMU´ protrudes the swept envelope defined in Appendix B of GM/RT2149
by only 7 mm, which is less than granted by 10/218/DGN and 08/145/DGN.
12. Impacts of the alternative provisions:
None, providing that structure clearance is provided in accordance with NR/GN/ELP/27010 5.9 for a
minimum dynamic shoegear height of 25 mm ARL.
13. What other options have been considered?
Comply with the requirements by raising the shoegear height, but this would cause poor contact between the
conductor rail and the shoegear as outlined above.
There is also limited space between the shoegear assembly and the lower face of the bogie frame. Raising
the shoegear would affect the bogie frame design and may cause strength issues.
14. Consultation with affected parties
N/A
15. Additional actions/observations:
Upon receipt, the applicant is required to identify affected, interfacing parties and copy this certificate,
together with supporting information, to those parties.
The holder of the certificate is responsible for checking that the original assumptions and conclusions
contained in the deviation certificate remain valid whenever any material changes occur. If the conditions of
the deviation certificate change, the deviation will no longer be valid. In these circumstances, the holder of
the deviation certificate may consider applying for a new deviation.
Time-limited deviations will be closed on the expiry date. However, please let us know if you no longer
require your non-time limited deviation certificate so that we may close it also.
16. Signature of applicant:
, Thameslink Rolling Stock Project Manager
Date of application:
01/11/2013
17. Lead Standards Committee details:
Name of Committee:
Date of meeting
Minute reference:
Rolling Stock
06/12/2013
3/RST/12/332
Authorised by:
Date of Authorisation:
Signed by Philip Hunt for Cliff Cork on 27/01/2014
27/01/2014
Cliff Cork
Head of Delivery, Infrastructure and Rolling Stock
Reference: 13/179/DEV
Page 3 of 3

Download Report