Rail Glass

Overview

PSV Bus Rail Glass Fitting

With post-privatisation rail rolling stock incorporating such glazing advances as direct-glazing, cassette-glazing and fire-retardant glazing, it became clear that an industry specialist was required to safely complete glass installation work meeting RGS GM/RT2456/2100, using the latest techniques and equipment, including mobile automated vacuum lifting interface devices. PSV Glass became that industry specialist.

The prime activity focuses on the supply and fitting of windscreens and body sideglass to main line trains, light rail trams and underground systems, 24 hours a day, 7 days a week, nationwide.

Secondary activities include frame fabrication, refurbishment work and consultancy services.

Accreditation

PSV Glass:

  • is competent to provide services in accordance with the principals set out in the ATOC Approved Code of Practice ACOP/EC/01003
  • can demonstrate competence to supply products and services to RGS GM/RT2450
  • will issue a Certificate of Conformity at each completed glass installation to confirm the loading requirements of GM/RT2456/2100 will be met and ensuring the operator's obligation to full compliance with the above Rail Group Standard has not been compromised
  • is Link-Up approved to supply glass and services

General Requirements

Glass must be resistant enough to contain passengers in the event of a collision or roll-over. This is achieved by having one of the panes in the double glazed unit constructed from laminated glass. Laminated glass provides excellent retention performance similar to a windscreen. The other pane is constructed from toughened glass, which provides good resilience and stability of the window unit. No longer are specific windows in a train carriage designed to provide a means of emergency escape. RGS GM/RT2100 (2009).

PSV Bus Rail Glass Fitting

Interior glass is generally constructed from one pane of toughened glass to BS:857. Exposed edges are smooth polished. Intrumescant glass is generally used in carriage end doors.

A train windscreen is constructed with multi-ply laminated glass and PVB. It should be sufficiently transparent so that it does not cause optical distortion of objects seen through it or cause confusion between colours used in trackside signals. The use of thermally toughened glass as the outer glass in a multi-layer laminate build up, in train windscreens, is unacceptable due to the complete loss of visibility if broken. However, chemically toughening the glass can strengthen the surfaces without impairing visibility.

In the event of a windscreen suffering impact damage, no glass spall should enter the driver's cab area. This is achieved by laminating an extra polycarbonate sheet to the inner face of the windscreen (anti-spall polycarbonate or ASP). Particular care must be taken when cleaning the ASP.

A train windscreen has to meet colour and secondary image separation rates defined in standard BR:566 making repairs impractical.

Drivers and passengers (and even train kitchen areas) need to be protected from potential glass spall. The use of an inner laminated polycarbonate shield is a very effective device used in train windscreens, needed due to the relative high speeds obtained and the inability of the driver to take any preventative actions. However, these devices, known as anti-spall protection (ASP), are costly.

Glass standards

The structural requirements for train windscreens and body sideglass windows are contained in Railway Group Standard GM/RT2456/2100.

Windscreens

The impact resistance specification for windscreens is referenced back to BR:566 and windscreens are graded into types according to their vehicle design speed range:
  • Type 1 windscreen - up to 81 MPH
  • Type 2 windscreen - up to 112 MPH
  • Type 3 windscreen - up to 149 MPH
  • Type 4 windscreen - up to 186 MPH

The higher the speed, the thicker the windscreen is built, to resist the penetration of a missile.

Any spall must be contained by the ASP.

Windscreens and the windscreen fixings must withstand loadings from both inside and outside the cab and the transient pressure pulse loadings caused by either other trains passing or when entering and exiting tunnels.

Body sideglass

Body sideglass shall provide the maximum possible containment of passengers and train crew in the event of an accident.

All body sideglass fitted to post-privatisation rolling stock is built with a construction of one pane of laminated glass and one pane of toughened glass. The requirements of toughened glass are contained within BS:857. The unit shall perform to BR:573 which specifies the containment of shattered glass under transient pressure pulse loadings, following an impact breakage.

The body sideglass, when installed in a vehicle, shall withstand the following pressure loadings:
  • A sustained pressure of 2.5kPa from outside the vehicle
  • A sustained pressure of 6 kPa from inside the vehicle
  • A concentrated perpendicular load of 0.8kN over an area of 10 sq cm
As the above loadings also apply to the body sideglass fixings, it is imperative that all procedures and process controls are strictly adhered to, particularly with direct glazed installations.

Competency and Training

Competence System design

The system is based around the requirements of the VMOI issued for each type of glazing installation by the OEM builders. Each VMOI glazing activity has been developed into a procedure to include a method statement and a risk assessment. Each procedure has been identified and grouped to form an element of competence.

Initial training

Induction includes a thorough understanding of all the generic glazing techniques and a theory workshop which takes in all of the principles of procedures, method statements, risk assessments and industry standards, both in written form and video.

Practical training takes place both in the fabrication workshops and working as the second-man in an installation team.

Assessment

Trainees are continually assessed by their Team Leader Glass Fitting Technician (TLGFT). Both TLGFTs and trainees are continually assessed unannounced by the Senior Glass Fitting Technician (SGFT, North or South). It is mandatory that trainees attend all glass industry courses for all the tools and materials they will ever use.

TLGFTs will be assessed for each genre of job they are likely to attend and will receive a certificate for each completed assessment. TLGTFs are also safety and skill assessed for practical and theoretical knowledge and must continually demonstrate competence in assessing trainees.

An annual competence licence is issued to GFTs by the Installations Manager.

annual competence licence

An overview chart planner is used to provide an outline illustration of all the competence certificates requiring review over the next three years. This is readily accessible and auditable.

Identification

Aperture identification

One of the biggest problems managing body sideglass installations is knowing the whereabouts of the newly fitted glass on the train. PSV Glass has overcome this problem by mapping out all the potential glass locations on a schematic and coding each location. This exclusive location code is recorded on the Job Completion Sheet and held for the whole life history of the vehicle. These records are readily accessible and auditable.

Glass identification

In addition to recording the aperture location code, the Job Completion Sheet number is acid etched onto the new glass, adjacent to the trade markings, on the outer pane reading outwards and on the inner pane reading inwards. This gives train operators an 'at a glance' view of which particular glass has been changed.

Parts Schematic

The unique PSV Glass mapping schematics are a visual aid to Procurement and Materials Managers to allow them to identify glass part numbers. These are available in both external glass and internal glass formats.



Adhesive Test Card

Adheshive Test Card

Technical

It is a good idea to consider applying polyester film to the inner face of cab sideglasses, (not windscreens*), to protect operating staff from glass spall in the event of glass breakage. Although later vehicles should have laminated cab sideglasses, it is still considered a sensible idea to film these too.



Appendices

Job Request Form

Link-Up Certificate

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