Found this interesting report on how to improve the GEML. Highlights include:
http://www.newanglia.co.uk/Assets/Files/Content/GEML%20Capacity%20Study%20-%20Final%20Report%20-%20V1.5%20%2830-10-2012%29.pdf
- A new three-tracked section at Boreham.
- New rolling stock including refurbishment of the Mark 3 coaches and new class 93 electric locomotives! (See GEML Capacity Study - possible new locos and Mk3 refurbishment?)
http://www.newanglia.co.uk/Assets/Files/Content/GEML%20Capacity%20Study%20-%20Final%20Report%20-%20V1.5%20%2830-10-2012%29.pdf
Extracts from the GEML Capacity Study document said:Infrastructure
4.1. Context
As discussed in Chapter 2, the Capacity Study has considered a range of Options which can work together to address the peak hour passenger capacity gap expected for the GEML by 2031. A 'core' package of measures has been identified with a series of 'supplementary' options. This Chapter sets out further information about these key infrastructure elements. The most critical infrastructure challenges identified are:
Proposed schemes have been identified to meet these challenges, as outlined in sections 4.2 and 4.3.
- the need to provide some additional tracking on the most congested section between Shenfield and Colchester (which is currently two track) to allow for regulation and to enable operators to recover service disruption; and
- the need to increase the number of services able to operate into London Liverpool Street Station (specifically in the busiest peak hour).
4.2. Boreham 3-Tracking
Between Shenfield and Norwich, the GEML is currently entirely two track, with a limited number of loops available for regulation purposes.
The majority of passenger loops are short and would require a train to stop within them to allow another service to pass. Apart from at Colchester and Ipswich, there is a lack of loops capable of accommodating modern freight trains. Modern inter-modal (container) trains can now exceed 700m in length. The only loops able to accommodate these trains are at Ipswich and Colchester.
None of the existing loops are sufficiently long enough to allow trains to use them without having to brake or accelerate on the mainline, which has the significant potential to cause knock-on delays to the following trains. This is particularly true of the loops outside of stations where there is less opportunity for a call at the station to be used to mitigate any braking/acceleration. AT 110 mph a typical passenger train needs just over a mile to brake and accelerate smoothly without causing a knock-on delay.
The lack of suitable goods and passenger loops limits timetables and regulation as stopping services and faster non-stopping services must co-exist without passing openings on large sections of the route.
Furthermore, this lack of flexibility limits service operators‟ ability to respond in the event of an incident on the network. Resilience is therefore low and service punctuality / reliability are likely to suffer with no little scope to recover from service disruptions. Having considered a range of different scenarios, it has been identified that providing additional tracks between Shenfield and Colchester should be a key element of any future infrastructure package for the GEML.
The opportunity to provide new 3 or 4-track sections between Colchester and Shenfield has been considered as a part of the options appraisal process. Providing an additional track over a length of 3 to 5 miles would allow separation of fast and slow services, as well as providing greater flexibility to accommodate freight services along the route. In cost terms, providing 3 tracking is significantly cheaper to deliver than a 4 tracking scheme and, if implemented with a bi-directional line, can deliver the same operational benefits as having a four-tracked section.
Opportunities to provide this infrastructure have been investigated and a location close to Boreham as indicated in Figure 12, to the north of Chelmsford has been explored. A new third track would be constructed to the north of the railway and a high-level feasibility assessment of this proposal has been completed to identify any significant existing constraints which could affect the deliverability of this scheme. The turnout locations indicated are approximate and it is the feasibility of developing a scheme in this section of track which is for consideration.
4.3 Bow Junction Remodelling Scheme
One of the key constrictions of the existing infrastructure is at the southern section of the route near to Bow Junction. The L&SE RUS identifies an infrastructure enhancement scheme to remodel this area which would support an increased output of services onto the GEML. The current alignment of the Bow Junction interchange, as presented in 0, allows for 23 services to operate in the busiest peak hour.
The main focus of a scheme would be to make the two Temple Mills lines between Stratford and Bow available to passenger trains. At present, these lines are generally restricted to freight and empty coaching stock. A scheme at Bow Junction could effectively create six, fully usable tracks for the entire route section between Stratford and Liverpool Street, two of which would be in the Crossrail tunnels.
Such a scheme would unlock capacity for additional main line services, once services are diverted from the 'Electric Lines' onto Crossrail in 2018. The proposed scheme could allow up to 28 trains to operate out of London Liverpool Street in the busiest peak hour. This is a significant increase on the 23 trains which can currently operate and would help to address the capacity gap challenge.
In increased output of 28 morning peak main line trains could be accommodated with services following two independent alignments before Stratford station, as shown in Figure 15. Half of trains could operate along the existing Up Main line, crossing to the Up Electric line after the Crossrail tunnel portal. These services would run via Stratford Platform 9 and into London Liverpool Street Platforms 13-15. Remaining services could run via Stratford Platform 10 and along a new Reversible Main line leading to the existing Up Main line and arriving into Platforms 8-12 at London Liverpool Street.
4.4.1. Line Speed Improvements
In enhancing the GEML, providing the necessary infrastructure to allow trains to run at 110mph is a key element of an overall package.
The Study recommends further investigation is completed included a full examination of signalling infrastructure and a review of possible power supply and platform clearance issues. Those areas excluded from Network Rail's study should be subjected to review. However, it is feasible to provide the necessary enhancements to allow line speed to increase.
4.4.2 New Rail Station at Chelmsford
Whilst Chelmsford benefits from a town centre location, the constraints of the current station site are considered to constrain rail user demand; the station is elevated above street level on a viaduct and offers little opportunity for expansion to meet rising passenger numbers. There is little car parking at the station and limited supply in the locality. This limits the catchment area for the station and there is anecdotal evidence of residents from newer estates driving to the other stations with a car park rather than use their local station in Chelmsford.
The proposed development at Beaulieu Park comprises a residential development of up to 3,600 dwellings, mixed uses, including up to 62,300 sq. metres employment floor space, comprising a business park, retail, hotel, leisure and open space, education and community facilities.
4.4.3 Braintree Branch Loop
In making available additional capacity to the GEML, the Witham- Braintree branch line is identified as a specific issue; constricted by only being single track. This means only one service can operate at any one time as there are no opportunities for services to pass. This adversely impacts the network as, on occasion, services are required to 'wait' on the main line whilst the previous Braintree service completes its journey on the branch line.
To investigate the opportunities to provide new tracking to allow a more frequent service to operate on the branch line, Braintree District Council commissioned a 'Socio-Economic Study' (Mott MacDonald, June 2012). The Study concluded that it is feasible, in principle, to provide a 30 minute train service between Witham and Braintree through the introduction of a new loop.
4.4.4 Liverpool Street Platforms Lengthening
To help address the passenger capacity gap for the busiest peak hour identified in the L&SE RUS, trains shall be required to lengthen and operate as 12-car services. To help facilitate this, works shall be required to lengthen platform 16-18 at terminus station, London Liverpool Street.
Currently GE Inner services use platforms 13-18 at London Liverpool Street Station and these platforms will become free when GE Inner services are replaced by Crossrail in 2018. For 12-car GEML services to use these lines, platforms 16-18 would need to be lengthened.
It is observed that the current track layout prohibits lengthening of all three platforms, and one platform may need to be lost in order to allow the remaining two to be lengthened sufficiently. Platforms 13-15 are already able to accommodate 12-car services.
