This is the second blog in a series of three on Crossrail, the major new rail tunnel running under London. The last entry focussed on the route West of Paddington, while here I'll focus on the two Eastern branches. The final entry will examine the central section and put forward a new proposal to improve the return on Crossrail dramatically.
The two eastern branches divide at Stepney Green, east of Whitechapel, where a shaft is being dug to allow access. The north-east branch goes to Shenfield and the south-east branch to Abbey Wood.
The Shenfield branch is designed to improve capacity and quality for the line that currently runs from Liverpool Street to Shenfield. Trains exit the central tunnel at Pudding Mill west of Stratford and then run on the slow line, leaving the fast line for services from Southend, Chelmsford and Colchester.
The slow line consists of existing stations spaced in a very similar way to tube lines. As such, it is clear that the plan for this branch is to operate it very like the District line to Upminster, or the Central to Epping. Although not 100% clear, it appears that the plan is to operate all services as "all stations" to Shenfield.
The Shenfield branch is due to operate at 12tph in the peak and 8tph off-peak. This is one train every 5 minutes in the peak, and one train every 7.5 minutes off-peak. Unfortunately, the route from Shenfield to London already has 15tph in the busiest peak hour. The current plan is for the additional "residual" 3 or 4tph to continue to run terminating in the main Liverpool Street station as they do now. This is undesirable as it means some platforms at congested Liverpool Street still have to be reserved for the local services. Off-peak, the current service is 6tph, so 8tph would be a welcome enhancement.
So, clearly the 12tph service is insufficient for the demands of the Shenfield route, however the situation is worse than that. Crossrail will be the fastest way to travel from Stratford to the West End, thus demand from Stratford in is likely to be higher than 12tph can handle. Many commuters from further out (Chelmsford, Colchester, Wickford, Epping, etc) are likely to want to change onto Crossrail at Stratford in order to avoid the change onto the Central line at Liverpool Street. This will place a lot of pressure on the service. Retention of the remaining services terminating at Liverpool Street shows that demand on this route is already high, so it seems unlikely that 12tph will be enough.
There is also difficulty with the timetable detail. The current peak timetable mixes services starting from Ilford, Gidea Park and Shenfield, with some of those from further out skipping some of the stations close to London. These commuters will probably want to keep this, but with no passing loops, it will be tricky. It may be that the service becomes tube-like "all stations" once Crossrail starts.
Looking at extensions, with the limitation of 12tph in the peak, I don't believe that it is feasible to servce any more destinations. Were the service receiving all 24tph from the central tunnel there might be more possibilities, but as it stands, Shenfield is all that is possible, and even that is troublesome.
In summary, the Shenfield branch is simple, self-contained and about the right length. The main problem is that there needs to be 24tph between Stratford and the City, and probably 18tph beyond that, yet only 12tph will be available. The "residual" Liverpool Street service is also a bit of a mess.
Abbey Wood branch
The prime reason for the Abbey Wood branch is to serve Canary Wharf. It is likely that the scheme only got political/business/financial support by routing via Canary Wharf. That said, it is certainly the case that Canary Wharf could do with another transport link. The Jubilee Line upgrade has shown how fragile transport to the area is and how the DLR cannot cope on its own. Once Canary Wharf was served, the line needed to terminate somewhere, and Abbey Wood was the option chosen.
Abbey Wood itself is effectively a convenient end-point however, rather than a true destination. It is basically a housing area, including access to Thamesmead area which has no rail access at all. Early planning did not terminate the line at Abbey Wood, instead it was intended to continue via Dartford to Ebbsfleet, see this 2002 pdf map. An extension from Abbey Wood to Dartford and Gravesend is still officially considered possible in the future.
The choice of Abbey Wood does have benefits to the services into Charing Cross and Cannon Street too. Some passengers will now travel via Crossrail rather than the existing route. This will provide some welcome relief on those lines. It should also have a effect on the DLR, as passengers switch from DLR to Crossrail.
The Canary Wharf station is being built in the dock just to the north of the main towers. This approach is perhaps the only possible option given the depth of foundations of the skyscrapers.
However, as with the Shenfield branch, the Abbey Wood branch will only be receiving 12tph - one train every five minutes. Given the crush on the Jubilee Line and DLR today, and massive growth in new buildings in the area it seems likely that 12tph simply won't be enough between Canary Wharf and the City. Beyond Canary Wharf to Abbey Wood the 12tph service will probably be enough.
Looking at extensions, the line to Dartford does make sense to be converted to Crossrail. In my opinion, other services should then terminate at Abbey Wood, such that only Crossrail serves the line between Abbey Wood and Dartford. If regeneration at Ebbsfleet takes off, then I think serving there rather than Gravesend would be the best choice.
In summary, the Abbey Wood branch exists to servce Canary Wharf and provide a useful link to the south east corner of London. The destination of Abbey Wood is clearly a cost-saving exercise as opposed to the more suitable destinations of Dartford and Ebbsfleet/Gravesend. As with the Shenfield branch, the main problem is that there needs to be 24tph between Canary Wharf and the City, but only 12tph are being provided.
The eastern side of Crossrail is a fudge. The two branches are fine in isolation, but trying to serve both will result in a lower quality railway and overcrowding. In the next blog I'll look at the choices for solving the problem of two eastern branches.