Having looked at the Route Engineering Report for High Speed 2, the preferred route from Northolt Junction is to run the HS2 lines to the north of the Chiltern lines which will be moved to accommodate HS2. The two Chiltern Lines at Northolt will run under the HS2 lines (along the alignment of the current down Chiltern line).
(See page 76 of the report at: http://www.dft.gov.uk/pgr/rail/pi/highspeedrail/hs2ltd/routeengineering/pdf/Chapter5.pdf)
The problem is that there's only enough space for two Chiltern lines whereas under Evergreen 3, there will be an extra down 100mph fast line at South Ruislip immediately adjacent to the current up line, with the current down line becoming a loop serving South Ruislip station. These will be in addition to the current three lines at West Ruislip.
The report doesn't seem to have taken Evergreen 3 into account which seems to be a notable oversight. It would be a shame if Chiltern's efforts to add capacity and speed up services were undermined by HS2. I know it's a long way off and the route isn't finalised yet, but if I were Adrian Shooter, I would pick up on this one pretty quickly as construction could start as early as 2015:
Quoting the report:
'At South Ruislip, the chiltern line from marylebone and Neasden joins the proposed corridor at a grade-separated junction. The diverging line towards marylebone is a single-track link; the route from marylebone is also a single-track link, passing under the Old Oak line, merging into it south of South Ruislip Station. The LUL central line lies to the south of all the other lines. A waste transfer facility lies in the triangle of land between these lines.
The HS2 route would be on the northern side of the chiltern line, so would need to cross both the Up and Down line to marylebone, while at the same time attempting not to involve the demolition of the waste transfer facility.
A number of layout options were investigated in this area with the aim of allowing HS2 to pass over the two chiltern lines, all with the aim of meeting chiltern Railways’ aspirations for improved line speeds. This would allow HS2 to pass through South Ruislip at, broadly, existing levels, rather than having to be grade-separated over the Up marylebone. more layout development work is needed.
The waste transfer facility is served by a rail link used on a daily basis. This would be in the footprint of the HS lines, resulting in this facility being lost. In order to maintain the facility, it would be necessary to develop a layout incorporating the various requirements in the area.
South Ruislip Station would be remodelled, generally by a southerly slewing of lines and platforms to allow HS2 to pass to the north, in a complex staged implementation sequence. The HS lines would pass along the side of an industrial yard, impacting both the existing buildings and the access road to the yard. There appears to be little scope to widen the corridor at the southern side and slew all the lines across, so the impacts on the industrial area would need to be assessed in detail.'
(See page 76 of the report at: http://www.dft.gov.uk/pgr/rail/pi/highspeedrail/hs2ltd/routeengineering/pdf/Chapter5.pdf)
The problem is that there's only enough space for two Chiltern lines whereas under Evergreen 3, there will be an extra down 100mph fast line at South Ruislip immediately adjacent to the current up line, with the current down line becoming a loop serving South Ruislip station. These will be in addition to the current three lines at West Ruislip.
The report doesn't seem to have taken Evergreen 3 into account which seems to be a notable oversight. It would be a shame if Chiltern's efforts to add capacity and speed up services were undermined by HS2. I know it's a long way off and the route isn't finalised yet, but if I were Adrian Shooter, I would pick up on this one pretty quickly as construction could start as early as 2015:
Quoting the report:
'At South Ruislip, the chiltern line from marylebone and Neasden joins the proposed corridor at a grade-separated junction. The diverging line towards marylebone is a single-track link; the route from marylebone is also a single-track link, passing under the Old Oak line, merging into it south of South Ruislip Station. The LUL central line lies to the south of all the other lines. A waste transfer facility lies in the triangle of land between these lines.
The HS2 route would be on the northern side of the chiltern line, so would need to cross both the Up and Down line to marylebone, while at the same time attempting not to involve the demolition of the waste transfer facility.
A number of layout options were investigated in this area with the aim of allowing HS2 to pass over the two chiltern lines, all with the aim of meeting chiltern Railways’ aspirations for improved line speeds. This would allow HS2 to pass through South Ruislip at, broadly, existing levels, rather than having to be grade-separated over the Up marylebone. more layout development work is needed.
The waste transfer facility is served by a rail link used on a daily basis. This would be in the footprint of the HS lines, resulting in this facility being lost. In order to maintain the facility, it would be necessary to develop a layout incorporating the various requirements in the area.
South Ruislip Station would be remodelled, generally by a southerly slewing of lines and platforms to allow HS2 to pass to the north, in a complex staged implementation sequence. The HS lines would pass along the side of an industrial yard, impacting both the existing buildings and the access road to the yard. There appears to be little scope to widen the corridor at the southern side and slew all the lines across, so the impacts on the industrial area would need to be assessed in detail.'