Any new development around the Grade II* listed portals should be planned to provide public access and a suitable viewing platform, and could be on either side of the tracks.
Creating a viewing platform for the tunnel portals just off Adelaide Road may conflict with tree preservation and with the rights of the residents of Blashford Tower. It may depend on redevelopment of the Adelaide Road surgery and of the Modern Motors site. Such redevelopment has been unsuccessful on more than one occasion recently, following both private and local authority initiatives, as its commercial justification depends on creating buildings taller than those acceptable to the community.
The HS2 vent shaft building has been proposed as a viewing platform, but this is too far from the portals and subject to the same tree preservation constraints on creating a clear view. It could nevertheless be linked with Stephenson Walk Extension and provide a view of Primrose Hill cutting, which features one of the most complex layouts in the entire railway system with its burrowing junctions.
The most promising viewing platform site is in King Henry’s Road, close to the junction with Primrose Hill Road. Ideally this would be accessed via the proposed extension to Stephenson Walk, but the two projects can be treated separately.
Extending the Walk over the tunnel portals to the King Henry’s Road site requires relocation of the terrace of properties at the corner with Primrose Hill Road. There were originally seven shop/maisonette units in the terrace, but settlement over the portals became a threat to the fast tunnel and demolition of part of the terrace has left three shops and four flats. Network Rail, which remains the freeholder, would be glad to see the remaining units removed.
Built in the early 1960s, their 99-year leases will by now have reduced to about 40 years. Network Rail will not extend the leasehold, and the proportion of commercial premises means that the leaseholders will be unable to buy the freehold. The properties consequently have limited and declining value and it should therefore be possible to tempt the leaseholders to move to better premises in King Henry’s Road, just around the corner.
Here an alternative viewing platform could be created close to the portals as part of redevelopment of the National Grid cooling station. This building in King Henry’s Road will be decommissioned over 2020-21, although this may be subject to delay following the current crisis. Final details for its future are yet to be confirmed. It should be noted that National Grid has a joint venture with the Berkeley Group, called St. William, to redevelop National Grid properties that become available.
The wall running along the pavement on the east side of Primrose Hill Road would also be removed, opening a green route over the portals to the proposed viewing area, which is shown in the Figure. These landscaping works would greatly enhance the setting of the Grade II listed St Mary the Virgin church.
