B&P tunnel map

USA: Amtrak has begun early construction activities as part of a programme to upgrade 6 km of the Northeast Corridor through central Baltimore and replace the national passenger operator’s oldest tunnel.

The 2·3 km Baltimore & Potomac Tunnel dates from 1873 and is now suffering from age-related issues including water infiltration, structural deterioration and a sinking floor. It also lacks many modern safety features.

The double-track bore is seen as a single point of failure for Amtrak services on the corridor, as well as MARC’s Penn Line commuter rail trains. According to Amtrak, it is the most significant bottleneck between Washington DC and New Jersey; the operator estimates that delays occur on 99% of weekdays and more than 10% of weekday trains suffer some form of delay.

The existing bore is to be bypassed by a new twin-bore tunnel on a less sharply-curved alignment, to be known as the Frederick Douglass Tunnel after a 19th century anti-slavery campaigner.

‘Replacing this Civil War-era B&P Tunnel will nearly triple train capacity on this critical section of the Northeast Corridor for the nine million annual Amtrak and MARC customers who rely on this vital connection’, explained Amtrak CEO Stephen Gardner.

The new tunnel forms the centrepiece of a $6bn upgrading programme which also includes new road and rail bridges, track renewals and the construction of a new MARC station at West Baltimore meeting modern accessibility requirements. The work will enable speeds through the area to be increased from less than 50 km/h to 175 km/h.

Diesel-hauled freight trains will not be permitted to use the new tunnel bores but will continue to be routed through the existing tunnel. MARC is expected to revert to electric haulage for its Penn Line services, where its older electric locomotives were replaced by diesel traction in recent years.

The new tunnel is expected to open in 2032, although the work remains subject to the confirmation of federal funding under the Infrastructure Investment & Jobs Act. The state of Maryland has recently committed $450m to the project and Amtrak has allocated a further $750m.

Work on the upgrading programme got underway on March 10 with the start of track renewals in the Halethorpe and West Baltimore areas. This will include drainage improvements as well as the replacement of wooden sleepers by concrete. This work is being funded by a grant from the FY2019 Federal-State Partnership for the State of Good Repair programme.

‘This initial project will directly reduce impacts during later construction phases and maximise the benefits of the new Frederick Douglass Tunnel with higher track speeds and greater system capacity’, said Amtrak’s Executive Vice-President, Capital Delivery Laura Mason.