Tilt or Not to Tilt? Debate Reopens Over Future of HS2 and WCML Trains

Calls have been made to reconsider tilting trains as part of future rolling stock plans for HS2 and the West Coast Main Line (WCML), reigniting debate over how best to boost capacity and cut journey times.

The proposal comes from rail industry figure Chris Gibb, who outlined his vision at an All-Party Parliamentary Rail Group meeting earlier this month. His plan suggests pairing the current order of 54 Class 895 HS2 trains with a new generation of longer, higher-capacity tilting trains to eventually replace the iconic Pendolino fleet.

A case for tilt

Gibb’s concept—dubbed the “Class 391”—would see 286-metre-long trains with around 750 seats, significantly more than today’s 11-car Pendolinos. These trains would operate beyond the HS2 core network, serving destinations such as Manchester and Glasgow.

He argues that tilting technology, which allows trains to travel faster through curves, remains underutilised despite decades of proven performance on the WCML.

“Tilting trains are the unspoken player in this debate,” he said, suggesting that advances such as digital signalling could unlock further speed gains—if included in future specifications.

Capacity vs complexity

A key driver behind the proposal is capacity. Current HS2 trains are shorter, with around 504 seats, and cannot operate in pairs north of Birmingham due to platform constraints. Gibb believes a dual-fleet approach could increase passenger capacity without the need for additional infrastructure.

However, not everyone is fully convinced. Rail consultant William Barter cautioned that the benefits of tilt can sometimes be overstated, noting that improvements depend heavily on what the comparison baseline is.

He also highlighted operational challenges, including mixed traffic on the WCML and the potential trade-off between higher speeds on conventional lines and lower speeds on HS2.

Rethinking the network

Gibb also proposed using HS2 trains on existing routes before the high-speed line is fully operational—particularly between Birmingham and Manchester—to ease congestion and build operational experience.

His wider plan would require a significant timetable overhaul, particularly in the North West, but he argues it could deliver faster journeys and more seats where demand is highest.

Big decisions ahead

The discussion comes as the rail industry begins to consider long-term replacements for the Pendolino fleet, expected from around 2040 onwards.

While no formal changes have been made to current HS2 rolling stock orders, the idea of a mixed fleet—and the infrastructure implications that come with it—is now firmly back on the table.

With capacity pressures growing and HS2 plans evolving, the question remains: should the UK stick with straight-line speed, or lean back into the curve with tilt?