1B46 14 45 Paddington to Swansea 13/4

[whole diary]

[insider]

Not really familiar with that route.  The only restrictions I'm aware of is Ledbury and Colwall tunnel on the Cotswold line where there's not enough clearance in the tunnel to open a slam door. 

What are the restrictions in these tunnels?

I think a-driver's post covered it. A HST^▸ (High Speed Train) set running on one power car wouldn't be allowed through the Ledbury or Colwall tunnels. Should there be an engine failure (or worse) you'd want to have the flexibility to get a set out of those tunnels in an emergency. If only one power car is working that wouldn't be possible.

I believe, but am open to correction, that similar emergency procedures are in place for the Severn Tunnel. A HST set, running in passenger service on one power car only, wouldn't be permitted to enter the Severn Tunnel.

The Only Restriction is Ledbury Tunnel, which are no powercars with sliding doors lock out can enter. As if evacuation required that's only way out and no clearance for normal doors.

There are no restrictions on Power Issues on FGW^▸ (First Great Western) network except clear runs on certain gradients (Reading Viaduct and Devon Banks for example) Also generally not allowed West of Plymouth on one engine,

[Worcester_Passenger]

Not really familiar with that route.  The only restrictions I'm aware of is Ledbury and Colwall tunnel on the Cotswold line where there's not enough clearance in the tunnel to open a slam door. 

What are the restrictions in these tunnels?

I think a-driver's post covered it. A HST^▸ (High Speed Train) set running on one power car wouldn't be allowed through the Ledbury or Colwall tunnels. Should there be an engine failure (or worse) you'd want to have the flexibility to get a set out of those tunnels in an emergency. If only one power car is working that wouldn't be possible.

I believe, but am open to correction, that similar emergency procedures are in place for the Severn Tunnel. A HST set, running in passenger service on one power car only, wouldn't be permitted to enter the Severn Tunnel.

The Only Restriction is Ledbury Tunnel, which are no powercars with sliding doors lock out can enter. As if evacuation required that's only way out and no clearance for normal doors.

There are no restrictions on Power Issues on FGW^▸ (First Great Western) network except clear runs on certain gradients (Reading Viaduct and Devon Banks for example) Also generally not allowed West of Plymouth on one engine,

Thanks for those - I understand now.

[chrisr_75]

I believe, but am open to correction, that similar emergency procedures are in place for the Severn Tunnel. A HST^▸ (High Speed Train) set, running in passenger service on one power car only, wouldn't be permitted to enter the Severn Tunnel.

Might in part be due to the gradients into and out of the tunnel? It's not unknown for heavy freight trains to stall on these gradients (reported on Wikipedia as 1:90 & 1:100 & presumable with relatively poor railhead conditions due to the location in deep, damp cuttings), so perhaps there is a concern that an HST could stall if only a single power car was operative?