The Chunnel has unusually big loading gauge. Shuttles are said to be
4100 mm wide - wider than Berne gauge or any other railway. How far
does the Shuttle gauge go on either side of Chunnel mouths?

Building of the Chunnel has been imminent long ago. After big rail
tunnels were built in 1870-s and 1880-s - 7 km underwater Severn
tunnel, around 15 km Mont Cenis, Simplon and Sankt Gotthard tunnels -
the completion of Chunnel is said to have been regarded so imminent
that a railway between London and midlands was built to Berne gauge.

Hitler designed Breitspurbahn, to go to Brest, and to Rostov on Don.

Were there any plans to build a Chunnel after Sealion? If yes, to
which gauge - Berne gauge, Breitspurbahn gauge or some other?

"Crown-Horned Snorkack"  skrev i meddelandet 
news:14361e7d-a583-45a2-8451-5f0577e5b758@c65g2000hsa.googlegroups.com...
> The Chunnel has unusually big loading gauge. Shuttles are said to be
> 4100 mm wide - wider than Berne gauge or any other railway. How far
> does the Shuttle gauge go on either side of Chunnel mouths?
>
AFAIK they're around 5000mm wide,  and double deck throughout for car 
shuttles.
However they're not running longer than from Eurotunnel Terminal France 
Calais-Coquelles (a loop around 6 km distance from tunnel mouth) to UK 
Terminal Folkestone, another loop just outside the UK tunnel mouth.