super express acceleration?

[TGV]

Bet thats a FGW HST ??, XC and East Coast drivers are a lot less cautious from a stand.

Played for and got, sir.

Agreed. I have some rough data on a (then) GNER HST and it was slightly quicker to 125mph than this - even with the extra carriage!!! Although we would have to compare gradient profiles (the brown line) to see what effect that had too.

 

[TheWalrus]

Hence I said "assuming linear acceleration". Unless you've got the acceleration curve for the IEP, a train that doesn't and probably won't ever exist, there's not much else to go on is there?

Read my first post!

 

[jopsuk]

Played for and got, sir.

Agreed. I have some rough data on a (then) GNER HST and it was slightly quicker to 125mph than this - even with the extra carriage!!! Although we would have to compare gradient profiles (the brown line) to see what effect that had too.

Apart from a slight wobble on a steeper uphill bit in the first mile, that curve seems pretty unaffected by gradient to my eye?

 

[TGV]

Apart from a slight wobble on a steeper uphill bit in the first mile, that curve seems pretty unaffected by gradient to my eye?

Yes, it's not much of a gradient in truth. What I meant is that the GNER plot shows the train reaching 125mph slightly sooner than the FGW one despite the extra load of another carriage - but if it's almost ALL downhill on the GNER example then it doesn't make the comparison fair. I'd have to dig out the trace to see.