As much as I would love for some of my local heritage lines to be able to fly along at 40 or 50mph, it would ruin the "heritage" experience because you would have to have so many safety systems. AWS. TPWS. Central Door Locking. Etc.
Also, am I right in thinking that heritage railways don't have to have yellow ends on their locos/units
because of the Light Railway Order and the low speed limit? If a train on the GCR in normal service was to run along at 40mph, it would end up having horrid yellow ends. Steam engines just don't suit yellow ends for one thing!
Yes, the diesels on heritage railways often have yellow ends, and would suit this sort of higher speed running requirement, but steam engines would be restricted to 25mph if the heritage line didn't want to ruin their locos.
Also, I find that one of the reasons for why heritage railways are better than the modern network is (in my book) the slam doors. Now that HSTs have ended in my area, the only way to see and hear this old type of coaches is on a rare railtour or a heritage railway. There's nothing like being able to either poke your head out* or reach out of the window, push the handle down, and open the door like that. I prefer this method of opening the doors to pushing a button
And those posts I see online about people moaning about having to
do work to open a door (good God, how dare they have to work?!
) are a load of rubbish.
-Peter
*(at safe speeds only, so 25mph on a clear heritage line like the GWSR is perfect)
EDIT: If you want to feel as though you are going at much faster than 25mph on a heritage line, go to the Chinnor & Princes Risborough Railway when they are running a Bubble Car 121 DMU. That is quite the experience! Bouncing around all over the shop.