Quick notes on Trenitalia's new maintenance facility at Maisons-Alfort Pompadour
It's been rumoured for months, and finally this week there was official confimation: Trenitalia has the location for its maintenance facility for its Frecciarossa high speed trains in France. News from Railway Gazette here.
And it will be at Maisons-Alfort Pompadour.
Zoom out a bit, and does anything strike you?
Yes, that location is perfect for Paris Gare de Lyon, and for trains to Lyon, Marseille and Milano.
It is most definitely not perfect for Paris Gare du Nord for eventual trains to London. Routing trains from there to Gare du Nord is likely going to have to be done like this - a full 106km route:

Why not do stock moves through the RER tunnel I hear you thinking? It's definitely shorter - just 19km. But RATP and not SNCF Réseau operates the infrastructure, and no one does stock moves that way. Does Trenitalia have some trick up its sleeve? There is no news yet that it does.
So what's the solution here?
Trenitalia's facility at Maisons-Alfort Pompadour - as per the Railway Gazette report - is to have three maintenance tracks, and stabling and cleaning facilities for up to 25 trains, and the talk is that initially Trenitalia will have 19 ETR 1000 units for its France and Channel Tunnel operations. So that all fits.
But I cannot see Trenitalia running empty trains more than 100km every night for the toilets to be emptied. So to make services to London work the company is going to at least need a stabling facility somewhere north of Paris, somewhere like Joncherolles.
Perhaps more far-fetched, Trenitalia could attempt to run the first and last trains of the day to Marne la Vallée rather than Paris Nord, as that station does have Channel Tunnel terminal facilities (Eurostar used to run its Disneyland services to there) and that station is en route to Maisons-Alfort Pompadour.
Or maybe Trenitalia will conclude that, after all, that London is too much hassle, and focus on France instead. Even 25 trains is not that many up against SNCF's 300-odd TGVs.
Live in Lyon and Marseille and favour Trenitalia Frecciarossa over SNCF's TGVs? This is good news for you. London? I am not sure yet.
[Update 21.3.2025, 12:30]
As Nicolai von Neudeck points out on Bluesky, yes there is another option - 40km, but requiring the train to reverse at Drancy, like this:

Due to the need to reverse I cannot see this one as being much more viable than running via Marne la Vallée.