I'm not sure whare all this fuss about depots is coming from. Wembley would do just fine for either 222s or 175s. Just because they're made by Alstom (collectively, since the buy out of Bombardier), doesn't mean they have to go to an Alstom depot. Contractually it may be easier, but it's not a must. Northern maintain Bombardier (Alstom) Turbostars at Neville Hill, despite Crofton being a stones throw away. EMT maintain 222s at Derby, rather than the purpose built, Bombardier (Alstom) facility at Central Rivers - again, no great distance away.
Simply, Chiltern would re-train its staff and suitably equip the depot for the new fleet, like many TOCs have done, up and down the country, since the advent of TMDs.
Personally, I'd suggest the 222s are a great fit for Chiltern. They compete favourably with the Pendolinos that Chiltern pitch as competition on the Birmingham - London flows, provide the potential for improvements in long distance journey times and are capable of taking advantage of any future route upgrades.
The 175s would also be a reasonable fit, however, it's not ideal to have formations of coupled short trains (without gangways) from an operational perspective - especially on long distance runs. A pass com pulled in the wrong part of the unit can play holy heck, in terms of disruption, especially when staffing (as on Chiltern), is sometimes DOO, and otherwise quite limited. Before I get a plethora of replies saying "but look at operator x", I'll re-iterate, "not ideal" - I'm sure if it's the chosen option this is no reason at all to stop it, it just introduces slightly more risk, which if I were making the decisions, would tip me toward the 222 fleet.
In either case, I would certainly argue that copious numbers of very suitable stock will be available on the "used" market, come time for renewal, itd be a great shame to see another new train order whilst there's some very capable stock with life still left in it.
Simply, Chiltern would re-train its staff and suitably equip the depot for the new fleet, like many TOCs have done, up and down the country, since the advent of TMDs.
Personally, I'd suggest the 222s are a great fit for Chiltern. They compete favourably with the Pendolinos that Chiltern pitch as competition on the Birmingham - London flows, provide the potential for improvements in long distance journey times and are capable of taking advantage of any future route upgrades.
The 175s would also be a reasonable fit, however, it's not ideal to have formations of coupled short trains (without gangways) from an operational perspective - especially on long distance runs. A pass com pulled in the wrong part of the unit can play holy heck, in terms of disruption, especially when staffing (as on Chiltern), is sometimes DOO, and otherwise quite limited. Before I get a plethora of replies saying "but look at operator x", I'll re-iterate, "not ideal" - I'm sure if it's the chosen option this is no reason at all to stop it, it just introduces slightly more risk, which if I were making the decisions, would tip me toward the 222 fleet.
In either case, I would certainly argue that copious numbers of very suitable stock will be available on the "used" market, come time for renewal, itd be a great shame to see another new train order whilst there's some very capable stock with life still left in it.