We have split advance tickets for the TPE to Newcastle arriving 09:11, the 09:22 TPE to Edinburgh arriving 11:05 and the 11:30 Scotrail to Aberdeen arriving 13:50. We plan to get the ferry to Lerwick so cannot arrive into Aberdeen more than 2 hours late.
My question is, if we have already commenced our journey but due to delays, cancellations or disruptions, it turns out we won't be able to make it, would we be able to return home and make the journey the next day on the same tickets?
We also have a tight 11 minute connection in Newcastle, and the next TPE train to Edinburgh doesn't depart until 12:06, so if our train to Newcastle arrives late, would we be able to travel on a crosscountry or LNER train to Edinburgh?
Many thanks
If you miss the connecting TPE service, under the PRO you're entitled to require TPE to re-route you at the earliest opportunity - since the delay in arriving at Aberdeen by waiting for the next TPE service would be clearly be far more than an hour.
This means that TPE would be obliged to arrange ticket acceptance - or if that can't be arranged, to endorse your ticket or issue you with a new one free of charge - to allow you to take the fastest available itinerary (regardless of operator or route) to get to Aberdeen.
In practice it's highly likely you'd be wrongly told that you have to wait for the next TPE service as there "isn't any ticket acceptance" or similar. It's best if you obtain clear evidence of any such refusal to re-route you (e.g. in writing by contacting TPE via social media) so that you have strong grounds for recovering the cost of any new tickets you have to buy as a result.
What you wouldn't be entitled to do is to simply board an alternative XC or LNER service without an appropriate new ticket, endorsement or ticket acceptance - these companies are under no obligation to accept "TPE only" tickets unless you would otherwise be stranded.
Of course it would be nice for them to do so, and there is no harm in asking the guard on the platform in Newcastle before buying a new ticket (if you have an app ready to hit "Pay now", that should give you enough time to obtain your ticket if they say no - remember you need to have your e-ticket downloaded before you board). But given the prevailing attitude to customer service on the railway I wouldn't hold out high hopes.
The PRO would alternatively entitle you to abandon the journey for a full refund, or to have your ticket redated for another date of
your convenience free of charge. Both of these rights are strictly speaking against the train company responsible for your delay (i.e. TPE) but it's ambiguous how the latter right in particular works in the context of having bought your ticket from a third party retailer.
Obtaining a refund under the former right generally isn't difficult, but although the NRCoT replicates the latter right, I'm not aware of any retailer or train company that has established policies for issuing redated tickets. You may well face refusals or claims that no such right exists - e.g. being told that your only option is to get a refund and rebook (likely at much higher cost). Again, the above advice re: re-routing applies - ideally get any refusal in writing so that you have clear grounds for recovering anything you're forced to pay.
FWIW it's always worth asking the guard on the inbound service to Newcastle, on the off-chance they can get TPE's Control to hold the connection for you. But it's fairly unlikely that Control would be willing to do so if you're the only affected passenger.
The above is also written assuming some or all of your Advances between Newcastle and Edinburgh are routed "TPE only" - if they're routed anything ending in "& Connections" then you are valid to use alternative operators without needing to rely on ticket acceptance, as the ticket isn't restricted to any one operator.
Realistically speaking I wouldn't advise planning on such a tight connection when your arrival time in Aberdeen is crucial. Given the unreliability and invariably poor customer service the railway provides during disruption, I would give serious consideration to flying to Aberdeen or indeed the Shetlands. There's a direct Loganair flight to Aberdeen most afternoons (or connecting BA flights via Heathrow). With a through booking to the Shetlands you'd be protected in the event of any missed connection too.