The Salisbury - Romsey loop service is an interesting one, as it uses 3 units - would only be two if it terminated at Romsey. So, what is the benefit of extending it to Salisbury? Clearly with only around 25,000 entries and exits each per year Dean and Dunbridge would not justify the extension, but that seems to be the only flow it serves, as it doesn't provide an alternative between Salisbury and Southampton. However, by operating a unit hourly from Salisbury to Romsey, I'm guessing that SWT▸ pick up a share of every fare from north of Salisbury to south of Romsey. So maybe it's an ORCATS▸ raid, disguised as providing a service to Dean and Dunbridge.
I don't quite understand your point about the service
not providing an alternative between Southampton and Salisbury. The running times are not too different due to the extra stops, and certainly northbound the services leave Southampton almost half an hour apart.
NRES▸ certainly shows it as a 2 tph service.
I also don't believe you can realistically view it as an 'ORCATS raid'. That would apply when a
TOC▸ made its own unilateral decision to add an extra service, or extra calls in an existing service. Whereas in this case an 'informed' decision was made by
DfT» (in SWT's 2006 SLC2 valid from Dec 2007) to extend the SWT service and transfer the intermediate calls to SWT,
IIRC▸ in order to speed up the
FGW▸ longer distance service. The proposal first surfaced in the Mar 2006
SWML▸ RUS▸ , apparently in response to stakeholder requests.
Then the additional calls at the two minor stations to make them hourly (during most of Mon - Sat) were later additions in an attempt to grow passenger numbers, originally SWT made no more calls at Dean and Dunbridge than FGW had done.
Paul