Newbie question: RHTT diagrams

[Farnborough]

(I know there is a RHTT 2026 thread, but considered this to be a bit of a diversion... if the Mods feel otherwise, I would understand)

Locally, a number of RHTT etc trains are listed on RTT etc, and are shown as Runs as required, including:

• 3S83 - Valid SX from 2026-05-18 to 2026-12-11
• 3S84 - Valid SX from 2026-05-18 to 2026-12-11
• 3S86 - Valid SX from 2026-05-18 to 2026-12-11
• 8Y82 - Valid SX from 2026-05-18 to 2026-12-11
• 8Y84 - Valid SX from 2026-05-18 to 2026-12-11
• 8Y85 - Valid FSX from 2026-05-18 to 2026-12-10

Despite the validity from May, they do not appear to be running at the moment (either explicitely Cancelled, or simply Not activated)...

Five questions:

1. Presumably, the May to December validity is aligned to the timetable period?
2. Presumably, they're booked daily to preserve the paths?
3. Presumably when they do run, they don't run every day - for example 3S84 and 3S86 are scheduled through Farnborough at the same time...
4. What is the difference between the 3Sxx and 8Yxx services?
5. And, finally, when will they start their runs?

 

[Freightmaster]

Five questions:

1. Presumably, the May to December validity is aligned to the timetable period?
2. Presumably, they're booked daily to preserve the paths?

Yes and yes.

1. Presumably when they do run, they don't run every day - for example 3S84 and 3S86 are scheduled through Farnborough at the same time...

All diagrams run daily from early October - 3S84 is the usual path out of 3S84 and 3S86.

1. What is the difference between the 3Sxx and 8Yxx services?

8Yxx are 'as required' de-icing runs used in the Winter months (January to March) as far as I am aware.

1. And, finally, when will they start their runs?

The exact start date differs from year to year depending on weather conditions
during September and the anticipated impact of leaf fall on railhead conditions.

Looking at RTT, the first day of operation last year was Friday September 26th:

https://www.realtimetrains.co.uk/search/detailed/gb-nr:XEJ/2025-09-26/0400-1900

 

[amn]

What is the difference between the 3Sxx and 8Yxx services?

At least on Southern, 3Ss are autumn MPVs, 3Ws are autumn loco hauled circuits, then in winter the 3Ys are loco hauled and the 8Ys are MPVs.

 

[Farnborough]

Thanks, both.