Connection time at High Wycombe and Gerrard Cross

[v199629]

Why are the connection time only 1 minute at these stations and not a more realistic time of 3 to 5 minutes?

 

[74A]

Because if the train is late the connecting train will also be delayed due to running on the same section of track.

 

[JonathanH]

Why are the connection time only 1 minute at these stations and not a more realistic time of 3 to 5 minutes?

It may allow some padding to be put in the timetables of terminating trains while still allowing connections into trains that follow.

For example, 2W42 1517 London Marylebone to High Wycombe is scheduled to arrive at High Wycombe at 1559 in the published timetable, 1557 in the working timetable and actually arrived at 1555 today.
https://www.realtimetrains.co.uk/service/gb-nr:G80090/2021-11-19/detailed

The following service, 1G43 1537 London Marylebone to Birmingham Snow Hill is scheduled to depart arrive and depart from High Wycombe at 1600. Clearly one follows the other. It would be a bit remiss to prevent the connection, even though the times are close, as it is pretty much guaranteed if the trains are running in order, but the padding to the terminating service doesn't give a false expectation of journey times.
https://www.realtimetrains.co.uk/service/gb-nr:G80117/2021-11-19/detailed

 

[Watershed]

This can cause problems for journeys where a north to south (or v.v.) interchange is suggested. For example if you have a 1 minute connection from platform 3 to 2 at High Wycombe, you've a fat chance of making it, even if your inbound service arrives right time and you know exactly which door to exit the train at!

 

[Starmill]

This can cause problems for journeys where a north to south (or v.v.) interchange is suggested. For example if you have a 1 minute connection from platform 3 to 2 at High Wycombe, you've a fat chance of making it, even if your inbound service arrives right time and you know exactly which door to exit the train at!

Indeed so! If I ask National Rail Enquiries for Saunderton to Birmingham at 1130 on a weekday it suggests precisely that, arriving at High Wycombe at 1200 and leaving at 1201.