Train time changes from 12th to 30th August

[whole diary]

[grahame]

And from journey check

Engineering work starting on 19/08/13 between Westbury and Swindon.
Track improvements and maintenance are taking place from 07:00 on 19/08/13 to 08:30 on 23/08/13 between Westbury and Swindon.
Whilst work is taking place, buses will replace trains between Chippenham and Swindon
Monday to Friday - The 0704 Westbury to Cheltenham Spa service will depart Westbury earlier at 0646 and will terminate at Chippenham.

I'm scratching my head when the bus runs ... I suspect you can't trust everything you read 

[grahame]

and ...

Engineering work starting on 24/08/13 between Swindon and Westbury.

Track improvements and maintenance are taking place from 15:00 on 24/08/13 to 17:00 on 24/08/13 between Swindon and Westbury.
Saturday - The 1522 Swindon to Warminster service will depart Swindon at 1612 and will terminate at Westbury.
An additional train will run from Westbury at 1608 to Warminster.

I've know about the time change for a while, but the reason is a bit of a surprise. 

On a regular Saturday, the Westbury - Swindon train gets into Swindon at around 15:50, and then forms a train via Kemble to Cheltenham Spa.  An earlier train from Cheltenham Spa via Kemble forms the 15:22 to Westbury.   I had assumed, incorrectly it seems from the above report, that the delay to the down train was so that the same set could be used for both trains during the Kemble blockade - "retimed for OPERATION CONVENIENCE" as might be written elsewhere 

Do they really mean "engineering works between Westbury and  Swindon", or it done to let a work train from Westbury to Swindon, of which there are plenty at the moment, through from Bradford Junction to Thingley?