I have just read through the notes I made on the Board of Trade inspections of the WSWR. The inspection for the opening in 1848 makes no mention of a west chord. It simply refers to there being no facing points on the main line. So the train had to reverse into a siding before taking the WSWR.

The other report is from 1875 after the narrowing of the gauge. Again no mention is made of a west chord, which one would expect, especially with respect to the arrangements at the junction

Thingley Junction and Bathampton Junctions (both mixed gauge) were provided with this weird single moveable blade point. Here the switch was on the common, outer rail. As the train took the points it moved onto the branch and the nearside wheels were dragged over the fixed nearside B-G rail onto the branch! The moveable rail acted as a check rail to guide the train to the branch.
(The National Archives Rail 1053-57 BoT report on Narrowing of the Gauge 12/6/1875)

Accidents did happen and it was eventually scrapped.

Colin Maggs in his book “The Bath to Weymouth line” suggests that the chord was laid out in the 1840s as an alternative to the Bathampton to Bradford route, which the GWR^▸ (Great Western Railway)/WSWR did not really want. However, like the south chord at Yeovil rails were not laid.
Then in WWII^▸ (World War 2 - 1939 to 1945) it became an alternative route in case of bomb damage.
Relevant page attached

Now a public path
https://www.theskyeguide.com/walking-mainmenu-32/14-strolls/93-marble-line-path

Have just found a photo of the upper level of the funicular railway at Devils Dyke, taken on a visit some years ago. It shows the base 'station'
The second shows the Devil's Dyke itself, across which the aerial flight was constructed

It was running down the SW mail line this morning
https://www.realtimetrains.co.uk/train/19004/2020-05-07/detailed

We loosely planned for our retirement when Marion and I got married almost 25 years ago. Then her retirement age was going to be 60. We took life decisions based on that and then, some years ago, were informed that her retirement age would now be 66. That shot serious holes in to the plan and meant that I was still supply teaching at 69, some four years ago.

It was this 6 year rise that has caught out so many of the mid-1950s women.

The NLS map of 1914 shows the aerial flight and incline, the route of the latter can still be traced and also seen on Google Earth.
That of 1895 also shows a switchback railway and “bicycle railway” by the hotel

If you do a Google search for
highways england historical railways estate
You will turn up a ‘whatdotheyknow.com/request‘ for the location of disused tunnels.
You can follow the outcome and download the list.
I have attached it here, assuming I have done it correctly!

We lived in Chippenham c1950, the house was on New Road just up from the station. Still have hazy memories of seeing the gas turbine at the station and a trip to Calne. We left in 1951, moving to Crewkerne.

According to R A Cooke's Track Layout Diagrams Section 21 Bath and Westbury p12 the down line was SLEWED to the island platform on 1st February 1976.

See attached image

As far as I can see from Google Earth and Traksy, it crossed over the WCML^▸ (West Coast Main Line) to the south of the station and then connected with both the WCML and the Bedford line.
There is a buffer stop 2km to the west of the viaduct, this section being used as Swanbourne sidings.

A problem with the point and signals at the west end of Templecombe has meant all services have been diverted via Westbury since lunchtime yesterday.
 
Loss of power causing signals to go blank and points fail to work or detect.

Expected to last until 13.00 today.

Photo from Twitter

https://twitter.com/networkrailwssx/status/1255857651822538754?s=21

Film 4 The Ladykillers, with shots of Kings Cross 12.50 to 14.40

This is today's and it plays by the Forum Rules!

https://twitter.com/gwrhelp/status/1254775487437484032?s=21

They were also doing some drainage work, not sure if that matches the place.

“Further up the line towards Bristol Parkway we're working on the Filton Bank - improving drainage at Horfield/Lockleaze & nr Filton Abbey Wood“

https://twitter.com/networkrailwest/status/1254417911424471040?s=21