It might be glaringly obvious, but I cannot work out what OTDIH stands for 

Re: detaching at Plymouth.
There used to be a shunting loco kept at Plymouth Station for this purpose (also handling the postal, and other movements), with a shunting person. However this came at a cost to cover both morning and evening movements. Removing the sleeper portion for Plymouth saved this cost at the expense of customer convenience. The loco would remain attached to the sleeper carriage in Platform 8.

On the NRE^‡(resolve) website:
“Engineering work is taking place between Plymouth and Newton Abbot, closing some lines on Monday to Thursday evenings [this week].
As a result, a reduced train service will run between Plymouth and Newton Abbot after 19:25 each night. Some trains will not run, and replacement buses will run between Plymouth and Newton Abbot. Trains that do run will be subject to extended journey times between these stations.”
I’m guessing there is single line working in operation hence reduced capacity.

More news about the improvements at Plymouth:

“Passengers heading in and out of Plymouth railway station are finding their route smoother and easier thanks to a gateline that’s doubled in size…….”

https://www.plymouth.gov.uk/newsroom/pressreleases/newgatelinejustticket

Details, timetable & fares on the line’s website: https://dartmoorline.com/

A detailed planning application has been submitted for the new multi-storey car park: https://planning.plymouth.gov.uk/online-applications/applicationDetails.do?activeTab=documents&keyVal=R075MCMMFG800

A press release from the City Council is here: https://www.plymouth.gov.uk/newsroom/pressreleases/anothermilestoneregenerationareaaroundplymouthstation

The new car park is six storeys, which will allow the old car park to be demolished and site re-purposed. A key element is the road layout will be substantially changed with two-way access from North Road East hence no traffic passing the station entrance.

Apologies, I failed to look at the calendar ☹️

The first train arrival at Exeter at 10am isn’t going to attract commuters!
Or is this just a draft and there will be something earlier?
Perhaps RichardB would comment (thanks).

I’ve just been past the site, and the road remains closed with scaffolding and propping in place. No doubt the repair has to ‘set’. The parapet has yet to be rebuilt.

There is a detailed report of the single line operating method applied here on the CRS news page here: http://www.cornwallrailwaysociety.org.uk/latest-input--news--old-pictures-etc

It’s dated 3rd September so you will need to scroll down the September news stories to locate it.

There was a comprehensive report from the site on BBC^» (British Broadcasting Corporation - home page) Spotlight this evening, about 10 minutes in. Available on iplayer until tomorrow.
An easy report for them to do as the BBC studios are only a few hundred yards away!
The NR^» (Network Rail - home page) engineer interviewed was hopeful that repairs would be complete for a normal service from Saturday (with an appropriate caveat).

About the gradient…
The point I was trying to make was that the steep gradient might have prompted the driver to have been accelerating, hence entering the arch at pace and with momentum.
I walked past a short while ago, and workmen were busy erecting scaffolding.
Methinks this is not going to be quick!

Yes, the road is VERY steep upwards under the bridge in the direction the truck was moving!  I guess the driver had ‘put his foot down’ having seen the gradient, hence making it worse.

Plymouth controls west up to the Liskeard distant.

And the answer Simon has provided is this:

“ Yes and no, the Mechanical Semaphores at Lostwithiel, Par and Truro are all being replaced with LED Colour Lights, they will be controlled by a VDU Workstation at Exeter rather than the panel. However, the Mechanical Semaphore Signals at Liskeard, St. Blazey, Goonbarrow and St. Erth will remain and worked by their respective boxes.”
 
So a partial resignalling then!