I've been seeing what I can find online and in my collection of railway books - I live very close to this area and the history of the rail lines around here is quite fascinating. I can't be sure that everything below is correct but it seems to make sense, there are a few sources which more or less match up in terms of a timeline of events.
1 - The LMSR line from Black Carr junc south to Rossington colliery. Am I right this opened in 1931 and closed in 1972 ?
This line is mentioned in an RMWeb post here -
https://www.rmweb.co.uk/community/i...seeking-info-on-closure-dates-near-doncaster/
Closure date of the LMS branch to Rossington Colliery - 31-May-1972
This is possibly related to the introduction of MGR trains around the same time - there's a brief mention here -
https://www.nmrs.org.uk/mines-map/c...les/yorkshire-coalfield/doncaster/rossington/
On the surface a rapid loading scheme for merry-go-round trains opened in 1971.
A google search brings up an Amberley book called
Doncaster's Railways by John Law, which mentions that the box at Black Carr Sidings East controlled the LMS connection direct to Rossington colliery, but that this connection had closed "prior to the period covered by this book" (given as 1967-2017 in the introduction).
A signalling diagram of Black Carr Sidings East can be found listed under the Dearne Valley Railway section of this page -
http://www.lymmobservatory.net/railways/sbdiagrams/sbdiagrams new 1.htm
Comparing that signal box diagram with a schematic map of the junctions around Black Carr in a little 1975 Dalesman book by C.T. Goode
Railways in South Yorkshire it appears that any traffic from Rossington using the LMS connection would have ended up in Black Carr sidings, which gave access to the Dearne Valley at the west end, or Bessacarr Jn at the east end. I don't think there was any access to Down Decoy from the vicinity of the current Flyover West Jn until the 1977 remodelling in preparation for the opening of Doncaster PSB, so it wouldn't have been a useful route for MGR traffic trying to reach Aire Valley or Trent Valley power stations. The RMWeb post linked earlier gives a 1972 closure date for Black Carr West to Bessacarr, which would match a 1972 closure date for the LMS branch - with Black Carr West to Bessacarr closed the LMS branch from Rossington would have been joining onto a closed line.
There are some signalling notices (93 1977 and 95 1977) which help explain the remodelling of this area (including the reopening of Black Carr East to Bessacarr as part of the route from the Down Side of the ECML over the flyover to Lincoln) on this page of the Signalling Record Society website if you search for "Black Carr" -
https://www.s-r-s.org.uk/ArchiveSignals/brer.php
After this remodelling it would have been useful if trains from Rossington could have used the former LMS connection to access Down Decoy without the run round that the surviving GNR branch required, but one possible reason for the survival of the GNR route instead of the LMS is that the M18 (this section completed in 1979 according to wikipedia) was already planned to cut across the LMS line. I think you can still make out the route of the LMS branch on Google maps.
In the 1977 Baker Atlas both the LMS and GNR connections out of Rossington are shown (although the LMS one would have already been closed if the above is correct). The next edition from 1978/1979 shows only the GNR connection remaining. There is also a connection into Yorkshire Main colliery shown from St Catherine's junction - a south to west chord onto the route of the Dearne Valley railway, the trackbed of which is still clearly visible on Google maps.
2 - The GNR branch to west to Rossington colliery. I believe this opened in 1913 but its reported closure / reopening dates are inconsistent, does anyone know the definitive dates ?
According to an Oakwood Press book
The South Yorkshire Joint Railway and the Coalfield Rossington colliery began production in 1917 and the link to the ECML opened in 1918. The RCH junction diagram of Doncaster for 1914 doesn't show any colliery connections. A later, undated diagram in the
Ian Allan Pre-Grouping Atlas and RCH Junction Diagrams shows the GNR link to the ECML.
My edition of the Cobb atlas has the GNR branch closed in the 1970s and the LMS branch closed from 1972 to 1994, but this doesn't really make sense - from what I can gather it appears the LMS branch closed in 1972 and stayed closed, while the GNR connection to the ECML presumably remained open throughout for MGR traffic until the closure of the colliery (and then for the current waste traffic to Roxby). The line is mentioned in a couple of BLS reports, one from 1989 and another from 2019:
https://www.branchline.uk/fixture-report.php?id=1384 and
https://www.branchline.uk/fixture-report.php?id=1327
I suspect that once the rapid loader had been installed in 1971 the layout at Rossington remained unchanged until closure, with all trains using the GNR branch.
3 - On some maps there is a short branch running NE into Bessacarr from the end section of the (ex) Dearne Valley Line, between Flyover West Junc and Bessacar Junc. What was this for and when was it opened and closed ?
This is clearly visible on the RailmapOnline maps -
https://railmaponline.com/UKIEMap.php and it's also marked as a ground frame on the signalling diagram for Black Carr Sidings East.
In another little book by C.T. Goode -
The Dearne Valley Railway he mentions the single track Dearne Valley Railway bridge which allowed trains heading to Lincoln to cross the then main Doncaster - Lincoln lines on a flyover before joining them - so a train from the Dearne Valley towards Lincoln would first cross the ECML on the other flyover that remains today, and then the Lincoln lines on a second, single track flyover. In the book he says:
As the single line curved round to join the Joint line at Bessacarr Jc. there was one final touch in the shape of a ground frame and siding off to the Bessacarr Gravel Company's quarry, odd in that the entrance was facing to normal running
There's no mention of opening and closure dates - with it being a siding rather than a branch as such I think it would be hard to find out. The historical OS maps at
https://maps.nls.uk/os/ don't seem to be particularly helpful. Possibly there are records of the original private siding agreement in an archive somewhere. The area of the quarry itself appears to have been built over with housing many years ago.