An enquiry about the branch/sidings on the exit from St Helens Central in the Wigan direction- I think this is the stump of the former Rainford/Ormskirk line?
This remnant of the line to Rainford/Ormskirk served the huge Pilkinton's Cowley Hill glass works. Mainly for sand wagons, but also lime and of course coal in its day.
After reading this thread I found some interesting photos of traffic to the three freight terminals at St Helens that survived in active use into the 90s - Cowley Hill and Ravenhead oil terminals, and Sutton Oak chemicals plant.
There's a picture of the oil terminal at Cowley Hill here in 1992 -
https://www.flickr.com/photos/8arail/51021728268/
I'm not sure when the last oil train ran to this terminal, I think the majority of operations ceased at the Cowley Hill site sometime around the end of 2013 but I think the last train had run possibly a few years before that.
The most recent photo I can find of a Cowley Hill oil working is this one from 2005 -
https://www.flickr.com/photos/mauretania/5862303223/
There's a photo of the other Pilkington oil terminal at Ravenhead here (date shows 2012 which must be wrong considering the traction) -
https://www.flickr.com/photos/terry47401/8160688305
The layout here was amended in 1992 (due a road scheme in the area) and the terminal was connected to the main line south of St Helens Central instead of being accessed from Ravenhead Junction.
The sidings stopped receiving oil traffic sometime between 2003-2006 I think, and were then reopened for sand traffic in box wagons from Middleton Towers -
https://www.flickr.com/photos/127646831@N03/27578108821/
A search for "Ravenhead oil" on flickr brings up a few interesting 1980s images of workings from Robeston with 25s and 47s (via Hereford and Crewe).
Prior to the 1992 changes, the Ravenhead terminal was accessed from Ravenhead Junction on the former St. Helens and Runcorn Gap Railway (map here):
http://disused-stations.org.uk/r/runcorn_gap/index.shtml
Ravenhead Junction, line continuing towards Sutton Oak chemicals plant (line from Ravenhead sidings from bottom right, from St Helens Central bottom left):
https://www.flickr.com/photos/ingythewingy/52460312
Ravenhead Junction looking in the other direction, with Ravenhead Sidings to the left and St Helens Central to the right:
https://www.flickr.com/photos/ingythewingy/8612469609/in/photostream/
Ravenhead Junction signal box diagram:
https://www.flickr.com/photos/ingythewingy/5246031499/in/photostream/
Most of those photos are part of a group of very interesting images concerning the St. Helens and Runcorn Gap Railway -
https://www.flickr.com/groups/2159413@N22/pool/
St. Helens Station signal box diagram from 1988, with the line to Ravenhead Jn bottom left, access to Cowley Hill by ground frame top right:
https://www.flickr.com/photos/ingythewingy/8612061657/
Paul Shannon in
Bulk Freight (Rail Freight since 1968) says there were sand trains from Oakamoor to Ravenhead until August 1988. Searching for "Oakamoor Ravenhead" on flickr brings up some nice images of this train with 25s and 40s on vacuum braked wagons. Apparently these were replaced by air braked PAA hoppers in 1985.
Class 47 on PAAs at Crewe a few weeks before the traffic ended -
https://www.flickr.com/photos/53055234@N08/33757408836/
The last surviving traffic on the line through the former Ravenhead Junction was Sulphuric Acid in tank wagons from the Hays Chemicals plant at Sutton Oak to Dalry -
https://www.flickr.com/photos/terry47401/51073427618/
This lasted until 2002, with small volumes (one or two tanks at a time) being tripped to Warrington and then on a trunk Speedlink / Enterprise service to Mossend.
https://www.flickr.com/photos/8arail/51727347884/
There was an old VHS cab ride video (Part of the Railvision North West Cab Ride series, filmed in the early 90s I think) on a Class 47 running light from the old Arpley loco holding sidings, via the curve at Ince Moss (Wigan) right into the Sutton Oak terminal (two fairly short sidings with a loading rack between for filling the tanks), then returning with loaded tanks to Arpley.
I'm not especially familiar with rail freight in the area prior to the 90s, but a search on flickr for "St Helens Shaw Street" brings up some nostalgic images of ballast workings in the goods yard with a variety of traction.