I'd say it's a rare (or at least infrequent) event to get a brand new private siding connection to the network installed, with associated resignalling and expense. A high-profile example that springs to mind (albeit from a few years ago) was the opening of the "East Midlands Gateway" (EMG) container terminal in 2020, on a large site near East Midlands Airport. It currently handles four trains a day from the ports (3 from Felixstowe, 1 from Southampton). It's classed as a "Strategic Railfreight Interchange." I think the general idea is that this type of infrastructure would be self-funding from the large amount of warehousing involved, although government probably pay for things like associated local road improvements. Providing rail facilities will be a key factor in getting planning permission in the first place. The containers on the trains will be eligible for "modal shift revenue support" from the government, in the form of a payment per container to offset the higher cost of moving them by rail. Freight Facilities grants for terminal infrastructure are available in Wales and Scotland but not England.
https://www.maritimetransport.com/n...ands-gateway-terminal-on-track-for-completion
https://www.slp-emg.com/
The terminal seems to be a success and has expanded slightly in a "phase 2" project which involved a couple more sidings and a second concrete pad for container loading and storage.
https://www.winvic.co.uk/case-studi...-east-midlands-gateway-rail-terminal-phase-2/
(The above link about phase 2 at EMG also links to further information on similar projects at "DIRFT III" and the Northampton project mentioned above).
Almost adjacent to the East Midlands Gateway site is its evil twin, the East Midlands Distribution Centre at Castle Donington, completed at the end of 2011. Despite including "a rail freight terminal with two 450m sidings, plus installation of a rail connection, signalling, rail track and ballast as well as construction of a dedicated rail off-loading zone complete with 2km of new rail track" I don't think it has ever seen a revenue-earning freight train conveying any products to or from the associated warehousing (most notably for M&S).
https://www.winvic.co.uk/case-studies/east-midlands-distribution-centre-castle-donington/
It's often used as an example of a situation where a rail terminal is built to secure planning permission, without there necessarily being firm plans to use it. However, in a further plot twist, the rail connection into Castle Donington has not been entirely wasted. The rail connection from EMG joins the main line facing west, and the run round loop at the entrance to Castle Donington is used to enable trains from EMG to run round and head east towards Felixstowe, avoiding the need to detour via Birmingham (providing the trains are gauge-cleared for the route via Loughborough - 2 out of the 3 Felixstowe services go this way currently).
While brand new private siding connections tend to be reserved for larger projects, a more common scenario is the re-use of existing connections into disused sidings, which do not require signalling alterations. In this way new terminals can be created with minimal outlay on new infrastructure. Unless a press release is sent out, these may not attract much attention. For example, a new terminal opened at Langley for Brett Aggregates last year:
In West London, a new Brett rail siding at Langley has been open and running since May 2023. It services customers for sand and gravel with material railed in from our marine wharves. There is room to expand on the site and we are keen to broaden the scope of the operations there. (Brett Aggregates Newsletter April 2024)
The Langley aggregate terminal is on the site of a former oil terminal which used to receive trains of aviation fuel from Lindsey Refinery (Humberside) for Heathrow Airport. Langley oil terminal was replaced by a facility at Colnbrook which is still rail-served, currently from the Isle of Grain. Langley sidings were later used as a base for loading contractors materials onto engineers trains during the electrification of the Great Western Main Line, but it's good to see them back in use as a rail freight terminal. Capital Concrete (joint venture between Brett Aggregates and Breedon) have also secured planning permission for a concrete batching plant on the site which will take in aggregate by rail and is probably in use by now. The terminal is served by trains of sea-dredged aggregates from both Cliffe and Newhaven.
Another terminal opened fairly recently (although perhaps slightly earlier than 2023) was the facility serving "
Quattro" within Acton Yard (aggregate supply and a concrete plant). This is a second stone terminal in the yard, in addition to the existing Foster Yeoman (now Aggregate Industries) hopper discharge facility. The new Quattro terminal involved minor track alterations to sidings in the yard, but I don't think it required any changes to signalling.
Freight terminals are recognised to be strategic assets, and closed terminals in useful locations are often retained for possible future re-use. With the exception of larger projects, any company looking to set up a new railfreight terminal would probably consider existing sites first (planning permission would be easier for a start). These are some Network Rail documents detailing freight terminals of various types, both active and inactive:
https://www.networkrail.co.uk/wp-content/uploads/2016/12/Intermodal-rail-sites.pdf
https://www.networkrail.co.uk/wp-co...work-Rail-freight-map-construction-sector.pdf
https://www.networkrail.co.uk/wp-content/uploads/2022/02/Network-Rail-freight-map-other-sectors.pdf
This "Target 26" document gives some interesting detail on proposed enhancements to allow longer 26-wagon trains of construction materials in London, giving some idea of the work involved even for fairly minor changes to sidings:
https://www.networkrail.co.uk/wp-content/uploads/2022/02/Target-26.pdf
