Super low45

Super Low45 (SL45) is our newest product, which comes under our Rail Freight Wagon products, so we have given a dedicated page for more detail.

SL45 is a permanently-coupled, twin-platform, low height container carrier capable of conveying 45ft (13.6m) x 9ft 6in x 2500mm containers or swap-bodies within the Network Rail static Loading Gauge designated ‘W8’. SL45 can also transport 40ft, 30ft or 2 x 20ft containers, if required.W.H. Davis studied the UK-market for container movements by rail and for that the requirement for movement of ‘deep-sea’ 20ft, 30ft or 40ft x 8ft 6in high containers was generally satisfied by the use of existing ‘standard’ 60ft flat deck container carrying wagons, supported by a number of low-deck/small wheel wagons together with a quantity of ‘pocket’ or ‘well’ wagons to cater, where necessary, for 40ft x 9ft 6in high boxes on restricted-gauge routes.

However, the survey noted that major global shippers were becoming concerned about a continuing inability to move (from ports), the newer 45ft x 9ft 6in high containers which were increasingly becoming the dominant box-size, particularly on ‘short-sea’ routes to/from mainland Europe.

W.H. Davis design-engineers evaluated several possible solutions and eventually concluded that the most appropriate way forward lay in a wagon designed with a full-length, low-height deck. Such a design would be capable of transporting various permutations of 9ft 6in high containers within the Network Rail ‘universal’ UK gauge designated ‘W8’.

Project SL45

Project SL45 called for a radical new design of bogie and W.H. Davis became aware of the development by Standard Car Truck Europe (SCTE) of such a new track-friendly, small-wheel design. W.H. Davis entered into negotiation with SCTE for the procurement of four bogies to be used with a prototype SL45.

The superstructure design and technical working drawings of SL45 were duly completed and this allowed W.H. Davis to confirm to interested operators (and end-users), that when compared with existing wagons/routes (on average) a train composed entirely of SL45 would convey an additional 4 x 45ft containers within permitted Network Rail Train Lengths.

Four new design, track-friendly bogies were received from SCTE which W.H. Davis to complete manufacture of the prototype SL45.

Network Rail had been commissioned to undertake the lengthy process of statutory static and dynamic testing which is required to gain approval under the new EU Directive ‘Technical Standards for Interoperability' (TSI). During this time, a temporary certificate was issued which allowed the prototype to accumulate over 30,000 miles of operational running completed. Final approval was given by the Office of Rail Regulation (ORR) in December 2010.


  • 45ft containers can now be moved by rail to most UK destinations
  • Every additional container moved benefits the congested UK road network
  • UK carbon footprint improved
  • Greater efficiency at ports by faster removal of containers
  • SL45 is approved to operate at 75mph both loaded and empty
  • On specific routes, SL45 can convey containers over 10ft high
  • Network Rail Route Availability 2 (RA2)
  • Network Rail Track Access Band 6
  • Track Access Charge reduction of 10-15% (when compared with existing wagons in lower TAC bands)
  • UK/Mainland European movements possible if Approval granted


Even today (2011), all movements of 45ft containers to destinations served by rail routes designated ‘W8’ are still moved by road, as prior to the ‘approval’ (Regulatory Certification) of SL45 in December 2010, no wagon design existed to cater for these restricted UK gauges.     

SL45 thus provides an ‘instant’ solution to move these ‘High Cube’ containers by rail within the UK (W8 gauge) and so provides the means of removing significant road journeys/miles to enable a reduction in the UK carbon footprint.

With regard to the cost of maintenance (always a concern for operators when small diameter wheels are offered), after 30,000 miles of operational service, prototype SL45 displayed no measureable wheel wear.

Additionally, subject to ‘mainland European’ regulatory certification/approval, SL45 would provide significant additional rail volume through the Channel Tunnel direct to the end-user terminal or distribution centre, without the need to tranship containers upon entry to the UK.

Super low45 Super low45


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Wagon conversion

Wagon conversion

W H Davis offer complete repair and refurbishment at their Langwith junction works with full shotblasting and painting facility from general repairs to full conversions…