Editing Freightliner Group (section)

===Return to British Railways===
The [[Transport Act 1978]] brought Freightliner back inside the control of British Railways, mostly driven by the investment required to 
ease the rail network's [[loading gauge]] restrictions that hampered the transport of shipping containers {{convert|8|ft|6|in|abbr=on}} and {{convert|9|ft|abbr=on}} in height.<ref name=RailArch50/>

Freightliner immediately made a major pitch to the BR Board to allow 8&nbsp;ft 6&nbsp;in contains to be carried on the [[East Coast Main Line]] (ECML), which involved lowering the track in {{clarify span|text=Stoke area|reason=Is this is a reference to Stoke Tunnel near Grantham?|date=January 2023}}, as well as in Peascliffe and [[Penmanshiel Tunnel|Penmanshiel]] tunnels (in [[Lincolnshire]] and the [[Scottish Borders]], respectively). The alterations were successfully completed at Stoke and Peascliffe, but Penmanshiel Tunnel [[Penmanshiel Tunnel#Tunnel collapse (1979)|collapsed in March 1979]] while work was underway, killing two workers and severing the ECML between [[Edinburgh Waverley railway station|Edinburgh]] and [[Berwick-upon-Tweed railway station|Berwick]].<ref name=mcN>{{cite book |last1=McNaughton |first1=Lt. Col. I.K.A. |title=Report on the Collapse of Penmanshiel Tunnel that occurred on 17th March 1979 in the Scottish Region British Railways |date=2 August 1983 |publisher=Her Majesty's Stationery Office |location=London |url=https://www.railwaysarchive.co.uk/documents/MoT_Penmanshiel1979.pdf |access-date=2 January 2023 |format=PDF |isbn=0-1155-0626-8}}</ref> The extent of the collapse meant that reconstruction was considered to be too dangerous and expensive, so the tunnel was bypassed by a new section of line constructed in an open cutting slightly to the west of the original alignment that opened five months later in late August.<ref name=mcN /> Freightliner later withdraw its services on that stretch of the ECML.<ref name=RailArch50/>

During the 1980s, Freighliner became part of BR's 1980s non-bulk [[Railfreight Distribution]] (RfD) division, which brought about its first ever allocation of locomotives. After experimenting with other rail operators solutions to coping with the new larger containers, in 1990 BR agreed the order of 700 flat-wagons from [[SNCF]] supplier [[Arbel Fauvet Rail]], which could immediately accommodate 8&nbsp;ft 6inch height containers at 75&nbsp;mph speeds.<ref name=RailArch50/> This was further supplemented in 1991 with leased flat-wagons from [[Tiphook]].<ref name=RailArch50/> Further experimentation with SNCF-leased Multifret flat-wagons {{ndash}} which could accommodate 9&nbsp;ft containers at speeds of up to {{convert|90|mph|abbr=on}} {{ndash}} led to an order of 45 BR-specified "Lowliner" wagons with a deck height of only {{convert|720|mm|ftin|abbr=on}}, which allowed the transport of {{avoid wrap|9-foot-high}} containers on routes approved for 8&nbsp;ft 6&nbsp;in containers using the existing wagon fleet.<ref name=RailArch50/>

Although designed to accommodate 9&nbsp;ft containers over the entire BR network, the slow delivery of Lowliners meant that the entire allocation was utilised instead to carry 8&nbsp;ft 6&nbsp;in containers on trains to and from [[London Thamesport]], circumventing the restricted clearances on the former [[South Eastern & Chatham Railway]].<ref name=RailArch50/> The withdrawal of [[Sealink|Sealink's]] dedicated freight service from Holyhead also brought about the end of Freightliner's dedicated service to Northern Ireland via North Wales.<ref name=RailArch50/>