BR(SR) Maunsell Push-Pull Coaching Stock — The Last Steam-Hauled Branch-Line Sets on the Southern

Quick Takeaways

• Twenty sets built: British Railways converted exactly 20 Maunsell corridor coaches into two-coach push-pull sets at Lancing Carriage Works between October 1959 and February 1961.
• Conversions only, not new builds: Both vehicle types — the Driving Brake Corridor Composite and the Trailer Second Open — were converted from 1930–1935 flush-sided Maunsell coaches, not constructed from scratch.
• Pneumatic control system: All sets used the LBSCR-derived compressed-air push-pull control system, operated via three air pipes and a Westinghouse pump on the locomotive.
• Two motive power classes: The LSWR M7 class 0-4-4T served the South Western and Central Divisions; the SECR H class 0-4-4T worked the South Eastern Division routes.
• BR(S) Green exclusively: All 20 sets ran throughout their lives in British Railways Southern Region green — none ever operated in push-pull form in Southern Railway livery.
• Three survivors at Swanage: BCK No. 6699, BCK No. 6697 (underframe only), and SO No. 1323 survive at the Swanage Railway, though none is currently operational.
• Hornby OO gauge coverage: Hornby produced multiple coach pack releases from 2012 onwards under catalogue number series R4534, making this one of the more accessible Southern Region branch-line prototypes to model.

Historical Background and Introduction

The Southern Railway — and then British Railways Southern Region — operated push-pull trains, also called motor trains or pull-push sets, on its branch and secondary lines from the early twentieth century. The principle was simple: equip a passenger coach with a driver's cab at one end so that the locomotive need not run round at terminus stations. The locomotive shunted to one end at the start of the day, the driver crossed to the coach cab for one direction of running, and the train could reverse without any shunting at all. On single-line branches with tight turnaround times, this was an enormous operational saving.

The Southern Railway inherited three incompatible push-pull control systems from its three main constituents: the London and South Western Railway's mechanical cable-and-pulley arrangement, the South Eastern and Chatham Railway's similar wire-based system, and the London Brighton and South Coast Railway's compressed-air pneumatic apparatus. Richard Maunsell, who served as SR Chief Mechanical Engineer from 1923 to 1937, rationalised this inherited chaos by standardising on the LBSCR pneumatic system as the most reliable of the three. Between 1930 and 1937, Maunsell oversaw the conversion of 36 M7 class 0-4-4T locomotives to air-push-pull equipment, but the coaching stock remained overwhelmingly pre-grouping throughout the Southern era.

By the mid-1950s this situation had become critical. British Railways management identified that all 46 surviving Southern Region pull-push sets were over 30 years old, wooden-bodied, and condemned under BTC rolling stock age limits. A small interim measure had been taken between 1949 and 1952, when five two-coach sets (numbered 381–385) were created using LSWR "Ironclad" 58ft coaches built in 1925. These sets comprised Brake Composites to SR Diagram 416 paired with six-compartment Brake Thirds to SR Diagram 137, and were allocated to Western Section duties. Set 384 met a premature end on 2 November 1963 when it was involved in a collision at Brockenhurst involving M7 No. 30053. The remainder were withdrawn between 1957 and 1959.

The longer-term solution came with the conversion programme of 1959–1961. The Kent Coast electrification was displacing Maunsell corridor coaches from main-line duties, and the cascaded vehicles were in good structural condition despite their age. Converting them into push-pull sets was cheaper than ordering new vehicles and faster than waiting for DMUs, which were already on order but insufficient in number. The work was authorised under Works Orders L4634 (June 1959) and L4746 (February 1960) and carried out at Lancing Carriage Works in Sussex. The first set, No. 600, was outshopped on 2 October 1959. The last, No. 614, emerged on 17 February 1961.

Design, Construction, and Technical Specifications

Each set comprised exactly two vehicles: a Driving Brake Corridor Composite (DBCK) and a Trailer Second Open (TSO). The combination was deliberate — the Composite provided First class accommodation for the minority who wanted it, while the Open Second maximised Third/Second class capacity in an accessible, open-saloon layout well suited to short journeys.

The DBCKs were converted from Diagram 2403 Brake Corridor Composites, specifically from Lot 799 built in 1935. These were flush-sided "Pattern 3" Maunsell coaches — recognisable by their smooth steel cladding without the earlier stepped waist profile. The conversion involved removing the corridor gangway at the brake end, plating over the corridor connection, cutting two forward observation windows into the new driving end, fitting a driver's wiper on the nearside window, replacing the guard's duckets with droplights, and installing the air-control valve gear and pipework. Inside, the accommodation comprised two First class compartments (three seats per side, 7ft 1in wide) and four Second class compartments (four seats per side, 6ft 3in wide), totalling 12 First and 32 Second class seats, with a small remaining brake/guard's area. All Pullman gangway fittings were removed from the driving end, though the inner gangway connecting to the TSO was retained.

The TSOs were converted from Diagram 2005 Open Thirds, reclassified as Diagram 2023 Open Seconds following the abolition of Third class on 3 June 1956. These coaches came from Lots 461 (1930) and 706 (1933), representing two slightly earlier construction batches with the characteristic Maunsell low-corridor-window profile. The open saloon layout — seven bays divided into three saloon sections — seated 56 Second class passengers. The outer gangway was removed and plated, and a set of large electric-stock-pattern buffers was fitted; the inner gangway was retained for connection to the DBCK.

Historical Insight — A Conversion Programme, Not a Build: It is easy to speak loosely of these as "Maunsell push-pull coaches" as if they were designed that way. They were not. The DBCK body began life as an ordinary Brake Corridor Composite hauled by a Merchant Navy on boat trains; the TSO spent its early years in Southern Railway olive green on secondary services. Push-pull operation was the third act of a long career, not the first. This matters when modelling pre-1959 scenes — these bodies were ordinary Maunsell coaches for over two decades before Lancing Carriage Works transformed them.

Sub-types, Diagrams, and Variants

The push-pull sets drew on two distinct source diagrams, and understanding the differences between them helps both historians and modellers get the details right.

The DBCK (Driving Brake Corridor Composite) conversions came exclusively from SR Diagram 2403 Brake Corridor Composites built in 1935 — flush-sided, Pattern 3 vehicles from Lot 799, originally numbered within the 6675–6699 block. Twenty of the 25 coaches from this lot were selected for conversion; the other five remained as ordinary BCKs. The converted vehicles retained their original numbers with the BR 'S' prefix and suffix added (e.g., S6699S). One visible external distinction from the ordinary Maunsell BCK was the driving-end treatment: the plated-over corridor vestibule, the pair of forward observation windows (only the nearside fitted with a wiper), and large electric-stock buffer stocks. The inner end retained its Pullman gangway and standard Maunsell SR buffers.

The TSO (Trailer Second Open) conversions came from SR Diagram 2005 Open Thirds (later Diagram 2023 Open Seconds), sourced from two lots: Lot 461 (1930) and Lot 706 (1933). These represented slightly earlier Pattern 1 construction with the lower corridor window line compared to the 1935 BCKs — a subtle but visible difference. The vehicles were selected from the 1312–1400 number range and had previously been classified as "Loose" (unallocated pool) stock. Their conversion was less radical than the BCKs: removal of both outer gangways, plating of the outer vestibule, and fitting of large buffer stocks at the non-driving end.

Sets 614 to 619 introduced a minor complication. The BCKs for these six sets were not sourced from standard pool Lot 799 stock but from the North Cornwall 'P' sets, where the Lot 799 BCKs had been allocated. When those 'P' sets were disbanded, their BCKs moved into the push-pull programme and the 'P' sets received older replacement BCKs. This means sets 614–619 had the same diagram vehicles as sets 600–613, but arrived via a different operational route.

A small number of sets received post-conversion variations during works visits. By late 1962, UIC yellow First class cantrail bands — a thin yellow stripe along the cantrail above First class windows — were being applied to some BR Southern Region coaches. Confirmed recipients among the push-pull sets include sets 606 (January 1964), 613 (June 1963), and 616 (October 1963). Similarly, air-horns were confirmed fitted to sets 606, 612, 613, 616, and 617. These are details that most general sources overlook entirely and which matter greatly to modellers wishing to depict specific sets accurately.

Service History and Operating Companies

From October 1959, the new push-pull sets filtered out to depots across the Southern Region, relieving and eventually displacing the elderly pre-grouping stock. Allocation was dictated by the push-pull fitted locomotive fleet: M7 tanks on the South Western and Central Divisions, H class tanks on the South Eastern Division.

South Western Division workings formed the operational core. The Brockenhurst–Lymington Pier branch was a principal allocation point, with the steeply graded run down to the ferry terminus ideally suited to push-pull operation. The Wareham–Swanage branch, winding through the Purbeck Hills, was another regular posting. Further west, sets worked the Seaton Junction–Seaton branch in Devon, the Sidmouth Junction–Exmouth line, and the endlessly reversal-prone Yeovil Town–Yeovil Junction shuttle, where the locomotive had previously to run round on every single trip. The Bere Alston–Callington branch in Cornwall was also served, as was the Reading South–Ash–Guildford cross-country route and the Salisbury and Dorset Junction Railway through Fordingbridge.

Central Division sets — typically M7-hauled — worked the Three Bridges–East Grinstead–Tunbridge Wells West route and the steeply graded Oxted–Groombridge–Tunbridge Wells West line, as well as the Brighton–Horsham–Guildford corridor (until August 1961 when Maunsell three-car sets displaced them). The Tunbridge Wells West–Eridge–Hailsham–Polegate–Eastbourne route through the East Sussex Weald was another regular.

On the South Eastern Division, H class tanks headed the sets on the Paddock Wood–Hawkhurst branch (closed 11 June 1961), the Dunton Green–Westerham branch, and the Gravesend–Allhallows-on-Sea branch across the Hoo Peninsula.

On busier workings, sets were strengthened with additional "loose" vehicles marshalled between the locomotive and the fixed pair. An ex-SECR 10-compartment Third (a 100-seater) was the most common addition, or a Second Open sourced from a disbanded set. Air-fitted Passenger and Miscellaneous Vans could also be included. Push-pull formation was always: locomotive + TSO + DBCK (driving end trailing).

Operational Insight — The M7 Monopoly: Only long-framed M7 locomotives could be converted for push-pull work with the Maunsell sets. The Westinghouse air compressor required to maintain reservoir pressure occupied the front of the running plate and needed specific clearances. The Ivatt 2-6-2T — widely used on Southern Region branch duties by the early 1960s — was incompatible with the Maunsell air-control equipment and could only haul the sets as ordinary locomotive-hauled stock.

Withdrawal, Preservation, and Surviving Examples

The operational life of the Maunsell push-pull sets was startlingly brief. Set 607 was the first casualty, written off in September 1961 after collision damage at Eastbourne when its driving end was crushed by C2X locomotive No. 32580 — less than two years into service. Sets 618 and 619 were disbanded in June 1963 for use on the Hayling Island branch, their BCKs repurposed as ordinary brake coaches working with Mk1 Seconds rather than in push-pull mode.

The December 1963 withdrawals removed sets 600, 601, 602, and 605, replaced by the new 3D diesel electric multiple units on the Oxted and East Grinstead routes. Sets 611 and 612 followed in May 1964. The final curtain fell on 1 October 1964, when the last operational sets — 603, 604, 606, 608, 609, 610, 613, 614, 615, 616, and 617 — were all condemned simultaneously. The last confirmed steam push-pull working took place on 16 May 1964 on the Lymington branch, with M7 No. 30052 at the controls.

Most condemned sets passed to scrap merchants, principally Peter Wood & Co. of Queenborough in Kent. No departmental conversions of push-pull vehicles are recorded. Only three vehicles escaped the cutters.

BCK No. 6699 (S6699S), from Set 619, is the most complete survivor. Outshopped in July 1960, disbanded June 1963, used briefly on the Hayling Island branch, and condemned at Romsey on 4 December 1963, this body-complete coach is stored at the Swanage Railway awaiting restoration. The aspiration is to reunite it with SO No. 1323 as a recreated Set 619, paired with M7 No. 30053 — which is also based at Swanage. If you visit Swanage, the coach may be visible in the yards at Herston or Norden, though it is not currently on public display.

BCK No. 6697 (S6697S), from Set 618, also resides at Swanage, but only the underframe survives. The body decayed beyond saving in preservation, and any restoration would require complete body reconstruction.

SO No. 1323 (S1323S), built 1932 and converted for Set 611 in 1960, was condemned at Wivelsfield on 20 April 1964. It too is stored at Swanage awaiting restoration. Note that two sister Maunsell SO vehicles at Swanage — Nos. 1381 and 1346 — are operational but were never converted for push-pull use, making them useful comparators rather than strict survivors of the push-pull fleet.

The Swanage Railway Trust's heritage coach restoration plan has budgeted for the push-pull set as a priority project, but locomotive restorations have taken precedence. No other heritage railway, museum, or private collection holds Maunsell push-pull coaching stock.

Modelling Significance and Scale Replications

The Maunsell push-pull sets punch well above their weight in the modelling world. Twenty sets, 40 coaches, five years of service, three survivors — by any measure, this is a minor footnote. Yet the combination of a distinctive prototype, a romantic branch-line setting, and strong Hornby support has made them one of the more popular Southern Region coaching stock subjects.

Hornby introduced their OO gauge (4mm:1ft, 1:76.2 scale) Maunsell push-pull models in June 2012 under the R4534 coach pack series, and the range has been revisited several times since. Each pack contains one DBCK and one TSO in BR(S) Brunswick Green, correctly identified as Era 5 (1957–1966). The models feature NEM coupling pockets with close-coupling cam, sprung metal buffers, flush glazing, separately applied roof details, and detailed interiors with correctly differentiated First and Second class seating colours.

All releases are Era 5 analogue-ready with NEM pockets suitable for DCC decoder-equipped locomotives. The models are generally well regarded for their accuracy and detailing, though one significant prototype inaccuracy exists: Hornby modelled sets 600 and 610 with air-horns fitted to the driving BCK. In reality, only sets 606, 612, 613, 616, and 617 are confirmed as having received air-horns. Modellers depicting sets 600 or 610 should note this discrepancy.

No Hornby release includes UIC yellow First class cantrail banding — applicable to sets 606, 613, and 616 from late 1962 onwards. Modellers wanting to depict these sets accurately after that date will need to add a thin yellow stripe above the First class windows themselves, using a fine brush or yellow lining tape.

Compatible Hornby M7 class locomotives include R3159 (No. 30055), R3165 (No. 30056), R2504 (No. 30051), and R2505 (No. 30031), all in BR lined black. H class models include R3539 (No. 31518), R3631 (No. 31265), R3731 (No. 31177), and R3763 (No. 1552 in SR black, suited to pre-nationalisation scenes using these same vehicles as ordinary coaches).

No other RTR manufacturer — Bachmann, Accurascale, Dapol, Revolution Trains, or Graham Farish — currently produces or has announced models of this prototype in any scale. In N gauge and O gauge, no RTR Maunsell push-pull models exist.

For kit builders, Branchlines historically offered a conversion kit for the driving BCK in 4mm, though current availability is uncertain. Roxey Mouldings produce etched-brass push-pull stock kits but only for pre-grouping SR types (SECR Birdcage, LBSCR), not the Maunsell conversions. Worsley Works offer etched brass side panels as scratch-building aids across multiple scales and can produce custom artwork on request.

Unique Modelling Tips and Layout Integration

The Maunsell push-pull set is one of the most self-contained and layout-friendly subjects in Southern Region modelling. Two coaches, one locomotive, one branch — and you have one of the most evocative scenes in 1950s and 1960s British railway history. Here is how to make the most of it.

Correct formation matters more than you might think. The prototype formation was always fixed: locomotive at the SO end, driving BCK trailing. This means on your layout, when the set approaches a terminus, the BCK arrives first with the driver looking through the observation windows. The locomotive is at the back, propelling the train. For push-pull working on a model, a DCC sound-fitted M7 or H class with appropriate momentum settings will reward you with realistic coasting and compression sound effects on arrival.

Modelling Tip — Choosing Your Set Number: If you want to model the absolute last days of Southern steam push-pull operation — the summer of 1963 and into 1964 — pick a set that survived to the October 1964 mass withdrawal. Sets 603, 604, 606, 608, 609, 610, 613, 614, 615, 616, and 617 all ran to the end. If you want early 1960s, any set from 600 to 619 is fair game. Sets 618 and 619 were disbanded in June 1963, so avoid them for later scenes. And remember: no Maunsell push-pull set ever ran with yellow cantrail banding before late 1962 — only sets 606, 613, and 616 received it at all.

Route authenticity adds narrative depth. Choosing a specific route for your layout unlocks authentic background detail. A Lymington branch scene suggests reed beds, estuary views, and Brockenhurst junction connection; a Swanage branch scene implies the chalk cutting at Corfe Castle and the Purbeck Hills in the background. For a South Eastern flavour, model the Hawkhurst branch: hop gardens, oast houses, and an H class rather than an M7. These details cost nothing but research and transform a "Southern branch" into a specific, recognisable place.

Strengthened formations open up options. On busier workings, a "loose" additional coach was added to the fixed two-coach set. In OO gauge, you can model this with a Hornby or Bachmann Maunsell Second Open or Third Open placed between the locomotive and the TSO. The result is a three-coach branch set that looks pleasingly substantial without over-stocking a small terminus. An ex-SECR 10-compartment Third — available from Hornby in both SR and BR liveries — is the most prototypically authentic option for South Eastern Division sets.

Scenery and infrastructure tips. Most push-pull branch termini were modest affairs: a single platform, a run-round loop rarely used, a small goods yard, and a platform lamp or two. The locomotive water column was important — M7s needed to take water at termini. A corrugated iron engine shed or even a simple platform canopy gives the right period feel. Southern Region concrete platform furniture (lamp posts, waiting shelters, fencing) is widely available from model suppliers and strongly associated with these routes.

Modelling Tip — Adding the Air Pipes: The three air-control pipes connecting locomotive to the DBCK are a distinctive prototype feature rarely modelled. On the prototype, these ran along the solebar or were clipped to the underframe. A fine length of thin flexible wire or rod painted silver-grey, attached from the locomotive to the TSO buffer beam, adds an authentic touch that will be immediately recognised by Southern Region enthusiasts.

Era accuracy for competition modellers. If you are entering a competition or building an exhibition layout, Era 5 classification covers 1957–1966, which is correct for all Maunsell push-pull operations. The Southern Region abolished First class on many rural branch services during the early 1960s, but the push-pull sets retained their Composite BCKs throughout — the First class compartments were simply not sold on quieter workings. BR(S) Green is the only correct livery; there is no scope for "what if" SR malachite or crimson and cream versions on push-pull stock.

Finally

The Maunsell push-pull sets occupy a paradoxical place in railway history. They were the most modern push-pull coaching stock the Southern Region ever operated, yet they served for barely five years. They were Maunsell designs only in the sense that their bodies were built during his CME tenure — the push-pull conversion itself was entirely a British Railways initiative, born of necessity in the final years of Southern steam. They replaced wooden pre-grouping coaches that had served for thirty years, then were themselves replaced almost immediately by diesel multiple units.

And yet the combination of the smooth flush-sided Maunsell body, the distinctive driving cab end with its two observation windows, and the knowledge that these sets were among the very last steam push-pull coaches to run on the Southern makes them uniquely compelling. On a model railway, a two-coach set trundling into a Hampshire terminus behind an M7 in lined black captures something genuinely true about the texture of British railway life in the early 1960s: economical, practical, a little faded — and unmistakably Southern.

Three of these coaches survive at the Swanage Railway, and the aspiration to recreate Set 619 — pairing BCK No. 6699 and SO No. 1323 behind M7 No. 30053 on the very branch line where their kind once worked daily — remains very much alive. If you can spare a donation to the Swanage Railway Trust's heritage coach fund, you would be contributing directly to the story these pages have told.

For modellers, the Hornby R4534 series is the obvious starting point. Pick your set number carefully, check the air-horn and cantrail details for your chosen era, and choose your route. Then find a Hornby M7 or H class, weather both lightly, and run the pair into your branch terminus. It is as close as most of us will get to a summer morning at Swanage in 1962.

Frequently Asked Questions

Were the Maunsell push-pull coaches purpose-built or converted?

They were conversions. British Railways Southern Region converted 20 surplus Maunsell corridor coaches at Lancing Carriage Works between October 1959 and February 1961 to create sets 600–619. The parent vehicles — Diagram 2403 Brake Corridor Composites (1935) and Diagram 2005 Open Thirds (1930–1933) — had been freed from main-line duties by electrification cascades.

What was the push-pull control system and how did it work on the Maunsell sets?

The sets used the LBSCR-derived pneumatic system, standardised by the Southern Railway under Maunsell. Three air pipes ran the full length of the train. A Westinghouse compressor on the locomotive maintained air reservoir pressure. From the driving cab in the BCK, the driver remotely operated the locomotive's regulator and brakes via compressed-air signals, while the fireman remained on the locomotive footplate throughout.

Which locomotives worked with the Maunsell push-pull sets?

Two classes were used. The LSWR M7 class 0-4-4T worked the South Western and Central Division sets; the SECR H class 0-4-4T operated South Eastern Division duties. Only long-framed M7 locomotives were compatible with the Maunsell air-control equipment. The Ivatt 2-6-2T, though widely used on Southern Region branches, could not operate push-pull with these sets.

Where can I see surviving Maunsell push-pull coaches today?

All three survivors are at the Swanage Railway in Dorset. BCK No. 6699 and SO No. 1323 are stored awaiting restoration; BCK No. 6697 survives as an underframe only. None is currently operational or on formal public display, though they may be visible in the Herston or Norden yards when visiting. The Swanage Railway Trust has a long-term aspiration to restore a complete set.

What Hornby OO gauge models are available of the Maunsell push-pull sets?

Hornby has produced multiple releases under catalogue numbers R3087 (train pack with M7, Set 600), R4534 through R4534E (coach packs covering sets 601, 603, 608, 610, 616, and 619), and R3512 (train pack with H class, Set 602). All are Era 5 in BR(S) Green. Most earlier releases are discontinued but available secondhand; R4534E (Set 601) retails at approximately £72 when in stock.

Are there any known inaccuracies in the Hornby Maunsell push-pull models?

Yes, two notable ones. Hornby fitted air-horns to the driving BCK on sets 600 and 610, but only sets 606, 612, 613, 616, and 617 are confirmed as having received air-horns in service. Additionally, no Hornby release carries UIC yellow First class cantrail banding, which was applied to sets 606, 613, and 616 from late 1962. Modellers depicting those sets in their final years should add this detail themselves.

Are Maunsell push-pull coaches available in N gauge or O gauge?

No ready-to-run models exist in N gauge or O gauge from any manufacturer. In OO gauge, Hornby is the only RTR producer. Bachmann, Accurascale, Dapol, Revolution Trains, and Graham Farish have not produced this prototype. Kit options are limited — Branchlines offered a 4mm conversion kit historically, but availability is currently uncertain. Worsley Works can supply etched brass sides as a scratch-building aid.

What liveries did the Maunsell push-pull coaches carry in service?

Exclusively BR(S) Brunswick Green throughout their push-pull careers (1959–1964). The parent coaches had previously carried SR Maunsell olive green (from new in the 1930s), SR Bulleid malachite green, and BR crimson and cream, but none of these liveries appeared on the converted sets. A small number of sets received UIC yellow First class cantrail banding from late 1962. BR blue/grey was introduced too late to affect these vehicles.

What routes did the Maunsell push-pull sets work on the Southern Region?

They served branch and secondary routes across all three SR operating divisions: Brockenhurst–Lymington Pier, Wareham–Swanage, Seaton Junction–Seaton, and Yeovil Town–Yeovil Junction on the South Western Division; Three Bridges–East Grinstead–Tunbridge Wells West and the Oxted lines on the Central Division; and Paddock Wood–Hawkhurst, Dunton Green–Westerham, and Gravesend–Allhallows on the South Eastern Division.

How did the Maunsell push-pull sets compare to other BR push-pull coaching stock of the era?

The Maunsell sets were broadly contemporary with the BR(W) GWR Autocoach descendants and BR(LM) converted push-pull trailers but differed in their pneumatic control system — GWR and LMS practice used mechanical or vacuum-operated systems. The Maunsell sets offered significantly more comfort than the wooden pre-grouping stock they replaced, with steel-panelled bodies and steam-heat throughout. They were, however, inherently a stopgap rather than a designed solution, which helps explain their brief service life.

When was the last day of steam push-pull operation using Maunsell sets?

The last confirmed steam push-pull working with a Maunsell set took place on 16 May 1964 on the Lymington branch, with M7 No. 30052. Push-pull operation on the Swanage branch and the Salisbury and Dorset Junction Railway had ended on 2 May 1964. The remaining sets continued running as ordinary locomotive-hauled pairs until the mass withdrawal of 1 October 1964.

What is the correct formation for modelling a Maunsell push-pull set?

The correct formation is always: locomotive + TSO (Trailer Second Open) + DBCK (Driving Brake Corridor Composite, driving end trailing). For a strengthened working, add a loose trailer — ideally a Maunsell or ex-SECR Second/Third Open — between the locomotive and the TSO. The driving cab end of the BCK should face away from the locomotive at all times, as the driver used the cab when the locomotive was propelling (pushing) the train.