Southern Railway's pioneering "Booster" electric locomotives

Historical Background and Context

The genesis of the Class CC locomotives emerged from the remarkable partnership between Oliver Bulleid, appointed Southern Railway Chief Mechanical Engineer in 1937, and Alfred Raworth, the brilliant Chief Electrical Engineer whose innovations had transformed Southern electrification since the 1920s. By the late 1930s, the Southern Railway operated approximately 540 route miles of third-rail electrified network at 660V DC—the world's largest electric suburban railway system—yet possessed no electric locomotive capability for freight or non-fixed-formation passenger work.

Raworth initially proposed dedicated goods locomotives to address the Southern's increasing freight demands, particularly coal traffic from the Kent coalfield and port operations at Southampton, Newhaven, and Dover. However, Bulleid intervened decisively, advocating for mixed-traffic locomotives capable of both heavy freight and express passenger services. This fundamental shift from pure goods to versatile mixed-traffic duty shaped the class's entire design philosophy and subsequent operational career, enabling the locomotives to work prestigious boat trains alongside mundane goods formations.

The fundamental engineering challenge confronting Raworth was the "gapping" problem unique to third-rail electric locomotives. Unlike electric multiple units with collector shoes spread across multiple vehicles maintaining continuous power pickup, a locomotive's shoes spanned a much shorter distance. This meant power supply could be lost entirely when crossing gaps in the conductor rail at points, crossings, and complex junction work—precisely the locations where continuous power was most critical for maintaining heavy train momentum.

Raworth's elegant solution represented revolutionary thinking. Rather than feeding traction motors directly from third-rail current as conventional electric traction practice dictated, he designed a motor-generator-flywheel "booster" system. Third-rail power drove large motor-generator sets with heavy flywheels, and when supply was briefly lost during gapping, the flywheel's stored kinetic energy kept generators turning, maintaining uninterrupted power to the traction motors. This sophisticated system also enabled voltage boosting to approximately 1,200V DC by combining generator output with third-rail supply, delivering enhanced performance without exceeding the civil engineering department's axle loading restrictions.

Construction began amid the desperate material shortages and competing priorities of wartime Britain. In October 1940, the War Cabinet ordered all new locomotive construction halted to conserve scarce resources for the war effort. However, CC1 and CC2 received specific exemption because the promised savings in labour and fuel over equivalent steam traction served strategic national interests. Despite this exemption, construction halted several times during 1940-1941 as steel, copper, and skilled labour were diverted to more immediately critical war production.

CC1 finally emerged from Ashford Works in 1941 in striking photographic grey livery with distinctive horizontal "speed whiskers" striping culminating at each cab end. The cab windows received metal blackout plates reducing their aperture—a grim reminder of the war conditions under which the locomotive entered service. Contemporary Southern Railway publicity materials celebrated this pioneering machine as demonstrating the company's innovative spirit and technical leadership, though wartime restrictions prevented the extensive publicity campaign the achievement warranted.

CC2 followed in 1945 after prolonged delays caused by continued material shortages and competing military priorities. This locomotive appeared directly in the Southern's elegant malachite green with "Sunshine" Southern lettering—a return to peacetime corporate image that symbolised approaching victory. C.M. Cock, who had succeeded Raworth as Chief Electrical Engineer, incorporated slight modifications based on CC1's operational experience, though the fundamental booster system design remained Raworth's original conception.

The locomotives utilised Southern Railway's adaptation of the French UIC classification system, where "C" denoted three driven axles per bogie. The "CC" designation—indicating two three-axle bogies providing the Co-Co wheel arrangement—reflected Bulleid's continental experience from his pre-First World War tenure at Westinghouse Electric's French branch and his wartime rail operating department service. This nomenclature distinguished Southern electric locomotives from the company's traditional numerical series whilst providing immediate indication of wheel arrangement to operating staff.

Design and Technical Specifications

The engineering sophistication of the Class CC design lay in the masterful integration of Bulleid's mechanical expertise with Raworth's electrical innovation. At the mechanical foundation sat the Co-Co wheel arrangement—three driven axles per bogie distributed across two six-wheel power bogies. This configuration emerged from necessity rather than choice: the Southern Railway's Permanent Way department mandated maximum axle loading restrictions reflecting the company's extensive infrastructure built during the Victorian era when civil engineering standards were less demanding than modern practice.

The original design specification called for Bo-Bo arrangement (two axles per bogie, four driven axles total), which would have created a more compact and lighter locomotive. However, distributing the substantial weight necessary for a practical mixed-traffic electric locomotive across just four axles would have exceeded permissible loadings. The Co-Co arrangement distributed weight across six axles instead, reducing individual axle loading to acceptable levels whilst providing the extended wheelbase that improved riding characteristics at speed.

Power output for CC1 and CC2 reached 1,470 hp (1,100 kW) delivered through six English Electric EE519-A traction motors producing 245 hp each. These DC series-wound motors received power from the booster control system rather than directly from the third rail, creating the locomotive's fundamental technical distinction from conventional electric traction. Maximum speed was specified at 75 mph—matching the civil engineer's permitted maximum for freight-rated locomotives on Southern Railway infrastructure—though the locomotives proved capable of exceeding this when circumstances demanded.

The revolutionary booster control system distinguished these locomotives from all previous British electric traction. The 26-tap controller changed resistances in the generator field coils rather than inserting large resistances in the power lines to the motors—the conventional resistance control method that generated substantial waste heat requiring heavy, bulky equipment. Raworth's field control approach meant unrequired power was simply not generated rather than being "burned off" as heat, making construction lighter and maintenance considerably easier whilst improving overall system efficiency.

Each locomotive carried two complete booster sets, one mounted in each bogie. Each set comprised a motor driven by third-rail supply (or pantograph when available), coupled to a heavy flywheel and a DC generator feeding the three traction motors in that bogie. The flywheels weighed several hundred pounds each—mass sufficient to maintain generator rotation for several seconds after supply interruption, bridging the brief gaps encountered at complex pointwork. The system proved remarkably effective, though it required attentive driving to ensure locomotives were not brought to a complete halt whilst gapping, which would allow the booster sets to run down completely.

For passenger work requiring train heating, each locomotive carried an electrically heated Bastian & Allen boiler providing steam for coaching stock heating systems. The boiler installation was completely partitioned from electrical equipment to prevent any possibility of water or steam ingress damaging sensitive components—a design precaution reflecting the Southern's rigorous safety standards and attention to reliability in a prototype design where operational experience was necessarily limited.

The third locomotive, 20003, emerged from Brighton Works in 1948 under British Railways ownership with notable technical and aesthetic differences. S.B. Warder—later Chief Electrical Engineer of the British Transport Commission and architect of Britain's 25kV AC overhead electrification system—served as Southern Railway Electrical Engineer during its design and incorporated accumulated operational experience from CC1 and CC2. The locomotive featured upgraded English Electric EE519/4D traction motors producing 265 hp each (compared to 245 hp), heavier flywheels adding approximately 200 lb per booster set, a larger water tank for the steam heating boiler, and increased design speed of 85 mph reflecting confidence in the proven mechanical design.

Externally, 20003 departed dramatically from its sisters' appearance. Rather than the gracefully curved cab ends styled after earlier EMU practice, 20003 featured slab-fronted cabs virtually identical to the contemporary 4SUB electric multiple units. This simpler construction reflected both the availability of existing 4SUB jigs at Brighton Works (enabling rapid, economical construction) and a pragmatic post-war approach emphasising cost-effectiveness over aesthetic refinement. The different cab styling makes 20003 immediately recognisable in photographs and creates challenges for modellers seeking to represent all three class members, as current tooling covers only the original CC1/CC2 design.

The mechanical construction followed Derby Works standards of robust simplicity. Inside plate frames provided rigid support for all mechanical components. The bogies employed conventional equalised suspension with helical springs and hydraulic dampers, delivering acceptable ride quality at speed whilst maintaining good adhesion during heavy haulage. The BFB (blind, flanged, blind) wheel pattern—flanged centre wheels with flangeless outer and inner wheels—enabled negotiation of curved track whilst minimising flange wear and noise.

Service History and Operations

CC1 entered service during 1941 primarily on wartime freight trials, supporting the vastly increased goods traffic flowing to south coast ports that supplied the Allied war effort. Before hostilities, Southern Railway traffic divided roughly 75% passenger to 25% freight; during the war, freight expanded to approximately 60% of total traffic whilst passenger numbers paradoxically remained similar despite severe operational restrictions. The locomotive's ability to haul 1,000-ton freight trains proved invaluable during this critical period, validating Raworth's booster concept under the most demanding operational conditions.

The wartime operational context was extraordinary. Britain's railways operated under immense strain, with aging steam locomotives working intensively whilst new construction was severely restricted and maintenance standards inevitably declined due to skilled labour shortages. CC1 represented cutting-edge technology in this desperate environment, demonstrating that innovative engineering could deliver strategic advantages even when conventional procurement was impossible. The locomotive's fuel efficiency compared to steam traction contributed meaningfully to coal conservation efforts—every ton saved represented shipping capacity that could transport military supplies rather than locomotive coal.

CC2 joined its sister in 1945 as war drew to its conclusion, immediately entering mixed-traffic duties across the Southern's electrified network. The two locomotives established themselves in freight operations whilst occasionally appearing on passenger services, building operational confidence in their capabilities and reliability. Contemporary railway periodicals praised their smooth operation and powerful performance, though the constant droning noise from booster sets attracted unfavourable comment from some observers unaccustomed to this distinctive acoustic characteristic.

The class achieved a significant milestone on 15 May 1949 when they assumed regular operation of the London Victoria to Newhaven Marine boat trains—the first electric locomotive-hauled long-distance express passenger trains in Britain. These prestigious workings replaced Brighton Atlantics that had previously worked the service, demonstrating unequivocally that electric locomotives could handle express passenger duties with the reliability and performance commercial operations demanded. The boat trains connected with cross-channel services to Dieppe, carrying international travellers, businessmen, and holidaymakers in formations typically comprising 8-12 vehicles mixing Pullman and first-class accommodation with bogie luggage vans.

Operating primarily from Stewarts Lane depot in South East London, the three locomotives settled into what contemporary accounts described as a "productive but unremarkable life doing exactly what they were designed to do." They routinely handled 1,000-ton freight trains from the Kent coalfield, 750-ton passenger consists including boat trains serving Southampton's ocean liner traffic, and general goods workings across the Southern's electrified network. The locomotives also occasionally hauled royal trains—testament to the confidence placed in their reliability by Southern Railway and subsequently British Railways operating authorities.

Nationalisation on 1st January 1948 brought renumbering to 20001, 20002, and 20003, and classification as Class 70 under British Railways' pre-TOPS locomotive classification scheme. The locomotives passed through multiple liveries documenting their operational career: Southern Railway photographic grey with speed whiskers (CC1 initially), malachite green with "Sunshine" Southern lettering, experimental light blue (Wedgewood blue) briefly applied to 20002 and exhibited at Kensington Addison Road in 1948/49, BR black with silver detailing, BR green with red side stripe, and finally BR Rail Blue with full yellow ends applied to 20001 alone shortly before withdrawal.

Headcode equipment evolved throughout the service career. CC1 and CC2 initially carried stencil panels, but as these proved unsuitable for freight workings (suitable headcodes simply didn't exist), the locomotives received six steam locomotive-style disc positions at each end. 20003 was fitted from new with disc positions. Later, with standardisation bringing comprehensive two-character alphanumeric codes, all three locomotives received roller-blind two-character headcode displays and the disc brackets were removed—though photographs from the 1960s show some locomotives with disc brackets still fitted despite being unused.

Various detail modifications accumulated during the service life. Three sandboxes per bogie were eventually removed from CC1 and CC2, simplifying maintenance without compromising adhesion thanks to the effective traction control provided by booster systems. Multiple unit jumpers and vacuum brake connections appeared at various times. Twin air horns were mounted on 20001's roof during its final years. The Bastian & Allen steam heating boilers required regular maintenance, and locomotives occasionally appeared in service with this equipment isolated when boiler problems developed.

The locomotives' operational capabilities earned respect from footplate crews and operating staff despite their prototype status and unique characteristics. The powerful acceleration from rest impressed observers accustomed to steam locomotive performance, whilst the smooth, vibration-free running at speed contrasted favourably with the rough riding characteristic of many contemporary diesel locomotives. The main operational challenge was managing the booster system—drivers needed to avoid halting on gaps where the flywheels would run down, requiring attentive throttle management and forward planning when approaching complex junction work.

Fleet

Withdrawal and Preservation Legacy

The withdrawal history of the Class 70 locomotives reflects the inevitable obsolescence of prototype designs in an era of rapid technological advancement and fleet standardisation. By the late 1960s, British Railways' modernisation strategy had delivered more powerful and numerous electric locomotive classes—the 2,552 hp Class 71 Bo-Bo locomotives (built 1958-1960 using Swiss practice with a single booster set per locomotive) and the versatile Class 73 electro-diesels capable of operating on both third rail and diesel power—that rendered these pioneering machines increasingly redundant.

The Class 71 locomotives particularly demonstrated the maturity of booster-based electric traction. Building on principles validated by Class 70 operational experience, the later design delivered substantially more power from a more compact, lighter platform whilst retaining the booster system's fundamental advantage of crossing gaps without power interruption. The Class 71 fleet numbered 24 locomotives compared to Class 70's three, providing operational flexibility and maintenance efficiency that prototype classes could never match.

20003 was withdrawn in October 1968, followed by 20002 in December 1968 and 20001 in January 1969. The locomotives had served for between 20 and 28 years—respectable lifespans given their prototype nature and the rapid technological changes transforming British Railways during their operational careers. None received TOPS classification numbers under the Total Operations Processing System implemented during the late 1960s, as their withdrawals preceded the system's complete rollout across electric traction fleets.

All three locomotives were scrapped: 20001 and 20002 at Cashmore's scrapyard in Newport, South Wales; 20003 at Cohen's scrapyard in Kettering, Northamptonshire. No museum preservation, no static display opportunities, no heritage railway rescue—the entire class vanished without a single representative surviving to demonstrate these pioneering machines to future generations. The complete extinction reflected both the locomotives' non-standard nature (making preservation societies reluctant to commit scarce resources) and the unfortunate timing of withdrawals that preceded the preservation movement's dramatic expansion during the 1970s.

However, parts of the electrical equipment survived longer than the complete locomotives. General Electric Company salvaged booster generators and flywheels for use as load simulators at their Preston test facilities, where locomotive traction equipment was dynamically tested under controlled conditions. Remarkably, these components from 1940s technology later tested traction systems for second-series Docklands Light Railway trains during the 1990s, demonstrating the robustness and longevity of Raworth's engineering. One original motor-generator set reportedly survives at Strawberry Hill depot, though its exact provenance and current condition remain uncertain.

The engineering legacy proved more enduring than any physical survivor. The Class 70 programme validated design principles that influenced British electric locomotive development for decades. The booster system's fundamental concept—using stored kinetic energy to bridge gaps in power supply—reappeared in the substantially more powerful Class 71 design. The Class 74 electro-diesels rebuilt from Class 71 locomotives in 1967-1968 retained booster equipment whilst adding diesel engines for non-electrified routes. Though the subsequent Class 73 took a different approach using small diesel engines for gap crossing, the success of Class 70 and 71 in proving electric locomotive viability on third rail informed its development.

Contemporary technical literature from the 1940s-1960s frequently referenced the Class CC design when discussing electric traction development. Raworth's booster control system received particular attention in electrical engineering publications as demonstrating elegant solutions to fundamental operational challenges. The motor-generator-flywheel concept influenced thinking about energy storage and power conditioning long before modern battery and capacitor systems provided alternative solutions. Engineering students studied the design as exemplifying creative problem-solving when conventional approaches proved inadequate.

Modelling Significance and Scale Replications

The Class CC / Class 70 locomotives present exceptional modelling significance due to their unique position as pioneering electric traction bridging Southern Railway malachite green elegance and British Railways modernisation, combined with fascinating operational stories spanning wartime freight, prestigious boat trains, and general mixed-traffic duties. For railway modellers seeking authentic Southern Region electric operations, these locomotives provide compelling prototype appeal enhanced by their rarity and the tragic absence of preserved examples making models the only way to appreciate Bulleid and Raworth's innovative design.

The modelling landscape remained entirely barren for over five decades despite the class's historical importance and distinctive appearance. No manufacturer—Hornby, Bachmann, Dapol, Heljan, Graham Farish, or specialist kit producers—offered Class 70 representations in any scale through the entire 1970s-2010s period. This inexplicable neglect left modellers of Southern Railway, BR Southern Region, and early electric traction operations without access to locomotives that should have been considered essential for authentic layout representation alongside contemporary EMU stock.

This changed dramatically when EFE Rail (operating under Bachmann Europe ownership following the 2016 acquisition of Exclusive First Editions) announced Class CC tooling development in 2021. The project emerged through partnership with Kernow Model Rail Centre, with development specifically targeting the CC1/CC2 design configuration. Engineering prototype samples appeared at exhibitions throughout 2022-2023, with decorated samples and final production models reaching enthusiasts during 2023. The reception proved enthusiastic, with modellers praising exceptional detail quality, comprehensive tooling variations, and thoughtful attention to the livery variations that characterised the class throughout its service career.

The OO gauge Class CC range encompasses five distinct catalogue numbers representing CC1 and CC2 through various livery periods. E82001 depicts CC1 in original SR photographic grey with speed whiskers and blackout cab windows. E82002 shows CC1 in malachite green with "Sunshine" Southern lettering. E82003 presents 20002 in BR black with silver detailing. E82004 captures 20002 in BR green with red side stripe. E82005 portrays 20001 in final BR Rail Blue with full yellow ends. Recommended retail pricing stands at £184.95, though various UK retailers offer significant discounts with street prices ranging £89.50-£157.20 depending on specific catalogue number and retailer stock levels.

The technical execution impresses throughout EFE Rail's development. A five-pole skew-wound motor with flywheel drives all six axles through geared transmission to both bogies, ensuring powerful performance and exceptionally smooth slow-speed operation appropriate for yard movements and passenger station work. All twelve wheels provide electrical pickup from track, with separate metal bearings on each axle minimising friction and maximising reliability. The diecast metal chassis block and bogie towers provide excellent weight distribution (approximately 193g) and low centre of gravity ensuring stability through complex trackwork. Models measure 241mm in length, closely matching the 17.30-metre CC1/CC2 prototype when scaled to OO gauge's 1:76 proportion.

Models are DCC-ready with a 21-pin decoder socket accepting standard decoders for digital control conversion. A pre-fitted speaker positioned within the body enables sound decoder installation without modification, though sound-fitted variants are not offered in the current range. Directional front lighting operates automatically in the forward direction (the real locomotives were not fitted with tail lights), whilst cab lighting can be operated using a magnetic wand when used on analogue DC control or via DCC functions when a decoder is fitted. Minimum radius is second-radius curves (438mm/17.25") suitable for most OO gauge layouts.

Detail quality reaches impressive standards for ready-to-run models. Separately applied components include handrails with distinctive Southern Railway pattern, vacuum brake pipes, multiple unit jumpers, roof-mounted pantograph (positionable up or down using sprung metal construction), and detailed underframe equipment. Factory-fitted glazing includes cab interior detail with basic equipment representation visible through windows. The body moulding captures the distinctive Bulleid/Raworth styling with graceful roof curves, recessed pantograph well, and characteristic proportions that distinguished these locomotives from contemporary electric traction elsewhere in Britain.

Livery application demonstrates meticulous research and execution. The SR photographic grey on E82001 precisely matches period photographs with correctly positioned speed whiskers and authentic blackout cab window configuration. Malachite green on E82002 replicates the Southern's elegant house colours with "Sunshine" Southern lettering and yellow lining at solebar and cantrail levels. BR black features accurate silver detailing whilst BR green includes the correct red side stripe characteristic of electric locomotives during this period. The Rail Blue on E82005 captures the final livery appearance with full yellow warning panels applied to 20001 shortly before withdrawal.

Current availability from UK retailers remains good with most variants in stock or readily obtainable. Major stockists including Rails of Sheffield, Kernow Model Rail Centre, Hattons Model Railways, Hampshire Models, and The Model Centre carry the range, with some offering initial-run stock at substantial discounts. Rails of Sheffield's special promotional pricing of £89.50-£99.50 for selected variants represents exceptional value for modellers willing to purchase during stock clearance periods.

However, the EFE Rail tooling covers CC1/CC2 (20001/20002) only. The third locomotive, 20003, with its distinctly different slab-fronted 4SUB-style cab design, cannot be produced from this tooling suite. Kernow Model Rail Centre has indicated the differences are too substantial for economic tooling modification. Modellers wishing to represent 20003 must undertake scratch-building or extensive conversion work—a daunting prospect given the substantial modifications required to transform the gracefully curved CC1/CC2 cab ends into 20003's angular slab front. This limitation means complete class representation remains impossible using commercially available models alone.

For N gauge enthusiasts, no ready-to-run models exist. Specialist body kit suppliers including BH Enterprises and Worsley Works have not announced Class 70 etched brass kits, though custom commissions might be possible for sufficiently determined modellers with appropriate scratch-building skills. The absence of suitable N gauge chassis mechanisms matching the Co-Co wheel arrangement and compact dimensions creates additional challenges beyond body construction.

O gauge modellers face complete absence of commercial options. No manufacturer produces or has announced Class CC models in O gauge (7mm scale, 1:43.5 proportion). The substantial development costs and limited market size make commercial production unlikely. Skilled O gauge modellers can scratch-build representations using period photographs and dimensional information, though this represents a major project requiring advanced modelling skills, extensive time investment, and access to appropriate Co-Co chassis components.

Models

Unique Modelling Tips and Layout Integration

Successfully incorporating Class CC / Class 70 models into layout operation requires understanding their specialised nature as pioneering mixed-traffic electric locomotives operating on the Southern Railway's extensive third-rail network. Unlike preserved steam or heritage diesel traction suitable for layouts spanning multiple decades, Class 70 representation demands careful attention to era-specific details, appropriate infrastructure, and prototypical operating scenarios reflecting their actual duties during the 1941-1969 service career.

Era selection proves fundamental for authentic Class 70 deployment. Southern Railway period layouts (1941-1947) demand either photographic grey or malachite green livery with wartime or immediate post-war infrastructure and rolling stock. British Railways Southern Region layouts (1948-1956) suit malachite green carrying-over from SR days, experimental light blue briefly applied to 20002, BR black, or early BR green. Late BR period layouts (1957-1969) require BR green or Rail Blue livery with appropriate contemporary infrastructure and rolling stock. Mixing eras creates jarring anachronisms—a malachite green Class CC appearing alongside 1960s EMUs would be as inappropriate as Bulleid Pacifics in early BR era carrying pre-nationalisation livery.

Authentic operating scenarios reflect the class's mixed-traffic capabilities. Victoria to Newhaven Marine boat trains represent the locomotives' most prestigious duty, typically comprising 8-12 coaches mixing Pullman cars, first-class corridor stock, and bogie luggage vans. These formations require Maunsell corridor coaches in SR olive green or malachite green (SR era), Bulleid 63ft and 59ft corridor stock in malachite green or BR crimson and cream (early BR era), or BR Mk 1 corridor coaches (late BR era). General freight workings demand period-appropriate wagon stock: 10-ton and 12-ton wooden coal wagons for Kent coalfield traffic (later 16-ton steel minerals in BR era), conflat wagons for containerised traffic, general goods wagons in SR brown or BR grey, and distinctive SR "Pillbox" brake vans.

Layout infrastructure authenticity demands comprehensive third-rail representation using Peco IL-120 conductor rail chairs with IL-1X code 60 rail section. These components mount approximately every fourth sleeper with slight positional variation creating natural appearance. Include gaps at points, crossings, and complex junction work reflecting prototype practice—these gaps represent the fundamental operational challenge that necessitated Raworth's booster system development. For depot and yard scenes, overhead wire gantries should appear where appropriate (notably Hither Green marshalling yard where pantograph operation was standard practice).

Station infrastructure should reflect Southern Railway's distinctive architectural character. Concrete platform edges, SR pattern concrete lamp standards, running-in boards displaying Southern Railway corporate identity (SR era) or BR Southern Region totem signs (BR era), and characteristic signal boxes with SR or BR Southern Region appearance all contribute to authentic atmosphere. Electrified routes featured distinctive equipment including conductor rail warning signs, shoe beam protective covers at platforms, and third rail insulation posts—details that distinguish electrified lines from steam-worked routes.

Train formations should match the locomotives' 1,470-1,560 hp power output and mixed-traffic classification. Boat train formations typically comprised 8-12 vehicles totalling approximately 400-500 tons—well within Class 70 capabilities whilst representing prestigious service. Freight workings could comprise 30-40 loaded goods wagons totalling 1,000 tons on level routes, with proportionally lighter trains on gradients. Empty coaching stock movements might include 10-15 vehicles being positioned between depots or to carriage sidings for cleaning and maintenance.

Operational sessions benefit from incorporating distinctive Class 70 characteristics. The constant droning noise from booster sets means these locomotives were never truly silent—even stationary examples at depot produced characteristic mechanical humming. The need to avoid halting on gaps requires attentive throttle management when approaching complex pointwork, creating engaging operational challenges for drivers in control. The pantograph equipment enables overhead wire operation in specific yard areas, providing visual variety and operational interest distinct from standard third-rail working.

Depot scenes provide excellent static display opportunities whilst demonstrating typical electric locomotive maintenance facilities. Stewarts Lane depot served as the primary Class 70 maintenance base—modellers can recreate inspection facilities, wheel lathes (electric locomotives required regular wheel reprofiling), electrical workshops for booster equipment maintenance, and the distinctive overhead wire gantries enabling pantograph operation within depot areas. Class 70s sharing space with contemporary EMU stock, SR/BR steam locomotives operating non-electrified routes, and early diesel traction creates authentic mid-20th century Southern Railway/BR Southern Region atmosphere.

Sound-equipped models (requiring aftermarket decoder installation as factory sound-fitted variants are not offered) benefit from careful programming reflecting electric traction characteristics. Electric locomotive sounds differ dramatically from steam or diesel traction—no exhaust beats, no prime mover rhythms, but distinctive motor whine varying with load, brake compressor operation, cooling fan noise, and the constant booster set droning characteristic of Class 70 operation. ESU, Zimo, and other decoder manufacturers offer electric locomotive sound projects that can be adapted for authentic Class 70 representation with appropriate parameter adjustments.

Finally

The Southern Railway Class CC, subsequently designated British Rail Class 70, represents far more than three pioneering electric locomotives; these machines embodied innovative problem-solving that overcame fundamental technical challenges preventing electric locomotive operation on Britain's extensive third-rail networks. Oliver Bulleid's elegant mechanical design combined with Alfred Raworth's revolutionary motor-generator-flywheel booster system delivered mixed-traffic capability from Victoria boat trains to Kent coalfield freight across 28 years of reliable service, proving definitively that electric traction could extend far beyond suburban multiple unit formations.

For railway historians, the Class CC programme provides fascinating insights into wartime innovation under desperate circumstances and post-war development consolidating technological advances achieved during conflict. The decision to exempt CC1 and CC2 from the 1940 construction halt demonstrated strategic thinking recognising that fuel and labour savings justified continued development despite competing priorities. Raworth's booster system represented genuine engineering innovation solving the "gapping" problem through stored kinetic energy rather than brute force approaches that would have created prohibitively heavy locomotives exceeding axle loading restrictions.

The tragic absence of preserved Class 70 examples represents one of British electric traction preservation's most regrettable gaps. These locomotives influenced subsequent Class 71 and Class 74 development, validated design principles that informed British electric locomotive thinking for two decades, and demonstrated Southern Railway's innovative spirit during the company's final years before nationalisation. Their withdrawal timing in 1968-1969 occurred just as the preservation movement was gathering momentum but before societies possessed sufficient resources and confidence to preserve electric traction, consigning the entire class to scrapyards without a single representative surviving for future generations.

This makes EFE Rail's exceptional OO gauge range particularly valuable. These meticulously detailed ready-to-run models provide the only way modern railway enthusiasts can appreciate Bulleid and Raworth's elegant design, with comprehensive tooling variations capturing the evolution from wartime photographic grey through Southern Railway malachite green to British Railways black, green, and ultimate Rail Blue. The five livery variants spanning CC1 and CC2's entire careers enable authentic period representation across nearly three decades of operational history.

Model railway enthusiasts find in the Class CC an ideal subject combining historical significance with practical modelling opportunities. The locomotives' moderate size suits layouts of all scales, the mixed-traffic operation provides engaging operational scenarios from prestigious boat trains to mundane goods workings, and the variety of liveries offers opportunities for collectors and operators alike. Whether representing wartime freight operations with photographic grey CC1, Southern Railway elegance with malachite green CC2, or late BR period service with Rail Blue 20001, these models bring character and authenticity to any Southern Railway or BR Southern Region themed layout.

The engineering legacy endures through subsequent electric locomotive development. The Class 71 fleet adopted Raworth's fundamental booster principle whilst incorporating Swiss manufacturing expertise and increased power output. The Class 74 electro-diesels rebuilt from Class 71s retained booster equipment whilst adding diesel capability for non-electrified routes. Though the Class 73 electro-diesels ultimately took a different approach using small diesel engines for gap crossing, the success of Classes 70 and 71 in proving electric locomotive viability on third rail directly informed its development.

As railway preservation continues evolving and new generations discover the fascination of Southern Railway operations and early electric traction, the Class CC / Class 70 stands as perfect exemplar of an era when innovative engineering overcame fundamental technical challenges through creative problem-solving rather than brute force solutions. These machines proved that third-rail electric systems could power mixed-traffic locomotives handling everything from 1,000-ton freight to prestigious boat expresses, validating design principles that influenced British electric traction development until overhead electrification rendered third-rail systems obsolete for new main line projects. The sight of a Class 70 working a Newhaven boat train—Bulleid's mechanical elegance propelled by Raworth's electrical ingenuity—represented Southern Railway innovation at its finest during the company's twilight years before nationalisation absorbed Britain's railways into a unified system.

Frequently Asked Questions

How many Southern Railway Class CC locomotives were built and when?

Just three Class CC locomotives were constructed: CC1 at Ashford Works in 1941, CC2 at Ashford Works in 1945, and 20003 at Brighton Works in 1948 under British Railways ownership. The small class size reflected their prototype nature proving electric locomotive viability on third-rail systems, with subsequent classes incorporating lessons learned from their operational experience.

What was the "booster" system and how did it work?

Alfred Raworth's booster system used motor-generator sets with heavy flywheels to overcome the "gapping" problem where third-rail gaps at points and crossings interrupted power supply. Third-rail power drove motor-generators with flywheels storing kinetic energy; when supply was lost during gapping, flywheel rotation maintained generator output powering traction motors. This elegant solution enabled continuous power delivery whilst also boosting voltage to approximately 1,200V DC.

What made 20003 different from CC1 and CC2?

20003 featured distinctly different slab-fronted cabs styled after contemporary 4SUB EMUs rather than CC1/CC2's gracefully curved ends, upgraded EE519/4D traction motors producing 265hp versus 245hp, heavier flywheels adding approximately 200lb per booster set, larger water tank, and increased design speed of 85mph. These modifications added five tons to design weight whilst improving performance and reflecting accumulated operational experience.

Were any Class 70 locomotives preserved?

Tragically no—all three locomotives were scrapped following withdrawal in 1968-1969. 20001 and 20002 went to Cashmore's scrapyard in Newport; 20003 to Cohen's scrapyard in Kettering. However, booster generators and flywheels were salvaged by GEC for load testing at Preston facilities, where they remarkably later tested Docklands Light Railway traction systems. One motor-generator set reportedly survives at Strawberry Hill depot.

What services did Class 70 locomotives typically work?

From May 1949, Class 70s regularly worked Victoria-Newhaven Marine boat trains connecting with cross-channel services—the first electric locomotive-hauled long-distance express passenger trains in Britain. They also handled 1,000-ton freight trains from the Kent coalfield, general goods workings across the Southern's electrified network, empty coaching stock movements, and occasionally royal trains, demonstrating their versatile mixed-traffic capabilities.

Why did Class 70 locomotives have pantographs?

The roof-mounted cross-arm pantographs enabled overhead power pickup in sidings and marshalling yards, particularly Hither Green where third rail at track level posed severe hazards to shunting staff working in wartime blackout conditions. The pantographs allowed yard operations from overhead wires installed specifically for this purpose, demonstrating the Southern Railway's commitment to staff safety whilst accommodating operational requirements.

What OO gauge Class CC models are currently available?

EFE Rail produces five variants covering CC1 and CC2: E82001 (CC1 SR photographic grey), E82002 (CC1 SR malachite green), E82003 (20002 BR black), E82004 (20002 BR green), and E82005 (20001 BR Rail Blue). Models feature five-pole motors driving all six axles, 21-pin DCC-ready sockets with pre-fitted speakers, directional lighting, and comprehensive tooling variations. RRP stands at £184.95 though discounts to £89.50-£157.20 are available.

Are Class 70 models available in N gauge or O gauge?

Unfortunately no ready-to-run models exist in either scale. EFE Rail's tooling covers OO gauge only, with no announced plans for N or O gauge production. Specialist kit suppliers have not offered Class 70 etched brass kits, though custom commissions might be possible for scratch-builders with appropriate skills. The absence of suitable N gauge mechanisms and the limited O gauge market make commercial production unlikely.

What coaching stock should I use with Class 70 models?

Authentic consists depend on era: SR period (1941-1947) requires Maunsell corridor stock in olive or malachite green plus Pullman cars for boat trains. Early BR period (1948-1956) suits Bulleid 63ft and 59ft corridor coaches in malachite green or BR crimson and cream. Late BR period (1957-1969) demands BR Mk 1 corridor stock. Typical boat train formations comprised 8-12 vehicles mixing Pullman and first-class accommodation with bogie luggage vans.

Can I model third rail authentically on my layout?

Yes—Peco IL-120 conductor rail chairs with IL-1X code 60 rail section provide authentic representation. Mount chairs approximately every fourth sleeper with slight variation, including gaps at points and crossings reflecting prototype practice. These gaps represent the fundamental operational challenge necessitating Raworth's booster system. For yard scenes depicting Hither Green, overhead wire gantries complete authentic settings where pantograph operation was standard.

Why isn't 20003 included in the EFE Rail range?

The EFE Rail tooling was designed specifically for CC1/CC2's gracefully curved cab ends, and 20003's substantially different slab-fronted 4SUB-style cab design cannot be produced from the same tooling. Kernow Model Rail Centre indicated the differences are too substantial for economic tooling modification. Modellers wishing to represent 20003 must undertake scratch-building or extensive conversion work requiring significant modification skills.

How should I weather Class 70 models authentically?

Focus on operational contact areas: collector shoe gear showing copper/bronze discoloration from third rail contact, oil staining around bogie pivots, brake dust on running gear, and road grime on lower body sides. Avoid coal dust or smokebox weathering inappropriate for electric traction. SR period examples should appear relatively clean reflecting the company's maintenance standards, whilst late BR examples can carry heavier neglect weathering appropriate for 1960s locomotives approaching withdrawal.